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WILLOX FARM - FDP240005 - SUBMITTAL DOCUMENTS - ROUND 2 - Stormwater Management Plan
♦ EPS W NORTHERN GROUP ENGINEERING STORMWATER MANAGEMENT PLAN Willox Farms FORT COLLINS, COLORADO SEPTEMBER, 2024 Project Number: 987-012 NORTHERN ENGINEERING.COM 970.221.4158 FORT COLLINS GREELEY E NORTHERN September 29,2024 City of Fort Collins Stormwater Development Review 700 Wood Street Fort Collins,CO 80521 RE: STORMWATER MANAGEMENT PLAN WILLOX FARMS To Whom It May Concern: Northern Engineering Services, Inc. is pleased to submit this Stormwater Management Plan for the Willox Farms project. This report outlines Best Management Practices (BMPs) to be implemented with the proposed construction to minimize potential pollutants in stormwater discharges. We have prepared this report to accompany the Colorado Department of Public Health and Environment General Permit for Stormwater Discharge Associated with Construction Activities (aka, Stormwater Discharge Permit or SDP).The General Permit No.for this SDP is(to be filled-in by permittee),and the Certification No.for this SDP is (to be filled-in by permittee). The Permit Certification is effective beginning (to be filled-in by permittee), and initial certification expires (to be filled-in by permittee). A copy of the issuance cover letter can be found in Appendix D of this document(to be filled-in by permittee). Please note this Stormwater Management plan (including the Site Maps) is not a static document. It is a dynamic device that should be kept current and logged as construction occurs. As such, this version was prepared to facilitate initial plan approvals and permits but does not necessarily reflect the final version or the transitions throughout the construction process. As the site develops and changes, the contractor is expected and encouraged to change the content, so the SWMP works as effectively and efficiently as possible. It shall be the responsibility of the SWMP Administrator and/or the permit holder (or applicant thereof) to ensure the plan is properly maintained and followed. If you should have any questions or comments as you review this report, please feel free to contact us at your convenience. Sincerely, NORTHERN ENGINEERING SERVICES,INC. Amanda Poincelot,El Project Manager NORTHERN ENGINEERING.COM 1970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY TABLE OF E � NORTHERN 1.0 PROJECT DESCRIPTIONS AND NATURE OF CONSTRUCTION..............................................1 1.1 EXISTING SITE DESCRIPTION ..................................................................................................................1 1.2 NATURE OF CONSTRUCTION ACTIVITY...................................................................................................1 1.3 SITE DISTURBANCE.................................................................................................................................1 1.4 EXISTING TOPOGRAPHIC AND SOIL DATA..............................................................................................2 1.5 RECEIVING WATERS.................................................................................................................................2 1.6 EXISTING SITE CONDITIONS AND VEGETATION......................................................................................3 1.7 EXISTING GROUNDWATER.......................................................................................................................3 1.8 EXISTING GROUND CONTAMINATION.....................................................................................................3 2.0 PROPOSED CONSTRUCTION ACTIVITIES.........................................................................3 2.1 SEQUENCE OF MAJOR ACTIVITIES..........................................................................................................3 3.0 GENERAL REQUIREMENTS............................................................................................3 3.1 OBJECTIVES.............................................................................................................................................3 3.2 SMWP AVAILABILITY.................................................................................................................................4 3.3 DEFINITIONS............................................................................................................................................4 3.4 ADDITIONAL PERMITTING.......................................................................................................................4 4.0 ENVIRONMENTAL IMPACT ............................................................................................4 5.0 POTENTIAL POLLUTION SOURCES.................................................................................4 5.1 DISTURBED AND STORED SOILS.............................................................................................................5 5.2 VEHICLE TRACKING OF SEDIMENT..........................................................................................................5 5.3 MANAGEMENT OF CONTAMINATED SOILS..............................................................................................6 5.4 LOADING AND UNLOADING OPERATIONS...............................................................................................6 5.5 OUTDOOR STORAGE OF CONSTRUCTION SITE MATERIALS, BUILDING MATERIALS,CHEMICALS, ETC. ..................................................................................................................................................................6 5.6 BULK STORAGE OF MATERIALS...............................................................................................................6 5.7 VEHICLE AND EQUIPMENT MAINTENANCE AND FUELING......................................................................7 5.8 SIGNIFICANT DUST OR PARTICULATE GENERATING PROCESSES.........................................................7 5.9 ROUTING MAINTENANCE ACTIVITIES INVOLVING FERTILIZER,PESTICIDES,DETERGENTS,FUELS, SOLVENTS,OILS......................................................................................................................................7 5.10 ON-SITE WASTE MANAGEMENT PRACTICES...........................................................................................8 5.11 CONCRETE TRUCK/EQUIPMENT WASHING ............................................................................................8 5.12 DEDICATED ASPHALT AND CONCRETE BATCH PLANTS.........................................................................8 5.13 NON-INDUSTRIAL WASTE SOURCES SUCH AS WORKER TRASH AND PORTABLE TOILETS...................9 5.14 SAW CUTTING AND GRINDING.................................................................................................................9 5.15 MATERIAL HANDLING AND SPILL PREVENTION......................................................................................9 5.16 NON-STORMWATER DISCHARGES, INCLUDING CONSTRUCTION DEWATERING NOT COVERED UNDER THE CONSTRUCTION DEWATERING DISCHARGES GENERAL PERMIT AND WASH WATER THAT MAY CONTRIBUTE TO POLLUTANTS TO THE MS4................................................................................10 6.0 STORMWATER MANAGEMENT CONTROLS.....................................................................11 6.1 SWMP ADMINISTRATOR.........................................................................................................................11 6.2 OWNER INFORMATION..........................................................................................................................11 6.3 BEST MANAGEMENT PRACTICES(BMPS) FOR STORMWATER POLLUTION PREVENTION...................11 6.4 STRUCTURAL PRACTICES FOR EROSION AND SEDIMENT CONTROL...................................................12 6.5 NON-STRUCTURAL PRACTICES FOR EROSION AND SEDIMENT CONTROL..........................................14 6.6 PHASED BMP INSTALLATION ................................................................................................................16 6.7 BMP INSPECTION...................................................................................................................................17 6.8 BMP MAINTENANCE...............................................................................................................................18 6.9 RECORD KEEPING..................................................................................................................................18 NORTHERN ENGINEERING.COM 1970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY TABLE OF CONTENTS � NORTHERN 7.0 FINAL STABILIZATION AND LONG-TERM STORMWATER MANAGEMENT.............................19 7.1 FINAL STABILIZATION............................................................................................................................19 7.2 LONG-TERM STORMWATER MANAGEMENT..........................................................................................20 8.0 ADDITIONAL SWMP AND BMP RESOURCES....................................................................20 9.0 REFERENCES ............................................................................................................21 FIGURES AND TABLES FIGURE 1-VICINITY MAP....................................................................................................................................1 TABLE 1- PRELIMINARY PERMIT AND CONSTRUCTION SCHEDULE...............................................................17 TABLE 2-CITY OF FORT COLLINS UPLAND MIX..............................................................................................20 APPENDICES APPENDIXA - SITE MAPS APPENDIX B - EROSION CONTROL DETAILS APPENDIX C - LANDSCAPE PLAN APPENDIX D - COPIES OF PERMITS/APPLICATIONS APPENDIX E - INSPECTION LOGS APPENDIX F - CONTRACTOR INSERTS(AS NEEDED) APPENDIX G - CONTRACTOR INSERTS(AS NEEDED) NORTHERNENGINEERING.COM 1 970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY i(,vEi GROUP NORTHERN 1.0 PROJECT DESCRIPTIONS AND NATURE OF CONSTRUCTION 1.1 EXISTING SITE DESCRIPTION A tract of land located in the northeast quarter of the northwest quarter of Section 2,Township 7 North, Range 69 West of the 6th Principal Meridian,City of Fort Collins,County of Larimer,State of Colorado.More specifically it is 19.012-acres of land just south of W.Willox Lane,bound on the east by Hickory Village,on the west by residential properties,and the south by Soft Gold Park. W Willox Ln W Willox Ln ISE, — AES MotorsportS 0 0 n r Garden Sweet S 0 3 m 3 119 Jit vo 0 bogV. J ro Project Location ,, r Hickor�r Village f ( � di Soft Gold Park D `I oa`�'� / I � Magpie 2 '.'eander S2p Hickory /Natur Area street Parking Scott esources9 Figure 1-Vicinity Map 1.2 NATURE OF CONSTRUCTION ACTIVITY The project includes the construction of 62 single family residential lots. Other proposed improvements include asphalt drives,sidewalks, and landscaped areas. Standard water quality, LID,and all associated storm infrastructure will be provided with this project.Detention will be provided on-site in the detention pond on the south side of site. Utilities will also be installed with construction. NORTHERN ENGINEERING.COM 1 970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY 1 1 21 i(,vEi GROUP NORTHERN 1.3 SITE DISTURBANCE The site disturbance will occur across roughly 19.06 acres. It is recommended that existing site condition photos be taken prior to the demolition. CALCULATIONS CHART TOTAL DISTURBED PROJECT AREA 20.44 ACRES TOTAL"ONSITE" AREA OF DISTURBANCE 19.01 ACRES TOTAL"OFFSITE" AREA OF DISTURBANCE 1.43 ACRES TOTAL STORAGE/STAGING AREA N/A ACRES TOTAL HAUL ROADS AREA N/A CONSTRUCTION VEHICLE TRAFFIC AREA N/A EST. PERCENT OF PROJECT AREA EXPOSED 100% EST. PERCENT VEGETATIVE COVER —40% DENSITY EXISTING SOIL TYPE D APPROX. GROUNDWATER DEPTH 5 FEET NUMBER OF PHASES W/PROJECT 1 TOTAL VOLUME OF IMPORTED (+)/EXPORTED (-) MATERIALS CUB. YD. TOTAL AREA OF STOCKPILING OF FILL OR BORROW AREAS OFF SITE SQ. FEET STEEPEST SLOPE 4:1 H:V DISTANCE FROM A RIPARIAN AREA OR SENSITIVE AREA N/A FEET 1.4 EXISTING TOPOGRAPHIC AND SOIL DATA In order to complete the associated construction plans,a topographical survey of the site was completed. This survey consisted of field measurements made by Northern Engineering in 11/2019 and 5/2020 and Majestic Surveying 11/2020 and 04/2022. A NRCS Custom Soil Resource Report of the property indicates that the soil on site consists of Caruso Clay Loam (Hydrologic Soil Group D) and Table Mountain Loam (Hydrologic Soil Group B). The calculations assume a Hydrologic Soil Group of D. Hydrologic Soil Group D has a very slow rate of water absorption and infiltration. According to the Natural Resources Conservation Service(NRCS)website,the average erosion factor(K), which indicates susceptibility of a soil to sheet and rill erosion,is 0.32.The Wind Erodibility for this site has a rating of 6, meaning that the site is less susceptible to this type of erosion. Impervious area and landscaping will permanently stabilize the areas disturbed by the proposed construction activity; therefore, the likelihood of erosion and sediment problems occurring on-site is minimal. During the interim period,in which the disturbed areas are open,the BMPs described herein were selected to prevent erosion and limit sediment migration. 1.5 RECEIVING WATERS Willox Farms is in the Cache la Poudre River Basin, it is a major tributary to the South Platte River. The property historically drains overland through the interior to the southeast across flat grades. Runoff from the site has historically overflow to the southeast property boundary and then to the Soft Gold Park. NORTHERN ENGINEERING.COM 1970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY 2 1 21 ,(,wEi GROUP NORTHERN Proposed conditions show that flows will be released from the detention pond into an existing swale that connects to the existing oxbow. 1.6 EXISTING SITE CONDITIONS AND VEGETATION The site currently exists as an undeveloped parcel with native ground cover.The existing ground slopes with a mild grade (±0.4%-0.6%) through the interior to the southeast across flat grades. The drainage continues through the southern property boundary to Soft Gold Park. It is highly recommended that pre-construction photos be taken to clearly document vegetative conditions prior to any disturbance activities. 1.7 EXISTING GROUNDWATER Groundwater depth was measured onsite in April 2022 by Earth Engineering Consultants, LLC. within various borings (see attached Subsurface Exploration Report). At the time of measurement (April 2022) groundwater depth was approximately 4.5'-5'below existing elevations. 1.8 EXISTING GROUND CONTAMINATION No existing groundwater contamination has been identified at this time. 2.0 PROPOSED CONSTRUCTION ACTIVITIES 2.1 SEQUENCE OF MAJOR ACTIVITIES To complete the project, many basic categories of construction activity will take place.The first part will be the removal and replacement of the existing asphalt pavement along W.Willox Lane.Once the existing pavements marked for demo have been removed and utilities have been tied into existing systems,the topsoil and native grasses that are currently on-site will be removed. Following topsoil stripping, rough grading of the proposed lot will commence.Next,utility installation including sanitary sewer,water mains, and storm sewer.Construction of the proposed buildings is expected to being once the storm sewer is in place. New curb/gutter, paving, and sidewalks on-site are expected to being after the foundations of the building are in place and will coincide with building construction. This also includes all construction activities within Soft Gold Park.The final stages of construction will be fine grading of the areas mentioned above, and installation of landscaping/seeding throughout the project.The sequencing is an initial best guess and is subject to change at the Contractor's discretion. This project is proposed to be built in one phase. Earthwork import is expected. 3.0 GENERAL REQUIREMENTS 3.1 OBJECTIVES The objective of a Stormwater Management Plan (SWMP) is to identify all potential sources of pollution likely to occur as a result of construction activity associated with the site construction and to describe the practices that will be used to reduce the pollutants in stormwater discharges from the site. The SWMP must be completed and implemented at the time the project breaks ground and revised as necessary as construction proceeds to accurately reflect the conditions and practices at the site. This report summarizes the Stormwater Management Plan for the construction activity that will occur with Willox Farms in Fort Collins, CO. This plan has been prepared according to regulations of the Colorado Department of Public Health and Environment (CDPHE),Water Quality Control Division. This report has NORTHERN ENGINEERING.COM 1970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY 3 121 4(,wEi GROUP NORTHERN been provided to meet the requirements of the City of Fort Collins Municipal Code§26-498 on water quality control. 3.2 SMWP AVAILABILITY This report is intended to remain on the construction site to allow for maintenance and inspection updates and for review during inspection. 3.3 DEFINITIONS BMP-Best Management Practice encompassing a wide range of erosion and sediment control practices, both structural and non-structural in nature, intended to reduce or eliminate any possible water quality impacts from stormwater leaving a construction site. Erosion Control BMPs - Practices that PREVENT the erosion of soil, such as minimizing the amount of disturbed area through phasing,temporary stabilization,and preserving existing vegetation. Sediment Control BMPs-Practices to REMOVE sediment from run-off,such as sediment basins,silt fence, or inlet protection. Non-structural BMPs - The implementation of methods, practices, and procedures to minimize water quality impacts, such as the preservation of natural vegetation, preventive maintenance, and spill response procedures. Structural BMPs - Physical devices that prevent or minimize water quality impacts, such as sediment basins,inlet protection,or silt fence. 3.4 ADDITIONAL PERMITTING As mentioned above,this Stormwater Management Plan is associated with the Colorado Department of Public Health and Environment Stormwater Permit that is issued by the Water Quality Control Division of the CDPHE. Additional Environmental permitting not described in this report may be required as a part of this project. An example is the Construction Dewatering Permit for groundwater. Another example is the Air Pollution Emission Notice(APEN). The CDPHE website contains links to both of these permits,as well as many other potential permits. The Contractor is responsible for ensuring the proper permits are acquired. 4.0 ENVIRONMENTAL IMPACT There are no known environmental impacts to endangered species or other environmentally sensitive features that have been identified in this project area.There is a species of plant,located offsite within the oxbow,that is not endangered, but has been noted due to this site's outfall location. Coordination with Fort Collins Natural Areas department will continue to protect this species. 5.0 POTENTIAL POLLUTION SOURCES As is typical with most construction sites,there are several potential pollution sources that could affect water quality. it is not possible for this report to identify all materials used or stored on the construction site. it is the sole responsibility of the contractor to identify and properly handle all materials that are potential pollution sources. Likely pollution sources are marked "YES," unlikely pollution sources are marked"NO."Detailed descriptions of each source are also provided for additional reference.Please note that not all items with a detailed description are present in the project, and there could be additional pollution sources that are not listed that must be addressed by the Contractor. NORTHERN ENGINEERING.COM 1970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY 4 121 4(,twEi GROUP NORTHERN • YES-Disturbed and stored soils • YES-Vehicle tracking of soils and sediment • NO-Management of contaminated soils • YES-Loading and unloading operations • YES-Outdoor storage of construction site materials,building materials,fertilizers,chemicals,etc. • NO-Bulk Storage of Materials • YES-Vehicle and equipment maintenance and fueling • YES-Significant dust or particulate generating processes • YES-Routine maintenance activities involving fertilizers,pesticides,detergents,fuels,solvents,oils, etc. • YES-On-site waste management practices(waste piles,dumpsters,etc.) • YES-Concrete truck/equipment washing • NO-Dedicated asphalt and concrete batch plants • YES-Non-industrial waste sources,such as worker trash and portable toilets • YES-Saw Cutting and Grinding • YES-Material Handling and Spill Prevention • NO - Non-Stormwater Discharges including construction dewatering not covered under the Construction Dewatering Discharges general permit and wash water that may contribute to pollutants to the MS4 5.1 DISTURBED AND STORED SOILS Approximately 19.06 acres of the site will be disturbed with the Construction Activities. Once soils have been disturbed,they do not retain the same compaction as in their native state,therefore surface runoff can cause more soil erosion than was historically observed. In the event that these erosion control practices do not keep sediment on site a structural barrier(silt fence)will be used and is called out for on the perimeter. If soil manages to migrate from the disturbed areas onto the hard surfaces,it will be swept or scraped (street sweeping)to prevent the migration of sediment. In case that sediment is washed away too quickly the curb inlets will need protection (rock sock style inlet protection). Soil stockpiles are expected on this site. Stockpiles in the same respect do not retain the same compaction and are more susceptible to soil erosion.Stockpiles on this site shall be placed in or near the center of the site and away from any drainage swales to not require perimeter run off controls (Materials/Site Management Control).The stockpile will be kept loose,not compacted,and watered as needed to prevent dust issues(site watering).The stockpile will be monitored for signs of erosion displacement and sediment accumulation and if conditions warrant it,the stockpile will be structurally covered or if it is going to sit a long while will be reseeded (temporary seeding). 5.2 VEHICLE TRACKING OF SEDIMENT Vehicle tracking of sediment may occur throughout the construction process and along all areas where the pavement meets the disturbed dirt.This occurs most often after any melt off or rain conditions when mud collects on vehicles tires and is tracked out onto the road consequently leaving site.This increases the possibility of sediment discharging to the storm system.To prevent tracking,access to the site will be limited to construction entrances (vehicle tracking pads to be installed) on the north side of the site. Vehicle access will be limited on muddy days(site management control),in this case parking will be kept to the stabilized staging area. The tracking pad will be monitored visually every day and if track-out becomes a significant problem a larger or more robust tracking pad may be installed.Otherwise,all track- NORTHERN ENG IN EERI NG.COM 1970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY 5 121 4(,twEi GROUP NORTHERN out that reaches the street will be scraped and swept(street sweeping).Secondary controls at the closest affected inlets will have protection(inlet protection)to capture sediment not swept up in a timely manner. Additional measures can be taken to minimize and control sediment discharges from the site due to vehicle tracking.These measures can include fencing around the site to control access points. The use of gravel parking areas and wash racks can also be implemented to ensure minimal vehicle tracking from the site. 5.3 MANAGEMENT OF CONTAMINATED SOILS All data about the site shows that there is no known contamination on the site. If encountered, the contractor will have the material stored in a covered area (materials management control) as to not mix with the stormwater until the material can be identified and proper classification and disposal methods can be determined in accordance with the various waste laws and with good construction safety and practices. 5.4 LOADING AND UNLOADING OPERATIONS It is not anticipated to be a significant amount of export leaving the site,only import. During this project there will be a diverse amount of loading and unloading.The foundation workers will have to deliver forms to the site and deliver premixed concrete.Landscapers will have to pile the materials on site to complete the landscape work.Though the loading and loading vehicles will be contributing to the track out of materials, depending on the material being delivered to the site they may have a significant spill potential. Where the trailers must access the site, an attempt will be made to keep the vehicle on the VTC or other stabilized storage areas.When loading and unloading is occurring,depending on the materials,there may be an increased problem of containers being dropped,punctured,or broken. These off-loading activities will be located away from storm drains and will have nearby spill kits accessible.Spills on site will be addressed using spill prevention and response procedures. 5.5 OUTDOOR STORAGE OF CONSTRUCTION SITE MATERIALS,BUILDING MATERIALS, CHEMICALS, ETC. It is anticipated that inert material like wood, tiles, and stone will be stored on site and outside in the elements. It is also anticipated that materials that do not weather well(cement, mortar,etc.)will also be located outside. Chemicals are not anticipated to be left outside. As the inert materials have a lower potential to leave the site, they will be monitored during inspection to make sure they are not being impacted by the exposure to the elements(site management control).The materials that will need added attention are the cements and mortars as they quickly mix with water and cause pollution issues.These materials when not stored inside will be placed on pallets to get above potential surface runoff and covered with tarps or plastic to prevent mixing with stormwater (materials management control). Very small quantities of chemical are needed to contaminate stormwater so the fertilizers, paints, form oils, petroleum products, and other typical chemicals,will be stored in the construction connex box,trailers, vehicles, or the like out of contact with precipitation (materials management control). If not stored in a location as described,secondary containment will be required.The contractor shall clearly designate site areas for staging and storage of building materials. 5.6 BULK STORAGE OF MATERIALS This site is not expected to store bulk liquid chemicals of more than 55-gallon drums. If this site does have the need to store liquid chemicals the following procedure should be followed. NORTHERN ENGINEERING.COM 1970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY 6 121 4(,wEi GROUP NORTHERN These materials should be stored in an area that if a rupture would occur,it would be contained. The area will need to be located away from the drainage areas and area inlets (site management / materials management).The containers will be stored in secondary containment area with a fence so that if a spill were to happen,it would pool in the bottom of the area and be contained. 5.7 VEHICLE AND EQUIPMENT MAINTENANCE AND FUELING Based on the size of the site and the duration of activities vehicle fueling and vehicle maintenance is highly likely. As fueling and equipment maintenance usually result in small spills of petroleum products it is important to monitor these activities carefully(site management control). Some grading companies will employee a fuel truck to fill the heavy equipment on site or require the maintenance of a broken machine. In those cases where the vehicle is not able to be maintained off site,these activities will be done in the least detrimental way possible. The maintenance and fueling will be located as far from stormwater feature as possible and at least 50 feet from a stormwater feature (site management/materials management). The fueling activity will have spill materials nearby and a bucket or other container and shovel located nearbyto hang a hose afterfillingto catch drips,and to scoop up anydirtthat inadvertently mixed with the soil (materials management).That container will have a lid and be disposed of when the activity is completed. The maintenance work will be done on a tarp or other material to prevent the residual oils and greases from mixing with the dirt(materials management). A clearly designated on-site fueling and maintenance area is suggested. 5.8 SIGNIFICANT DUST OR PARTICULATE GENERATING PROCESSES This project will result in earth moving activities, street sweeping, and track-out and carry out, bulk materials transport, and saw cutting. As these activities will result in offsite transport of atmospheric pollution reasonable precautions shall be taken.The project will follow all required"BMPs"articulated in the Fugitive Dust Manual and a least one additional BMP included during each of the identified activities in accordance with City Ordinance No.044 2016.Also a copy of the Dust Control Manual will be kept in the trailer during construction for reference. Such activities will include but not limited to watering the site, covering trucks,slower site speeds and vehicle tracking mentioned above. 5.9 ROUTING MAINTENANCE ACTIVITIES INVOLVING FERTILIZER,PESTICIDES,DETERGENTS, FUELS,SOLVENTS,OILS Fertilizers and Pesticides will be used during the later phases of the project when trying to establish a healthy vegetation.These chemicals are highly water soluble and are easily and unnoticeably carried in the stormwater.Proper application rates and recommended timing of application will be strictly followed and not on days, or the next day, where the weather is calling for precipitation (materials management control).As most of these types of chemicals will be brought on by the landscaper,they will be required to keep these products in their vehicles until time of application and not be allowed to leave these materials on the site (site management control). If these materials are stored on site,they shall be kept inside or outside covered and above the ground to prevent the materials from mixing with water and runoff (materials management control). Detergents, paints,acids,cement,grout,and solvents will be prevalent in the interior work of the building (materials management). These materials also are typically easily mixed with water yet are typically noticeable by discolored,cloudy,or sudsy water.As such,the contractor will always keep an eye out for these types of differences in water around the site (site management control).However,these materials are to be handled,operated,and cleaned up all within the inside of the structure,where external use is concerned these materials will be stored in the construction connex box, trailers,vehicles,or the like out of contact with precipitation (materials management). If not stored in a location as described secondary containment will be required (materials management). Fuels and oils NORTHERN ENGINEERING.COM 1970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY 7 121 4(,wEi GROUP NORTHERN might be associated with the smaller equipment used on site, chainsaws, pumps, generators, etc. As petroleum products are easily suspended in water and are spread across the top of the water surface. These products when located in water have rainbow sheen on them. They are also monitored during construction (site management controls). These products will be stored in the construction connex box, trailers,vehicles,or similar structure that will minimize contact with precipitation(materials maintenance controls). If not stored in a location as described secondary containment will be required (materials maintenance).Any untreated runoff from these activities can be detrimental to wildlife if not cleaned up. 5.10 ON-SITE WASTE MANAGEMENT PRACTICES All large and heavy weighted waste piles(concrete chunks,excavated pipes,etc.)will be kept in a neatly grouped pile until the material is to be disposed of properly. These piles will only be stored the shortest duration possible and will be kept 50 feet from any drainage course or inlet (Administrative Control).All dry wastes will be maintained through dumpsters and monthly hauler removal (hauler will be notified if dumpster becomes full and hauled off as needed).Where available by the hauling company the dumpster will be covered. If not practical or available by the haul company,an increased removal schedule will be followed and the"Max fill line"on the dumpster will be strictly followed.Corners of the dumpsters will be monitored for"Dumpster Juice"leaking into the soil in dry conditions and rain/melt off conditions looking for it mixing with the runoff. Dumpsters, like the waste piles, will be located at least 50 feet from any drainage course or inlet.Workers will be sent around at the end of the day to collect trash to prevent trash being left out overnight. No construction debris(including broken concrete)will be buried on site. 5.11 CONCRETE TRUCK/EQUIPMENT WASHING Concrete will be a portion of this project. It is anticipated that it will be used with the joints around the manholes,pour in place inlets,curb and gutter installation,sidewalks and culvert construction. Premixed concrete trucks will be used in this process and will be delivered to the site and when pouring the culvert components. Washing of the concrete equipment will be required to maintain the concrete equipment. This concrete wash water has a high alkaline content which is hazardous material to terrestrial and aquatic wildlife.A section of dirt near the entrance will be excavated and compacted around the sides formed to retain the concrete wash water on site(as an acceptable practice by the State)so long as the wash water is kept in the washout(concrete washout).There will be a rock pad for the truck to park on while washing as to prevent tracking from this washout(VTC).The placement of this washout will be located at least 50 feet from any drainage course or inlet. Later in the project after the parking lots curb and gutter has been poured the use of a mobile washout facility will be used on site in a similar location and after the ground has been leveled (concrete washout - mobile). The contractor (including all masonry and concrete tradesmen) shall clean out equipment within the washout area so that the runoff is not allowed to leave the washout.The only exception would be for them to wash in the next day's pour location.All concrete workers will be made aware of the where they are to wash (site management controls & education). If there is a significant amount of spillage when the transfer from concrete truck to pump truck occurs, a tarp or other ground cloth should be used to collect spillage(ground cover control). 5.12 DEDICATED ASPHALT AND CONCRETE BATCH PLANTS There will be no dedicated asphalt or concrete batch plants erected onsite for this project. Premixed concrete and paving materials will be delivered to the site and placed. In the event that a plant is needed, the Contractor should be aware that additional permitting will be required. In particular,an Air Pollutant Emission Notice(APEN)will need to be obtained from the CDPHE. NORTHERN ENGINEERING.COM 1970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY 8 121 ,(,wEi GROUP NORTHERN 5.13 NON-INDUSTRIAL WASTE SOURCES SUCH AS WORKER TRASH AND PORTABLE TOILETS Since facilities are not located nearby for workers to use,trash and sanitary facilities will be required on the site. Worker trash will be comingled with the industrial trash and will follow the same controls with the caveat that a trashcan will be located near the entrance of the site as the contractor will need to dump their trash from lunch,etc. and this will be emptied weekly or more frequently, if needed. Designate trash and bulk waste collection areas on-site. Dumpsters should be located near site entrances to minimize traffic on disturbed soils, and they should be placed on a level soil surface. When possible, materials should be recycled. Hazardous material waste should be segregated from other solid waste. If tipped over and when being cleaned, portable toilet facilities become a potential discharge if not cleaned up. If human waste is spilled,it will need to be treated as a biological hazard of untreated sewage and will need to be cleaned up in accordance with Larimer County Health Department Guidance. The toilets will be staked in a way to prevent tipping on a dirt surface and located at least 50 feet from a drainage course or inlet. If the site cannot accommodate a portable toilet on dirt, a containment pan or other secondary containment will be provided. They will also be anchored prevent from tipping. All materials shall be properly disposed of in accordance with the law. 5.14 SAW CUTTING AND GRINDING The trench work and street connections will require cutting into the City street (W. Willox Lane). This project will need the use of hardened saws. These saws generate a significant amount of dust. Watering the cutting surface to prevent airborne particulates (BMP in the City's Fugitive Dust Manua[) is required. The cutting slurry has a high content of fine particulates (Silica Dust, Metals, etc.) that is not allowed to discharge as runoff from the site. To prevent slurry from discharging offsite, contractors will use the minimum amount of water needed to prevent dust and blades from overheating (site management control). Cutting slurry will be collected via vacuum or allowed to dry out and be scraped and swept up after the cutting has finished (saw cutting). The following protocol is recommended to prevent dust and slurry from asphalt and concrete saw cutting activities from migrating into the existing storm drain system. • Slurry and cuttings shall be vacuumed during cutting and surfacing operations. • Slurry and cuttings shall not remain on permanent concrete or asphalt pavement overnight. • Slurry and cuttings shall not drain to any natural or constructed drainage conveyance. • Collected slurry and cuttings shall be disposed of in a manner that does not violate groundwater or surface water standards. 5.15 MATERIAL HANDLING AND SPILL PREVENTION Potential pollution sources, as discussed in earlier sections, are to be identified by the contractor. Spill prevention procedures are to be determined and put in place before construction by the contractor.Aspill and flooding response procedure must also be determined and put in place before construction by the contractor. Additionally, steps should be taken to reduce the potential for leaks and spills to come in contact with stormwater run-off,such as storing and handling toxic materials in covered areas or storing chemicals within berms or other secondary containment devices. A notification procedure must be put in place by the contractor, by which workers would first notify the site construction superintendent, who would then notify the SWMP Administrator. Depending on the severity of the spill,the site construction superintendent and SWMP Administrator would possibly notify NORTHERN ENGINEERING.COM 1970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY 9 121 4(,twEi GROUP NORTHERN the Colorado Department of Public Health and Environment-Water Quality Control Division,downstream water users, or other appropriate agencies. The release of any chemical, oil, petroleum product, sewage, etc., which enter waters of the State of Colorado (which include surface water, groundwater, and dry gullies or storm sewers leading to surface water) must be reported immediately to the Division's emergency spill reporting line at (877) 518-5608. All spills requiring cleanup,even if the spill is minor and does not need to be reported to the State,should still be reported to the City of Fort Collins Utilities office at 970-221-6700. It will be the responsibility of the Contractor to designate a fueling area and take the necessary precautions to ensure that no stormwater pollution occurs if a fueling area is needed. Fueling areas shall be located a minimum 100 feet from all drainage courses. A 12-inch-high compacted earthen ridge capable of retaining potential spills shall enclose fueling areas. Other secondary containment devices can be used instead of the earthen ridge. The area shall be covered with a non-porous lining to prevent soil contamination. Printed instructions for cleanup procedures shall be posted in the fueling area and appropriate fuel absorbents shall be available along with containers for used absorbents within the fueling area. 5.16 NON-STORMWATER DISCHARGES, INCLUDING CONSTRUCTION DEWATERING NOT COVERED UNDER THE CONSTRUCTION DEWATERING DISCHARGES GENERAL PERMIT AND WASH WATER THAT MAY CONTRIBUTE TO POLLUTANTS TO THE MS4 The Stormwater Construction Permit only covers discharges composed entirely of stormwater. The discharge of pumped stormwater,ONLY,from excavations, ponds,depressions,etc.to surface waters,or to a municipal storm sewer system is allowed by the Stormwater Construction Permit, as long as the dewatering activity and associated BMPs are identified in the Stormwater Management Plan (SWMP)and are implemented in accordance with the SWMP. Aside from the exceptions noted above, non-stormwater discharges must be addressed in a separate permit issued for that discharge. If groundwater is encountered, and dewatering is required, a Construction Dewatering Permit must be acquired from the Colorado Department of Public Health and Environment. Based upon a subsurface exploration report done in 2022 by Earth Engineering Consultants, LLC,ground water levels indicate that it may be present during construction activities at approximately 5' deep. If encountered,dewatering activities may be required.Groundwater has in most excavations mixed with the dirt and as they are pumped, they will add an increased velocity coming out of the out-flow end contributing to erosion and speeding the transport of the suspended sediment particles. Also, construction dewatering activities must be identified in the Erosion Control Report if they are to be infiltrated on site. If the material is anticipated to be pumped to a stormwater conveyance the proper Construction Dewatering Permit must be pulled from the State of Colorado. If pumping activities are to occur on the site,the use of rock packs on the intake end of the pump will be used and a silt bag will be used on the outflow end of the pump to reduce the silt and sediment from leaving the activity(dewatering Control Measure). If this will be under a Dewatering Permit water samples will be collected in accordance with that permit. NORTHERN ENGINEERING.COM 1970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY 10 121 i(,twEi GROUP NORTHERN 6.0 STORMWATER MANAGEMENT CONTROLS 6.1 SWMP ADMINISTRATOR A SWMP Administrator must be designated in conjunction with the Stormwater Permit.This person shall be responsible for developing, implementing, maintaining, and revising the SWMP. The SWMP Administrator will also be the contact for all SWMP-related issues and will be the person responsible for the accuracy,completeness,and implementation of the SWMP.The Administrator should be a person with the authority to adequately manage and direct day-to-day stormwater quality management activities at the site. The SWMP Administrator for this site is: Name: (to be filled in by permittee) Company: (to be filled in by permittee) Phone: (to be filled in by permittee) E-mail: (to be filled in by permittee) 6.2 OWNER INFORMATION Name: James Righeimer Company: Capri Colorado Holdings LLC Phone: (714)404-7867 E-mail: Jim@rfcomsites.com 6.3 BEST MANAGEMENT PRACTICES(BMPS) FOR STORMWATER POLLUTION PREVENTION Beginning from mobilization, and throughout the entire construction of the project, erosion control devices shall be installed to ensure minimal pollutant migration. These erosion control devices may be installed in phases, or not at all, depending on actual conditions encountered at the site. It is the responsibility of the Contractor to make the determination as to what practices should be employed and when. In the event that a review agency deems BMPS to be insufficient,it shall be the responsibility of the contractor to implement modifications as directed. Best Management Practices(BMPS)are loosely defined as a method,activity,maintenance procedure,or other management practice for reducing the amount of pollution entering a water body. The term originated from rules and regulations in Section 208 of the Clean Water Act. Details for Structural and Non-Structural BMPS have been included in Appendix B. These details should be used for additional information on installation and maintenance of BMPS specified in this report. It is also intended to serve as a resource for additional BM Ps that may be appropriate for the site that have not specifically been mentioned in the report. NORTHERN ENGINEERING.COM 1970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY 11 121 4(,twEi GROUP NORTHERN 6.4 STRUCTURAL PRACTICES FOR EROSION AND SEDIMENT CONTROL Structural BMPs are physical devices that are implemented to prevent erosion from happening or to limit erosion once it occurs. These devices can be temporary or permanent, and installation of individual components will vary depending on the stage of construction. A table depicting construction sequence and BMP application/removal has been placed on the"Dynamic Site Plan"to help document the implementation of these BMPs. Refer to the Stormwater Management Plan Static Site Plan in the Appendix for the assumed location of all BMPs. Construction Details for Temporary BMPs are located in the Appendix for reference. Again,the final determination for which BMP's will be installed,where they will be located,and when they will be installed shall be made by the Contractor, along with all documentation throughout the construction process. Silt Fencing(Phase I-III) Silt fencing shall be provided to prevent migration of sediment off-site or into adjacent properties. All silt fencing shall be installed prior to any land disturbing activity(demolition,stockpiling,stripping,grading, etc.). Silt fencing is to be installed prior to site excavation or earthwork activities. Inspections of the silt fence should identify tears or holes in the material and should check for slumping fence or undercut areas that allow flows to bypass the fencing. Damaged sections of the silt fence should be removed to maintain BMP effectiveness,typically before it reaches a depth of 6 inches. It is suggested that silt fencing be located along the property boundary. Refer to the Erosion Control Plan (Sheet EC1-EC3)for additional clarification. Sediment Control Log-aka"Straw Wattles"(Phase I-III) A Sediment Control Log is a linear roll made of natural materials, such as straw, coconut fiber, or other fibrous material trenched into the ground and held with a wooden stake. Sediment Control Logs can be used in many instances. Examples include perimeter control for stockpiles, as part of inlet protection designs, as check dams in small drainage ways,on disturbed slopes to shorten flow lengths,or in lieu of silt fencing(where appropriate). Sediment Control Logs should be inspected for excess sediment accumulation. Sediment should be removed priorto reaching half the height of the log. At a minimum, Sediment Control Logs should be used around soil stockpiles (including landscape material) and at all stormwater discharge locations other than inlets. All proposed landscape swales, including ones discharging into detention ponds shall have a straw wattle installed perpendicularto flow every 4" of elevation difference. Refer to the Erosion Control Plan (Sheet EC1 - EC3) for additional clarification. Vehicle Tracking Control Pads(Phase I-III) Vehicle tracking control pads shall be provided to minimize tracking of mud and sediment onto paved surfaces and neighboring roadways. All vehicle tracking control pads shall be installed prior to any land disturbing activity (demolition - as necessary, stockpiling, stripping, grading, etc.). Location of vehicle tracking control pads will be located at any and all existing and future vehicle accesses being used during any of the construction phases. These locations will primarily be dictated by gates or openings in the temporary construction fencing that is expected to be installed. Vehicle tracking control pads are to be installed prior to demolition(as appropriate),site excavation or earthwork activities. NORTHERN ENGINEERING.COM 1970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY 12 121 4(,twEi GROUP NORTHERN Vehicle tracking pads should be inspected for degradation and aggregate material should be replaced as needed.If the area becomes clogged with water,excess sediment should be removed. Aggregate material should remain rough, and at no point should aggregate be allowed to compact in a manner that causes the tracking pad to stop working as intended. During the initial and interim phases of Erosion Control the suggested location of the vehicle tracking pad is at the east entrance of the project site. Refer to the Erosion Control Plan(Sheet ECl-EC3)for additional clarification. Inlet Protection(Phase I-III) Inlet protection shall be provided for existing inlets to prevent sediment transport from adjacent earthwork disturbance. Installation of these filters shall occur before adjacent earth disturbing activities (Phase I implementation). Wattle type filters are to be implemented for new and existing inlets where asphalt does not exist. For these inlets,if pavement is constructed adjacent to the structure or if the area adjacent to the inlet is changed such that the wattle type filter is no longer effective, it shall be the responsibility of the Contractor to ensure that an appropriate method is used instead. For example,the wattle filter could be reused,or a gravel-block inlet filter may be installed. It will be left to the discretion of the Contractor as to whether replacement of any inlet filter is necessary. Inlet protection should be inspected regularly for tears that can result in sediment entering an inlet. Inlet protection should also be inspected for sediment accumulation upstream of the inlet, and sediment should be removed when the less than half of the capacity is available,or per manufacturer specifications. All proposed curb inlets, sidewalk chases and upstream flared end sections shall have inlet protection. Refer to the Erosion Control Plan(Sheet EC1-EC3)for additional clarification. Erosion Control Blankets(Phase II) A temporary degradable rolled erosion control product composed of natural flexible fibers shall be used on all seeded slopes 4:1 and greater(excluding mulched shrub bed areas).Erosion control blankets should be utilized to provide erosion control and to facilitate vegetation establishment. During installation, it is important to ensure that no gaps or voids exist under the material and that all corners of the material are secured using stakes and trenching. Stakes should be made of materials that are biodegradable. Continuous contact between the product and the soil is necessary to avoid failure. Erosion Control Blankets should be inspected regularly for signs of erosion,including beneath the mat. If voids are apparent, they should be filled with suitable soil. Inspections should also identify loose or damaged stakes,as well as loose portions of the blanket. If deficiencies are found,they should be repaired or replaced. Concrete Washout Area(Phase II-III) A concrete washout should be provided on the site. The washout can be lined or unlined excavated pits in the ground,commercially manufactured prefabricated containers,or aboveground holding areas. The concrete washout must be located a minimum of400 feet from any natural drainage way or body of water, and at least 1000 feet from any wells or drinking water sources. Washout areas should not be located in an area where shallow groundwater may be present. Contractor shall clearly show the desired location and access to the Concrete Washout Area on the Stormwater Management Plan - Dynamic Site Plan. Contractor shall place a Vehicle Tracking Pad if the selected location for the Concrete Washout Area is detached from pavement. Clear signage identifying the concrete washout should also be provided. NORTHERN ENGINEERING.COM 1970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY 13 121 4(,twEi GROUP NORTHERN The Concrete Washout Area should be inspected regularly. Particular attention should be paid to signage to ensure that the area is clearly marked. Confirmation that the washout is being used should also be noted to ensure that other undesignated areas of the site are not being used incorrectly as a concrete washout. It is suggested the Contractor build a concrete wash out pit for this project. It is recommended that the concrete wash out pit be placed adjacent to the proposed drive on the east side of the site.This location is to ensure minimum distance from wash out to exiting the site.This location is only a suggestion and can be relocated at the discretion of the Contractor. Permanent/Established Vegetation(Phase IV) Permanent or established vegetation and landscaping is considered a permanent form of sediment and erosion control for common open spaces, steep slopes and areas not exposed to prolonged scour velocities, or acute incipient motion bed shear stresses that will create soil erosion, rill formation and subsequent sediment transport. Areas where the previous conditions apply will contain sufficient permanent BMPs,such as riprap or cobble mulch. Permanent vegetation shall conform to the approved Landscape Plan prepared by the landscape architect. Permanent/Established vegetation and hardscape defines Phase IV of development. 6.5 NON-STRUCTURAL PRACTICES FOR EROSION AND SEDIMENT CONTROL Non-Structural BMPs are practices or activities that are implemented to prevent erosion from happening or to limit erosion once it occurs. These BMPs can be a practice resulting in physical change to the site, such as mulching or slope stabilization. They can also result in behavioral changes on the site, such as changes to construction phasing to minimize exposure to weather elements, or increased employee awareness gained through training. Protection of Existing Vegetation(Phases I-IV) Protection of existing vegetation on a construction site can be accomplished through installation of a construction fence around the area requiring protection. In cases where up-gradient areas are disturbed, it may also be necessary to install perimeter controls to minimize sediment loading to sensitive areas such as wetlands. Trees that are to remain after construction is complete must be protected. Most tree roots grow within the top 12"-18"of soil, and soil compaction is a significant threat to tree health. As such, particular care should be taken to avoid activities within the drip-line of the tree. Direct equipment damage should also be prevented. The most effective way to ensure the health of trees is to establish a protection zone at the drip-line of the tree to prevent unintended activity in the area directly surrounding the tree. Fencing should be inspected and repaired when needed. If damage occurs to a tree,an arborist should be consulted on how to care for the tree. If a tree is damage beyond repair, the City Forester should be consulted on remediation measures. At a minimum,protection to all trees identified for retention on the plans by the landscape architect. Stockpile Management(Phases 1-III) Stockpile management should be utilized to minimize erosion and sediment transport from soil stockpiles. In general,soil stockpiles should be located a minimum of 100 feet from any drainage way and 50 feet from any storm sewer inlets. Where practical, choose a stockpile location that will remain undisturbed for the longest period of time as the phases of construction progress. Sediment control BMPs should be placed around the perimeter of the stockpile, and a designated access point on the upstream NORTHERN ENGINEERING.COM 1970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY 14 121 i(,tw I GROUP side of the stockpileshouldbeidentified. BM Ps such as surface roughening,temporary seeding,mulching, erosion control blankets,or soil binders should be used to stabilize the stockpile surface. As a part of stockpile management,regular inspections of the perimeter controls should be completed. If BMPs have been utilized to stabilize the surface of the stockpile,they should be inspected and repaired as needed. While soil stockpiles are not expected with this project, it is possible that foundation excavation or the delivery landscaping material may generate temporary stockpiles. The location of any such stockpiles shall be the responsibility of the SWMP Administrator. Mulching(Phase 1-III) Mulching helps reduce erosion by protecting bare soil from rainfall impact, increasing infiltration, and reducing runoff. Although often applied in conjunction with temporary or permanent seeding,it can also be used for temporary stabilization of areas that cannot be reseeded due to seasonal constraints. The most common type of mulch used is hay or grass that is crimped into the soil to keep it secure. However, crimping may not be practical on slopes steeper than three to one(3H:1V). The Contractor shall mulch all planted areas within twenty-four(24) hours after planting. Only weed-free and seed-free straw mulch may be used. Straw mulch should be applied at two(2)tons per acre,and shall be adequately secured by crimping,tackifier, netting or blankets. Hydraulic mulching may also be used on steep slopes or where access is limited. In the case that hydraulic mulching is utilized,the Contractor shall use wood cellulose fibers mixed with water at two thousand to two thousand five hundred (2,000- 2,500) pounds per acre and organic tackifier at one hundred to four hundred (100-400) pounds per acre. The Contractor is responsible for applying wood chip mulch to all planted trees and shrubs as shown on the Landscape Plan prepared by the landscape architect. Wind Erosion/Dust Control(Phase I-IV) Wind Erosion and Dust Control BMP's help to keep soil particles from entering the air as a result of land disturbing construction activities. Attached at the end of the Appendix B is the Fort Collins Dust Prevention and Control Manual. The purpose of this manual is to establish minimum requirements consistent with nationally recognize BMP's for controlling fugitive dust emissions and to describe applicable best management practices to prevent, minimize,and mitigate off-property transport or off-vehicle transport of fugitive dust emissions pursuant to Chapter 12,Article X of the Fort Collins City Code (§12-150 et. seq) for specific dust generating activities and sources. Examples include use of a water truck or irrigation/sprinkler system to wet the top layer of disturbed soil, seeding and mulching, soil binders, or wind fences. Street Sweeping(Phases I-IV) Street sweeping should be used to remove sediment that has been tracked onto adjacent roadways. Roadways should be inspected at least once a day,and sediment should be removed as needed.A check of the area inlet protection should be completed after sweeping to ensure nothing was displaced during sweeping operations. Street sweeping can reduce the sediment washed into the existing storm drain system.Street sweeping may be necessary on the existing hardscape areas which receive runoff from the disturbed areas. Good Housekeeping Practices(All phases) Good housekeeping practices that will prevent pollution associated with solid, liquid, and hazardous construction-related materials and wastes should be implemented throughout the project. Examples of NORTHERN ENGINEERING.COM 1970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY 15 121 4(,wEi GROUP NORTHERN good housekeeping include providing an appropriate location for waste management containers, establishing proper building material staging areas, designating paint and concrete washout areas, establishing proper equipment/vehicle fueling and maintenance practices. Development of a spill prevention and response plan is another example of Good Housekeeping practices that should be used on the project. The following items are detailed examples of some of the good housekeeping practices that should be utilized throughout the project. It should be noted that a complete list of practices and detailed discussion regarding good housekeeping has been included within the Potential Pollution Sources section of this report. Street Sweeping and Vacuuming - Street sweeping and vacuuming should be used to remove sediment that has been tracked onto adjacent roadways. Roadways should be inspected at least once a day, and sediment should be removed as needed. A check of inlet protection should be completed after sweeping to ensure nothing was displaced during sweeping operations. Waste Management- Designate trash and bulk waste collection areas on-site. When possible, materials should be recycled. Hazardous material waste should be segregated from other solid waste. Waste collection areas should be located away from streets,gutters,watercourses,and storm drains. Dumpsters should be located near site entrances to minimize traffic on disturbed soils,and they should be placed on a level soil surface. Establish Proper Building Material Handling and Staging areas-Clearly designate site areas for staging and storage of building materials. Provide appropriate BMPs to ensure that spills or leaks are contained. Establish Proper Equipment/Vehicle Fueling and Maintenance Practices - If needed, create a clearly designated on-site fueling and maintenance area that is clean and dry. Provide appropriate BMPs to ensure that spills or leaks are contained. 6.6 PHASED BMP INSTALLATION It is important to recognize the four(4) major Development Phases as defined by the State of Colorado's Stormwater Discharge Permit (SDP). These four development phases (referred to as Sequencing by the City of Fort Collins) have been distinguished to aid in the appropriate timing of installation/ implementation of BMPs at different stages of the construction process. These phases are described as follows: Phase I- Demolition Stage; BMPs for initial installation of perimeter controls.The Initial Erosion Control Plan within the Utility Plans shows the BMPs needed for this Phase. Phase II-Infrastructure Stage;BMPs for utility,paving,and curb installation.The Interim Erosion Control Plan within the Utility Plans shows the BMPs needed for this Phase. Phase III -Vertical Construction Stage; BMPs for individual building construction. The Interim Erosion Control Plan within the Utility Plans shows the BMPs needed for this Phase.These will be similar to,if not the same,BMPs used in Phase II. Phase IV- Permanent BMPs and final site stabilization.The Final Erosion Control Plan within the Utility Plans shows the BMPs needed for this Phase. The following is a rough estimate of the anticipated construction sequence for site improvements. The schedule outlined below is subject to change as the project progresses and as determined by the General Contractor. NORTHERN ENGINEERING.COM 1970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY 16 121 1 GROUP NORTHERN TASK BEGINNING DATE ENDING DATE BMP PHASE OF DEVELOPMENT" Development Construction Permit Jan. 2025 Feb. 2025 I Issued by City of Fort Collins Overlot Grading (Demolition) Jan. 2025 Feb. 2025 I Utility Installation March 2025 May 2025 II Paving and Vertical Construction March 2025 June 2025 III Final Stabilization June 2025 Aug. 2025 IV Table 1-Preliminary Permit and Construction Schedule Included in the back map pockets are two Site Plans:a "Static" Site Plan and a "Dynamic"Site Plan.The "Static"plan serves to display the overall management plan all at once.However,proper implementation of BMPs does not occur at once, and certain BMPs may move location in the construction process; therefore,the"Dynamic"Site Plan is intended forthe contractor to write in the BMP symbols to document the location and time the BMPs are installed and maintained throughout the entire construction process. 6.7 BMP INSPECTION All temporary erosion control facilities shall be inspected at a minimum of once every two(2)weeks and after each significant storm event or snowmelt. Repairs or reconstruction of BMPs, as necessary, shall occur as soon as possible to ensure the continued performance of their intended function. It is the responsibility of the SWMP Administrator to conduct bi-weekly inspections, maintain BMPs if needed, keep records of site conditions and inspections,and update the SWMP as necessary. The construction site perimeter, disturbed areas, all applicable/installed erosion and sediment control measures,and areas used for material storage exposed to precipitation shall be inspected for evidence of, or the potential for, pollutants entering the drainage system. Erosion and sediment control measures identified in the SWMP shall be observed to ensure they are operating correctly.Attention should be paid to areas with a significant potential for stormwater pollution,such as demolition areas,concrete washout locations,and vehicle entries to the site.The inspection must be documented to ensure compliance with the permit requirements. NORTHERN ENGINEERING.COM 1970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY 17 121 4(,wEi GROUP NORTHERN 6.8 BMP MAINTENANCE Any BMPs not operating in accordance with the SWMP must be addressed as soon as possible, immediately in most cases, to prevent the discharge of pollutants. If modifications are necessary, such modifications shall be documented so that the SWMP accurately reflects on-site conditions. The SWMP needs to accurately represent field conditions at all times. Uncontrolled releases of mud, muddy water, or measurable amounts of sediment found offsite will be recorded with a brief explanation of the measures taken to clean up the sediment that has left the site,as well as the measures are taken to prevent future releases. This record shall be made available to the appropriate public agencies (Colorado Department of Public Health and Environment, Water Quality Control Division; Environmental Protection Agency;City of Fort Collins;etc.) upon request. Preventative maintenance of all temporary and permanent erosion control BMPs shall be provided to ensure the continued performance of their intended function.Temporary erosion control measures are to be removed after the site has been sufficiently stabilized, as determined by the City of Fort Collins. Maintenance activities and actions to correct problems shall be noted and recorded during inspections. Inspection and maintenance procedures specific to each BMP identified with this SWMP are discussed in Section 3. Details have also been included in Appendix B. 6.9 RECORD KEEPING Documentation of site inspections must be maintained.The following items are to be recorded and kept with the SWMP: • Date of Inspection • Name(s)and title(s)of personnel making the inspection • Location(s)of sediment discharges or other pollutants from the site • Location(s)of BMPs that need to be maintained • Location(s)of BMPs that failed to operate as designed or proved inadequate • Locations(s)where additional BMPs are needed that were not in place at the time of inspection • Deviations from the minimum inspection schedule • Descriptions of corrective action taken to remedy deficiencies that have been identified • The report shall contain a signed statement indicating the site is in compliance with the permit to the best of the signer's knowledge and belief after corrective actions have been taken. Provided within Appendix E of this SWMP is an Example Inspection Log to aid in the record keeping of BMP inspections and maintenance. Photographs,field notebooks,drawings,and maps should be included by the SWMP Administrator when appropriate. NORTHERN ENGINEERING.COM 1970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY 18 121 4(,trEi GROUP NORTHERN In addition to the Inspection Log,records should be kept documenting: • BMP maintenance and operation • Stormwater contamination • Contacts with suppliers • Notes on the need for and performance of preventive maintenance and other repairs • Implementation of specific items in the SWMP • Training events(given or attended) • Events involving materials handling and storage • Contacts with regulatory agencies and personnel • Notes of employee activities,contact,notifications,etc. Records of spills, leaks,or overflows that result in the discharge of pollutants must be documented and maintained.A record of other spills responded to,even if they do not result in a discharge of pollutants, should be made. Information that should be recorded for all occurrences includes the time and date, weather conditions, reasons for the spill, etc. Some spills may need to be reported to authorities immediately.Specifically,a release of any chemical,oil,petroleum product,sewage,etc.,which may enter waters ofthe State of Colorado(which include surface water,groundwater,and dry gullies or storm sewers leading to surface water) must be reported to the CDPHE. Additionally,the"Dynamic Site Plan"is intended to be a"living"document where the SWMP Administrator can handwrite the location of BMPs as they are installed to appropriately reflect the current site conditions. Also on the "Dynamic Site Plan" is a "Table of Construction Sequence and BMP Application/Removal" the SWMP Administrator can use to document when BMPs were installed or removed in conjunction with construction activities. These items have been included as an aid to the SWMP Administrator,and other methods of record keeping are at his or her discretion. This Stormwater Management Plan(both the text and map)is not a static document.It is a dynamic device intended to be kept current and logged as construction occurs. It shall be the responsibility of the SWMP Administrator and/or the permit holder (or applicant thereof) to ensure the plan is properly maintained and followed. Diligent administration is critical, including processing the Notice to Proceed and noting on the Stormwater Management Plan the dates that various construction activities occur and respective BMPs are installed and/or removed. 7.0 FINAL STABILIZATION AND LONG-TERM STORMWATER MANAGEMENT 7.1 FINAL STABILIZATION Final stabilization of the site will be achieved by either leaving a gravel surface in place of the existing asphalt roadway or by reseeding. If reseeding is to be used, all disturbed areas will be seeded,crimped, and mulched within 24 hours of seeding per the FCDCM Chapter 2 Section 6.1.4.9. Soil amendments such as compost, peat, aged manure, or other similar materials shall also be utilized. Soil amendments shall be tilled into the soil to a minimum depth of 6" and should comply with the requirements found in City Code Section 12-132(also refer to Land Use Code 3.8.21). Per the Landscaping Plans,the City of Fort Collins Upland Mix is specified everywhere other than around the detention ponds. Per the Landscaping Plans,the City of Fort Collins Detention Basin Mix is specified. Please refer to the landscaping plans for a more information. NORTHERN ENGINEERING.COM 1970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY 19 121 I GROTP NORTHERN Table 2-City Of Fort Collins Upland Mix COMMON NAME PLS/ACRE PLAINS COREOPSIS 0.17 ROCKY MTN PENSTEMON 0.35 PURPLE PRAIRIE CLOVER 0.81 INDIAIN BLANKETFLOWER 1.85 MEXICAN HAT 0.2 INDIAN RICEGRASS 1.13 SIDEOATS GRAMA 1.15 BUFFALOGRASS 3.27 BLUE GRAMA 0.25 BOTTLEBRUSH SQUIRRELTAIL 0.95 PRAIRIE J UN EGRASS 0.08 GREEN NEDDLEGRASS 1.01 SWITCHGRASS 0.71 WESTERN WHEAT 1.61 SAND DROPSEED 0.04 TOTAL 13.58 *If broadcast method is used, rates shall be doubled Non-seed stabilization is expected to be completed soon after hardscape construction is complete. Seeded areas will require more time to establish and may need to be irrigated to establish growth. As defined by the Colorado Department of Public Health and Environment(CDPHE) in the General Permit Application for Stormwater Discharges,"Final stabilization is reached when all soil disturbing activities at the site have been completed,and uniform vegetative cover has been established with a density of at least 70 percent of pre-disturbance levels or equivalent permanent, physical erosion reduction methods have been employed." Establishment of 70 percent is required for a determination for project closure by the City of Fort Collins. 7.2 LONG-TERM STORMWATER MANAGEMENT The primary method of long-term stormwater management will be bio-retention basins.The bio-retention basins will remove suspended sediment and pollutants from developed run-off before entering drainage facilities downstream of the site. After stabilization, before project closure, all sediment shall be removed from storm piping per FCDCM Chapter 2 Section 6.1.4.9. All disturbed areas will receive permanent paving or be vegetated per the Landscape Plan. Low Impact Development(LID)treatment will provide significant water quality enhancement and will serve the long- term stormwater management goals for this project. 8.0 ADDITIONAL SWMP AND BMP RESOURCES Mile High Flood District Urban Storm Drainage Criteria Manual-Volume 3"Best Management Practices" NORTHERN ENGINEERING.COM 1970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY 20 121 ,(,trEi GROUP NORTHERN Colorado Department of Transportation Erosion Control and Stormwater Quality Guide BMP Field Academy EPA Menu of BMPs Construction Site Storm Water Runoff Control International Stormwater Best Management(BMP) Database Rocky Mountain Education Center Rocky Mountain Education Center Red Rocks Community College, Lakewood Keep It Clean Partnership Boulder 9.0 REFERENCES 1. Final Drainage Report and Erosion Control Report-Willox Farms, Northern Engineering,April 12th,2024 (NE Project No.987-012) 2. City of Fort Collins Landscape Design Guidelines for Stormwater and Detention Facilities, November 5, 2009,BHA Design,Inc.with City of Fort Collins Utility Services. 3. Fort Collins Stormwater Criteria Manual,City of Fort Collins,Colorado,adopted by Ordinance No. 174, 2011,and referenced in Section 26-500(c)of the City of Fort Collins Municipal Code 4. Larimer County Urban Area Street Standards,Adopted January 2,2001, Repealed and Reenacted, Effective October 1,2002,Repealed and Reenacted, Effective April 1,2007 5. Soil Resource Report for Larimer County Area,Colorado,Natural Resources Conservation Service, United States Department of Agriculture. 6. Urban Storm Drainage Criteria Manual,Volumes 1-3,Mile High Flood Control District,Wright- McLaughlin Engineers,Denver,Colorado,Revised April 2008. NORTHERN ENGINEERING.COM 1970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY 21 121 EPS E GROUP NORTHERN APPENDIXA SITE MAPS 1 � \ r ' j NORTHERNENGINEERING.COM 970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY APPENDIX MATCH LINE — SEE THIS SHEET LEFT NORTH WON a a s� 991E4990 — �H--——GH —==== ==—_OH — _ _ — __ _ _ _ 80 0 80 160 240 Feet _ — — — =4992=499$990 _ II _ _ x -WEST \ � _—_� I O III (IN FEET) 93�- - — WESTWILLOXLANE - - - - - - F — y — —I \\\ \\\ 4984� \� /J / // � `\\ \ 1 I y— \ I I I 1 inch= 80 ft. 4 — - - - -______ ________ — �— _. — —'�— — — —� — — — — _ 99E499 = 49 — _ — WEST WILLOX LANE 4950—�_ �, — — e = — — ,4989_ 9 i 499 I I I ro -- ---- �, — — F - — yy �- X- \\\\ \ / / al JI ! \\�\\\\\�, / I I III - T ITI 000 \ \ p ACKELSON CONNIE A. 603 \\\ KAFKA, AMY \ i W WILLOX LANE, W WILLOX LANE, <r SOFT GOLD PARK I 1 I \ h it s \� \I\\ \\\ / I Q I HICKORY TREET 1 �\ \ L 9, \\\ / // / Q II ® KEYMAP (n O fn T L(n L \\ N �t0 - (b'1 I I. NTS p' � \ \\\ I \ / LEGEND: C)° � �� �La 0 LLI x PROPOSED STORM SEWER \m o C.° U) a c \ I \ \\ PROPOSED CONTOUR 93 � o o o aEi - Q) EXISTING CONTOUR — — — —4953- - - - - D S•o o o co s o a PROPOSED SWALE ------------------- a w a 0"J c�w PROPOSED CURB&GUTTER I PROPERTY BOUNDARY o� J LIMITS OF DISTURBANCE —LOD LOD X =W SILT FENCE SF $F ,u E a \\\ J \\ \�� 1 //'� ���� \\I\\ \ II CJF l / WATTLE DIKE im� °c z gob—a _ \\\\ \ \p\ ROCK SOCK = RS i 4984_ \\\� � ILd \ I PEREZ DANIEL A. \ ' — _ _ _ i �/ I % ° �� / I } \ //) gym/ > — s l\\ \ �\ — \\ \ \ \C —� 1 — // 1. \ \I o ass - — J 14 I SF 400 HICKORY STREET 149 / / I �9�9 // ((/ ! to, ( 2 \ \\�\ l°f/ / ! I CONCRETE WASH AREA CWA 0 A � '' V) \l VEHICLE TRACKING CONTROL PAD O } / �\\ \, I 3 �I J Z �//�/� !�/�/V// //� I)(/ ��`` 00 LLI /\ / \\ \I ��J/ �/ / I / I X INLET PROTECTION I y �\ I.' oo I ll ;//�/ /ill \ � ► I I \ \ �\ � � \ ( / I I �P NZ I I li/i/// \ r / I I \\ — of PITT, JEAN I N — 1522 WOOD LANE, I \� 00 \il /� � � J ` \��\�\III ! / \ `\ \\�p/ 1 �I \\ BALE OUTLET PROTECTION BOP o l ' *>!'I► I ,�� /� - //!/ ///// WOOD 0� 1-1 \ / RIPRAP L )<_71 RP N w o DUCK — ,- — � � � \ \ ^ I x / L 1/�{ `r 0�, / 0 Q o - T —_— \\ r \�\�\\ I ( I I / \ /I�l POND I \ ( / I / � Ld Q C \ \ / \ \ \ / I / \ CD zc �� �i— / \ MULCH MU u %�\\ 00 ((nn:- �Q ^ `\ < \� l /i \ BENCHMARK/BASIS OF BEARING: ✓� —� — — — - —� - - - - -L--- --- - - - - - - PROJECT DATUM: NAVD88 ��, o m — �1-- - -� - - — r==� \c �-�- I— � Wo z o z n OF 1 \ \ — — \ City of Fort Collins Benchmark NO. 9-07. 0 r, V) Q \ - - _��- — _ -•-�- T -I _., _ . — — — — — _—= Southeast corner of Shields ST. and Willox Lane on the South east win wall of 00 w Of _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - - _ -_ — _ _ g O) 0 m 0 m GBP LLC I , \ / \ \ / / — — — — _ — — - - _ / of the bridge over an irrigation ditch. 1434 WOOD LANE, I I g;a \\ /�1// I\ � / � � — _ - - - - - � / - - - - � - - - - " — � � � o 0 6 \ \ // — —/ I II I \�' / _ _ _ ELEV.=4999.15 NGS Benchmark V-401. In Fort Collins, at the 'unction of U.S. 287 and Bristlecone Drive, 59.4 meters � (194.9 ft) east of the north bound lanes of the highway, 14.7 \ meters (48.2 ft) North of the center of the drive, and 1.1 meters (3.6 ft) north J I II I I I,I-III .� . 01 of a utility pole and powerline crossing the drive, Note--access to the datum is R i I �;\\ �\ ^ I through a 5-inch logo cap. l J I I PEREZ DANIEL A. ELEV. 4977.81 7 OD V 4985 4 0 HICKORY STREET 149 Z \ \ I I i Please Note: This plan set is using NAVD88 for a vertical datum. I \ I Surrounding developments have used NGVD29 Unadjusted for their vertical 0 i I i1 \/ I al datums. J III If NGVD29 Unadjusted Datum is required for any purpose, the following OD / I� I TABLE OF CONSTRUCTION SEQUENCE AND BMP equation should be used: 0- o. I I �9e �,tw► / // I I APPLICATION NGVD29 Unadjusted = NAVD88- 3.18' J `- / \ � i I ` l / II CONSTRUCTION PHASE PHASE I PHASE II PHASE III PHASE IV Basis of Bearings �y O SF ��9� / (DESCRIPTION) (GRADING) (INFRASTRUCTURE) (VERTICAL (PERMANENT Assuming the North line of the Northeast Quarter of the Northwest Quarter of LL - - , Q North, Range 69 West of the 6th P. s bearing CONSTRUCITON) BMP'S) Section 2, Township, 7 R n e M. a �n ---------------------------------- - - x- North East. 1`o __-__ - Grading(Include Offsite) o I III17! 1 ------------------ ---------9a ------ E o ___- $ O o as . Overlot IIIIIII IIII I' ! �— _ +�X— P GENERAL NOTES: X O —SOFT GOLD PARK Pipeline Installation O Stormwater 1. CONTRACTOR SHALL IMMEDIATELY STABILIZE ALL DISTURBED SLOPES BY CRIMP J r , MULCHING OR SIMILAR METHODS. v —�\ I Sewer Service k' ro 00 I I \\ \4 9322- %� ,\ I iWE 44�8Y \\\\\ I / �111h Water Service 2. SWMPContacNISTRATOR: \ U N I I ( \\ \ Concrete Installation Company S W I I I �) \ LL Address O cd II h \ I I Site Walls aN I °' \\ ,l I tttt Phone o I ICI III I a \ \\ `tttttt x Building Structure /'\ �J Z n I IUIIIII h I \\\\ ��/ I \ Curb and Gutter 3. CONTRACTOR TO PROVIDE VEHICLE TRACKING CONTROL FOR CONCRETE O z z `vJ I I x p \ WASHOUT AREA IF ACCESS IS OFF PAVEMENT. a p ¢ \ I I \\\\ �// / \ 1 4. REFER TO THE Final Drainage Report dated April 12,2024 BY NORTHERN o rl I I \ / I 1 Hardscape Amenities ENGINEERING FOR ADDITIONAL INFORMATION. N oo Ill IIII \ ti 11 s + � � I ' I ,y z IIIIIII II IIII I \\ \\ esr� / BEST MANAGEMENT PRACTICES 5. DEVELOPER/CONTRACTOR SHALL RECEIVE A PERMIT THROUGH THE PARKS W W Lu O IIIIII IIIIIII \ \ \ — — / I \ 1 I� Temporary DEPARTMENT PRIOR TO COMMENCEMENT OF ANY CONSTRUCTION WORK.THIS ICI I I I III I \\ TT 1 _ — — I \1 I I PERMIT WILL INCLUDE ALL REQUESTED DETAILS AND INFORMATION REGARDING Inlet Protection (IP Q III ) THE USE OF THE PARK PROPERTY FOR ALL CONSTRUCTION WORK AND CID E w " I I�'■ \\� ■ \;, �'� ■ �� ■ ■ ■ ■ ■ ■ ` Vehicle Tracking Control (VTC) ACTIVITY, DATES OF CONSTRUCTION, DETAILS RESTORATION PLANS, ETC. CALL UTILITY NOTIFICATION CENTER OF N F MATCH LINE — SEE THIS SHEET RIGHT Flow Barriers(Wattles,Rock Socks,etc.) (RS) COLORADO Concrete Washout Area (CWA) m •i S Preventative Maintenance Activities/Meetings/etc. a � Silt Fence(SF)/Construction Fence(CF) a Permanent Sheet x z o Mulching/Sealant Q F Know what's below. EC1 o Permanent Seed Planting Call before you dig. Turf Reinforcement Mat(TRM) CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU DIG,GRADE,OR EXCAVATE FOR THE MARKING OF Erosion Control Fabric(EF) UNDERGROUND MEMBER UTILITIES. 58 of 64 MATCH LINE - SEE THIS SHEET LEFT Q; �� ■ ■ ■■�� ■ � ■ � �� �/ ■ ■ � ■ ■ � ■ ■ � ■ ■ Ii� �■ � NORTH ° — \�\ \ \ I I _ \ I I IY x 80 0 80 160 240 Feet �—� OH' OH 013 OH _ _ _ ` �/ I \\ \ \ 1 I / ' eF_— __ — — _ — _ — _ _=4999 499�590-= = \ / I 1 inch= 80 ft. LI (IN FEET) I - - - - -WEST WILLOX LANE - - - - - - - - - F 1 `- - i — I \\\\ \ �� \�/J / / ` \ II 4984 � / � ' � \ I I WEST WILLOX LANE — — — Il\\/92 ----- I / �I � I — — --------------- � 1 l J/ \ � I I ICI, ellI ws \\\ f \\\�\ `, \ !,�\ \V\ I( V I PROPOSED - w CONCRETE P N O d o ACKELSON CONNIE A. 603 \ \\\\\ \ �� / I I I / KAFKA, AMY I I I III — I W WILLOX LANE, I `\ \\\\\ \ \�, /f I I 1 / I I W WILLOX LANE, r III i `\ \ \ \\ \ // I I I �_ I � — J Imo — ' I I I \ \� — I \ EC2 \ / // I I I I I�I / j Iccw S 11VT� ti co a� I I SOFT �,� I I v�v +\\\\v .° I 1 I GOLD PARK 1 I - - - �, I • � � - � 1\�� /� I 11 p I t 1 (n I I \ I sF - / I HICKORY TREET ws \ r --- -� - J aF �9� \� V., \ / / 1\ 1 @ �I KEYMAP 0 ®NTS Q O ° ��L� L � LEGEND: � _ ' 0'0z I I I I 1 ` 1 \\\ 1 \ /// PROPOSED STORM SEWER w o o° o rn II \ I . I N 1 11 I I rI �t LLN 0-0 � 0o. PROPOSED4' LEE PROPOSED CONTOUR 93 � 0 -L-- CONCRETE PAN COI EXISTING CONTOUR - - - -4953- o c a-) ' C _ 1 J1 w/7"CURBS ow6 - co PROPOSED SWALE � � Ld PROPOSED CURB&GUTTER — \` / I ( I I PROPERTY BOUNDARY _ _ o \ \ - -r I \ m 1 I x 11\II I ,�c I o� \ \ 00 r - I I ® 1 \� I I I\ \ \ — — PROPOSED 2' LOD 1 1 � , — L 1 ( LIMITS OF DISTURBANCE � LOD I I ` I I = CONCRETE PAN �C2 "W x PROPOSED 4' I CONCRETE PAN - - - I I SILT FENCE SF LL1 vv/7"CURBS W a�x �g8 .® I I \\\\ 1 � I I aA \ c? p _ I WATTLE DIKE - I - - - L —_J L - - L I �949 —,A \ \ O / W Z 11 \ \" �I C L � o ROCK SOCK 48 -- sewPEREZ DANIEL A. = R$ r I 400 HICKORY STREET 149 j /\�- — / // \ /boy°�- —_ - l\\ \ ^ - 9 L- - . . . - . . . 9 .4sa7- sF /// //- / \/i I / /-�9s // //�// /�/ =— \)�\_ _ 1 1^Q \ I \ o p - — MOLLER STREET_ 1 I / 1k / // / CONCRETE WASH AREA CWA - 8F 9 p w �, / _ / III // ///II� LLJ W — I V - - - - — — �•/ 1 I // / I \ \ \ \ / - - � O V � � �// \ j� I / \ \ - i OF I VEHICLE TRACKING CONTROL PAD0 - '� 0 W I L — _- ( // / I P/ 1I = — I \ \ \ \ \ a / / VTC } LU WI , / I \I �z ' � 1 //��%/ //// JIB/ /�= �� = \I J\\ \\ \ \ \ I I / I �' I �DLA W I L — — 1 I // / /// / \ �� / /I °° W I \y I I I I I I �!/��I l/�ll V /// I)�/ , \// \\ \ ` \ \ J �/ / I I - - •�\ cnIIl I I I I II ® / O�o- oZp� °rn ��<\/i �// j \ INLET PROTECTION z L , I /F F- I � — - PROPOSED4'PITT, JEAN BQP �o \ BALE OUTLET PROTECTIONILL / °'-'O L - LL //f! //�/1522 WOOD LANE, W/7"CURBS o o L � wooD U 0 � = DUCK RIPRAP o /i /// POND � Q oL — _ - N f �T Q6 � � MULCH MU I I 00 v d i:- Q \ n i I - - - - I 8 w8 L-- - -I- ram-- _- I m .. L- � �\ \ �� / \�\\clV\ L \ BENCHMARK/BASIS OF BEARING: PROJECT DATUM: NAVD88 M w8 / I I : - - // — - -� - -� - - _- - - - - - - fir- - - -�___— _�-� —1— � - - - - o m UN Wt L sF I I "- �. — • • --. — . . — . . . ' \ I _ - _ — FJICKORY STREET _ City of Fort Collins Benchmark NO. 9 07. o N Q SAINT GRACE p / L — — — L �// . // '- —'� ��—_— — -- — - — — — — Illox Lane on the South east w1 g all of Do W Of GBPLLC / / _ - - - - - - - - - - - - - - - - - -- - - -- - - �- / Southeast corner of Shields n w om om \ STREET— �/ �// — — — — — — — — — — I II ` of the bridge over an irrigation ditch. 1434 WOOD LANE, �I T \ ��_. / - - _ — ELEV.=4999.15 RP /// JJ/ /— \ I II ^ J NGS Benchmark V-401. I I� ' In Fort Collins, at the junction of U.S. 287 and Bristlecone Drive, 59.4 meters wP (194.9 ft) east of the north bound lanes of the highway, 14.7 meters (48.2 ft) North of the center of the drive, and 1.1 meters (3.6 ft) north 01 of a utility pole and powerline crossing the drive, Note--access to the datum is through a 5-inch logo cap. N J I — — — \ PEREZ DANIEL A. ELEV.=4977.81 0 Is �` ` ' ` ` - - - - �`O LL` 49 S, 4 0 HICKORY STREET 149 Please Note: This plan set is using NAVD88 for a vertical datum. Surrounding developments have used NGVD29 Unadjusted for their vertical 0 5 ::::: : / I d datums. J i I PROPOSED 2' S I I CONCRETE PAN I I n a — III If NGVD29 Unadjusted Datum is required for any purpose, the following Lf OD ® I- /I I TABLE OF CONSTRUCTION SEQUENCE AND BMP equation should be used: J OC v a� ®a5 " ' l / $� // I APPLICATION NGVD29 Unadjusted = NAVD88- 3.18' / 5— -' Basis of Bearings O �a 8F 87 6SJ g8 CONSTRUCTION PHASE PHASE I PHASE II PHASE III PHASE IV gs n/ /�/ C 8F (GRADING) (INFRASTRUCTURE) (PERMANENT of �j 11-IL'. _ _ - - - - x- - Nort a g 69 West of the 6th P. s bead g (DESCRIPTION) IN RE) (VERTICAL PERMANEN Assuming the North line o the Northeast carter o the Northwest carter CONSTRUCITON) BMP'S) Section 2, Township, 7 h R n e M. a n I ----------- --- Grading(Include Offsite) o � �� e m — — North 89 3313 East. LL aD 0 1/l 111 111 _ _ Jk9� \ z W � I Ii�ll I I I r = \�_ _ —SOFT GOLD PARK +��� \\ \ O�erlot GENERAL NOTES: X W Nc II I I I I I I)II I / — t\�\ \ _ — \ Pipeline Installation O O a FUTURE CITY OF FORT COLLINS / \ x Stormwater F I( \��\\ — — + \\ / / 1. CONTRACTOR SHALL IMMEDIATELY STABILIZE ALL DISTURBED SLOPES BY CRIMP J N PARKS DEPT. IRRIGATION LINE / 7 c (TO BE DESIGNED BY OTHERS) �\ \\�� �j �'_' �\ I \ �/ J L i \\\ 4�3" /i \�` \ / / Sewer Service MULCHING OR SIMILAR METHODS. — — _982" i Water Service 2. SWMP ADMINISTRATOR: N 4�8Y �\ \ \ I Concrete Installation Contact N N il 11111 \ Company AddressSite Walls O Phone II a I I d I °°I \\\ II / / I Building Structure /'\ z W l III I� I \\ \ J// II X- / f/ p I\\ I Curb and Gutter 3. CONTRACTOR TO PROVIDE VEHICLE TRACKING CONTROL FOR CONCRETE c I 1 I WASHOUT AREA IF ACCESS IS OFF PAVEMENT. O a J r `� 1 2 4. REFER TO THE Final Drainage Report dated April 12,2024 BY NORTHERN N o O O 1j11 I Ilf l I \\ � IJI R9e -}- I 1 \ I Hardscape Amenities ENGINEERING FOR ADDITIONAL INFORMATION. Of 0 r,, O O IIII II IIII 1 \ \\ \ BEST MANAGEMENT PRACTICES ow I �1`No�', / I I x 5. DEVELOPER/CONTRACTOR SHALL RECEIVE A PERMIT THROUGH THE PARKS W X o IIIIII III I III \ \ \\ °a'tl \ I 1\ I 111 it Temporary DEPARTMENT PRIOR TO COMMENCEMENT OF ANY CONSTRUCTION WORK.THIS W IIII III I III I \\ \\ I I \ Inlet Protection (IP) PERMIT WILL INCLUDE ALL REQUESTED DETAILS AND INFORMATION REGARDING E > III I \ \ \ \ 1 1 Q IIII THE USE OF THE PARK PROPERTY FOR ALL CONSTRUCTION WORK AND o ■ \' ■ �/ ■ ■ ■ ■ � ■ ■ I■ �I Vehicle Tracking Control (VTC) ACTIVITY, DATES OF CONSTRUCTION, DETAILS RESTORATION PLANS, ETC. i F Flow Barriers(Wattles,Rock Socks,etc.) (RS) CALL UTILITY NOTIFICATION CENTER OF MATCH LINE - SEE THIS SHEET RIGHT COLORADO Concrete Washout Area (CWA) co •i S Preventative Maintenance Activities/Meetings/etc. a ro ° Silt Fence(SF)/Construction Fence(CF) a Y� Permanent Sheet x z o Mulching/Sealant Q F Know what's below. EC2 o Permanent Seed Planting Call before you dig. Turf Reinforcement Mat(TRM) CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU DIG,GRADE,OR EXCAVATE FOR THE MARKING OF Erosion Control Fabric(EF) UNDERGROUND MEMBER UTILITIES. 59 of 64 MATCH LINE - SEE THIS SHEET LEFT ■ ■ ■ ■ ■ � � �� ■ ■ �� ■ ■ � ■ ■ ■ ■ I� NORTH V wvm'i \\ I \ III \ \ I \\ I I 80 0 80 160 240 Feet OHD: OHU _ � I I IN FEET — — — — — — — —— _ ^ 499$990— - - - - - - - -WEST WI LLOX LANE - - - - - - - - F — `� — —H, I \\\\ \ 4ss /� \ J / \ I I ( ) - a =——-- — — — — — -- — ——-- _=-4ss — — °j — �— — J \ \�\�\ 4 / —\\\\0 \\Il I / illl 1 inch= 80 ft. — — — — — — ss4ss = - WEST WILLOX LANE — — — — _ ss / 9 = - - s sow _ - - \ \\\ \ /(JI 92 -------------- — — I r — — — — — — — — — — — -\= 1- ------------- `�\ I / I III Mu / rLc� \1 lJ/ j I II Ij PROPOSED 2' \\ \ — I P \\\ \ \.l c O Y l - I Ir III l 9� ` ACKELSON CONNIE A. 603 \` \\\�\ ��' `� \ �'j // I I I > KAFKA, AMY I MU I I W WILLOX LANE, I W WILLOX LANE, �r \ r I I i \\\ \� \\ \\� j J // '/ I I I\I EC3 JL J w _ / I I w S //�/T` \ \ I J I i I \ \\\ \\ anti I I I II SOFT / I O ` I I � W � ✓OS\ \ l \ \ \\ ~ �� 1 I I GOLD PARK _w Q ► \ ` i \ / \ HICKORY NTS_ - I MU \\ \ --- _ / Q'' KEYMAP a c I I I \ — — \ -v J \\\ I kCP o a LEGEND: w PROPOSED STORM SEWER L`' o a � o a°�w o . N \ \ 11 \ J / I I II Ltd PROPOSED CONTOUR 93 � o o o aEi - � PROPOSED 4' \ / I t — — — — c N CONCRETE PAN m \ 11 EXISTING CONTOUR 4953- — — — - D - o c a ° a 1 1 U7 Zt \ I I PROPOSED SWALE ------------------- ° w a o"J -w m D- I � \ w/7"CURBS, \ I I � — \\ I \ \ I N PROPOSED CURB&GUTTER \ \ 1 m , I \ i \ ` r , \� �g011 I / I I PROPERTY BOUNDARY \ \ m 11 J , II 11\II l I l i o0 \ r PROPOSED 2' 1 I I� ( I °o \\ \ I I I I — — _ \ CONCRETE PAN I \ — iO I LIMITS OF DISTURBANCE �LOD LOD >n X PROPOSED 4' I — — /I^ I t \\\ t Q / ) I ` / I W M Mo CONCRETE PAN I -I I �\\� , f9 ? I SILT FENCE SF $F r w/7"CURBS WATTLE DIKE Icy-- °c z C�\ In — \ 4984Ld . I I \ \'� I ROCK SOCK — \ PEREZ DANIEL A. /'� / / I I )// >A,e 400 HICKORY STREET 149 o \ _. . . . —. .. — .. \ v`°'• v CONCRETE WASH AREA CWA W 9 I \ — MOLLER STREET.-9p 1 I J �l I / // / / I///� / ll� \ \\_\� \ \ \ 1 \ i / I Y 9 — -_ - - ^ / / / III / � \ \ \ I / r 1 � � i. i/ I/ I / \ \ _ i 8F I VEHICLE TRACKING CONTROL PAD � w / I /,�/ I I I \ \ \ \ \ o / Ld w wl - - - I I I I / I \I z %� 1 // //Illll% - - !\ /J�\ \\\\ \ \ I\� // 1 /i Ilh(�I 'I / lCo / I I \ ( IP W O .I orn \ // //// //II \ \ 1 \ \ \ / I I INLET PROTECTION — - - -� I— = _ \ 1� I 1/I //i// //// � � r _ \ Nz I— I F_ — Q III / \ ` / °o \\ I I //�I ////% / // \l/, I \ \ / / I \ % / / I 1 \ \ / I I \— — 0) � — —I � �� I I I I � — O � / //_ // ;to� � 1 ( \ ��I I ( t— A v� jl �O PITT, JEAN II I` I I I I PROPOSED 4' t = \I / //�/ /�/ M-0, ��\III / \ \ \ `+/ / I �'I \ BALE OUTLET PROTECTION BOP _ _ O 1522 WOOD LANE, I I — J I� MU Ll — CONCRETE PAN LL O II �� �� ~ w/7"CURBS / / O �t• %// //// ( _\�.�• \ / / � / I 0 �I I * , I I L I l I \ ' /� I )�/// ////// wooD \` `_ _ s / UU o I . I _ //� \ ///�I, 111/ / DUCK — — — — � J/ \ \\ ( / � RIPRAP RP w 0 Mu � — —1 I I _ - - -- - - - _ _ I - - - I / ILJ POND I \ \�/ A \ \ \ I l I / \ � 0-6 04 zG / \ I I /I I / �\ Q �o- I I s I I / \ // /I /i\ \ / I / 1 \ I MULCH MU 00 cn� dQ \ v / / \\ c \ \I I BENCHMARK/BASIS OF BEARING: �\ — f — \ w� �� ---- ---- T-�_ _-��- - - - - - - /� PROJECT DATUM: NAVD88 m J - \ — 0 m Y—= — — — — — — H N \ it - - -�� _ - I -i /��`- - - - - - - - - - r- l- �- - � - - _ Wo z o z / - - - City of Fort Collins Benchmark NO. 9-07. Y \ / I — - - - \ — F�ICKORY STREET — — o� N Q / •- — � _—�_ - - - - - - _ -� - - - _•- _: - - - = Southeast corner of Shields ST. and Willox Lane on the South east wingwall of CO w Of SAINT GRACE -8 - - � / / - - - - - - - - - _ __ - -__- I _ \v J/ l o of the bridge over an irrigation ditch. a_0) o m o m GBPLLC a ; T � � \� STREET- — - t fv/ //j1// I�� �/ / - - \ - - g g 14 4WOOD LANE l i' _/ - � / ELEV.=4999.15 i I , NGS Benchmark V-401. V \ _ _ / // / \ / / \ IIIII I III I / - - In Fort Collins, at the junction of U.S. 287 and Bristlecone Drive, 59.4 meters \ \R / � � \ � � l � � l ' � � / // � I / / IIIII I � II ►� I (194.9 ft) east of the north bound lanes of the highway, 14.7 meters (48.2 ft) North of the center of the drive, and 1.1 meters (3.6 ft) north 01 �I III of a utility pole and powerline crossing the drive, Note--access to the datum is through a 5-inch logo cap. I v I ELEV.=4977.81 PEREZ DANIEL A. 7 _ - - - - 4s $ 4 0 HICKORY STREET 149 Please Note: This Ian set is usingNAVD88 for a vertical datum. e` I I I Surrounding developments have used NGVD29 Unadjusted for their vertical 0 5 •• LL:- 1 datums. J PROPOSED 2' 0 1 i CONCRETE PAN III If NGVD29 Unadjusted Datum is required for any purpose, the following Mu I equation should be used: ge / I NGVD29 Unadjusted = NAVD88- 3.18' J 9 o � I �� MU $� s +�► l �� I � O < 35 / 1 Basis of Bearings g 87 6 y I Assuming the North line of the Northeast Quarter of the Northwest Quarter of - -ILII -�� North, Range 69 West of the 6th P. s bearing_- _- __87_ -_ -- - _ _- - - Section 2, Township, 7 h R n e M. aQ ` J L 1 (1117 jll ---------------- _ _ X- - a ----------------- --- _ _ North 89°33'13" East. � I/I III I I I I — , ^ ,k9a _ — x Z z II I►111 Illy _ -- — ��\ — _ \\\ GENERAL NOTES: X O z N aI I IIIII I I III \\\ —— \ — SOFT GOLD PARK �, + \ \ O _ N FUTURE CITY OF FORT COLLINS 1. CONTRACTOR SHALL IMMEDIATELY STABILIZE ALL DISTURBED SLOPES BY CRIMP g 12 PARKS DEPT. IRRIGATION LINE I( / \�\\\ / — — \ �/ \ \ / / v MULCHING OR SIMILAR METHODS. (TO BE DESIGNED BY OTHERS) \\�� ���\ J,;-�-. \ I / TABLE OF CONSTRUCTION SEQUENCE AND BMP APPLICATION J oI I I \\ \4498; \1 l \ / 2. SWMP ADMINISTRATOR: z Project: WILLOX FARMS Company ttt UTILITIES FLAT WORK VERTICAL wI III I I ��� \\\� III I \ CONSTRUCTION PHASE MOBILIZATION DEMOLITION GRADING INSTALLATION INSTALLATION INSTALLATION LANDSCAPE DEMOBILIZATION phoness O I ICI III I \\ I / \ BEST MANAGEMENT PRACTICES(BMPS) u 1 3. CONTRACTOR TO PROVIDE VEHICLE TRACKING CONTROL FOR CONCRETE ♦♦♦ ~ J W 1 I I 1 I STRUCTURAL"INSTALLATION" WASHOUT AREA IF ACCESS IS OFF PAVEMENT. p z vj Q I O II Silt Fence Barriers 4. REFER TO THE Final Drainage Report dated April 12,2024 BY NORTHERN O Ihll II IIIII \\ ` 9� + / I \ I \ I 1 I Concrete Washout Area* ENGINEERING FOR ADDITIONAL INFORMATION. Of Vehicle Tracking Pad* W I I �x 5. DEVELOPER/CONTRACTOR SHALL RECEIVE A PERMIT THROUGH THE PARKS Z I I I I \ ��Nrn \ DEPARTMENT PRIOR TO COMMENCEMENT OF ANY CONSTRUCTION WORK.THIS x W I I I I I I I \ �rna�`r \` I Straw Wattles aD W U) II II 11 I III I \ \ \ \\ III I \\ I 11 II PERMIT WILL INCLUDE ALL REQUESTED DETAILS AND INFORMATION REGARDING W I I I I) \ \ \ \ Q I II I Inlet Protection* Any prior inlets that cou d use protecting THE USE OF THE PARK PROPERTY FOR ALL CONSTRUCTION WORK AND o I�■ \ ' ■ �� ■ ■ ■ ■ ■ ■ ■ ` ACTIVITY, DATES OF CONSTRUCTION, DETAILS RESTORATION PLANS, ETC. � u Rock Socks* Any prior in ets that cou d use protecting a CALL UTILITY NOTIFICATION CENTER OF N F MATCH LINE - SEE THIS SHEET RIGHT *All Temporary BMPs to be Removed once Construction is Complete COLORADO co a � I a ro Vegetative , Temporary Seeding Planting Anytime the site wit sit dormant longer t an 30 ays Mulching/Sealant Anytime the sz1zite wil sit dormant longer t an 30 a Sheet c� z o Permanent Seeding Planting Know what's below. EC3 a ~ o Call before you dig. Sod Installation CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU Rolled Products:Netting/Blankets/Mats Anytime the site wil sit dormant longer t an 30 ays DIG,GRADE,OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES. 60 of 64 EPS E GROUP NORTHERN APPENDIX B EROSION • R• ti ?rx= �norxsn`w.. NORTHERNENGINEERING.COM 970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY APPENDIX iv INSTALLATION NOTES: +' 1 1" (MINUS) CRUSHED ROCK ENCLOSED IN WIRE MESH 1. VEHICLE TRACKING CONTROL PAD SHALL BE LOCATED AT EVERY ACCESS POINT TO THE CONSTRUCTION SITE. 6' MAX RS 2. A SIGN SHALL BE PLACED NEXT TO THE VEHICLE TRACKING CONTROL PAD TO DESIGNATE THE LOCATION AS THE CONSTRUCTION ENTRANCE/EXIT. 3. VEHICLE TRACKING CONTROL PADS SHALL CONSIST OF HARD, DENSE, DURABLE STONE, ANGULAR IN SHAPE AND RESISTANT TO WEATHERING. ROUNDED STONE (i.e. RIVER ROCK AND COBBLES) SHALL NOT BE USED. THE STONES SHALL BE A MINIMUM OF 3" AND A MAXIMUM OF 6" ;i:,' DIAMETER. THE STONES SHALL HAVE A SPECIFIC GRAVITY OF AT LEAST 2.6. CONTROL OF GRADATION WILL BE BY VISUAL INSPECTION. POSTS WIRE TIE ENDS 4. ANY CRACKED OR DAMAGED CURB AND GUTTER AND SIDEWALK SHALL BE REPLACED BY CONTRACTOR. SIGN TO INDICATE THE - 5. ALTHOUGH NOT NORMALLY USED, THE CITY RESERVES THE RIGHT TO REQUIRE VEHICLE TRACKING CONTROL WITH A TEMPORARY CATTLE GUARD SILT FENCE FABRIC (ASTM D6461) ANCHORED IN rF I LOCATION OF THE AND/OR WHEEL WASH FACILITIES AT SITES WHERE TRACKING ONTO PAVED AREAS BECOMES A SIGNIFICANT PROBLEM AS DETERMINED BY THE CITY TRENCH AND ATTACHED TO POST. CONCRETE WASHOUT AREA _ - INSPECTOR. 6. IF VEHICLE TRACKING CONTROL WITH WHEEL WASH FACILITIES ARE REQUIRED, ALL WHEELS ON EVERY VEHICLE LEAVING THE SITE SHALL BE CLEANED OF MUD USING A PRESSURE-WASHER. THE CONTRACTOR SHALL BE RESPONSIBLE FOR OBTAINING A WATER SOURCE AND CONSTRUCTING A WASHWATER SEDIMENT TRAP. 24" MIN MAINTENANCE NOTES: BERM AROUND PERIMETER 0" ON BEDROCK %% OR HARD SURFACE,T GROUND SURFACE 4" TO 6" MAX AT CURBS, 1. CONTRACTOR SHALL INSPECT VEHICLE TRACKING CONTROL PAD DAILY. ROCK SURFACE SHALL BE CLEAN AND LOOSE ENOUGH TO RUT SLIGHTLY 2" IN SOIL OTHERWISE 6"-10" DEPENDING UNDER WHEEL LOADS AND CAUSE LOOSE ROCK TO DISLODGE MUD FROM TIRES. WHEN ROCK BECOMES COMPACTED OR FILLED WITH SEDIMENT SO GROUND SURFACE THAT THE EFFECTIVENESS OF THE PAD IS DIMINISHED, CONTRACTOR SHALL RIP, TURN OVER, OR OTHERWISE LOOSEN ROCK, PLACE ADDITIONAL NEW ON EXPECTED SEDIMENT LOADS ROCK, OR REPLACE WITH NEW ROCK AS NECESSARY TO RESTORE EFFECTIVENESS. 00 2. SEDIMENT AND OTHER MATERIAL SPILLED, DROPPED OR TRACKED ONTO PAVED SURFACES SHALL BE REMOVED IMMEDIATELY OR BY THE END OF 12" MIN ROCK SOCK SECTION ROCK SOCK PLAN EACH WORKING DAY. FLOW 3. VEHICLE TRACKING CONTROL PAD SHALL BE REMOVED AT THE END OF CONSTRUCTION. THE AREA SHOULD BE TOPSOILED, SEEDED, CRIMPED, AND MULCHED OR OTHERWISE 12" 2'-0" MIN. ANY GAP AT JOINT SHALL BE FILLED WITH AN ADEQUATE STABILIZED. 4. IF VEHICLE WHEEL WASH FACILITIES ARE REQUIRED, CONTRACTOR SHALL INSPECT VEHICLE TRACKING CONTROL AND WHEEL WASH FACILITIES DAILY. �- AMOUNT OF 11" (MINUS) CRUSHED ROCK AND WRAPPED ACCUMULATED SEDIMENTS SHALL BE REMOVED FROM THE PAD SURFACE. WITH ADDITIONAL WIRE MESH SECURED TO ENDS OF ROCK 5. ACCUMULATED SEDIMENT IN THE WASH WATER/SEDI MEN T TRAP SHALL BE REMOVED WHEN THE SEDIMENT REACHES AN AVERAGE DEPTH OF 12-INCHES. O REINFORCED SOCK. AS AN ALTERNATIVE TO FILLING JOINTS INSTALLATION NOTES: O 50' MIN. _ '� 12" BETWEEN ADJOINING ROCK SOCKS WITH CRUSHED ROCK AND 1. DRIVE POSTS VERTICALLY INTO THE GROUND TOAMINIMUM DEPTH OF 18". > ROCK SOCK ADDITIONAL WIRE WRAPPING, ROCK SOCKS CAN BE 2. EXCAVATE A TRENCH APPROXIMATELY 4"WIDE AND 4"DEEP ALONG THE N (TYP.) 12' OVERLAPPED (TYPICALLY 12-INCH OVERLAP) TO AVOID GAPS. COMPACTED BACKFILL LINE OF POSTS AND UPSLOPE FROM THE BARRIER. � COMPACTED EMBANKMENT 3. ANCHOR TRENCH SHALL BE EXCAVATED BY HAND,WITH TRENCHER,OR MATERIAL, TYP. WITH SILT FENCE INSTALLATION MACHINE.NO ROAD GRADERS,BACKHOES, 000 3H:1 V OR FLATTER GRADATION TABLE w PLAN 4. ETC.SHALL BE USED. 00 * IMPERMEABLE LINER MAY SIDE SLOPES 0 1 NOT LESS THAN THE BOTTOM V OF THE SILT FENCE FABRIC SHALL BE BE NEEDED IF GROUND 8'x 8' MIN MASS PERCENT + 1/"x 1/z WOODEN FENCE POSTS 5. BURIED IN THE TRENCH. OR AS REQUIRED TO THE TRENCH SHALL BE COMPACTED BY HAND,WITH"JUMPING JACK"OR BY ii WATER IS ENCOUNTERED. CONTAIN WASTE CONCRETE SIEVE SIZE PASSING SQUARE In WHEEL ROLLING.COMPACTION SHALL BE SUCH THAT THE SILT FENCE 6. RESISTS BEING PULLED OUT OF ANCHOR TRENCH BY HAND. MESH SIEVES > R-5 SILT FENCE INDICATED IN THE PLANS SHALL BE INSTALLED PRIOR TO ANY ROCK SOCK JOINTING N0.4 . LAND-DISTURBING ACTIVITIES. SILT FENCE FABRIC (ASTM D6461) ANCHORED IN 7 USE WOOD POSTS OROTHERMATERIALASACCEPTEDBYTHECITY. TRENCH AND ATTACHED TO POST. 2" 100 CURB AND GUTTER2SS MINIMUM 12" 1-1/2" s0-100 24'" MIN COMPACTED BACKFILL 4"MIN. -��FLOW 1" 20-55 42' MIN MAINTENANCE NOTES: O 0-15 A I 3' - 6' ROCK 20' MIN. 16 1. THE CONTRACTOR SHALL INSPECT SILT FENCE EVERY TWO WEEKS AND z RUNOFF 3/8" 0-5 / AFTER SIGNIFICANT STORM EVENTS AND MAKE REPAIRS OR CLEAN OUT NOTES: UPSTREAM SEDIMENT AS NECESSARY. iv MATCHES SPECIFICATIONS FOR NO.4 COARSE AGGREGATE FOR / 2. SEDIMENT ACCUMULATED UPSTREAM OF SILT FENCE SHALL BE REMOVED 1. CONCRETE WASHOUT AREA SHALL BE INSTALLED PRIOR TO ANY CONCRETE PLACEMENT ON SITE. - CONCRETE PER AASHTO M43.ALL ROCK SHALL BE FRACTURED FACE, 18" MINANY WHEN THE UPSTREAM SEDIMENT REACHES A DEPTH OF 6". Q- '" s_ ALL SIDES / 4"MIN. 3. SILT FENCE SHALL BE REMOVED WHEN THE UPSTREAM DISTURBED AREA IS O N O O m-0 d N 2. VEHICLE TRACKING CONTROL IS REQUIRED IF ACCESS TO CONCRETE WASHOUT AREA IS OFF PAVEMENT. STABILIZED AND GRASS COVER IS ACCEPTED BY THE CITY.IF ANY (D .�+ a E-0 W .� 4"x4" TRENCH DISTURBED AREA EXISTS AFTER REMOVAL,IT SHALL BE SEEDED AND I`- T, O•-,� L 3. SIGNS SHALL BE PLACED AT THE CONSTRUCTION ENTRANCE, AT THE WASHOUT AREA, AND ELSEWHERE AS WIRE ENCLOSED 1 1/2" O MULCHED OR OTHERWISE STABILIZED IN A MANNER ACCEPTED BY THE CITY. (n a) O rn O O 0 NECESSARY TO CLEARLY INDICATE THE LOCATION OF THE CONCRETE WASHOUT AREA TO OPERATORS OF WASHED ROCK w i >,c LJ - CONCRETE TRUCKS AND PUMP RIGS. T o m(D o.2 U) o T 4. THE CONCRETE WASHOUT AREA SHALL BE REPAIRED AND ENLARGED OR CLEANED OUT AS NECESSARY TO MARKETUBULAR ` 0 CO: E C ` SIGN "CONSTRUCTION ENTRANCE" ci Q) O p Q) MAINTAIN CAPACITY FOR WASTED CONCRETE. PREASSEMBLED SILT FENCE POSTS SHALL OVERLAP c-p 1n 0) 7 C- 5. THE CONCRETE WASHOUT SHOULD BE EMPTIED WHEN HALF OF TOTAL HOLDING CAPACITY HAS BEEN REACHED. AT JOINTS SO THAT NO > ° O O 6. AT THE END OF CONSTRUCTION, ALL CONCRETE SHALL BE REMOVED FROM THE SITE AND DISPOSED OF AT AN CONSTRUCTION FENCE, TYP., TO DISCOURAGE GAPS EXIST IN SILT FENCE. - w p U) CO w ACCEPTED WASTE SITE. ROCK SOCK INSTALLATION NOTES VEHICLE ACCESS EXCEPT AT VTC o- - rn H 7. WHEN THE CONCRETE WASHOUT AREA IS REMOVED, THE DISTURBED AREA SHALL BE SEEDED AND MULCHED OR ,. SEE PLAN VIEW FOR: OTHERWISE STABILIZED IN A MANNER ACCEPTED BY THE CITY. - LOCATION (S) OF ROCK SOCKS. �2 MIN. r 6" MIN. 8. LOCATION OF CONCRETE WASHOUT AREA ON SHEET EC1 IS CONCEPTUAL ONLY. FINAL LOCATION TO BE 2. CRUSHED ROCK SHALL BE 1 j" (MINUS) IN SIZE WITH A FRACTURED FACE (ALL SIDES) AND SHALL �� + 6" MIN. JOIN FIRST ROTATE SECOND o� DETERMINED IN THE FIELD AT CONTRACTOR'S DISCRETION. COMPLY WITH GRADATION SHOWN ON THIS SHEET (1}" MINUS). _ , Y= O O Q1 3. WIRE MESH SHALL BE FABRICATED OF 10 GAGE POULTRY MESH, OR EQUIVALENT, WITH A MAXIMUM - OPENING OF RECOMMENDED MINIMUM ROLL WIDTH OF 48". NO MATERIALS INCLUDING 2x4'S, PIPES, DIRT, GRAVEL OR ASPHALT, SHALL BE 3" - 6" ROCK - NOTE, c Z PLACED IN GUTTER TO FACILITATE W CWA/� 4. WIRE MESH SHALL BE SECURED USING "HOG RINGS" OR WIRE TIES AT 6' CENTERS ALONG ALL MOUNTING CURB; HOWEVER, CURB THICKNESS OF GEOTEXTILE 5p JOINTS AND AT 2" CENTERS ON ENDS OF SOCKS. MAY BE CUT DOWN TO A HEIGHT OF 2" VTC d 0- EASIER ACCESS AND POST SHALL BE JOINED AS SHOWN,THEN HAS BEEN EXAGGERATED. 1L1 c d REPLACED ATOR HIGHER RPROJECT COMPLETION. ROTATED 180"IN DIRECTION SHOWN AND =W. N 2 5 FOR SOME MUNICIPALITIES ROCK LENCLOSUREALLOW THE USE OF FILTER FABRIC AS AN ALTERNATIVE TO WIRE MESH OTHER ACCESS DEVICES MAY BE USED SECTION A DRIVEN INTO THE GROUND. AS ACCEPTED BY THE CITY. ii00 !=c3 c z SF _SF SILT FENCE JOINTSw o 001 CONCRETE WASHOUT AREA 002 ROCK SOCK rO3 VEHICLE TRACKING PAD NOT TO SCALE NOT TO SCALE NOT TO SCALE H EC5 EC5 EC5 004 SILT FENCE O EC5 NOT TO SCALE 0 c� I� - W (n W LA W LA W A MANHOLE CURB INLET B MANHOLE STAKES SHOULD BE DRIVEN THROUGH THE MIDDLE IF AREA ADJACENT TO CURB INLET BOX IS NOT STABILIZED, OF THE WATTLE. LEAVING 2 - 3 INCHES OF THE - INSTALL A TEMPORARY - -----� Yx 4"WOOD STUD EXTENDED �--� STAKE PROTRUDING ABOVE THE WATTLE. A SEDIMENT/EROSION CONTROL INTO CONCRETE BLOCKS -�.. HEAVY SED MENT LOAD WILL TEND TO PICK THE 04(n BMP UNTIL THE SURROUNDING • AREA IS-ZIENTLr s' WATTLE UP AND COULD PULL IT OFF THE STAKES OUTLET 0 J STABILIZED. -• • - .• - ` "' IF THEY ARE DRIVEN DOWN TOO LOW. IT MAY BE _J BMP WIDTH VARIES -I=--- BMP WIDTH VARIES S TR U C TU R E --;..-fir:�`'�° `.: ',. I i •';'tr NECESSARY TO MAKE A HOLE IN THE WATTLE WITH 0)0 A PICK END OF YOUR MADDOX IN ORDER TO GET '*'• •;. ,g i ROCK BERM SHALL BE PLACED j:, '�• ♦ i THE STAKE THROUGH THE STRAW. WHEN STRAW TIGHTLY AGAINST CURB FACE I x•"•"".,;t• I I " a' I,.mow,t._�,.yr„r�::•,a:, � I •.•i �� WATTLES ARE USED FOR FLAT GROUND p I'4'.'0.:•'•' of ; �•+"� i'i I APPLICATIONS, DRIVE THE STAKES STRAIGHT DOWN; ..+.•; �.�.:a Q I •"f •'.• CURB AND GUTTER ., •_, .: r WHEN INSTALLING WATTLES ON SLOPES, DRIVE THE STAKES PERPENDICULAR TO THE SLOPE. A A 1' I I •:'1:'a••�y..5 ;:.. t I,I -MIN I " r x..:..�:'.�•.• v MIN ', MIN Q I E:" : �.:..� `:�C • OR I' .• h CURB AND GUTTER A !J:•.. a I CV U STAKES SHOULD DRIVEN ACROSS FROM EACH WQ \ Q OTHER AND ON EACH SIDE OF THE WATTLE. I-\ Q Q N 3 LEAVING 4"-6" OF STAKE PROTRUDING ABOVE THE 0 O 0 Z d Q ROCK BERM SHALL WATTLE. BAILING WIRE OR NYLON ROPE SHOULD BE BE PLACED TIGHTLY F TIED TO THE STAKES ACROSS THE WATTLE. STAKES ® ® AGAINST CURB FACE SHOULD THEN BE DRIVEN UNTIL THE BAILING WIRE A WIRE ENCLOSED 1 1/2" B ® OR NYLON ROPE IS SUFFICIENTLY SNUG TO THE WIRE ENCLOSED TUBULAR 1Y2 ANGULAR WASHED ROCK m WASHED ROCK � WATTLE. WRAPPED IN FILTER FABRIC N o m i 1/2"WASHED ROCK MARKER CONCRETE TUBULAR TUBULAR PLAN VIEW BLOCKS MARKER PLAN VIEW MARKER W V) z TUBULAR MARKER TUBULAR MARKER POINT A POINT A O NLLI Q GRAVEL FILTER SHALL BE PLAN VIEW of 00W O U U Of 1/2"TO I"BELOW TOP OF CURB RFLOW FLOW O P m 0) 0 m Q m OVE WIRE ENCLOSED 2'x4°WOOD STUD 4" MIN A A POINT B GRAVEL FILTER f BMP WIDTH VARIES E ENCLOSED 5" MAX BMP WIDTH VARIES GRAVEL FILTER • OUTLET " POINT B ENTRENCH 3" a � •• e� `•'' �' \ POINTS A MUST BE HIGHER THAN POINT B STRUCTURE FILTERED SETTLED RUNOFF "y RUNOFF POINT A SECTION A-A ° \. A •` •` POINT A FINISHED GRADE a° CURB INLET CURB INLET POND BOTTOM WQCV °•° ° .< 01 SECTION A-A SECTION B-B \, \ WATTLE DIKE rnn R �. DITCH INSTALLATION WD •� 2 Aa A A vJ N CURB INLET BLOCK AND GRAVEL FILTER CURB INLET GRAVEL FILTER \ d•' • 0 (INLET IN SUMP) (CONTINUOUS GRADE) OR . I OD GENERAL NOTES MAINTENANCE NOTES: 1. INTERIM CONFIGURATION INLET PROTECTION IN STREETS SHALL BE INSTALLED WITHIN 48 HOURS OF POURING INLET.INLET PROTECTION(AFTER PAVING) V SHALL BE INSTALLED WITHIN 48 HOURS AFTER PAVING IS PLACED. 2. WASHED ROCK SHALL COMPLY WITH A 1-1/2"MINUS GRADATION. PLAN VIEW 1. THE CONTRACTOR SHALL INSPECT DIKES EVERY TWO WEEKS AND AFTER SIGNIFICANT N 3. WIRE MESH SHALL BE FABRICATED OF 10 GAUGE WIRE TWISTED INTO A MESH WITH A MAXIMUM OPENING OF 1°(COMMONLY TERMED'CHICKEN WIRE").ROLL 0 WIDTH SHALL BE 48". WATTLE STORM EVENTS AND MAKE REPAIRS OR CLEAN OUT UPSTREAM SEDIMENT AS NECESSARY. 4. TUBULAR MARKERS SHALL MEET REQUIREMENTS OF MANUAL ON UNIFORM TRAFFIC CONTROL DEVICES(MUTTH CD). (1 O" MIN. DA.) 2. SEDIMENT ACCUMULATED UPSTREAM OF DIKES SHALL BE REMOVED WHEN THE UPSTREAM 5. OTHER CURB INLET PROTECTION METHODS WILL BE ALLOWED IF ACCEPTED BY THE CITY. SEDIMENT REACHES 1/2 OF THE DESIGN DEPTH. SECTION A-A W 3. DIKES ARE TO REMAIN IN PLACE UNTIL THE UPSTREAM DISTURBED AREA IS STABILIZED C c �j MAINTENANCE NOTES: AND GRASS COVER IS ACCEPTED BY THE CITY. COD 1. THE CONTRACTOR SHALL INSPECT INLET PROTECTION EVERY TWO WEEKS AND AFTER SIGNIFICANT STORM EVENTS AND MAKE REPAIRS OR CLEAN OUT AS 4. WHEN REINFORCED ROCK BERMS ARE REMOVED, ANY DISTURBED AREA SHALL BE SEEDED, Q NECESSARY. CRIMPED AND MULCHED OR OTHERWISE STABILIZED IN A MANNER ACCEPTED BY THE CITY. d 2. SEDIMENT ACCUMULATED UPSTREAM OF INLET PROTECTION SHALL BE REMOVED WHEN THE SEDIMENT DEPTH UPSTREAM OF ROCK BERM IS 2 1/2"OF THE 3. INLET PROTECTION IS TO REMAIN IN PLACE UNTIL THE UPSTREAM DISTURBED AREA IS STABILIZED AND GRASS COVER IS ACCEPTED.UNLESS THE CITY rOO7 ACCEPTS EARLIER REMOVAL OF INLET PROTECTION IN STREETS. OUTLET PROTECTION J 0. EC5 NOT TO SCALE 0 0 1 005 CURB INLET PROTECTION 006 SWALE WATTLE DIKE Q $ EC5 NOT TO SCALE EC5 NOT TO SCALE O z w 'JC`\/ I Z C14< u 0 0 C4 O x J N p I m NI _j V � o o � W N O O Z � CD 3 � Oa o ry w W OD rn E � I 3 o CALL UTILITY NOTIFICATION CENTER OF N F COLORADO o I m •i 0 coa � s a Sheet z 0 Know what's below. o Call before you dig. EC5 CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU DIG,GRADE,OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES. 61 of 64 Chapter 7 Construction BMPs Pre-Construction 7= ■ Develop Site Plan 0 Obtain Stormwater Construction Permits • Obtain Site Survey,Hydrology and Soils (State and Local) Information 0 Obtain Other Relevant Permits • Prepare SWMP (e.g.,404, Floodplain, Dewatering) Representative Phases: Management Practices: ■ Clearing and Grubbing K Phase Construction Activities to Minimize ■ Rough Grading Disturbed Area at a Given Time ■ Road Construction Sequence Contruction within Phases to Avoid Idle Disturbed Areas • Utility and Infrastructure Installation ■ Install,Inspect and Proactively Maintain BMPs • Vertical Construction(Buildings) Appropriate for Each Phase of Construction ■ Final Grading Maintain and Update SWMP as Construction Progresses Final Stabilization ■ Revegetate Site ■ Activate Post Construction BMPs (e.g.,convert sediment basin to extended Closeout State and Local Stormwater Permits detention basin) • ■ Remove Temporary BMPs Figure 7-2. Construction Stormwater Management November 2010 Urban Drainage and Flood Control District 7-13 Urban Storm Drainage Criteria Manual Volume 3 Construction BMPs Construction BMPs Table 7-2. Overview of Construction BMPs Erosion Sediment Site/Material Functions Control Control Management Erosion Control BMPs Surface Roughening Yes No No Temporary/Permanent Seeding Yes No No Soil Binders Yes No Moderate Mulching Yes Moderate No Compost Blankets and Filter Berms Yes Moderate No Rolled Erosion Control Products Yes No No Temporary Slope Drains Yes No No Temporary Outlet Protection Yes Moderate No Rough Cut Street Control Yes Moderate No Earth Dikes/Drainage Swales Yes Moderate No Terracing Yes Moderate No Check Dams Yes Moderate No Streambank Stabilization Yes No No Wind Erosion/Dust Control Yes No Moderate Sediment Control BMPs Silt Fence No Yes No Sediment Control Log Moderate Yes No Straw Bale Barrier No Moderate No Brush Barrier Moderate Moderate No Rock Sock(perimeter control) No Yes No Inlet Protection(various forms) No Yes No Sediment Basins No Yes No Sediment Traps No Yes No Vegetative Buffers Moderate Yes Yes Chemical Treatment Moderate Yes No Materials Management Concrete Washout Area No No Yes Stockpile Management Yes Yes Yes Good Houskeeping(multiple practices) No No Yes Site Management and Other Specific Practices Construction Phasing Moderate Moderate Yes Protection of Existing Vegetation Yes Moderate Yes Construction Fence No No Yes Vehicle Tracking Control Moderate Yes Yes Stabilized Construction Roadway Yes Moderate Yes Stabilized Staging Area Yes Moderate Yes Street Sweeping/Vacuuming No Yes Yes Temporary Diversion Channel Yes No No Dewatering Operations Moderate Yes Yes Temporary Stream Crossing Yes Yes No Temporary Batch Plants No No Yes Paving and Grinding Operations No No Yes 7-14 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Surface Roughening (SR) EC-1 Description Surface roughening is an erosion control - practice that involves tracking, scarifying, imprinting,or tilling a - - disturbed area to provide temporary stabilization of disturbed areas. Surface roughening creates variations in the soil surface that help to minimize wind and = - - water erosion. Depending on the technique used, surface roughening may also help establish conditions favorable �. to establishment of vegetation. s - - Appropriate Uses = Surface roughening can be used to Photograph SR-1. Surface roughening via imprinting for temporary provide temporary stabilization of stabilization. disturbed areas, such as when revegetation cannot be immediately established due to seasonal planting limitations. Surface roughening is not a stand-alone BMP, and should be used in conjunction with other erosion and sediment controls. Surface roughening is often implemented in conjunction with grading and is typically performed using heavy construction equipment to track the surface. Be aware that tracking with heavy equipment will also compact soils,which is not desirable in areas that will be revegetated. Scarifying,tilling, or ripping are better surface roughening techniques in locations where revegetation is planned. Roughening is not effective in very sandy soils and cannot be effectively performed in rocky soil. Design and Installation Typical design details for surfacing roughening on steep and mild slopes are provided in Details SR-1 and SR-2,respectively. Surface roughening should be performed either after final grading or to temporarily stabilize an area during active construction that may be inactive for a short time period. Surface roughening should create depressions 2 to 6 inches deep and approximately 6 inches apart. The surface of exposed soil can be roughened by a number of techniques and equipment. Horizontal grooves (running parallel to the contours of the land) can be made using tracks from equipment treads, stair-step grading,ripping, or tilling. Fill slopes can be constructed with a roughened surface. Cut slopes that have been smooth graded can be roughened as a subsequent operation. Roughening should follow along the contours of the slope. The tracks left by truck mounted equipment working perpendicular to the contour can leave acceptable horizontal depressions; Surface Roughening however,the equipment will also compact the soil. Functions Erosion Control Yes Sediment Control No Site/Material Management No November 2010 Urban Drainage and Flood Control District SR-1 Urban Storm Drainage Criteria Manual Volume 3 EC-1 Surface Roughening (SR) Maintenance and Removal Care should be taken not to drive vehicles or equipment over areas that have been surface roughened. Tire tracks will smooth the roughened surface and may cause runoff to collect into rills and gullies. Because surface roughening is only a temporary control, additional treatments may be necessary to maintain the soil surface in a roughened condition. Areas should be inspected for signs of erosion. Surface roughening is a temporary measure, and will not provide long-term erosion control. SR-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Surface Roughening (SR) EC-1 x SR l - TRACKING OR IMPRINTING f!r r 6" MAX l FURROWS 2" TO 4" DEEP 2" TO WITH 6" MAXIMUM SPACING 4" DEEP f PARALLEL TO CONTOURS SR- 1 . SURFACE ROUGHENING FOR STEEP SLOPES (3:1 OR STEEPER) SCARIFYING OR TILLING i / ROUGHENED ROWS SHALL BE 4" TO 6'* 4" TO 6" DEEP WITH 6" MAXIMUM SPACING PARALLEL DEEP TO CONTOURS SR-2. SURFACE ROUGHENING FOR LOW SLOPES (LESS THAN 3:1) November 2010 Urban Drainage and Flood Control District SR-3 Urban Storm Drainage Criteria Manual Volume 3 EC-1 Surface Roughening (SR) SURFACE ROUGHENING INSTALLATION NOTES 1. SEE PLAN VIEW FOR: —LOCATION(S) OF SURFACE ROUGHENING. 2 SURFACE ROUGHENING SHALL BE PROVIDED PROMPTLY AFTER COMPLETION OF FINISHED GRADING (FOR AREAS NOT RECEIVING TOPSOIL) OR PRIOR TO TOPSOIL PLACEMENT OR ANY FORECASTED RAIN EVENT. 3 AREAS WHERE BUILDING FOUNDATIONS, PAVEMENT, OR SOD WILL BE PLACED WITHOUT DELAY IN THE CONSTRUCTION SEQUENCE, SURFACE ROUGHENING IS NOT REQUIRED. 4. DISTURBED SURFACES SHALL BE ROUGHENED USING RIPPING OR TILLING EQUIPMENT ON THE CONTOUR OR TRACKING UP AND DOWN A SLOPE USING EQUIPMENT TREADS. 5. A FARMING DISK SHALL NOT BE USED FOR SURFACE ROUGHENING. SURFACE ROUGHENING MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE. NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION, INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACE UPON DISCOVERY OF THE FAILURE. 4. VEHICLES AND EQUIPMENT SHALL NOT BE DRIVEN OVER AREAS THAT HAVE BEEN SURFACE ROUGHENED. 5. IN NON—TURF GRASS FINISHED AREAS, SEEDING AND MULCHING SHALL TAKE PLACE DIRECTLY OVER SURFACE ROUGHENED AREAS WITHOUT FIRST SMOOTHING OUT THE SURFACE 6. IN AREAS NOT SEEDED AND MULCHED AFTER SURFACE ROUGHENING, SURFACES SHALL BE RE—ROUGHENED AS NECESSARY TO MAINTAIN GROOVE DEPTH AND SMOOTH OVER RILL EROSION. (DETAILS ADAPTED FROM TOWN OF PARKER. COLORADO. NOT AVAILABLE IN ALITOCAD) NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. SR-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Temporary and Permanent Seeding (TS/PS) EC-2 Description Temporary seeding can be used to stabilize disturbed areas that will be inactive for an extended period. Permanent seeding should be used to stabilize areas at final grade that will not be otherwise stabilized. Effective seeding includes preparation of a seedbed, selection of an appropriate seed mixture, proper planting techniques,and protection of the seeded area with mulch,geotextiles, or other appropriate measures. " ^ Appropriate Uses - When the soil surface is disturbed and Photograph TS/PS-1. Equipment used to drill seed. Photo courtesy of will remain inactive for an extended Douglas County. period(typically 30 days or longer), proactive stabilization measures should be implemented. If the inactive period is short-lived(on the order of two weeks),techniques such as surface roughening may be appropriate. For longer periods of inactivity,temporary seeding and mulching can provide effective erosion control. Permanent seeding should be used on finished areas that have not been otherwise stabilized. Typically, local governments have their own seed mixes and timelines for seeding. Check jurisdictional requirements for seeding and temporary stabilization. Design and Installation Effective seeding requires proper seedbed preparation,selection of an appropriate seed mixture,use of appropriate seeding equipment to ensure proper coverage and density, and protection with mulch or fabric until plants are established. The USDCM Volume 2 Revegetation Chapter contains detailed seed mix, soil preparations, and seeding and mulching recommendations that may be referenced to supplement this Fact Sheet. Drill seeding is the preferred seeding method. Hydroseeding is not recommended except in areas where steep slopes prevent use of drill seeding equipment, and even in these instances it is preferable to hand seed and mulch. Some jurisdictions do not allow hydroseeding or hydromulching. Seedbed Preparation Prior to seeding, ensure that areas to be revegetated have soil conditions capable of supporting vegetation. Overlot Temporary and Permanent Seeding grading can result in loss of topsoil,resulting in poor quality subsoils at the ground surface that have low nutrient value, Functions little organic matter content, few soil microorganisms, Erosion Control Yes rooting restrictions, and conditions less conducive to Sediment Control No infiltration of precipitation. As a result,it is typically Site/Material Management No necessary to provide stockpiled topsoil, compost, or other November 2010 Urban Drainage and Flood Control District TS/PS-1 Urban Storm Drainage Criteria Manual Volume 3 EC-2 Temporary and Permanent Seeding (TS/PS) soil amendments and rototill them into the soil to a depth of 6 inches or more. Topsoil should be salvaged during grading operations for use and spread on areas to be revegetated later. Topsoil should be viewed as an important resource to be utilized for vegetation establishment, due to its water-holding capacity, structure,texture, organic matter content,biological activity, and nutrient content. The rooting depth of most native grasses in the semi-arid Denver metropolitan area is 6 to 18 inches. At a minimum,the upper 6 inches of topsoil should be stripped, stockpiled, and ultimately respread across areas that will be revegetated. Where topsoil is not available, subsoils should be amended to provide an appropriate plant-growth medium. Organic matter, such as well digested compost,can be added to improve soil characteristics conducive to plant growth. Other treatments can be used to adjust soil pH conditions when needed. Soil testing,which is typically inexpensive, should be completed to determine and optimize the types and amounts of amendments that are required. If the disturbed ground surface is compacted,rip or rototill the surface prior to placing topsoil. If adding compost to the existing soil surface,rototilling is necessary. Surface roughening will assist in placement of a stable topsoil layer on steeper slopes,and allow infiltration and root penetration to greater depth. Prior to seeding,the soil surface should be rough and the seedbed should be firm,but neither too loose nor compacted. The upper layer of soil should be in a condition suitable for seeding at the proper depth and conducive to plant growth. Seed-to-soil contact is the key to good germination. Seed Mix for Temporary Vegetation To provide temporary vegetative cover on disturbed areas which will not be paved,built upon, or fully landscaped or worked for an extended period(typically 30 days or more),plant an annual grass appropriate for the time of planting and mulch the planted areas. Annual grasses suitable for the Denver metropolitan area are listed in Table TS/PS-l. These are to be considered only as general recommendations when specific design guidance for a particular site is not available. Local governments typically specify seed mixes appropriate for their jurisdiction. Seed Mix for Permanent Revegetation To provide vegetative cover on disturbed areas that have reached final grade,a perennial grass mix should be established. Permanent seeding should be performed promptly(typically within 14 days)after reaching final grade. Each site will have different characteristics and a landscape professional or the local jurisdiction should be contacted to determine the most suitable seed mix for a specific site. In lieu of a specific recommendation, one of the perennial grass mixes appropriate for site conditions and growth season listed in Table TS/PS-2 can be used. The pure live seed(PLS)rates of application recommended in these tables are considered to be absolute minimum rates for seed applied using proper drill-seeding equipment. If desired for wildlife habitat or landscape diversity, shrubs such as rubber rabbitbrush(Chrysothamnus nauseosus), fourwing saltbush(Atriplex canescens)and skunkbrush sumac (Rhus trilobata) could be added to the upland seedmixes at 0.25, 0.5 and 1 pound PLS/acre,respectively. In riparian zones, planting root stock of such species as American plum(Prunus americans),woods rose(Rosa woodsii), plains cottonwood(Populus sargentii), and willow(Populus spp.)may be considered. On non-topsoiled upland sites, a legume such as Ladak alfalfa at 1 pound PLS/acre can be included as a source of nitrogen for perennial grasses. TS/PS-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Temporary and Permanent Seeding (TS/PS) EC-2 Seeding dates for the highest success probability of perennial species along the Front Range are generally in the spring from April through early May and in the fall after the first of September until the ground freezes. If the area is irrigated, seeding may occur in summer months, as well. See Table TS/PS-3 for appropriate seeding dates. Table TS/PS-1. Minimum Drill Seeding Rates for Various Temporary Annual Grasses Pounds of Planting Species' Growth Pure Live Seed Depth (Common name) Season (PLS)/acre (inches) 1. Oats Cool 35 - 50 1 -2 2. Spring wheat Cool 25 - 35 1 -2 3. Spring barley Cool 25 -35 1 -2 4. Annual ryegrass Cool 10-15 '/z 5. Millet Warm 3 - 15 '/2-3/4 6. Sudangrass Warm 5-10 '/2-3/4 7. Sorghum Warm 5-10 'h-% 8. Winter wheat Cool 20-35 1 -2 9. Winter barley Cool 20-35 1 -2 10. Winter rye Cool 20-35 1 -2 11. Triticale Cool 25-40 1 -2 a Successful seeding of annual grass resulting in adequate plant growth will usually produce enough dead-plant residue to provide protection from wind and water erosion for an additional year. This assumes that the cover is not disturbed or mowed closer than 8 inches. Hydraulic seeding may be substituted for drilling only where slopes are steeper than 3:1 or where access limitations exist. When hydraulic seeding is used, hydraulic mulching should be applied as a separate operation,when practical,to prevent the seeds from being encapsulated in the mulch. See Table TS/PS-3 for seeding dates. Irrigation,if consistently applied, may extend the use of cool season species during the summer months. Seeding rates should be doubled if seed is broadcast,or increased by 50 percent if done using a Brillion Drill or by hydraulic seeding. November 2010 Urban Drainage and Flood Control District TS/PS-3 Urban Storm Drainage Criteria Manual Volume 3 EC-2 Temporary and Permanent Seeding (TS/PS) Table TS/PS-2. Minimum Drill Seeding Rates for Perennial Grasses Commona Botanical Growth Growth Seeds/ Pounds of Name Name Season Form Pound PLS/acre Alakali Soil Seed Mix Alkali sacaton Sporobolus airoides Cool Bunch 1,750,000 0.25 Basin wildrye Elymus cinereus Cool Bunch 165,000 2.5 Sodar streambank wheatgrass Agropyron riparium 'Sodar' Cool Sod 170,000 2.5 Jose tall wheatgrass Agropyron elongatum 'Jose' Cool Bunch 79,000 7.0 Arriba western wheatgrass Agropyron smithii'Arriba' Cool Sod 110,000 5.5 Total 17.75 Fertile Loamy Soil Seed Mix Ephriam crested wheatgrass Agropyron cristatum Cool Sod 175,000 2.0 Ephriam' Dural hard fescue Festuca ovina 'duriuscula' Cool Bunch 565,000 1.0 Lincoln smooth brome Bromus inermis leyss Cool Sod 130,000 3.0 'Lincoln' Sodar streambank wheatgrass Agropyron riparium 'Sodar' Cool Sod 170,000 2.5 Arriba western wheatgrass Agropyron smithii Arriba' Cool Sod 110,000 7.0 Total 15.5 High Water Table Soil Seed Mix Meadow foxtail Alopecurus pratensis Cool Sod 900,000 0.5 Redtop Agrostis alba Warm Open sod 5,000,000 0.25 Reed canarygrass Phalaris arundinacea Cool Sod 68,000 0.5 Lincoln smooth brome Bromus inermis leyss Cool Sod 130,000 3.0 Lincoln' Pathfinder switchgrass Panicum virgatum Warm Sod 389,000 1.0 'Pathfinder' Alkar tall wheatgrass Agropyron elongatum Cool Bunch 79,000 5.5 Alkar' Total 10.75 Transition Turf Seed Mix` Ruebens Canadian bluegrass Poa compressa 'Ruebens' Cool Sod 2,500,000 0.5 Dural hard fescue Festuca ovina 'duriuscula' Cool Bunch 565,000 1.0 Citation perennial ryegrass Lolium perenne'Citation' Cool Sod 247,000 3.0 Lincoln smooth brome Bromus inermis leyss Cool Sod 130,000 3.0 Lincoln' Total I I I 1 1 7.5 TS/PS-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Temporary and Permanent Seeding (TS/PS) EC-2 Table TS/PS-2. Minimum Drill Seeding Rates for Perennial Grasses (cont.) Common Botanical Growth Growth Seeds/ Pounds of Name Name Season Form Pound PLS/acre Sandy Soil Seed Mix Blue grama Bouteloua gracilis Warm Sod-forming 825,000 0.5 bunchgrass Camper little bluestem Schizachyrium scoparium Warm Bunch 240,000 1.0 'Camper' Prairie sandreed Calamovilfa longifolia Warm Open sod 274,000 1.0 Sand dropseed Sporobolus cryptandrus Cool Bunch 5,298,000 0.25 Vaughn sideoats grama Bouteloua curtipendula Warm Sod 191,000 2.0 'Vaughn' Arriba western wheatgrass Agropyron smithii'Arriba' Cool Sod 110,000 5.5 Total 10.25 Heavy Clay,Rocky Foothill Seed Mix Agropyron cristatum Ephriam crested wheatgrass d 'Ephriam' Cool Sod 175,000 1.5 Oahe Intermediate wheatgrass Agropyron intermedium Cool Sod 115,000 5.5 'Oahe' Vaughn sideoats grama' 'Vaughn'oua curtipendula' Warm Sod 191,000 2.0 'Vaug Lincoln smooth brome Bromus inermis leyss Cool Sod 130,000 3.0 Lincoln' Arriba western wheatgrass Agropyron smithii'Arriba' Cool Sod 110,000 5.5 Total 17.5 a All of the above seeding mixes and rates are based on drill seeding followed by crimped hay or straw mulch. These rates should be doubled if seed is broadcast and should be increased by 50 percent if the seeding is done using a Brillion Drill or is applied through hydraulic seeding. Hydraulic seeding may be substituted for drilling only where slopes are steeper than 3:1. If hydraulic seeding is used,hydraulic mulching should be done as a separate operation. b See Table TS/PS-3 for seeding dates. If site is to be irrigated,the transition turf seed rates should be doubled. d Crested wheatgrass should not be used on slopes steeper than 6H to IV. Can substitute 0.5 lbs PLS of blue grama for the 2.0 lbs PLS of Vaughn sideoats grama. November 2010 Urban Drainage and Flood Control District TS/PS-5 Urban Storm Drainage Criteria Manual Volume 3 EC-2 Temporary and Permanent Seeding (TS/PS) Table TS/PS-3. Seeding Dates for Annual and Perennial Grasses Annual Grasses Perennial Grasses (Numbers in table reference species in Table TS/PS-1) Seeding Dates Warm Cool Warm Cool January 1—March 15 ✓ ✓ March 16—April30 4 1,2,3 ✓ ✓ May 1—May 15 4 ✓ May 16—June 30 4,5,6,7 July 1—July 15 5,6,7 July 16—August 31 September 1—September 30 8,9,10,11 October 1—December 31 1 ✓ ✓ Mulch Cover seeded areas with mulch or an appropriate rolled erosion control product to promote establishment of vegetation. Anchor mulch by crimping,netting or use of a non-toxic tackifier. See the Mulching BMP Fact Sheet for additional guidance. Maintenance and Removal Monitor and observe seeded areas to identify areas of poor growth or areas that fail to germinate. Reseed and mulch these areas,as needed. An area that has been permanently seeded should have a good stand of vegetation within one growing season if irrigated and within three growing seasons without irrigation in Colorado. Reseed portions of the site that fail to germinate or remain bare after the first growing season. Seeded areas may require irrigation,particularly during extended dry periods. Targeted weed control may also be necessary. Protect seeded areas from construction equipment and vehicle access. TS/PS-6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Soil Binders (SB) EC-3 Description Soil binders include a broad range of treatments that can be applied to exposed soils for temporary stabilization to reduce wind and water erosion. Soil binders may be applied alone or as tackifiers in conjunction with mulching and seeding applications. Acknowledgement: This BMP Fact Sheet has been adapted from the 2003 California Stormwater Quality Association (CASQA)Stormwater BMP Handbook: Construction - (www.cabmphandbooks.com). Photograph SB-1. Tackifier being applied to provide temporary soil Appropriate Uses stabilization. Photo courtesy of Douglas County. Soil binders can be used for short-term,temporary stabilization of soils on both mild and steep slopes. Soil binders are often used in areas where work has temporarily stopped,but is expected to resume before revegetation can become established. Binders are also useful on stockpiled soils or where temporary or permanent seeding has occurred. Prior to selecting a soil binder, check with the state and local jurisdiction to ensure that the chemicals used in the soil binders are allowed. The water quality impacts of some types of soil binders are relatively unknown and may not be allowed due to concerns about potential environmental impacts. Soil binders must be environmentally benign(non-toxic to plant and animal life), easy to apply,easy to maintain, economical, and should not stain paved or painted surfaces. Soil binders should not be used in vehicle or pedestrian high traffic areas,due to loss in effectiveness under these conditions. Site soil type will dictate appropriate soil binders to be used. Be aware that soil binders may not function effectively on silt or clay soils or highly compacted areas. Check manufacturer's recommendations for appropriateness with regard to soil conditions. Some binders may not be suitable for areas with existing vegetation. Design and Installation Properties of common soil binders used for erosion control are provided in Table SB-1. Design and installation Soil Binders guidance below are provided for general reference. Follow the manufacturer's instructions for application rates and Functions procedures. Erosion Control Yes Sediment Control No Site/Material Management Moderate November 2010 Urban Drainage and Flood Control District SB-1 Urban Storm Drainage Criteria Manual Volume 3 EC-3 Soil Binders (SB) Table SB-1. Properties of Soil Binders for Erosion Control(Source: CASQA 2003) Binder Type Evaluation Criteria Plant Material Plant Material Polymeric Cementitious- Based Based Emulsion Blends Based Binders (short lived) (long lived) Resistance to Leaching High High Low to Moderate Moderate Resistance to Abrasion Moderate Low Moderate to High Moderate to High Longevity Short to Medium Medium Medium to Long Medium Minimum Curing Time 9 to 18 hours 19 to 24 hours 0 to 24 hours 4 to 8 hours before Rain Compatibility with Good Poor Poor Poor Existing Vegetation Photodegradable/ Photodegradable/ Mode of Degradation Biodegradable Biodegradable Chemically Chemically Degradable Degradable Water Truck or Water Truck or Specialized Application Water Truck or Water Truck or Hydraulic Hydraulic Equipment Hydraulic Mulcher Hydraulic Mulcher Mulcher Mulcher Liquid/Powder Powder Liquid Liquid/Powder Powder Yes,but Yes,but dissolves on Surface Crusting dissolves on Yes Yes rewetting rewetting Clean Up Water Water Water Water Erosion Control Varies Varies Varies 4,000 to 12,000 Application Rate lbs/acre Typ. S13-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Soil Binders (SB) EC-3 Factors to consider when selecting a soil binder generally include: ■ Suitability to situation: Consider where the soil binder will be applied,if it needs a high resistance to leaching or abrasion,and whether it needs to be compatible with existing vegetation. Determine the length of time soil stabilization will be needed, and if the soil binder will be placed in an area where it will degrade rapidly. In general, slope steepness is not a discriminating factor. ■ Soil types and surface materials: Fines and moisture content are key properties of surface materials. Consider a soil binder's ability to penetrate, likelihood of leaching, and ability to form a surface crust on the surface materials. ■ Frequency of application: The frequency of application can be affected by subgrade conditions, surface type,climate, and maintenance schedule. Frequent applications could lead to high costs. Application frequency may be minimized if the soil binder has good penetration, low evaporation, and good longevity. Consider also that frequent application will require frequent equipment clean up. An overview of major categories of soil binders, corresponding to the types included in Table SB-1 follows. Plant-Material Based (Short Lived) Binders ■ Guar: A non-toxic,biodegradable,natural galactomannan-based hydrocolloid treated with dispersant agents for easy field mixing. It should be mixed with water at the rate of 11 to 15 lbs per 1,000 gallons. Recommended minimum application rates are provided in Table S13-2. Table SB-2. Application Rates for Guar Soil Stabilizer Slo a(H:V) Flat 4:1 3:1 2:1 1:1 Application Rate(lb/acre) 40 45 50 60 70 ■ Psyllium: Composed of the finely ground muciloid coating of plantago seeds that is applied as a wet slurry to the surface of the soil. It dries to form a firm but rewettable membrane that binds soil particles together but permits germination and growth of seed. Psyllium requires 12 to 18 hours drying time. Application rates should be from 80 to 200 lbs/acre,with enough water in solution to allow for a uniform slurry flow. ■ Starch: Non-ionic,cold-water soluble(pre-gelatinized) granular cornstarch. The material is mixed with water and applied at the rate of 150 lb/acre. Approximate drying time is 9 to 12 hours. Plant-Material Based (Long Lived) Binders ■ Pitch and Rosin Emulsion: Generally, a non-ionic pitch and rosin emulsion has a minimum solids content of 48 percent. The rosin should be a minimum of 26 percent of the total solids content. The soil stabilizer should be a non-corrosive,water dilutable emulsion that upon application cures to a water insoluble binding and cementing agent. For soil erosion control applications,the emulsion is diluted and should be applied as follows: o For clayey soil: 5 parts water to 1 part emulsion November 2010 Urban Drainage and Flood Control District S13-3 Urban Storm Drainage Criteria Manual Volume 3 EC-3 Soil Binders (SB) o For sandy soil: 10 parts water to 1 part emulsion Application can be by water truck or hydraulic seeder with the emulsion and product mixture applied at the rate specified by the manufacturer. Polymeric Emulsion Blend Binders ■ Acrylic Copolymers and Polymers: Polymeric soil stabilizers should consist of a liquid or solid polymer or copolymer with an acrylic base that contains a minimum of 55 percent solids. The polymeric compound should be handled and mixed in a manner that will not cause foaming or should contain an anti-foaming agent. The polymeric emulsion should not exceed its shelf life or expiration date;manufacturers should provide the expiration date. Polymeric soil stabilizer should be readily miscible in water,non-injurious to seed or animal life,non-flammable, should provide surface soil stabilization for various soil types without inhibiting water infiltration, and should not re-emulsify when cured. The applied compound should air cure within a maximum of 36 to 48 hours. Liquid copolymer should be diluted at a rate of 10 parts water to 1 part polymer and the mixture applied to soil at a rate of 1,175 gallons/acre. ■ Liquid Polymers of Methacrylates and Acrylates: This material consists of a tackifier/sealer that is a liquid polymer of methacrylates and acrylates. It is an aqueous 100 percent acrylic emulsion blend of 40 percent solids by volume that is free from styrene, acetate,vinyl, ethoxylated surfactants or silicates. For soil stabilization applications,it is diluted with water in accordance with manufacturer's recommendations,and applied with a hydraulic seeder at the rate of 20 gallons/acre. Drying time is 12 to 18 hours after application. ■ Copolymers of Sodium Acrylates and Acrylamides: These materials are non-toxic, dry powders that are copolymers of sodium acrylate and acrylamide. They are mixed with water and applied to the soil surface for erosion control at rates that are determined by slope gradient, as summarized in Table SB-3. Table SB-3. Application Rates for Copolymers of Sodium Acrylates and Acrylamides Slope H: Flat to 5:1 5:1 to 3:1 2:2 to 1:1 Application Rate(lb/acre) 3.0-5.0 5.0-10.0 10.0-20.0 ■ Polyacrylamide and Copolymer of Acrylamide: Linear copolymer polyacrylamide is packaged as a dry flowable solid. When used as a stand-alone stabilizer, it is diluted at a rate of 11 lb/1,000 gal. of water and applied at the rate of 5.0 lb/acre. ■ Hydrocolloid Polymers: Hydrocolloid Polymers are various combinations of dry flowable polyacrylamides,copolymers, and hydrocolloid polymers that are mixed with water and applied to the soil surface at rates of 55 to 60 lb/acre. Drying times are 0 to 4 hours. Cementitious-Based Binders ■ Gypsum: This formulated gypsum based product readily mixes with water and mulch to form a thin protective crust on the soil surface. It is composed of high purity gypsum that is ground, calcined and processed into calcium sulfate hemihydrate with a minimum purity of 86 percent. It is mixed in a hydraulic seeder and applied at rates 4,000 to 12,000 lb/acre. Drying time is 4 to 8 hours. S13-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Soil Binders (SB) EC-3 Installation After selecting an appropriate soil binder,the untreated soil surface must be prepared before applying the soil binder. The untreated soil surface must contain sufficient moisture to assist the agent in achieving uniform distribution. In general,the following steps should be followed: ■ Follow manufacturer's written recommendations for application rates,pre-wetting of application area, and cleaning of equipment after use. ■ Prior to application,roughen embankment and fill areas. ■ Consider the drying time for the selected soil binder and apply with sufficient time before anticipated rainfall. Soil binders should not be applied during or immediately before rainfall. ■ Avoid over spray onto roads, sidewalks,drainage channels, sound walls, existing vegetation, etc. ■ Soil binders should not be applied to frozen soil,areas with standing water,under freezing or rainy conditions, or when the temperature is below 40°F during the curing period. ■ More than one treatment is often necessary, although the second treatment may be diluted or have a lower application rate. ■ Generally, soil binders require a minimum curing time of 24 hours before they are fully effective. Refer to manufacturer's instructions for specific cure time. ■ For liquid agents: o Crown or slope ground to avoid ponding. o Uniformly pre-wet ground at 0.03 to 0.3 gal/yd2 or according to manufacturer's recommendations. o Apply solution under pressure. Overlap solution 6 to 12 in. o Allow treated area to cure for the time recommended by the manufacturer,typically at least 24 hours. o Apply second treatment before first treatment becomes ineffective,using 50 percent application rate. o In low humidity,reactivate chemicals by re-wetting with water at 0.1 to 0.2 gal/yd2. Maintenance and Removal Soil binders tend to break down due to natural weathering. Weathering rates depend on a variety of site- specific and product characteristics. Consult the manufacturer for recommended reapplication rates and reapply the selected soil binder as needed to maintain effectiveness. Soil binders can fail after heavy rainfall events and may require reapplication. In particular, soil binders will generally experience spot failures during heavy rainfall events. If runoff penetrates the soil at the top of a slope treated with a soil binder,it is likely that the runoff will undercut the stabilized soil layer and discharge at a point further down slope. November 2010 Urban Drainage and Flood Control District S13-5 Urban Storm Drainage Criteria Manual Volume 3 EC-3 Soil Binders (SB) Areas where erosion is evident should be repaired and soil binder or other stabilization reapplied, as needed. Care should be exercised to minimize the damage to protected areas while making repairs. Most binders biodegrade after exposure to sun,oxidation,heat and biological organisms;therefore, removal of the soil binder is not typically required. SB-6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Mulching (MU) EC-4 Description s Mulching consists of evenly applying L.6 straw,hay, shredded wood mulch,bark or compost to disturbed soils and securing the mulch by crimping,tackifiers,netting or other measures. Mulching helps reduce erosion by protecting bare soil from rainfall impact, increasing infiltration,and reducing runoff. Although often applied in conjunction with temporary or s permanent seeding, it can also be used for temporary stabilization of areas that cannot be reseeded due to seasonal constraints. Mulch can be applied either using standard mechanical dry application methods or using hydromulching equipment Photograph MU-1. An area that was recently seeded,mulched, that hydraulically applies a slurry of water, and crimped. wood fiber mulch,and often a tackifier. Appropriate Uses Use mulch in conjunction with seeding to help protect the seedbed and stabilize the soil. Mulch can also be used as a temporary cover on low to mild slopes to help temporarily stabilize disturbed areas where growing season constraints prevent effective reseeding. Disturbed areas should be properly mulched and tacked,or seeded,mulched and tacked promptly after final grade is reached(typically within no longer than 14 days)on portions of the site not otherwise permanently stabilized. Standard dry mulching is encouraged in most jurisdictions; however,hydromulching may not be allowed in certain jurisdictions or may not be allowed near waterways. Do not apply mulch during windy conditions. Design and Installation Prior to mulching, surface-roughen areas by rolling with a crimping or punching type roller or by track walking. Track walking should only be used where other methods are impractical because track walking with heavy equipment typically compacts the soil. A variety of mulches can be used effectively at construction sites, including the following types: Mulch Functions Erosion Control Yes Sediment Control Moderate Site/Material Management No November 2010 Urban Drainage and Flood Control District MU-1 Urban Storm Drainage Criteria Manual Volume 3 EC-4 Mulching (MU) ■ Clean,weed-and seed-free,long-stemmed grass hay(preferred)or cereal grain straw. Hay is preferred because it is less susceptible to removal by wind. Mulch should be applied evenly at a rate of 2 tons per acre and must be tacked or fastened by an approved method suitable for the type of mulch used. At least 50 percent of the grass hay mulch,by weight, should be 10 inches or more in length. ■ Grass hay mulch must be anchored and not merely placed on the surface. This can be accomplished mechanically by crimping or with the aid of tackifiers or nets. Anchoring with a crimping implement is preferred,and is the recommended method for areas flatter than 3:1. Mechanical crimpers must be capable of tucking the long mulch fibers into the soil to a depth of 3 inches without cutting them. An agricultural disk, while not an ideal substitute,may work if the disk blades are dull or blunted and set vertically; however,the frame may have to be weighted to afford proper soil penetration. ■ On small areas sheltered from the wind and heavy runoff, spraying a tackifier on the mulch is satisfactory for holding it in place. For steep slopes and special situations where greater control is needed,erosion control blankets anchored with stakes should be used instead of mulch. ■ Hydraulic mulching consists of wood cellulose fibers mixed with water and a tackifying agent and should be applied at a rate of no less than 1,500 pounds per acre(1,425 lbs of fibers mixed with at least 75 lbs of tackifier)with a hydraulic mulcher. For steeper slopes,up to 2000 pounds per acre may be required for effective hydroseeding. Hydromulch typically requires up to 24 hours to dry;therefore,it should not be applied immediately prior to inclement weather. Application to roads,waterways and existing vegetation should be avoided. ■ Erosion control mats,blankets,or nets are recommended to help stabilize steep slopes(generally 3:1 and steeper) and waterways. Depending on the product,these may be used alone or in conjunction with grass or straw mulch. Normally,use of these products will be restricted to relatively small areas. Biodegradable mats made of straw and jute,straw-coconut, coconut fiber, or excelsior can be used instead of mulch. (See the ECM/TRM BMP for more information.) ■ Some tackifiers or binders may be used to anchor mulch. Check with the local jurisdiction for allowed tackifiers. Manufacturer's recommendations should be followed at all times. (See the Soil Binder BMP for more information on general types of tackifiers.) ■ Rock can also be used as mulch. It provides protection of exposed soils to wind and water erosion and allows infiltration of precipitation. An aggregate base course can be spread on disturbed areas for temporary or permanent stabilization. The rock mulch layer should be thick enough to provide full coverage of exposed soil on the area it is applied. Maintenance and Removal After mulching,the bare ground surface should not be more than 10 percent exposed. Reapply mulch, as needed,to cover bare areas. MU-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Compost Blanket and Filter Berm (CB) EC-5 Description CHI I a _ A compost blanket is a layer of compost uniformly applied -_ to the soil in disturbed areas to control erosion, facilitate : . revegetation, and retain sediment resulting from sheet-flow r - runoff. ` A compost filter berm is a dike of compost or a compost t e product that is laced perpendicular to runoff to control P p p tP erosion in disturbed areas and retain sediment. Compost berms can be placed at regular intervals to help reduce the formation of rill and gully erosion when a compost blanket is stabilizing a slope. fi Appropriate Uses Compost blankets can be used as an alternative to erosion control blankets and mulching to help stabilize disturbed areas where sheet flow conditions are present. Compost blankets should not be used in areas of concentrated flows. Compost provides an excellent source of nutrients for plant Photograph CB-1. Application of a compost growth, and should be considered for use in areas that will be blanket to a disturbed area. Photo courtesy of permanently vegetated. Caltrans. Design and Installation See Detail CB-1 for design details and notes. Do not place compost in areas where it can easily be transported into drainage pathways or waterways. When using a compost blanket on a slope,berms should be installed periodically to reduce the potential for concentrated flow and rilling. Seeding should be completed before an area is composted or incorporated into the compost. Compost quality is an important consideration when selecting compost blankets or berms. Representative compost quality factors include pH, salinity,moisture content, organic matter content, stability(maturity), and physical contaminants. The compost should meet all local, state,and federal quality requirements. Biosolids compost must meet the Standards for Class A biosolids outlined in 40 CFR Part 503. The U.S. Composting Council(USCC)certifies compost products under its Seal of Testing Assurance(STA) Program. Compost producers whose products have been certified through the STA Program provide customers with a standard product label that allows comparison between compost products. Only STA certified, Class I compost should be used. Compost Blankets and Berms Functions Erosion Control Yes Sediment Control Moderate Site/Material Management No November 2010 Urban Drainage and Flood Control District CB-1 Urban Storm Drainage Criteria Manual Volume 3 EC-5 Compost Blanket and Filter Berm (CB) Maintenance and Removal When rills or gullies develop in an area that has been composted, fill and cover the area with additional compost and install berms as necessary to help reduce erosion. Weed control can be a maintenance challenge in areas using compost blankets. A weed control strategy may be necessary,including measures such as mechanical removal and spot application of targeted herbicides by licensed applicators. For compost berms, accumulated sediments should be removed from behind the berm when the sediments reach approximately one third the height of the berm. Areas that have been washed away should be replaced. If the berm has experienced significant or repeated washouts,a compost berm may not be the appropriate BMP for this area. Compost blankets and berms biodegrade and do not typically require removal following site stabilization. C13-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Compost Blanket and Filter Berm (CB) EC-5 � OT2' MIN CBMIN 15' MAk 1' MIN CLASS 1 COMPOST FILTER BERM 1" TO 3" THICK (2" TYP.) STA CERTIFIED CLASS 1 COMPOST BLANKET PROPER SOIL PREPARATION AND SURFACE ROUGHENING WHEN APPROPRIATE 2 TABLE CB-1. CLASS 1 COMPOST PARAMETERS CHARACTERISTIC MINIMUM STABILITY INDICATOR STABLE TO VERY STABLE SOLUBLE SALTS MAXIMUM 5 mmhos/cm PH 6.0 — 8.0 AG INDEX > 10 MATURITY INDICATOR EXPRESSED AS 80+/80+ PERCENTAGE OF GERMINATION/VIGOR MATURITY INDICATOR EXPRESSED AS < 4 AMMONIA N/ NITRATE N RATIO MATURITY INDEX AS CARBON TO 20:1 NITROGEN RATIO TESTED FOR CLOPYRALID YES/NEGATIVE RESULT MOISTURE CONTENT 30-60% ORGANIC MATTER CONTENT 25-45% OF DRY WEIGHT PARTICLE SIZE DISTRIBUTION 3" (75mm) 100% PASSING PRIMARY, SECONDARY NUTRIENTS; TRACE MUST BE REPORTED ELEMENTS TESTING AND TEST REPORT SUBMITTAL STA + CLOPYRALID REQUIREMENTS ORGANIC MATTER PER CUBIC YARD MUST REPORT CHEMICAL CONTAMINANTS COMPLY WITH US EPA CLASS A STANDARD, 40 CFR 503.1 TABLES 1 & 3 LEVELS MINIMUM MANUFACTURING/PRODUCTION FULLY PERMITTED UNDER COLORADO DEPARTMENT OF REQUIREMENT PUBLIC HEALTH AND ENVIRONMENT, HAZARDOUS MATERIALS AND WASTE MANAGEMENT DIVISION RISK FACTOR RELATING TO PLANT LOW GERMINATION AND HEALTH CB- 1 . COMPOST BLANKET AND COMPOST FILTER BERM November 2010 Urban Drainage and Flood Control District C13-3 Urban Storm Drainage Criteria Manual Volume 3 EC-5 Compost Blanket and Filter Berm (CB) COMPOST FILTER BERM AND COMPOST BLANKET INSTALLATION NOTES 1. SEE PLAN VIEW FOR —LOCATION OF COMPOST FILTER BERM(S). —LENGTH OF COMPOST FILTER BERM(S). 2. COMPOST BERMS AND BLANKETS MAY BE USED IN PLACE OF STRAW MULCH OR GEOTEXTILE FABRIC IN AREAS WHERE ACCESS TO LANDSCAPING IS DIFFICULT DUE TO LANDSCAPING OR OTHER OBJECTS OR IN AREAS WHERE A SMOOTH TURF GRASS FINISH IS DESIRED. 3. FILTER BERMS SHALL RUN PARALLEL TO THE CONTOUR. 4. FILTER BERMS SHALL BE A MINIMUM OF 1 FEET HIGH AND 2 FEET WIDE. 5. FILTER BERMS SHALL BE APPLIED BY PNEUMATIC BLOWER OR BY HAND. 6. FILTER BERMS SHALL ONLY BE UTILIZED IN AREAS WHERE SHEET FLOW CONDITIONS PREVAIL AND NOT IN AREAS OF CONCENTRATED FLOW. 7. COMPOST BLANKETS SHALL BE APPLIED AT A DEPTH OF 1 —3 INCHES (TYPICALLY 2 INCHES). FOR AREAS WITH EXISTING VEGETATION THAT ARE TO BE SUPPLEMENTED BY COMPOST, A THIN 0.5—INCH LAYER MAY BE USED. 8. SEEDING SHALL BE PERFORMED PRIOR TO THE APPLICATION OF COMPOST. ALTERNATIVELY, SEED MAY BE COMBINED WITH COMPOST AND BLOWN WITH THE PNEUMATIC BLOWER. 9. WHEN TURF GRASS FINISH IS NOT DESIRED, SURFACE ROUGHENING ON SLOPES SHALL TAKE PLACE PRIOR TO COMPOST APPLICATION. 10. COMPOST SHALL BE A CLASS 1 COMPOST AS DEFINED BY TABLE CB-1. COMPOST FILTER BERM MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. COMPOST BERMS AND BLANKETS SHALL BE REAPPLIED OR REGRADED AS NECESSARY IF RILLING IN THE COMPOST SURFACE OCCURS. (DETAILS ADAPTED FROM ARAPAHOE COUNTY, COLORADO, NOT AVAILABLE IN AUTOCAD) NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. CB-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Rolled Erosion Control Products (RECP) EC-6 Description ' Y Rolled Erosion Control Products �_ •»- _.'- �:� (RECPs)include a variety of temporary or permanently installed i ir�i, manufactured products designed to � - _ - control erosion and enhance vegetation establishment and survivability, particularly on slopes and in channels. - For applications where natural vegetation alone will provide sufficient permanent erosion protection, temporary products such as netting, open weave textiles and a variety of erosion control blankets(ECBs)made of biodegradable natural materials Photograph RECP-1. Erosion control blanket protecting the slope from (e.g., straw, coconut fiber)can be used. erosion and providing favorable conditions for revegetation. For applications where natural vegetation alone will not be sustainable under expected flow conditions,permanent rolled erosion control products such as turf reinforcement mats (TRMs)can be used. In particular,turf reinforcement mats are designed for discharges that exert velocities and sheer stresses that exceed the typical limits of mature natural vegetation. Appropriate Uses RECPs can be used to control erosion in conjunction with revegetation efforts,providing seedbed protection from wind and water erosion. These products are often used on disturbed areas on steep slopes, in areas with highly erosive soils,or as part of drainageway stabilization. In order to select the appropriate RECP for site conditions, it is important to have a general understanding of the general types of these products,their expected longevity, and general characteristics. The Erosion Control Technology Council(ECTC 2005)characterizes rolled erosion control products according to these categories: ■ Mulch control netting: A planar woven natural fiber or extruded geosynthetic mesh used as a temporary degradable rolled erosion control product to anchor loose fiber mulches. ■ Open weave textile: A temporary degradable rolled erosion control product composed of processed natural or polymer yarns woven into a matrix,used to provide erosion control and facilitate vegetation establishment. ■ Erosion control blanket(ECB): A temporary degradable rolled erosion control product composed of processed natural or polymer fibers which are Rolled Erosion Control Products mechanically, structurally or chemically bound together to form a continuous matrix to provide erosion control Functions and facilitate vegetation establishment. ECBs can be Erosion Control Yes further differentiated into rapidly degrading single-net Sediment Control No and double-net types or slowly degrading types. Site/Material Management No November 2010 Urban Drainage and Flood Control District RECP-1 Urban Storm Drainage Criteria Manual Volume 3 EC-6 Rolled Erosion Control Products (RECP) ■ Turf Reinforcement Mat(TRM): A rolled erosion control product composed of non-degradable synthetic fibers,filaments,nets,wire mesh, and/or other elements,processed into a permanent,three- dimensional matrix of sufficient thickness. TRMs,which may be supplemented with degradable components,are designed to impart immediate erosion protection, enhance vegetation establishment and provide long-term functionality by permanently reinforcing vegetation during and after maturation. Note: TRMs are typically used in hydraulic applications, such as high flow ditches and channels,steep slopes, stream banks, and shorelines,where erosive forces may exceed the limits of natural,unreinforced vegetation or in areas where limited vegetation establishment is anticipated. Tables RECP-1 and RECP-2 provide guidelines for selecting rolled erosion control products appropriate to site conditions and desired longevity. Table RECP-1 is for conditions where natural vegetation alone will provide permanent erosion control,whereas Table RECP-2 is for conditions where vegetation alone will not be adequately stable to provide long-term erosion protection due to flow or other conditions. RECP-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Rolled Erosion Control Products (RECP) EC-6 Table RECP-1. ECTC Standard Specification for Temporary Rolled Erosion Control Products (Adapted from Erosion Control Technology Council 2005) Slope Channel Minimum Expected Product Description Applications* Applications* Tensile Longevity Strength Maximum C Factor2'5 Max. Shear Gradient Stress ' ' @ Mulch Control Nets 5:1 (H:V) <0.10 0.25 lbs/ft2 5 lbs/ft5:1 (12 Pa) (0.073 kN/m) Netless Rolled <0.10 @ 0.5 lbs/ft2 5 lbs/ft Erosion Control 4:1 (H:V) 4:1 (24 Pa) (0.073 kN/m) Blankets Up to 12 Single-net Erosion <0.15 @ 1.51bs/ft2 50 lbs/ft months Control Blankets& 3:1 (H:V) 3:1 (72 Pa) (0.73 kN/m) Open Weave Textiles Double-net Erosion <0.20 @ 1.75 lbs/ft2 75 lbs/ft Control Blankets 2:1 (H:V) — 2:1 (84 Pa) (1.09 kN/m) Mulch Control Nets 5:1 (H:V) <0.10 @ 0.25 lbs/ft2 25 lbs/ft5:1 (12 Pa) (0.36 Min) 24 months Erosion Control Blankets &Open _<0.25 @ 2.00 lbs/ft2 1001bs/ft Weave Textiles L5:1 (H:V) 1.5:1 (96 Pa) (1.45 kN/m) 24 months (slowly degrading) Erosion Control <0.25 @ 2.25 lbs/ft2 125 lbs/ft Blankets &Open 1:1 (H:V) — 36 months Weave Textiles 1:1 (108 Pa) (1.82 kN/m) * C Factor and shear stress for mulch control nettings must be obtained with netting used in conjunction with pre-applied mulch material. (See Section 5.3 of Chapter 7 Construction BMPs for more information on the C Factor.) ' Minimum Average Roll Values,Machine direction using ECTC Mod. ASTM D 5035. 2 C Factor calculated as ratio of soil loss from RECP protected slope(tested at specified or greater gradient,H:V)to ratio of soil loss from unprotected(control)plot in large-scale testing. 3 Required minimum shear stress RECP(unvegetated)can sustain without physical damage or excess erosion(> 12.7 min(0.5 in) soil loss)during a 30-minute flow event in large-scale testing. 4 The permissible shear stress levels established for each performance category are based on historical experience with products characterized by Manning's roughness coefficients in the range of 0.01 -0.05. 5 Acceptable large-scale test methods may include ASTM D 6459,or other independent testing deemed acceptable by the engineer. 6 Per the engineer's discretion. Recommended acceptable large-scale testing protocol may include ASTM D 6460, or other independent testing deemed acceptable by the engineer. November 2010 Urban Drainage and Flood Control District RECP-3 Urban Storm Drainage Criteria Manual Volume 3 EC-6 Rolled Erosion Control Products (RECP) Table RECP-2. ECTC Standard Specification for Permanent' Rolled Erosion Control Products (Adapted from: Erosion Control Technology Council 2005) Product Type Slope Channel Applications Applications Maximum Maximum Minimum Gradient Shear Stress4'S Tensile Strength 2,1 TRMs with a minimum thickness of 2 125 lbs/ft(1.82 0.5:1 (H:V) 6.0 lbs/ft (288 Pa) 0.25 inches(6.35 mm)per ASTM D kN/m) 6525 and UV stability of 80%per ASTM D 4355 (500 hours 2 150 lbs/ft(2.19 exposure). 0.5:1 (H:V) 8.0 lbs/ft (384 Pa) kN/m) 0.5:1 (H:V) 10.0 lbs/ft2(480 Pa) 175 lbs/ft(2.55 kN/m) ' For TRMs containing degradable components, all property values must be obtained on the non- degradable portion of the matting alone. 2 Minimum Average Roll Values,machine direction only for tensile strength determination using ASTM D 6818 (Supersedes Mod. ASTM D 5035 for RECPs) 3 Field conditions with high loading and/or high survivability requirements may warrant the use of a TRM with a tensile strength of 44 kN/m(3,000 lb/ft)or greater. 4 Required minimum shear stress TRM(fully vegetated) can sustain without physical damage or excess erosion(> 12.7 mm(0.5 in.) soil loss) during a 30-minute flow event in large scale testing. 5 Acceptable large-scale testing protocols may include ASTM D 6460, or other independent testing deemed acceptable by the engineer. Design and Installation RECPs should be installed according to manufacturer's specifications and guidelines. Regardless of the type of product used, it is important to ensure no gaps or voids exist under the material and that all corners of the material are secured using stakes and trenching. Continuous contact between the product and the soil is necessary to avoid failure. Never use metal stakes to secure temporary erosion control products. Often wooden stakes are used to anchor RECPs;however,wood stakes may present installation and maintenance challenges and generally take a long time to biodegrade. Some local jurisdictions have had favorable experiences using biodegradable stakes. This BMP Fact Sheet provides design details for several commonly used ECB applications,including: ECB-1 Pipe Outlet to Drainageway ECB-2 Small Ditch or Drainageway ECB-3 Outside of Drainageway RECP-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Rolled Erosion Control Products (RECP) EC-6 Staking patterns are also provided in the design details according to these factors: ■ ECB type ■ Slope or channel type For other types of RECPs including TRMs,these design details are intended to serve as general guidelines for design and installation;however, engineers should adhere to manufacturer's installation recommendations. Maintenance and Removal Inspection of erosion control blankets and other RECPs includes: ■ Check for general signs of erosion,including voids beneath the mat. If voids are apparent, fill the void with suitable soil and replace the erosion control blanket, following the appropriate staking pattern. ■ Check for damaged or loose stakes and secure loose portions of the blanket. Erosion control blankets and other RECPs that are biodegradable typically do not need to be removed after construction. If they must be removed,then an alternate soil stabilization method should be installed promptly following removal. Turf reinforcement mats,although generally resistant to biodegradation, are typically left in place as a dense vegetated cover grows in through the mat matrix. The turf reinforcement mat provides long-term stability and helps the established vegetation resist erosive forces. November 2010 Urban Drainage and Flood Control District RECP-5 Urban Storm Drainage Criteria Manual Volume 3 EC-6 Rolled Erosion Control Products (RECP) ECB UNDISTURBED PERIMETER JOINT ANCHOR TOP OF SOIL ANCHOR TRENCH, TYP. CHANNEL BANK TRENCH, TYP. f ANCHOR DETAILS GEOTEXTILE FABRIC OR MAT, TYP. --I I-- 3" MIN, TYP. Y 'MIN, YP. NGLE EDGE AKE, TYP. [ TYPE OF ECG AS INDICATED/IN PLAN VIEW. INSTALL IN ALL BACKFILL, TYP. DISTURBED AREAS OF STREAMS AND DRAINAGE CHANNELS TO DEPTH PERIMETER ANCHOR TRENCH D A8OVE CHANNEL INVERT. ECB SHALL GENERALLY BE ORIENTED PARALLEL TO FLOW DIRECTION (I.E. LONG DIMENSIONS OF BLANKET PARALLEL TO FLOWLINES) STAKING PATTERN SHALL MATCH EC8 AND/OR CHANNEL TYPE. ECB- 1 . PIPE OUTLET TO DRAINAGEWAY F TWOocEs ADJACENT ROLLS TYPE OF ECB, JOINT ANCHOR TRENCH JOINT ANCHOR TRENCH, TYP, INDICATED IN PLAN VIEW LOOP FROM TOPSOIL �. ECB SHALL ~ MIDDLE OF M EXTEND TO THE ROLL TOP OF THE �• j CHANNEL INTERMEDIATE ANCHOR TRENCH r D PERIMETER ANCHOR FLOW ---�� TRENCH, TYP. COMPACTED SUBGRADE STAKING PATTERN PER MANUFACTURER SPEC. OR PATTERN BASED ON ECB AND/OR CHANNEL TYPE (SEE STAKING OVERLAPPING JOINT PATTERN DETAIL) �I I�ECB-2. SMALL DITCH OR DRAINAGEWAY - 3" MIN. 12" MIN. WOOD STAKE DETAIL RECP-6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Rolled Erosion Control Products (RECP) EC-6 STAGGER OVERLAPS DIVERSION DITCH OVERLAPPING JOINT TYPICALLY AT TOP OF SLOPE STAKING PATTERN PER MANUFACTURER SPEC. OR PATTERN BASED ON ECB AND/OR SLOPE TYPE (SEE STAKING PATTERN DETAIL) ERIMETER ANCHOR TRENCH ECB-3. OUTSIDE OF DRAINAGEWAY ROLL PERIMETER WIDTH ANCHOR W TYP, TRENCH OR JOINT, TYP. l2 W 0 I Y2 W � 3' o o � W W o 0 6' 0 6' 0 ~0 h W I t�3 4' I T F 1 0 0 0 12' STRAW STRAW-COCONUT COCONUT OR EXCELSIOR STAKING PATTERNS BY ECB TYPE 3' 2' ---I �-- Y2 W 0 0 3' 4• 0—o Y4 W 6' }t� W 6 o W o —i h W F1-I Y. W o 0 0 0 4:1-3:1 3:1-2:1 2:1 AND STEEPER SLOPES 2 SLOPES SLOPES 4' o'bo h W 4' 000 h W 0 0 0 0000 2' 20" 20" I� 0 0 0 LOW FLOW CHANNEL HIGH FLOW CHANNEL STAKING PATTERNS BY SLOPE OR CHANNEL TYPE November 2010 Urban Drainage and Flood Control District RECP-7 Urban Storm Drainage Criteria Manual Volume 3 EC-6 Rolled Erosion Control Products (RECP) EROSION CONTROL BLANKET INSTALLATION NOTES 1. SEE PLAN VIEW FOR: —LOCATION OF ECB. —TYPE OF ECB (STRAW, STRAW—COCONUT, COCONUT, OR EXCELSIOR). —AREA, A, IN SQUARE YARDS OF EACH TYPE OF ECB. 2. 100% NATURAL AND BIODEGRADABLE MATERIALS ARE PREFERRED FOR RECPS, ALTHOUGH SOME JURISDICTIONS MAY ALLOW OTHER MATERIALS IN SOME APPLICATIONS. 3. IN AREAS WHERE ECBs ARE SHOWN ON THE PLANS, THE PERMITTEE SHALL PLACE TOPSOIL AND PERFORM FINAL GRADING, SURFACE PREPARATION, AND SEEDING AND MULCHING. SUBGRADE SHALL BE SMOOTH AND MOIST PRIOR TO ECB INSTALLATION AND THE ECB SHALL BE IN FULL CONTACT WITH SUBGRADE. NO GAPS OR VOIDS SHALL EXIST UNDER THE BLANKET. 4. PERIMETER ANCHOR TRENCH SHALL BE USED ALONG THE OUTSIDE PERIMETER OF ALL BLANKET AREAS. 5. JOINT ANCHOR TRENCH SHALL BE USED TO JOIN ROLLS OF ECBs TOGETHER (LONGITUDINALLY AND TRANSVERSELY) FOR ALL ECBs EXCEPT STRAW WHICH MAY USE AN OVERLAPPING JOINT. 6. INTERMEDIATE ANCHOR TRENCH SHALL BE USED AT SPACING OF ONE—HALF ROLL LENGTH FOR COCONUT AND EXCELSIOR ECBs. 7. OVERLAPPING JOINT DETAIL SHALL BE USED TO JOIN ROLLS OF ECBs TOGETHER FOR ECBs ON SLOPES. S. MATERIAL SPECIFICATIONS OF ECBs SHALL CONFORM TO TABLE ECB—I. 9. ANY AREAS OF SEEDING AND MULCHING DISTURBED IN THE PROCESS OF INSTALLING ECBS SHALL BE RESEEDED AND MULCHED. 10. DETAILS ON DESIGN PLANS FOR MAJOR DRAINAGEWAY STABILIZATION WILL GOVERN IF DIFFERENT FROM THOSE SHOWN HERE. TABLE ECB-1. ECB MATERIAL SPECIFICATIONS TYPE COCONUT STRAW EXCELSIOR RECOMMENDED CONTENT CONTENT CONTENT NETTING" STRAW' — 100% _ DOUBLE/ NATURAL STRAW— 30% MIN 70% MAX _ DOUBLE/ COCONUT NATURAL COCONUT 100% — — DOUBLE/ NATURAL EXCELSIOR 100% DOUBLE/ NATURAL •STRAW CBS MAY ONLY BE USED OUTSIDE OF STREAMS AND DRAINAGE CHANNEL. ••ALTERNATE NETTING MAY BE ACCEPTABLE IN SOME JURISDICTIONS RECP-8 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Rolled Erosion Control Products (RECP) EC-6 EROSION CONTROL BLANKET MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. ECBs SHALL BE LEFT IN PLACE TO EVENTUALLY BIODEGRADE, UNLESS REQUESTED TO BE REMOVED BY THE LOCAL JURISDICTION. 5. ANY ECB PULLED OUT, TORN, OR OTHERWISE DAMAGED SHALL BE REPAIRED OR REINSTALLED. ANY SUBGRADE AREAS BELOW THE GEOTEXTILE THAT HAVE ERODED TO CREATED A VOID UNDER THE BLANKET, OR THAT REMAIN DEVOID OF GRASS SHALL BE REPAIRED, RESEEDED AND MULCHED AND THE ECB REINSTALLED. NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. (DETAILS ADAPTED FROM DOUGLAS COUNTY, COLORADO AND TOWN OF PARKER COLORADO, NOT AVAILABLE IN AUTOCAO) November 2010 Urban Drainage and Flood Control District RECP-9 Urban Storm Drainage Criteria Manual Volume 3 Temporary Slope Drains (TSD) EC-7 Description A temporary slope drain is a pipe or culvert used to convey water down a slope where there is a high potential for erosion. A drainage channel or swale at the top of the slope typically directs upgradient runoff to the pipe entrance for conveyance down the slope. The pipe outlet must be equipped with outlet protection. Photograph TSD-1. A temporary slope drain installed to convey runoff down a slope during construction. Photo courtesy of the City of Aurora. Appropriate Uses Use on long, steep slopes when there is a high potential of flow concentration or rill development. Design and Installation Effective use of temporary slope drains involves design of an effective collection system to direct flows to the pipe,proper sizing and anchoring of the pipe, and outlet protection. Upgradient of the temporary slope drain, a temporary drainage ditch or swale should be constructed to collect surface runoff from the drainage area and convey it to the drain entrance. The temporary slope drain must be sized to safely convey the desired flow volume. At a minimum,it should be sized to convey the 2-year,24-hour storm. Temporary slope drains may be constructed of flexible or rigid pipe,riprap, or heavy(30 mil)plastic lining. When piping is used,it must be properly anchored by burying it with adequate cover or by using an anchor system to secure it to the ground. The discharge from the slope drain must be directed to a stabilized outlet,temporary or permanent channel, and/or sedimentation basin. See Detail TSD-1 for additional sizing and design Temporary Slope Drains information. Functions Erosion Control Yes Sediment Control No Site/Material Management No November 2010 Urban Drainage and Flood Control District SD-1 Urban Storm Drainage Criteria Manual Volume 3 EC-7 Temporary Slope Drains (TSD) Maintenance and Removal Inspect the entrance for sediment accumulation and remove,as needed. Clogging as a result of sediment deposition at the entrance can lead to ponding upstream causing flooding or overtopping of the slope drain. Inspect the downstream outlet for signs of erosion and stabilize, as needed. It may also be necessary to remove accumulated sediment at the outfall. Inspect pipe anchors to ensure that they are secure. If the pipe is secured by ground cover, ensure erosion has not compromised the depth of cover. Slope drains should be removed when no longer needed or just prior to installation of permanent slope stabilization measures that cannot be installed with the slope drain in place. When slope drains are removed,the disturbed areas should be covered with topsoil, seeded,mulched or otherwise stabilized as required by the local jurisdiction. SD-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Temporary Slope Drains (TSD) EC-7 COMPACTED O MIN (TOP OF PIPE TO TOP TSD EMBANKMENT A OF EMBANKMENT, PIPE MUST BE ANCHORED BERM CHECK HEADWATER WITH SOIL OR OTHER >3 _ DEPTH) SUITABLE ANCHOR RIPRAP 2xD50 MIN SCH 40 PIPE D= 12" (MIN) ` PLASTIC PIPE, HEAVY CANVAS RIPRAP t STOCK. RIPRAP LINED TRENCH, BEDDING 6xD50 MIN OR GEOMEMBRANE LINED TRENCH TEMPORARY SLOPE DRAIN PROFILE 12" MIN COVER (CHECK HEADWATER DEPTH COMPACTED AND PROVIDE FOR ARMORED OVERFLOW EMBANKMENT BERM FOR EVENTS EXCEEDING DESIGN STORM) UNDISTURBED OR COMPACTED SOIL SECTION A D (10" MIN) PERIMETER ANCHOR „Y TRENCH, SEE ECB 30 MIL (MIN) IMPERMEABLE GEOMEMBRANE �2xD50 � 4xD RIPRAP MIN COMPACTED EMBANKMENT BERM UNDISTURBED OR COMPACTED SOIL TERMINATION OF RIPRAP GEOMEMBRANE LINED SLOPE DRAIN LINED SLOPE DRAIN 30 MIL (MIN) IMPERMEABLE PERIMETER ANCHOR GEOMEMBRANE TRENCH, SEE ECB D (10" MIN) 1L >3 4xD MIN TERMINATION OF GEOMEMBRANE LINED SLOPE DRAIN TSD- 1 . TEMPORARY SLOPE DRAIN PROFILE November 2010 Urban Drainage and Flood Control District SD-3 Urban Storm Drainage Criteria Manual Volume 3 EC-7 Temporary Slope Drains (TSD) SLOPE DRAIN INSTALLATION NOTES 1. SEE PLAN VIEW FOR: —LOCATION AND LENGTH OF SLOPE DRAIN —PIPE DIAMETER, D, AND RIPRAP SIZE, D50. 2. SLOPE DRAIN SHALL BE DESIGNED TO CONVEY PEAK RUNOFF FOR 2—YEAR 24—HOUR STORM AT A MINIMUM. FOR LONGER DURATION PROJECTS, LARGER MAY BE APPROPRIATE. 3. SLOPE DRAIN DIMENSIONS SHALL BE CONSIDERED MINIMUM DIMENSIONS; CONTRACTOR MAY ELECT TO INSTALL LARGER FACILITIES. 4. SLOPE DRAINS INDICATED SHALL BE INSTALLED PRIOR TO UPGRADIENT LAND—DISTURBING ACTIVITIES. 5. CHECK HEADWATER DEPTHS FOR TEMPORARY AND PERMANENT SLOPE DRAINS. DETAILS SHOW MINIMUM COVER; INCREASE AS NECESSARY FOR DESIGN HEADWATER DEPTH. 6. RIPRAP PAD SHALL BE PLACED AT SLOPE DRAIN OUTFALL. 7. ANCHOR PIPE BY COVERING WITH SOIL OR AN ALTERNATE SUITABLE ANCHOR MATERIAL. SLOPE DRAIN MAINTENANCE NOTES 1. INSPECT 8MPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. INSPECT INLET AND OUTLET POINTS AFTER STORMS FOR CLOGGING OR EVIDENCE OF OVERTOPPING. BREACHES IN PIPE OR OTHER CONVEYANCE SHALL BE REPAIRED AS SOON AS PRACTICABLE IF OBSERVED. 5. INSPECT RIPRAP PAD AT OUTLET FOR SIGNS OF EROSION. IF SIGNS OF EROSION EXIST, ADDITIONAL ARMORING SHALL BE INSTALLED. 6. TEMPORARY SLOPE DRAINS ARE TO REMAIN IN PLACE UNTIL NO LONGER NEEDED, BUT SHALL BE REMOVED PRIOR TO THE END OF CONSTRUCTION. WHEN SLOPE DRAINS ARE REMOVED, THE DISTURBED AREA SHALL BE COVERED WITH TOP SOIL, SEEDED, MULCHED OR OTHERWISE STABILIZED IN A MANNER APPROVED BY THE LOCAL JURISDICTION. (DETAIL ADAPTED FROM DOUGLAS COUNTY, COLORADO AND THE CITY OF COLORADO SPRINGS, COLORADO. NOT AVAILABLE IN AurocAD) NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. SD-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Temporary Outlet Protection (TOP) EC-8 Description Outlet protection helps to reduce erosion immediately downstream of a pipe, culvert, slope drain,rundown or other conveyance with concentrated,high- r velocityflows. Typical outlet protection Yp P consists of riprap or rock aprons at the - .r - conveyance outlet. Appropriate Uses Outlet protection should be used when a conveyance discharges onto a disturbed area where there is potential for accelerated Photograph TOP-1. Riprap outlet protection. erosion due to concentrated flow. Outlet protection should be provided where the velocity at the culvert outlet exceeds the maximum permissible velocity of the material in the receiving channel. Note: This Fact Sheet and detail are for temporary outlet protection, outlets that are intended to be used for less than 2 years. For permanent,long-term outlet protection,see the Major Drainage chapter of Volume 1. Design and Installation Design outlet protection to handle runoff from the largest drainage area that may be contributing runoff during construction(the drainage area may change as a result of grading). Key in rock,around the entire perimeter of the apron,to a minimum depth of 6 inches for stability. Extend riprap to the height of the culvert or the normal flow depth of the downstream channel,whichever is less. Additional erosion control measures such as vegetative lining, turf reinforcement mat and/or other channel lining methods may be required downstream of the outlet protection if the channel is susceptible to erosion. See Design Detail OP-1 for additional information. Maintenance and Removal Inspect apron for damage and displaced rocks. If rocks are missing or significantly displaced,repair or replace as necessary. If rocks are continuously missing or displaced, consider increasing the size of the riprap or deeper keying of the perimeter. Remove sediment accumulated at the outlet before the outlet protection becomes buried and ineffective. When sediment accumulation is noted, check that upgradient BMPs, including inlet protection,are in effective operating condition. Outlet Protection Outlet protection may be removed once the pipe is no longer draining an upstream area,or once the downstream area has Functions been sufficiently stabilized. If the drainage pipe is Erosion Control Yes permanent, outlet protection can be left in place;however, Sediment Control Moderate permanent outlet protection should be designed and Site/Material Management No constructed in accordance with the requirements of the Major Drainage chapter of Volume 2. November 2010 Urban Drainage and Flood Control District TOP-1 Urban Storm Drainage Criteria Manual Volume 3 EC-8 Temporary Outlet Protection (TOP) EXTEND RIPRAP TO HEIGHT OF CULVERT OR NORMAL CHANNEL O DEPTH, WHICHEVER IS LESS 3(Do) Do 4(Do) .j TEMPORARY OUTLET PROTECTION PLAN Lo 0% r D - 2 x 050 1� NON-WOVEN GEOTEXTILE L KEY IN TO 2 x D50 AROUND PERIMETER SECTION A TABLE OP-1. TEMPORARY OUTLET PROTECTION SIZING TABLE PIPE APRON RIPRAP D50 DIAMETER, DISCHARGE, DIAMETER Do Q (CFS) LENGTH, La MIN (INCHES) (FT) MIN 8 2.5 5 4 5 10 6 12 5 10 4 10 13 6 10 10 6 18 20 16 9 30 23 12 40 26 16 30 16 9 40 26 9 `� 50 26 12 60 30 16 OP- 1 . TEMPORARY OUTLET PROTECTION TOP-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Temporary Outlet Protection (TOP) EC-8 TEMPORARY OUTLET PROTECTION INSTALLATION NOTES 1. SEE PLAN VIEW FOR —LOCATION OF OUTLET PROTECTION. —DIMENSIONS OF OUTLET PROTECTION. 2. DETAIL IS INTENDED FOR PIPES WITH SLOPE S 10%. ADDITIONAL EVALUATION OF RIPRAP SIZING AND OUTLET PROTECTION DIMENSIONS REQUIRED FOR STEEPER SLOPES. 3. TEMPORARY OUTLET PROTECTION INFORMATION IS FOR OUTLETS INTENDED TO BE UTILIZED LESS THAN 2 YEARS. TEMPORARY OUTLET PROTECTION INSPECTION AND MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. (DETAILS ADAPTED FROM AURORA, COLORADO AND PREVIOUS VERSION OF VOLUME 3, NOT AVAILABLE IN AUTOCAO) November 2010 Urban Drainage and Flood Control District TOP-3 Urban Storm Drainage Criteria Manual Volume 3 Rough Cut Street Control (RCS) EC-9 Description Rough cut street controls are rock or earthen berms placed along dirt roadways that are under construction or used for : construction access. These temporary berms intercept sheet flow and divert runoff from the roadway, and control erosion by minimizing concentration of flow and reducing runoff velocity. u Appropriate Uses Appropriate uses include: ■ Temporary dirt construction roadways that have not received roadbase. Photograph RCS-1.Rough cut street controls. ■ Roadways under construction that will not be paved within 14 days of final grading, and that have not yet received roadbase. Design and Installation Rough cut street controls are designed to redirect sheet flow off the dirt roadway to prevent water from concentrating and eroding the soil. These controls consist of runoff barriers that are constructed at intervals along the road. These barriers are installed perpendicular to the longitudinal slope from the outer edge of the roadside swale to the crown of the road. The barriers are positioned alternately from the right and left side of the road to allow construction traffic to pass in the lane not barred. If construction traffic is expected to be congested and a vehicle tracking control has been constructed,rough-cut street controls may be omitted for 400 feet from the entrance. Runoff from the controls should be directed to another stormwater BMP such as a roadside swale with check dams once removed from the roadway. See Detail RCS-1 for additional information. Maintenance and Removal Inspect street controls for erosion and stability. If rills are forming in the roadway or cutting through the control berms,place the street controls at shorter intervals. If earthen berms are used,periodic recompaction may be necessary. When rock berms are used, repair and/or replace as necessary when damaged. Street Rough Cut Street Control controls may be removed 14 days prior to road surfacing and Functions paving. Erosion Control Yes Sediment Control Moderate Site/Material Management No November 2010 Urban Drainage and Flood Control District RCS-1 Urban Storm Drainage Criteria Manual Volume 3 EC-9 Rough Cut Street Control (RCS) RCS A SPACING 200' MAXIMUM (SEE TABLE RCS-2) PL EXCAVATED STREET :j W = 1/2 ROADBED ROADBED SLOPE WIDTH CL - - - X SEE TABLE RCS-1 8' MINIMUM SPACING B FOR VEHICLE PASSAGE PL GEOTEXTILE SOCK(S) FILLED WITH CRUSHED ROCK OR COMPACTED EARTHEN BERM(S) ROUGH CUT STREET CONTROL PLAN PL CL W PL EFW y FLOW GEOTEXTILE SOCK(S) FILLED EXCAVATED ROADBED WITH CRUSH ROCK OR COMPACTED EARTHEN BERM(S) SECTION A l2" TO 18" ;_; 12" TO 18" SECTION B TABLE RCS-1 TABLE RCS-2 W (FT) X (FT) LONGITUDINAL SPACING (FT) STREET SLOPE (%) 20-30 5 <2 NOT TYPICALLY NEEDED 2 200 31-40 7 3 200 41-50 9 4 150 51-60 10.5 5 100 6 50 61-70 12 7 25 8 25 RCS- 1 . ROUGH CUT STREET CONTROL RCS-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Rough Cut Street Control (RCS) EC-9 ROUGH CUT STREET CONTROL INSTALLATION NOTES 1, SEE PLAN VIEW FOR —LOCATION OF ROUGH CUT STREET CONTROL MEASURES. 2. ROUGH CUT STREET CONTROL SHALL BE INSTALLED AFTER A ROAD HAS BEEN CUT IN, AND WILL NOT BE PAVED FOR MORE THAN 14 DAYS OR FOR TEMPORARY CONSTRUCTION ROADS THAT HAVE NOT RECEIVED ROAD BASE. ROUGH CUT STREET CONTROL INSPECTION AND MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. (DETAILS ADAPTED FROM AURORA, COLORADO, NOT AVAILABLE IN AUTOCAD) NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. November 2010 Urban Drainage and Flood Control District RCS-3 Urban Storm Drainage Criteria Manual Volume 3 Earth Dikes and Drainage Swales (ED/DS) EC-10 Description Earth dikes and drainage swales are temporary storm conveyance channels constructed either to divert runoff around slopes or to convey runoff to additional sediment control BMPs prior to discharge of runoff from a site. Drainage swales may be lined or unlined,but if an unlined swale is used,it must be well compacted and capable of resisting erosive velocities. Appropriate Uses = *� Earth dikes and drainage swales are typically used to control the flow path of : . runoff at a construction site by diverting , runoff around areas prone to erosion,such 4_ as steep slopes. Earth dikes and drainageY swales may also be constructed as temporary conveyance features. This will direct runoff to additional sediment control Photograph ED/DS-1. Example of an earth dike used to divert flows at a construction site. Photo courtesy of CDOT. treatment BMPs, such as sediment traps or basins. Design and Installation When earth dikes are used to divert water for slope protection,the earth dike typically consists of a horizontal ridge of soil placed perpendicular to the slope and angled slightly to provide drainage along the contour. The dike is used in conjunction with a swale or a small channel upslope of the berm to convey the diverted water. Temporary diversion dikes can be constructed by excavation of a V-shaped trench or ditch and placement of the fill on the downslope side of the cut. There are two types of placement for temporary slope diversion dikes: ■ A dike located at the top of a slope to divert upland runoff away from the disturbed area and convey it in a temporary or permanent channel. ■ A diversion dike located at the base or mid-slope of a disturbed area to intercept runoff and reduce the effective slope length. Depending on the project, either an earth dike or drainage swale may be more appropriate. If there is a need for cut on the project,then an excavated drainage Swale may be better suited. When the project is primarily Earth Dikes and Drainage Swales fill,then a conveyance constructed using a berm may be the better option. Functions All dikes or swales receiving runoff from a disturbed Erosion Control Yes area should direct stormwater to a sediment control Sediment Control Moderate BMP such as a sediment trap or basin. Site/Material Management No November 2010 Urban Drainage and Flood Control District ED/DS-1 Urban Storm Drainage Criteria Manual Volume 3 EC-10 Earth Dikes and Drainage Swales (ED/DS) Unlined dikes or swales should only be used for intercepting sheet flow runoff and are not intended for diversion of concentrated flows. Details with notes are provided for several design variations, including: ED-1. Unlined Earth Dike formed by Berm DS-1. Unlined Excavated Swale DS-2. Unlined Swale Formed by Cut and Fill DS-3. ECB-lined Swale DS-4. Synthetic-lined Swale DS-5. Riprap-lined Swale The details also include guidance on permissible velocities for cohesive channels if unlined approaches will be used. Maintenance and Removal Inspect earth dikes for stability, compaction,and signs of erosion and repair. Inspect side slopes for erosion and damage to erosion control fabric. Stabilize slopes and repair fabric as necessary. If there is reoccurring extensive damage, consider installing rock check dams or lining the channel with riprap. If drainage swales are not permanent,remove dikes and fill channels when the upstream area is stabilized. Stabilize the fill or disturbed area immediately following removal by revegetation or other permanent stabilization method approved by the local jurisdiction. ED/DS-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Earth Dikes and Drainage Swales (ED/DS) EC-10 ED/ DS 5" NJ TRANSV SE FLOW TO SWALE EXISTING GRADE ED- 1 . COMPACTED UNLINED EARTH DIKE FORMED BY BERM TRANSVERSE FLOW f TO WALE 1- r_ � � EXISTING GRADE 15" MIN.rZ- >3 >3 DS- 1 . COMPACTED UNLINED EXCAVATED SWALE r LOW >3 F _L 1 EXISTING GRADE >_3 15" MIN DS-2. COMPACTED UNLINED SWALE FORMED BY CUT AND FILL W 5' MIN. STAKES (SEE ECB) GEOTEXTILE OR MAT (SEE ECB) D (10" MIN.) ANCHOR TRENCH AT PERIMETER OF I BLANKET AND AT OVERLAPPING JOINTS WITH ANY ADJACENT ROLLS OF BLANKET INTERMEDIATE ANCHOR TRENCH AT (SEE ECB) ONE-HALF ROLL LENGTH (SEE ECB) TRANSVERSE ANCHOR TRENCHES AT PERIMETER OF BLANKET AND AT OVERLAPPING JOINTS WITH ANY ADJACENT ROLLS OF BLANKET (SEE ECB) DS-3. ECB LINED SWALE (CUT AND FILL OR BERM November 2010 Urban Drainage and Flood Control District ED/DS-3 Urban Storm Drainage Criteria Manual Volume 3 EC-10 Earth Dikes and Drainage Swales (ED/DS) NO 30 MIL MIN. W (5. MIN.) STAKING THICKNESS rD (10" MIN.) ANCHOR TRENCH AT PERIMETER OF BLANKET AND AT OVERLAPPING JOINTS WITH ANY ADJACENT ROLLS OF BLANKET, INTERMEDIATE ANCHOR / SIMILAR TO ECB, BUT NO TRENCH AT ONE-HALF ROLL STAKING LENGTH SIMILAR TO ECB, TRANSVERSE ANCHOR TRENCHES AT PERIMETER OF BUT NO STAKING BLANKET AND AT OVERLAPPING JOINTS WITH ANY ADJACENT ROLLS OF BLANKET, SIMILAR TO ECB, BUT NO STAKING DS-4. SYNTHETIC LINED SWALE THICKNESS=2 X D50 W (5' MIN.) D (10" MIN.) I LINE WITH AASHTO #3 ROCK (COOT SECT. 703. #3) OR RIPRAP CALLED FOR IN THE PLANS DS-5. RIPRAP LINED SWALE EARTH DIKE AND DRAINAGE SWALE INSTALLATION NOTES 1. SEE SITE PLAN FOR- - LOCATION OF DIVERSION SWALE - TYPE OF SWALE (UNLINED, COMPACTED AND/OR LINED). - LENGTH OF EACH SWALE. - DEPTH, D, AND WIDTH, W DIMENSIONS. - FOR ECB/TRM LINED DITCH, SEE ECB DETAIL. - FOR RIPRAP LINED DITCH, SIZE OF RIPRAP, D50. 2 SEE DRAINAGE PLANS FOR DETAILS OF PERMANENT CONVEYANCE FACILITIES AND/OR DIVERSION SWALES EXCEEDING 2-YEAR FLOW RATE OR 10 CFS. 3. EARTH DIKES AND SWALES INDICATED ON SWMP PLAN SHALL BE INSTALLED PRIOR TO LAND-DISTURBING ACTIVITIES IN PROXIMITY. 4. EMBANKMENT IS TO BE COMPACTED TO 90% OF MAXIMUM DENSITY AND WITHIN 2% OF OPTIMUM MOISTURE CONTENT ACCORDING TO ASTM D698. 5. SWALES ARE TO DRAIN TO A SEDIMENT CONTROL BMP. 6 FOR LINED DITCHES, INSTALLATION OF ECB/TRM SHALL CONFORM TO THE REQUIREMENTS OF THE ECB DETAIL. 7. WHEN CONSTRUCTION TRAFFIC MUST CROSS A DIVERSION SWALE, INSTALL A TEMPORARY CULVERT WITH A MINIMUM DIAMETER OF 12 INCHES. ED/DS-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Earth Dikes and Drainage Swales (ED/DS) EC-10 EARTH DIKE AND DRAINAGE SWALE MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. SWALES SHALL REMAIN IN PLACE UNTIL THE END OF CONSTRUCTION; IF APPROVED BY LOCAL JURISDICTION, SWALES MAY BE LEFT IN PLACE. 5, WHEN A SWALE IS REMOVED, THE DISTURBED AREA SHALL BE COVERED WITH TOPSOIL, SEEDED AND MULCHED OR OTHERWISE STABILIZED IN A MANNER APPROVED BY LOCAL JURISDICTION. (DETAIL ADAPTED FROM OOUCLAS COUNTY, COLORADO AND THE CITY OF COLORADO SPRINGS, COLORADO. NOT AVAILABLE IN AUTOCAD) NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED, November 2010 Urban Drainage and Flood Control District ED/DS-5 Urban Storm Drainage Criteria Manual Volume 3 Terracing (TER) EC-11 Description Terracing involves grading steep slopes into a series of relatively flat sections, or terraces,separated at intervals by steep slope segments. Terraces shorten the uninterrupted flow lengths on steep slopes,helping to reduce the „• ••4L .� development of rills and gullies. + ~ Retaining walls,gabions,cribbing, deadman anchors,rock-filled slope .« mattresses,and other types of soil ` retention systems can be used in terracing. Photograph TER-1. Use of a terrace to reduce erosion by controlling slope length on a long,steep slope. Photo courtesy of Douglas Appropriate Uses county. Terracing techniques are most typically used to control erosion on slopes that are steeper than 4:1. Design and Installation Design details with notes are provided in Detail TER-1. The type,number, and spacing of terraces will depend on the slope, slope length, and other factors. The Revised Universal Soil Loss Equation(RUSLE)may be helpful in determining spacing of terraces on slopes. Terracing should be used in combination with other stabilization measures that provide cover for exposed soils such as mulching, seeding, surface roughening, or other measures. Maintenance and Removal Repair rill erosion on slopes and remove accumulated sediment, as needed. Terracing may be temporary or permanent. If terracing is temporary,the slope should be topsoiled,seeded, and mulched when the slope is graded to its final configuration and terraces are removed. Due to the steepness of the slope, once terraces are graded, erosion control blankets or other stabilization measures are typically required. If terraces are permanent,vegetation should be established on slopes and terraces as soon as practical. Terracing Functions Erosion Control Yes Sediment Control Moderate Site/Material Management No November 2010 Urban Drainage and Flood Control District TER-1 Urban Storm Drainage Criteria Manual Volume 3 EC-11 Terracing (TER) TER W — (--� ) EXISTING GRADE "H" VARIES (1 5' MAX.) ~ _ SEE GRADING PLAN FINISHED _�^ 3% MIN., TYP. GRADE TER- 1 . TERRACING TERRACING INSTALLATION NOTES 1. SEE PLAN VIEW FOR: —LOCATION OF TERRACING —WIDTH (W), AND SLOPE (Z). 2. TERRACING IS TYPICALLY NOT REQUIRED FOR SLOPES OF 4:1 OR FLATTER. 3. GRADE TERRACES TO DRAIN BACK TO SLOPE AT A MINIMUM OF 3% GRADE. TERRACING MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPS IN EFFECTIVE OPERATING CONDITION, INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. RILL EROSION OCCURRING ON TERRACED SLOPES SHALL BE REPAIRED, RESEEDED, MULCHED OR STABILIZED IN A MANNER APPROVED BY LOCAL JURISDICTION. 5. TERRACING MAY NEED TO BE RE—GRADED TO RETURN THE SLOPE TO THE FINAL DESIGN GRADE. THE SLOPE SHALL THEN BE COVERED WITH TOPSOIL, SEEDED AND MULCHED, OR OTHERWISE STABILIZED AS APPROVED BY LOCAL JURISDICTION. (DETAIL ADAPTED FROM DOUGLAS COUNTY, COLORADO AND TOWN OF PARKER, COLORADO, NOT AVAILABLE IN AUTOCAD) NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. TER-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Check Dams (CD) EC-12 Description - Check dams are temporary grade control structures placed in drainage channels to limit the erosivity of stormwater by reducing flow velocity. Check dams are typically constructed from rock, gravel bags, sand bags, or sometimes, proprietary devices. Reinforced check dams are typically constructed from rock and wire gabion. Although the primary function of check dams is to reduce the velocity of concentrated flows, a secondary benefit is sediment trapping Photograph CD-1. Rock check dams in a roadside ditch. Photo upstream of the structure. courtesy of W WE. Appropriate Uses Use as a grade control for temporary drainage ditches or swales until final soil stabilization measures are established upstream and downstream. Check dams can be used on mild or moderately steep slopes. Check dams may be used under the following conditions: ■ As temporary grade control facilities along waterways until final stabilization is established. ■ Along permanent swales that need protection prior to installation of a non-erodible lining. ■ Along temporary channels,ditches or swales that need protection where construction of a non- erodible lining is not practicable. ■ Reinforced check dams should be used in areas subject to high flow velocities. Design and Installation Place check dams at regularly spaced intervals along the drainage swale or ditch. Check dams heights should allow for pools to develop upstream of each check dam, extending to the downstream toe of the check dam immediately upstream. When rock is used for the check dam,place rock mechanically or by hand. Do not dump rocks into the drainage channel. Where multiple check dams are used,the top of the lower dam should be at the same elevation as the toe of the upper dam. When reinforced check dams are used,install erosion control fabric under and around the check dam to prevent erosion on the upstream and downstream sides. Each section of the dam should be keyed in to reduce the potential Check Dams for washout or undermining. A rock apron upstream and Functions downstream of the dam may be necessary to further control Erosion Control Yes erosion. Sediment Control Moderate Site/Material Management No November 2010 Urban Drainage and Flood Control District CD-1 Urban Storm Drainage Criteria Manual Volume 3 EC-12 Check Dams (CD) Design details with notes are provided for the following types of check dams: ■ Rock Check Dams (CD-1) ■ Reinforced Check Dams (CD-2) Sediment control logs may also be used as check dams; however, silt fence is not appropriate for use as a check dam. Many jurisdictions also prohibit or discourage use of straw bales for this purpose. Maintenance and Removal Replace missing rocks causing voids in the check dam. If gravel bags or sandbags are used,replace or repair torn or displaced bags. Remove accumulated sediment, as needed to maintain BMP effectiveness,typically before the sediment depth upstream of the check dam is within'/2 of the crest height. Remove accumulated sediment prior to mulching, seeding, or chemical soil stabilization. Removed sediment can be incorporated into the earthwork with approval from the Project Engineer,or disposed of at an alternate location in accordance with the standard specifications. Check dams constructed in permanent swales should be removed when perennial grasses have become established,or immediately prior to installation of a non-erodible lining. All of the rock and accumulated sediment should be removed, and the area seeded and mulched, or otherwise stabilized. CD-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Check Dams (CD) EC-12 CD LENGTH, L CREST LENGTH, CL B SECTION B TYP_ D SECTION A (1. 6" MIN") - 1' 6" 2 (MIN) 1f COMPACTED (TYP.) CHANNEL GRADE UPSTREAM AND TOP OF CHECK DAM DOWNSTREAM A CHECK DAM ELEVATION VIEW 2' 6' CHANNEL GRADE 1 6 FLOW - MIN. r 1' MIN. ~ EXCAVATION TO NEAT ," „_, •� LINE, AVOID OVER-EXCAVATION, (TYP.) D50 = 12" RIPRAP, TYPE M OR TYPE L 050= 9" (SEE TABLE MD-7, MAJOR DRAINAGE, VOL. 1 FOR GRADATION) SECTION A FLOW -- CHANNEL GRADE `1 EXCAVATION TO NEAT 1' MIN. i w�pi LINE, AVOID OVER-EXCAVATION D50 = 12" RIPRAP, TYPE M OR TYPE L D50=9" (SEE TABLE MD-7, MAJOR DRAINAGE, VOL. 1 FOR GRADATION) SECTION B SPACING BETWEEN CHECK DAMS SUCH THAT q A AND B ARE EQUAL ELEVATION CHANNEL GRADE PROFILE CD- 1 . CHECK DAM November 2010 Urban Drainage and Flood Control District CD-3 Urban Storm Drainage Criteria Manual Volume 3 EC-12 Check Dams (CD) CHECK DAM INSTALLATION NOTES 1. SEE PLAN VIEW FOR: —LOCATION OF CHECK DAMS. —CHECK DAM TYPE (CHECK DAM OR REINFORCED CHECK DAM). —LENGTH (L), CREST LENGTH (CL), AND DEPTH (D). 2. CHECK DAMS INDICATED ON INITIAL SWMP SHALL BE INSTALLED AFTER CONSTRUCTION FENCE, BUT PRIOR TO ANY UPSTREAM LAND DISTURBING ACTIVITIES. 3. RIPRAP UTILIZED FOR CHECK DAMS SHOULD BE OF APPROPRIATE SIZE FOR THE APPLICATION. TYPICAL TYPES OF RIPRAP USED FOR CHECK DAMS ARE TYPE M (D50 12") OR TYPE L (D50 9"). 4. RIPRAP PAD SHALL BE TRENCHED INTO THE GROUND A MINIMUM OF 1'. 5. THE ENDS OF THE CHECK DAM SHALL BE A MINIMUM OF 1' 6" HIGHER THAN THE CENTER OF THE CHECK DAM. CHECK DAM MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. SEDIMENT ACCUMULATED UPSTREAM OF THE CHECK DAMS SHALL BE REMOVED WHEN THE SEDIMENT DEPTH IS WITHIN YZ OF THE HEIGHT OF THE CREST. 5. CHECK DAMS ARE TO REMAIN IN PLACE UNTIL THE UPSTREAM DISTURBED AREA IS STABILIZED AND APPROVED BY THE LOCAL JURISDICTION. 6 WHEN CHECK DAMS ARE REMOVED, EXCAVATIONS SHALL BE FILLED WITH SUITABLE COMPACTED BACKFILL. DISTURBED AREA SHALL BE SEEDED AND MULCHED AND COVERED WITH GEOTEXTILE OR OTHERWISE STABILIZED IN A MANNER APPROVED BY THE LOCAL JURISDICTION. (DETAILS ADAPTED FROM DOUGLAS COUNTY. COLORADO. NOT AVAILABLE IN AUTOCAD) NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. CD-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Check Dams (CD) EC-12 RCD ALTERNATIVE TO STEPS ON BANKS ABOVE CREST DEFORM GABIONS AS NECESSARY TO ALIGN TOP OF GABIONS WITH GROUND SURFACE: AVOID GAPS BETWEEN GABIONS A LENGTH L MAX. STEP CREST LENGTH CL HEIGHT 1'6" D I S4 6 TYP (1'6" MIN) COMPACTED } ROCK FILLED GABION BACKFILL HOG RINGS MIN. BURY J SECURED TO (TYP) DEPTH 1'6" ADJACENT GABION REINFORCED CHECK DAM ELEVATION VIEW 3' D50=6" RIPRAP ENCLOSED IN GABION 6" MIN. FLOW - 1'6" MIN } _ - -- !_ 1,6„ 172XTILE CHANNEL GRADE COMPACTED BACKFILL r' BLANKET SECTION A REINFORCED CHECK DAM INSTALLATION NOTES 1. SEE PLAN VIEW FOR: -LOCATIONS OF CHECK DAMS. -CHECK DAM TYPE (CHECK DAM OR REINFORCED CHECK DAM). -LENGTH (L), CREST LENGTH (CL), AND DEPTH (0). 2. CHECK DAMS INDICATED ON THE SWMP SHALL BE INSTALLED PRIOR TO AN UPSTREAM LAND-DISTURBING ACTIVITIES. 3. REINFORCED CHECK DAMS, GABIONS SHALL HAVE GALVANIZED TWISTED WIRE NETTING WITH A MAXIMUM OPENING DIMENSION OF 02" AND A MINIMUM WIRE THICKNESS OF 0.10". WIRE "HOG RINGS" AT 4" SPACING OR OTHER APPROVED MEANS SHALL BE USED AT ALL GABION SEAMS AND TO SECURE THE GABION TO THE ADJACENT SECTION. 4. THE CHECK DAM SHALL BE TRENCHED INTO THE GROUND A MINIMUM OF 1' 6". 5. GEOTEXTILE BLANKET SHALL BE PLACED IN THE REINFORCED CHECK DAM TRENCH EXTENDING A MINIMUM OF 1' 6" ON BOTH THE UPSTREAM AND DOWNSTREAM SIDES OF THE REINFORCED CHECK DAM. CD-2. REINFORCED CHECK DAM November 2010 Urban Drainage and Flood Control District CD-5 Urban Storm Drainage Criteria Manual Volume 3 EC-12 Check Dams (CD) REINFORCED CHECK DAM MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. SEDIMENT ACCUMULATED UPSTREAM OF REINFORCED CHECK DAMS SHALL BE REMOVED AS NEEDED TO MAINTAIN THE EFFECTIVENESS OF BMP, TYPICALLY WHEN THE UPSTREAM SEDIMENT DEPTH IS WITHIN Y2 THE HEIGHT OF THE CREST. 5. REPAIR OR REPLACE REINFORCED CHECK DAMS WHEN THERE ARE SIGNS OF DAMAGE SUCH AS HOLES IN THE GABION OR UNDERCUTTING. 6. REINFORCED CHECK DAMS ARE TO REMAIN IN PLACE UNTIL THE UPSTREAM DISTURBED AREA IS STABILIZED AND APPROVED BY THE LOCAL JURISDICTION. 7. WHEN REINFORCED CHECK DAMS ARE REMOVED, ALL DISTURBED AREAS SHALL BE COVERED WITH TOPSOIL, SEEDED AND MULCHED, AND COVERED WITH A GEOTEXTILE BLANKET, OR OTHERWISE STABILIZED AS APPROVED BY LOCAL JURISDICTION. (DETAIL ADAPTED FROM DOUGLAS COUNTY, COLORADO AND CITY OF AURORA, COLORADO. NOT AVAILABLE IN AUTOCAD) NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. CD-6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Streambank Stabilization (SS) EC-13 Description Streambank stabilization involves a combination of erosion and sediment control practices to protect streams, banks, and in-stream habitat from '""�N -` accelerated erosion. BMPs associated with streambank stabilization may include protection of existing vegetation,check dams/grade control, temporary and permanent seeding, outlet protection,rolled erosion control products,temporary diversions, `p. dewatering operations and = bioengineering practices such as brush layering, live staking and fascines. Photograph SS-1. Streambank stabilization using geotextiles Appropriate Uses following installation of a permanent in-stream grade control structure. Streambank stabilization may be a construction activity in and of itself, or it may be in conjunction with a broader construction project that discharges to a waterway that is susceptible to accelerated erosion due to increases in the rate and volume of stormwater runoff. Depending on the health of the stream,water quality sampling and testing may be advisable prior to and/or during construction to evaluate health and stability of the stream and potential effects from adjacent construction activities. Design and Installation Streambank stabilization consists of protecting the stream in a variety of ways to minimize negative effects to the stream environment. The following lists the minimum requirements necessary for construction streambank stabilization: ■ Protect existing vegetation along the stream bank in accordance with the Vegetated Buffers and Protection of Existing Vegetation Fact Sheets. Preserving a riparian buffer along the streambank will help to remove sediment and decrease runoff rates from the disturbed area. ■ Outside the riparian buffer,provide sediment control in the form of a silt fence or equivalent sediment control practice along the entire length of the stream that will receive runoff from the area of disturbance. In some cases,a double-layered perimeter control may be justified adjacent to sensitive receiving waters and wetlands to provide additional protection. ■ Stabilize all areas that will be draining to the stream. Use rolled erosion control products,temporary or permanent seeding, or other appropriate measures. ■ Ensure all point discharges entering the stream are Streambank Stabilization adequately armored with a velocity dissipation device and appropriate outlet protection. Functions Erosion Control Yes See individual design details and notes for the various BMPs Sediment Control No referenced in this practice. Additional information on bioengineering techniques for stream stabilization can be Site/Material Management No November 2010 Urban Drainage and Flood Control District SS-1 Urban Storm Drainage Criteria Manual Volume 3 EC-13 Streambank Stabilization (SS) found in the Major Drainage chapter of Volume 1 and additional guidance on BMPs for working in waterways can be found in UDFCD's Best Management Practices for Construction in Waterways Training Manual. Maintenance and Removal Inspect BMPs protecting the stream for damage on a daily basis. Maintain,repair, or replace damaged BMPs following the guidance provided in individual BMP Fact Sheets for practices that are implemented. Some streambank stabilization BMPs are intended to remain in place as vegetation matures(e.g. erosion control blankets protecting seeded stream banks and turf reinforcement mats). For BMPs that are not to remain in place as a part of final stabilization such as silt fence and other temporary measures, BMPs should be removed when all land disturbing activities have ceased and areas have been permanently stabilized. SS-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Wind Erosion/Dust Control (DC) EC-14 Description Wind erosion and dust control BMPs help to keep soil particles from entering ' the air as a result of land disturbing construction activities. These BMPs include a variety of practices generally focused on either graded disturbed areas or construction roadways. For graded areas,practices such as seeding and mulching,use of soil binders, site watering, or other practices that provide prompt surface cover should be used. For construction roadways,road watering and stabilized surfaces should be considered. Photograph DC-1. Water truck used for dust suppression. Photo courtesy of Douglas County. Appropriate Uses Dust control measures should be used on any site where dust poses a problem to air quality. Dust control is important to control for the health of construction workers and surrounding waterbodies. Design and Installation The following construction BMPs can be used for dust control: ■ An irrigation/sprinkler system can be used to wet the top layer of disturbed soil to help keep dry soil particles from becoming airborne. ■ Seeding and mulching can be used to stabilize disturbed surfaces and reduce dust emissions. ■ Protecting existing vegetation can help to slow wind velocities across the ground surface,thereby limiting the likelihood of soil particles to become airborne. ■ Spray-on soil binders form a bond between soil particles keeping them grounded. Chemical treatments may require additional permitting requirements. Potential impacts to surrounding waterways and habitat must be considered prior to use. ■ Placing rock on construction roadways and entrances will help keep dust to a minimum across the construction site. ■ Wind fences can be installed on site to reduce wind speeds. Install fences perpendicular to the prevailing Wind Erosion Control/ wind direction for maximum effectiveness. Dust Control Functions Maintenance and Removal Erosion Control Yes When using an irrigation/sprinkler control system to aid in Sediment Control No dust control,be careful not to overwater. Overwatering will Site/Material Management Moderate cause construction vehicles to track mud off-site. November 2010 Urban Drainage and Flood Control District DC-1 Urban Storm Drainage Criteria Manual Volume 3 Concrete Washout Area (CWA) MM-1 Description Concrete waste management involves designating and properly managing a specific area of the construction site as a concrete washout area. A concrete niannun,,mllnm III'4nI Xl[I m,Iminml. IW,,,,IplADlllp,,lli 1,11111:mnmT Inn AIfOA FI IVI,IAIII,I Ii1NElA washout area can be created using one of - - several approaches designed to receive wash water from washing of tools and concrete mixer chutes, liquid concrete waste from dump trucks,mobile batch mixers, or pump trucks. Three basic approaches are available: excavation of a pit in the ground,use of an above ground storage area, or use of prefabricated haul- away concrete washout containers. Surface discharges of concrete washout water from construction sites are prohibited. Photograph CWA-1. Example of concrete washout area. Note gravel tracking pad for access and sign. Appropriate Uses Concrete washout areas must be designated On all sites that will generate concrete wash water or liquid concrete waste from onsite concrete mixing or concrete delivery. Because pH is a pollutant of concern for washout activities,when unlined pits are used for concrete washout,the soil must have adequate buffering capacity to result in protection of state groundwater standards; otherwise, a liner/containment must be used. The following management practices are recommended to prevent an impact from unlined pits to groundwater: ■ The use of the washout site should be temporary(less than 1 year), and ■ The washout site should be not be located in an area where shallow groundwater may be present, such as near natural drainages, springs,Or wetlands. Design and Installation Concrete washout activities must be conducted in a manner that does not contribute pollutants to surface waters or stormwater runoff. Concrete washout areas may be lined or unlined excavated pits in the ground, commercially manufactured prefabricated washout containers,or aboveground holding areas constructed of berms, sandbags or straw bales with a plastic liner. Although unlined washout areas may be used, lined pits may be required to protect groundwater under certain conditions. Concrete Washout Area Do not locate an unlined washout area within 400 feet Functions of any natural drainage pathway or waterbody or within 1,000 feet of any wells or drinking water Erosion Control No sources. Even for lined concrete washouts,it is Sediment Control No advisable to locate the facility away from waterbodies Site/Material Management Yes and drainage paths. If site constraints make these November 2010 Urban Drainage and Flood Control District CWA-1 Urban Storm Drainage Criteria Manual Volume 3 MM-1 Concrete Washout Area (CWA) setbacks infeasible or if highly permeable soils exist in the area,then the pit must be installed with an impermeable liner(16 mil minimum thickness) or surface storage alternatives using prefabricated concrete washout devices or a lined aboveground storage area should be used. Design details with notes are provided in Detail CWA-1 for pits and CWA-2 for aboveground storage areas. Pre-fabricated concrete washout container information can be obtained from vendors. Maintenance and Removal A key consideration for concrete washout areas is to ensure that adequate signage is in place identifying the location of the washout area. Part of inspecting and maintaining washout areas is ensuring that adequate signage is provided and in good repair and that the washout area is being used,as opposed to washout in non-designated areas of the site. Remove concrete waste in the washout area, as needed to maintain BMP function(typically when filled to about two-thirds of its capacity). Collect concrete waste and deliver offsite to a designated disposal location. Upon termination of use of the washout site,accumulated solid waste, including concrete waste and any contaminated soils,must be removed from the site to prevent on-site disposal of solid waste. If the wash water is allowed to evaporate and the concrete hardens,it may be recycled. '�• HCRErE Photograph CWA-2. Prefabricated concrete washout. Photo Photograph CWA-3. Earthen concrete washout. Photo courtesy of CDOT. courtesy of CDOT. CWA-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Concrete Washout Area (CWA) MM-1 CONCRETE WASHOUT A SIGN CWA 3:1 4' MIN. 3:1 8 X 8 MIN. 3:1 VEHICLE TRACKING CONTROL (SEE ' VTC DETAIL) OR �- OTHER STABLE . ltlr", - - - SURFACE 3:1 � 25 MIN. I i CONCRETE WASHOUT AREA PLAN 12" TYP. COMPACTED BERM AROUND >4 THE PERIMETER 1F- 2% SLOPE 1L S3' MIN. <- UNDISTURBED OR >3 >3 COMPACTED SOIL S X 8 MIN. VEHICLE TRACKING CONTROL (SEE VTC SECTION A DETAIL CWA- 1 . CONCRETE WASHOUT AREA CWA INSTALLATION NOTES 1. SEE PLAN VIEW FOR: -CWA INSTALLATION LOCATION, 2. DO NOT LOCATE AN UNLINED CWA WITHIN 400' OF ANY NATURAL DRAINAGE PATHWAY OR WATERBODY. DO NOT LOCATE WITHIN 1,000' OF ANY WELLS OR DRINKING WATER SOURCES. IF SITE CONSTRAINTS MAKE THIS INFEASIBLE, OR IF HIGHLY PERMEABLE SOILS EXIST ON SITE, THE CWA MUST BE INSTALLED WITH AN IMPERMEABLE LINER (16 MIL MIN. THICKNESS) OR SURFACE STORAGE ALTERNATIVES USING PREFABRICATED CONCRETE WASHOUT DEVICES OR A LINED ABOVE GROUND STORAGE ARE SHOULD BE USED. 3. THE CWA SHALL BE INSTALLED PRIOR TO CONCRETE PLACEMENT ON SITE. 4. CWA SHALL INCLUDE A FLAT SUBSURFACE PIT THAT IS AT LEAST 8' BY 8' SLOPES LEADING OUT OF THE SUBSURFACE PIT SHALL BE 3:1 OR FLATTER. THE PIT SHALL BE AT LEAST 3' DEEP. 5. BERM SURROUNDING SIDES AND BACK OF THE CWA SHALL HAVE MINIMUM HEIGHT OF 1'- 6. VEHICLE TRACKING PAD SHALL BE SLOPED 2% TOWARDS THE CWA. 7. SIGNS SHALL BE PLACED AT THE CONSTRUCTION ENTRANCE, AT THE CWA, AND ELSEWHERE AS NECESSARY TO CLEARLY INDICATE THE LOCATION OF THE CWA TO OPERATORS OF CONCRETE TRUCKS AND PUMP RIGS. 8. USE EXCAVATED MATERIAL FOR PERIMETER BERM CONSTRUCTION. November 2010 Urban Drainage and Flood Control District CWA-3 Urban Storm Drainage Criteria Manual Volume 3 MM-1 Concrete Washout Area (CWA) CWA MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. I WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. THE CWA SHALL BE REPAIRED, CLEANED, OR ENLARGED AS NECESSARY TO MAINTAIN CAPACITY FOR CONCRETE WASTE. CONCRETE MATERIALS, ACCUMULATED IN PIT, SHALL BE REMOVED ONCE THE MATERIALS HAVE REACHED A DEPTH OF 2'. 5. CONCRETE WASHOUT WATER, WASTED PIECES OF CONCRETE AND ALL OTHER DEBRIS IN THE SUBSURFACE PIT SHALL BE TRANSPORTED FROM THE JOB SITE IN A WATER—TIGHT CONTAINER AND DISPOSED OF PROPERLY. 6. THE CWA SHALL REMAIN IN PLACE UNTIL ALL CONCRETE FOR THE PROJECT IS PLACED. 7. WHEN THE CWA IS REMOVED, COVER THE DISTURBED AREA WITH TOP SOIL, SEED AND MULCH OR OTHERWISE STABILIZED IN A MANNER APPROVED BY THE LOCAL JURISDICTION. (DETAIL ADAPTED FROM DOUGLAS COUNTY, COLORADO AND THE CITY OF PARKER, COLORADO, NOT AVAILABLE IN AUTOCAD). NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. CWA-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Stockpile Management (SP) MM-2 Description Stockpile management includes _ measures to minimize erosion and _ sediment transport from soil stockpiles. Appropriate Uses Stockpile management should be used when soils or other erodible materials ~; are stored at the construction site. ,s,. _ - �� ' � A.. �= ►- Special attention should be given to stockpiles in close proximity to natural or manmade storm systems. Photograph SP-1. A topsoil stockpile that has been partially Design and Installation revegetated and is protected by silt fence perimeter control. Locate stockpiles away from all drainage system components including storm sewer inlets. Where practical,choose stockpile locations that that will remain undisturbed for the longest period of time as the phases of construction progress. Place sediment control BMPs around the perimeter of the stockpile, such as sediment control logs,rock socks, silt fence, straw bales and sand bags. See Detail SP-1 for guidance on proper establishment of perimeter controls around a stockpile. For stockpiles in active use,provide a stabilized designated access point on the upgradient side of the stockpile. Stabilize the stockpile surface with surface roughening,temporary seeding and mulching, erosion control blankets, or soil binders. Soils stockpiled for an extended period(typically for more than 60 days) should be seeded and mulched with a temporary grass cover once the stockpile is placed(typically within 14 days). Use of mulch only or a soil binder is acceptable if the stockpile will be in place for a more limited time period(typically 30-60 days). Timeframes for stabilization of stockpiles noted in this fact sheet are "typical" guidelines. Check permit requirements for specific federal,state, and/or local requirements that may be more prescriptive. Stockpiles should not be placed in streets or paved areas unless no other practical alternative exists. See the Stabilized Staging Area Fact Sheet for guidance when staging in roadways is unavoidable due to space or right-of-way constraints. For paved areas,rock socks must be used for perimeter control and all inlets with the potential to receive sediment from the stockpile(even from vehicle tracking)must be protected. Maintenance and Removal Inspect perimeter controls and inlet protection in accordance with their respective BMP Fact Sheets. Where seeding,mulch and/or soil binders are used,reseeding or reapplication of soil binder may be necessary. When temporary removal of a perimeter BMP is necessary Stockpile Management to access a stockpile,ensure BMPs are reinstalled in Functions accordance with their respective design detail section. Erosion Control Yes Sediment Control Yes Site/Material Management Yes November 2010 Urban Drainage and Flood Control District SP-1 Urban Storm Drainage Criteria Manual Volume 3 MM-2 Stockpile Management (SM) When the stockpile is no longer needed,properly dispose of excess materials and revegetate or otherwise stabilize the ground surface where the stockpile was located. SP-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Stockpile Management (SP) MM-2 3.0' MIN STOCKPILE / A SILT FENCE (SEE SF DETAIL FOR INSTALLATION REQUIREMENTS) STOCKPILE PROTECTION PLAN MAXIMUM 2 SILT FENCE (SEE SF DETAIL FOR 1 INSTALLATION REQUIREMENTS) i SECTION A SP- 1 . STOCKPILE PROTECTION STOCKPILE PROTECTION INSTALLATION NOTES 1. SEE PLAN VIEW FOR: -LOCATION OF STOCKPILES. -TYPE OF STOCKPILE PROTECTION. 2. INSTALL PERIMETER CONTROLS IN ACCORDANCE WITH THEIR RESPECTIVE DESIGN DETAILS. SILT FENCE IS SHOWN IN THE STOCKPILE PROTECTION DETAILS; HOWEVER, OTHER TYPES OF PERIMETER CONTROLS INCLUDING SEDIMENT CONTROL LOGS OR ROCK SOCKS MAY BE SUITABLE IN SOME CIRCUMSTANCES. CONSIDERATIONS FOR DETERMINING THE APPROPRIATE TYPE OF PERIMETER CONTROL FOR A STOCKPILE INCLUDE WHETHER THE STOCKPILE IS LOCATED ON A PERVIOUS OR IMPERVIOUS SURFACE, THE RELATIVE HEIGHTS OF THE PERIMETER CONTROL AND STOCKPILE, THE ABILITY OF THE PERIMETER CONTROL TO CONTAIN THE STOCKPILE WITHOUT FAILING IN THE EVENT THAT MATERIAL FROM THE STOCKPILE SHIFTS OR SLUMPS AGAINST THE PERIMETER, AND OTHER FACTORS. 3 STABILIZE THE STOCKPILE SURFACE WITH SURFACE ROUGHENING, TEMPORARY SEEDING AND MULCHING, EROSION CONTROL BLANKETS, OR SOIL BINDERS. SOILS STOCKPILED FOR AN EXTENDED PERIOD (TYPICALLY FOR MORE THAN 60 DAYS) SHOULD BE SEEDED AND MULCHED WITH A TEMPORARY GRASS COVER ONCE THE STOCKPILE IS PLACED (TYPICALLY WITHIN 14 DAYS). USE OF MULCH ONLY OR A SOIL BINDER IS ACCEPTABLE IF THE STOCKPILE WILL BE IN PLACE FOR A MORE LIMITED TIME PERIOD (TYPICALLY 30-60 DAYS). 4. FOR TEMPORARY STOCKPILES ON THE INTERIOR PORTION OF A CONSTRUCTION SITE, WHERE OTHER DOWNGRADIENT CONTROLS, INCLUDING PERIMETER CONTROL, ARE IN PLACE, STOCKPILE PERIMETER CONTROLS MAY NOT BE REQUIRED. November 2010 Urban Drainage and Flood Control District SP-3 Urban Storm Drainage Criteria Manual Volume 3 MM-2 Stockpile Management (SM) STOCKPILE PROTECTION MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPS SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. I WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. STOCKPILE PROTECTION MAINTENANCE NOTES 4. IF PERIMETER PROTECTION MUST BE MOVED TO ACCESS SOIL STOCKPILE, REPLACE PERIMETER CONTROLS BY THE END OF THE WORKDAY. 5. STOCKPILE PERIMETER CONTROLS CAN BE REMOVED ONCE ALL THE MATERIAL FROM THE STOCKPILE HAS BEEN USED. (DETAILS ADAPTED FROM PARKER, COLORADO. NOT AVAILABLE IN AUTOCAD) NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. SP-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Stockpile Management (SP) MM-2 © A POLY LINER SA ® ® R BERM ORANGE SAFETY CONE SOIL/LANDSCAPE MATERIAL � m m POLY TARP TARP ANCHOR 6" PVC PIPE FOR DRAINAGE IN FLOWLINE ® CURB LINE ROAD CL TARP ANCHOR (CINDER POLY TARP BLOCK, OR 5 GALLON BUCKET OF WATER) ROADWAY �; 6' MAX. POLY LINER BERM MATERIAL (TRIANGULAR SILT DIKE, 6"MIN. SEDIMENT CONTROL LOG, 1 6' MAX., MUST NOT 6" PVC PIPE ROCK SOCK, OR OTHER I BE LOCATED WITHIN WRAPPED MATERIAL) A DRIVE LANE SP-2. MATERIALS STAGING IN ROADWAY MATERIALS STAGING IN ROADWAYS INSTALLATION NOTES 1. SEE PLAN VIEW FOR -LOCATION OF MATERIAL STAGING AREA(S). -CONTRACTOR MAY ADJUST LOCATION AND SIZE OF STAGING AREA WITH APPROVAL FROM THE LOCAL JURISDICTION. 2. FEATURE MUST BE INSTALLED PRIOR TO EXCAVATION, EARTHWORK OR DELIVERY OF MATERIALS. 3. MATERIALS MUST BE STATIONED ON THE POLY LINER. ANY INCIDENTAL MATERIALS DEPOSITED ON PAVED SECTION OR ALONG CURB LINE MUST BE CLEANED UP PROMPTLY. 4. POLY LINER AND TARP COVER SHOULD BE OF SIGNIFICANT THICKNESS TO PREVENT DAMAGE OR LOSS OF INTEGRITY. 5. SAND BAGS MAY BE SUBSTITUTED TO ANCHOR THE COVER TARP OR PROVIDE BERMING UNDER THE BASE LINER. 6. FEATURE IS NOT INTENDED FOR USE WITH WET MATERIAL THAT WILL BE DRAINING AND/OR SPREADING OUT ON THE POLY LINER OR FOR DEMOLITION MATERIALS. 7. THIS FEATURE CAN BE USED FOR: -UTILITY REPAIRS. -WHEN OTHER STAGING LOCATIONS AND OPTIONS ARE LIMITED. -OTHER LIMITED APPLICATION AND SHORT DURATION STAGING. November 2010 Urban Drainage and Flood Control District SP-5 Urban Storm Drainage Criteria Manual Volume 3 MM-2 Stockpile Management (SM) MATERIALS STAGING IN ROADWAY MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. I WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. INSPECT PVC PIPE ALONG CURB LINE FOR CLOGGING AND DEBRIS. REMOVE OBSTRUCTIONS PROMPTLY. 5. CLEAN MATERIAL FROM PAVED SURFACES BY SWEEPING OR VACUUMING. NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. (DETAJLS ADAPTED FROM AURORA, COLORADO) SP-6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Good Housekeeping Practices (GH) MM-3 Description - Implement construction site good housekeeping practices to _ prevent pollution associated with solid, liquid and hazardous construction-related materials and wastes. Stormwater Management Plans (SWMPs) should clearly specify BMPs jzuoGO including these good housekeeping practices: - ■ Provide for waste management. ■ Establish proper building material staging areas. ■ Designate paint and concrete washout areas. ■ Establish proper equipment/vehicle fueling and maintenance practices. ■ Control equipment/vehicle washing and allowable non- stormwater discharges. ■ Develop a spill prevention and response plan. _ Acknowledgement: This Fact Sheet is based directly on EPA guidance provided in Developing Your Stormwater Photographs GH-1 and GH-2. Proper materials Pollution Prevent Plan(EPA 2007). storage and secondary containment for fuel tanks are important good housekeeping practices. Photos Appropriate Uses courtesy of CDOT and City of Aurora. Good housekeeping practices are necessary at all construction sites. Design and Installation The following principles and actions should be addressed in SWMPs: ■ Provide for Waste Management. Implement management procedures and practices to prevent or reduce the exposure and transport of pollutants in stormwater from solid,liquid and sanitary wastes that will be generated at the site. Practices such as trash disposal,recycling,proper material handling, and cleanup measures can reduce the potential for stormwater runoff to pick up construction site wastes and discharge them to surface waters. Implement a comprehensive set of waste-management practices for hazardous or toxic materials, such as paints, solvents,petroleum products,pesticides, wood preservatives, acids,roofing tar, and other materials. Practices should include storage, handling, inventory,and cleanup procedures, in case of spills. Specific practices that should be considered include: Solid or Construction Waste Good Housekeeping o Designate trash and bulk waste-collection areas on- Functions site. Erosion Control No Sediment Control No Site/Material Management Yes November 2010 Urban Drainage and Flood Control District GH-1 Urban Storm Drainage Criteria Manual Volume 3 MM-3 Good Housekeeping Practices (GH) o Recycle materials whenever possible(e.g.,paper,wood, concrete, oil). o Segregate and provide proper disposal options for hazardous material wastes. o Clean up litter and debris from the construction site daily. o Locate waste-collection areas away from streets,gutters,watercourses, and storm drains. Waste- collection areas(dumpsters, and such) are often best located near construction site entrances to minimize traffic on disturbed soils. Consider secondary containment around waste collection areas to minimize the likelihood of contaminated discharges. o Empty waste containers before they are full and overflowing. Sanitary and Septic Waste o Provide convenient,well-maintained, and properly located toilet facilities on-site. o Locate toilet facilities away from storm drain inlets and waterways to prevent accidental spills and contamination of stormwater. o Maintain clean restroorn facilities and empty portable toilets regularly. o Where possible,provide secondary containment pans under portable toilets. o Provide tie-downs or stake-downs for portable toilets. o Educate employees, subcontractors,and suppliers on locations of facilities. o Treat or dispose of sanitary and septic waste in accordance with state or local regulations. Do not discharge or bury wastewater at the construction site. o Inspect facilities for leaks. If found,repair or replace immediately. o Special care is necessary during maintenance(pump out)to ensure that waste and/or biocide are not spilled on the ground. Hazardous Materials and Wastes o Develop and implement employee and subcontractor education, as needed, on hazardous and toxic waste handling, storage, disposal, and cleanup. ., o Designate hazardous waste-collection areas on-site. o Place all hazardous and toxic material wastes in secondary containment. Photograph GH-3. Locate portable toilet facilities on level surfaces away from waterways and storm drains. Photo courtesy of W WE. GH-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Good Housekeeping Practices (GH) MM-3 o Hazardous waste containers should be inspected to ensure that all containers are labeled properly and that no leaks are present. ■ Establish Proper Building Material Handling and Staging Areas. The SWAP should include comprehensive handling and management procedures for building materials,especially those that are hazardous or toxic. Paints, solvents,pesticides,fuels and oils, other hazardous materials or building materials that have the potential to contaminate stormwater should be stored indoors or under cover whenever possible or in areas with secondary containment. Secondary containment measures prevent a spill from spreading across the site and may include dikes,berms, curbing, or other containment methods. Secondary containment techniques should also ensure the protection of groundwater. Designate staging areas for activities such as fueling vehicles,mixing paints,plaster,mortar,and other potential pollutants. Designated staging areas enable easier monitoring of the use of materials and clean up of spills. Training employees and subcontractors is essential to the success of this pollution prevention principle. Consider the following specific materials handling and staging practices: o Train employees and subcontractors in proper handling and storage practices. o Clearly designate site areas for staging and storage with signs and on construction drawings. Staging areas should be located in areas central to the construction site. Segment the staging area into sub-areas designated for vehicles, equipment, or stockpiles. Construction entrances and exits should be clearly marked so that delivery vehicles enter/exit through stabilized areas with vehicle tracking controls(See Vehicle Tracking Control Fact Sheet). o Provide storage in accordance with Spill Protection, Control and Countermeasures(SPCA requirements and plans and provide cover and impermeable perimeter control, as necessary, for hazardous materials and contaminated soils that must be stored on site. o Ensure that storage containers are regularly inspected for leaks, corrosion, support or foundation failure,or other signs of deterioration and tested for soundness. o Reuse and recycle construction materials when possible. ■ Designate Concrete Washout Areas. Concrete contractors should be encouraged to use the washout facilities at their own plants or dispatch facilities when feasible;however, concrete washout commonly occurs on construction sites. If it is necessary to provide for concrete washout areas on- site, designate specific washout areas and design facilities to handle anticipated washout water. Washout areas should also be provided for paint and stucco operations. Because washout areas can be a source of pollutants from leaks or spills, care must be taken with regard to their placement and proper use. See the Concrete Washout Area Fact Sheet for detailed guidance. Both self-constructed and prefabricated washout containers can fill up quickly when concrete,paint, and stucco work are occurring on large portions of the site. Be sure to check for evidence that contractors are using the washout areas and not dumping materials onto the ground or into drainage facilities. If the washout areas are not being used regularly,consider posting additional signage, relocating the facilities to more convenient locations,or providing training to workers and contractors. When concrete,paint, or stucco is part of the construction process, consider these practices which will help prevent contamination of stormwater. Include the locations of these areas and the maintenance and inspection procedures in the SWMP. November 2010 Urban Drainage and Flood Control District GH-3 Urban Storm Drainage Criteria Manual Volume 3 MM-3 Good Housekeeping Practices (GH) o Do not washout concrete trucks or equipment into storm drains, streets, gutters,uncontained areas, or streams. Only use designated washout areas. o Establish washout areas and advertise their locations with signs. Ensure that signage remains in good repair. o Provide adequate containment for the amount of wash water that will be used. o Inspect washout structures daily to detect leaks or tears and to identify when materials need to be removed. o Dispose of materials properly. The preferred method is to allow the water to evaporate and to recycle the hardened concrete. Full service companies may provide dewatering services and should dispose of wastewater properly. Concrete wash water can be highly polluted. It should not be discharged to any surface water, storm sewer system, or allowed to infiltrate into the ground in the vicinity of waterbodies. Washwater should not be discharged to a sanitary sewer system without first receiving written permission from the system operator. ■ Establish Proper Equipment/Vehicle Fueling and Maintenance Practices. Create a clearly designated on-site fueling and maintenance area that is clean and dry. The on-site fueling area should have a spill kit,and staff should know how to use it. If possible, conduct vehicle fueling and maintenance activities in a covered area. Consider the following practices to help prevent the discharge of pollutants to stormwater from equipment/vehicle fueling and maintenance. Include the locations of designated fueling and maintenance areas and inspection and maintenance procedures in the SWMP. o Train employees and subcontractors in proper fueling procedures(stay with vehicles during fueling,proper use of pumps, emergency shutoff valves, etc.). o Inspect on-site vehicles and equipment regularly for leaks, equipment damage, and other service problems. o Clearly designate vehicle/equipment service areas away from drainage facilities and watercourses to prevent stormwater run-on and runoff. o Use drip pans,drip cloths,or absorbent pads when replacing spent fluids. o Collect all spent fluids, store in appropriate labeled containers in the proper storage areas, and recycle fluids whenever possible. ■ Control Equipment/Vehicle Washing and Allowable Non-Stormwater Discharges. Implement practices to prevent contamination of surface and groundwater from equipment and vehicle wash water. Representative practices include: o Educate employees and subcontractors on proper washing procedures. o Use off-site washing facilities,when available. o Clearly mark the washing areas and inform workers that all washing must occur in this area. o Contain wash water and treat it using BMPs. Infiltrate washwater when possible,but maintain separation from drainage paths and waterbodies. GH-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Good Housekeeping Practices (GH) MM-3 o Use high-pressure water spray at vehicle washing facilities without detergents. Water alone can remove most dirt adequately. o Do not conduct other activities, such as vehicle repairs,in the wash area. o Include the location of the washing facilities and the inspection and maintenance procedures in the SWMP. ■ Develop a Spill Prevention and Response Plan. Spill prevention and response procedures must be identified in the SWMP. Representative procedures include identifying ways to reduce the chance of spills, stop the source of spills,contain and clean up spills, dispose of materials contaminated by spills, and train personnel responsible for spill prevention and response. The plan should also specify material handling procedures and storage requirements and ensure that clear and concise spill cleanup procedures are provided and posted for areas in which spills may potentially occur. When developing a spill prevention plan, include the following: o Note the locations of chemical storage areas, storm drains,tributary drainage areas, surface waterbodies on or near the site, and measures to stop spills from leaving the site. o Provide proper handling and safety procedures for each type of waste. Keep Material Safety Data Sheets(MSDSs)for chemical used on site with the SWMP. o Establish an education program for employees and subcontractors on the potential hazards to humans and the environment from spills and leaks. o Specify how to notify appropriate authorities, such as police and fire departments,hospitals, or municipal sewage treatment facilities to request assistance. Emergency procedures and contact numbers should be provided in the SWMP and posted at storage locations. o Describe the procedures, equipment and materials for immediate cleanup of spills and proper disposal. o Identify personnel responsible for implementing the plan in the event of a spill. Update the spill prevention plan and clean up materials as changes occur to the types of chemicals stored and used at the facility. November 2010 Urban Drainage and Flood Control District GH-5 Urban Storm Drainage Criteria Manual Volume 3 MM-3 Good Housekeeping Practices (GH) Spill Prevention, Control,and Countermeasure(SPCC)Plan Construction sites may be subject to 40 CFR Part 112 regulations that require the preparation and implementation of a SPCC Plan to prevent oil spills from aboveground and underground storage tanks. The facility is subject to this rule if it is a non-transportation-related facility that: ■ Has a total storage capacity greater than 1,320 gallons or a completely buried storage capacity greater than 42,000 gallons. ■ Could reasonably be expected to discharge oil in quantities that may be harmful to navigable waters of the United States and adjoining shorelines. Furthermore, if the facility is subject to 40 CFR Part 112,the SWMP should reference the SPCC Plan. To find out more about SPCC Plans, see EPA's website on SPPC at www.epa. og v/oilspill/spcc.htm. Reporting Oil Spills In the event of an oil spill,contact the National Response Center toll free at 1-800-424- 8802 for assistance, or for more details,visit their website: www.nrc.uscg.mil. Maintenance and Removal Effective implementation of good housekeeping practices is dependent on clear designation of personnel responsible for supervising and implementing good housekeeping programs, such as site cleanup and disposal of trash and debris,hazardous material management and disposal,vehicle and equipment maintenance, and other practices. Emergency response "drills" may aid in emergency preparedness. Checklists may be helpful in good housekeeping efforts. Staging and storage areas require permanent stabilization when the areas are no longer being used for construction-related activities. Construction-related materials,debris and waste must be removed from the construction site once construction is complete. Design Details See the following Fact Sheets for related Design Details: MM-1 Concrete Washout Area MM-2 Stockpile Management SM-4 Vehicle Tracking Control Design details are not necessary for other good housekeeping practices;however,be sure to designate where specific practices will occur on the appropriate construction drawings. GH-6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Silt Fence (SF) SC-1 Description A silt fence is a woven geotextile fabric 4 attached to wooden posts and trenched into the ground. It is designed as a sediment barrier to intercept sheet flow runoff from disturbed areas. Appropriate Uses -- A silt fence can be used where runoff is conveyed from a disturbed area as sheet flow. Silt fence is not designed to receive concentrated flow or to be used as a filter fabric. Typical uses include: ■ Down slope of a disturbed area to accept sheet flow. Photograph SF-1. Silt fence creates a sediment barrier,forcing sheet flow runoff to evaporate or infiltrate. ■ Along the perimeter of a receiving water such as a stream,pond or wetland. ■ At the perimeter of a construction site. Design and Installation Silt fence should be installed along the contour of slopes so that it intercepts sheet flow. The maximum recommended tributary drainage area per 100 lineal feet of silt fence,installed along the contour, is approximately 0.25 acres with a disturbed slope length of up to 150 feet and a tributary slope gradient no steeper than 3:1. Longer and steeper slopes require additional measures. This recommendation only applies to silt fence installed along the contour. Silt fence installed for other uses, such as perimeter control, should be installed in a way that will not produce concentrated flows. For example,a"J-hook" installation may be appropriate to force runoff to pond and evaporate or infiltrate in multiple areas rather than concentrate and cause erosive conditions parallel to the silt fence. See Detail SF-1 for proper silt fence installation,which involves proper trenching, staking, securing the fabric to the stakes,and backfilling the silt fence. Properly installed silt fence should not be easily pulled out by hand and there should be no gaps between the ground and the fabric. Silt fence must meet the minimum allowable strength requirements, depth of installation requirement,and other specifications in the design details. Improper installation of silt fence is a common reason for silt fence failure; however, Silt Fence when properly installed and used for the appropriate purposes, it can be highly effective. Functions Erosion Control No Sediment Control Yes Site/Material Management No November 2010 Urban Drainage and Flood Control District SF-1 Urban Storm Drainage Criteria Manual Volume 3 SC-1 Silt Fence (SF) Maintenance and Removal „ Inspection of silt fence includes observing the material for tears or holes and checking for slumping fence and undercut areas bypassing flows. Repair of silt fence typically involves replacing the damaged section with a new section. Sediment accumulated behind silt fence should be removed, as needed to maintain BMP effectiveness,typically before it reaches a depth of 6 inches. = Silt fence may be removed when the upstream area { has reached final stabilization. Photograph SF-2. When silt fence is not installed along the contour,a"J-hook"installation may be appropriate to ensure that the BMP does not create concentrated flow parallel to the silt fence. Photo courtesy of Tom Gore. SF-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Silt Fence (SF) SC-1 SF SF - SF S F 1 YZ" x 1 Y1„ (RECOMMENDED) WOODEN FENCE POST WITH 10' MAX SPACING SILT FENCE GEOTEXTILE A COMPACTED BAC KFI LL FJ OW --- 36"-48„ "- -> TYP. EXISTING GROUND 6" MIN 1 8' AT LEAST 10" MIN OF SILT FENCE "TAIL" SHALL BE 4" MIN BURIED SILT FENCE POSTS SHALL OVERLAP AT JOINTS SO THAT NO GAPS JOIN EXIST IN SILT FENCE FIRST ROTATE SECOND POSTS SHALL BE JOINED AS SHOWN, THEN ROTATED 180 DEC. THICKNESS OF GEOTEXTILE HAS , IN DIRECTION SHOWN AND DRIVEN BEEN EXAGGERATED, TYP INTO THE GROUND SECTION A SF- 1 . SILT FENCE November 2010 Urban Drainage and Flood Control District SF-3 Urban Storm Drainage Criteria Manual Volume 3 SC-1 Silt Fence (SF) SILT FENCE INSTALLATION NOTES 1. SILT FENCE MUST BE PLACED AWAY FROM THE TOE OF THE SLOPE TO ALLOW FOR WATER PONDING. SILT FENCE AT THE TOE OF A SLOPE SHOULD BE INSTALLED IN A FLAT LOCATION AT LEAST SEVERAL FEET (2-5 FT) FROM THE TOE OF THE SLOPE TO ALLOW ROOM FOR PONDING AND DEPOSITION_ 2. A UNIFORM 6" X 4" ANCHOR TRENCH SHALL BE EXCAVATED USING TRENCHER OR SILT FENCE INSTALLATION DEVICE. NO ROAD GRADERS, BACKHOES, OR SIMILAR EQUIPMENT SHALL BE USED. 3. COMPACT ANCHOR TRENCH BY HAND WITH A "JUMPING JACK" OR BY WHEEL ROLLING. COMPACTION SHALL BE SUCH THAT SILT FENCE RESISTS BEING PULLED OUT OF ANCHOR TRENCH BY HAND. 4. SILT FENCE SHALL BE PULLED TIGHT AS IT IS ANCHORED TO THE STAKES. THERE SHOULD BE NO NOTICEABLE SAG BETWEEN STAKES AFTER IT HAS BEEN ANCHORED TO THE STAKES. 5. SILT FENCE FABRIC SHALL BE ANCHORED TO THE STAKES USING 1" HEAVY DUTY STAPLES OR NAILS WITH 1" HEADS. STAPLES AND NAILS SHOULD BE PLACED 3" ALONG THE FABRIC DOWN THE STAKE. 6. AT THE END OF A RUN OF SILT FENCE ALONG A CONTOUR, THE SILT FENCE SHOULD BE TURNED PERPENDICULAR TO THE CONTOUR TO CREATE A "J—HOOK." THE "J—HOOK" EXTENDING PERPENDICULAR TO THE CONTOUR SHOULD BE OF SUFFICIENT LENGTH TO KEEP RUNOFF FROM FLOWING AROUND THE END OF THE SILT FENCE (TYPICALLY 10' — 20'). 7. SILT FENCE SHALL BE INSTALLED PRIOR TO ANY LAND DISTURBING ACTIVITIES. SILT FENCE MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY, 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. SEDIMENT ACCUMULATED UPSTREAM OF THE SILT FENCE SHALL BE REMOVED AS NEEDED TO MAINTAIN THE FUNCTIONALITY OF THE BMP, TYPICALLY WHEN DEPTH OF ACCUMULATED SEDIMENTS IS APPROXIMATELY 6". 5. REPAIR OR REPLACE SILT FENCE WHEN THERE ARE SIGNS OF WEAR, SUCH AS SAGGING, TEARING, OR COLLAPSE. 6. SILT FENCE IS TO REMAIN IN PLACE UNTIL THE UPSTREAM DISTURBED AREA IS STABILIZED AND APPROVED BY THE LOCAL JURISDICTION, OR IS REPLACED BY AN EQUIVALENT PERIMETER SEDIMENT CONTROL BMP. 7. WHEN SILT FENCE IS REMOVED, ALL DISTURBED AREAS SHALL BE COVERED WITH TOPSOIL, SEEDED AND MULCHED OR OTHERWISE STABILIZED AS APPROVED BY LOCAL JURISDICTION. (DETAIL ADAPTED FROM TOWN OF PARKER, COLORADO AND CITY OF AURORA, NOT AVAILABLE IN AUTOCAD) NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. SF-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Sediment Control Log (SCL) SC-2 Description A sediment control log is a linear roll made of natural materials such as straw, coconut fiber, or other fibrous material trenched into the ground and held with a wooden stake. Sediment control logs are also often referred to as "straw wattles." They are used as a - sediment barrier to intercept sheet flow - runoff from disturbed areas. - Appropriate Uses Sediment control logs can be used in the following applications to trap sediment: ■ As perimeter control for stockpiles and the site. ■ As part of inlet protection designs. ■ As check dams in small drainage ditches. (Sediment control logs r are not intended for use in channels with high flow velocities.) Photographs SCL-1 and SCL-2. Sediment control logs used as 1)a perimeter control around a soil stockpile;and,2)as a'J-hook" ■ On disturbed slopes to shorten flow perimeter control at the corner of a construction site. lengths(as an erosion control). ■ As part of multi-layered perimeter control along a receiving water such as a stream,pond or wetland. Sediment control logs work well in combination with other layers of erosion and sediment controls. Design and Installation Sediment control logs should be installed along the contour to avoid concentrating flows. The maximum allowable tributary drainage area per 100 lineal feet of sediment control log, installed along the contour,is approximately 0.25 acres with a disturbed slope length of up to 150 feet and a tributary slope gradient no steeper than 3:1.Longer and steeper slopes require additional measures. This recommendation only applies to sediment control logs installed along the contour. When installed for other uses, such as perimeter control, it should be installed in a way that will not produce concentrated flows. For example, a"J-hook" Sediment Control Lo installation may be appropriate to force runoff to pond and Functions evaporate or infiltrate in multiple areas rather than concentrate Erosion Control Moderate and cause erosive conditions parallel to the BMP. Sediment Control Yes Site/Material Management No November 2010 Urban Drainage and Flood Control District SCL-1 Urban Storm Drainage Criteria Manual Volume 3 SC-2 Sediment Control Log (SCL) Although sediment control logs initially allow runoff to flow through the BMP,they can quickly become a barrier and should be installed is if they are impermeable. Design details and notes for sediment control logs are provided in Detail SCL-1. Sediment logs must be properly trenched and staked into the ground to prevent undercutting,bypassing and displacement. When installed on slopes, sediment control logs should be installed along the contours(i.e.,perpendicular to flow). Improper installation can lead to poor performance. Be sure that sediment control logs are properly trenched, anchored and tightly jointed. Maintenance and Removal Be aware that sediment control logs will eventually degrade. Remove accumulated sediment before the depth is one-half the height of the sediment log and repair damage to the sediment log,typically by replacing the damaged section. Once the upstream area is stabilized,remove and properly dispose of the logs. Areas disturbed beneath the logs may need to be seeded and mulched. Sediment control logs that are biodegradable may occasionally be left in place(e.g.,when logs are used in conjunction with erosion control blankets as permanent slope breaks). However,removal of sediment control logs after final stabilization is typically recommended when used in perimeter control, inlet protection and check dam applications. SCL-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Sediment Control Log (SCL) SC-2 SCL A 111'. x 1112" x 18" (MIN) WOODEN STAKE 9" DIAMETER (MIN) } SEDIMENT CONTROL LOG l 3" 4' MAX. CENTER (TYP.) 6" �. Y3 FLOW �� OF SCL DIAM. ` Y!` NOTE: LARGER (TYP.) / SC � DIAMETER SEDIMENT CONTROL LOGS MAY v ��\��,,,"""�� \yam' \� • / NEED TO BE EMBEDDED DEEPER. SEDIMENT CONTROL LOG CENTER STAKE IN CONTROL LOG COMPACTED EXCAVATED 3 9" DIAMETER (MIN) TRENCH SOIL SEDIMENT CONTROL LOG FLOW Y3 DIAM. SCL (TYP.) SECTION A 12" OVERLAP 1Y2" x 1Y1" x 18" (MIN) WOODEN STAKE 9" DIAMETER (MIN) SEDIMENT CONTROL LOG SEDIMENT CONTROL LOG JOINTS SCL- 1 . SEDIMENT CONTROL LOG November 2010 Urban Drainage and Flood Control District SCL-3 Urban Storm Drainage Criteria Manual Volume 3 SC-2 Sediment Control Log (SCL) COMPACTED EXCAVATED 3 CENTER STAKE IN CONTROL LOG TRENCH SOIL 9" DIAMETER (MIN) SEDIMENT CONTROL LOG FLOW —� PLACE LOG AGAINST BACK OF CURB Y3 DIAM. SCL (TYP.) 6" MIN. SCL-2. SEDIMENT CONTROL LOG AT BACK OF CURB CENTER STAKE IN CONTROL LOG 3 9" DIAMETER (MIN) SEDIMENT CONTROL LOG TREE LAWN (TYPICAL) Y3 DIAM. SCL (TYP.) CURB FLOW MIN:: '� •z//� �; ., ,/ ''ijs i% '''/,•a•i.. ;i;; .'�%:<!:;v,z(i; `��,�•'`., ii ,'!j'''.�;:i: I NO SCL-3. SEDIMENT CONTROL LOG AT SIDEWALK WITH TREE LAWN STAKING AT 4' MAX. ON CENTER (TYP. VERTICAL SPACING VARIES DEPENDING ON SLOPE \\ice:' CONTINUOUS SCL z x/ AT PERIMETER OF "' '' •% '' ! CONSTRUCTION SITE SCL-4. SEDIMENT CONTROL LOGS TO CONTROL SLOPE LENGTH SCL-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Sediment Control Log (SCL) SC-2 SEDIMENT CONTROL LOG INSTALLATION NOTES 1. SEE PLAN VIEW FOR LOCATION AND LENGTH OF SEDIMENT CONTROL LOGS. 2. SEDIMENT CONTROL LOGS THAT ACT AS A PERIMETER CONTROL SHALL BE INSTALLED PRIOR TO ANY UPGRADIENT LAND—DISTURBING ACTIVITIES. 3 SEDIMENT CONTROL LOGS SHALL CONSIST OF STRAW, COMPOST, EXCELSIOR OR COCONUT FIBER, AND SHALL BE FREE OF ANY NOXIOUS WEED SEEDS OR DEFECTS INCLUDING RIPS, HOLES AND OBVIOUS WEAR. 4. SEDIMENT CONTROL LOGS MAY BE USED AS SMALL CHECK DAMS IN DITCHES AND SWALES. HOWEVER, THEY SHOULD NOT BE USED IN PERENNIAL STREAMS OR HIGH VELOCITY DRAINAGE WAYS. 5. IT IS RECOMMENDED THAT SEDIMENT CONTROL LOGS BE TRENCHED INTO THE GROUND TO A DEPTH OF APPROXIMATELY Y3 OF THE DIAMETER OF THE LOG IF TRENCHING TO THIS DEPTH IS NOT FEASIBLE AND/OR DESIRABLE (SHORT TERM INSTALLATION WITH DESIRE NOT TO DAMAGE LANDSCAPE) A LESSER TRENCHING DEPTH MAY BE ACCEPTABLE WITH MORE ROBUST STAKING 6. THE UPHILL SIDE OF THE SEDIMENT CONTROL LOG SHALL BE BACKFILLED WITH SOIL THAT IS FREE OF ROCKS AND DEBRIS. THE SOIL SHALL BE TIGHTLY COMPACTED INTO THE SHAPE OF A RIGHT TRIANGLE USING A SHOVEL OR WEIGHTED LAWN ROLLER. 7. FOLLOW MANUFACTURERS' GUIDANCE FOR STAKING. IF MANUFACTURERS' INSTRUCTIONS 00 NOT SPECIFY SPACING, STAKES SHALL BE PLACED ON 4' CENTERS AND EMBEDDED A MINIMUM OF 6" INTO THE GROUND. 3" OF THE STAKE SHALL PROTRUDE FROM THE TOP OF THE LOG. STAKES THAT ARE BROKEN PRIOR TO INSTALLATION SHALL BE REPLACED. SEDIMENT CONTROL LOG MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4, SEDIMENT ACCUMULATED UPSTREAM OF SEDIMENT CONTROL LOG SHALL BE REMOVED AS NEEDED TO MAINTAIN FUNCTIONALITY OF THE BMP, TYPICALLY WHEN DEPTH OF ACCUMULATED SEDIMENTS IS APPROXIMATELY Y6 OF THE HEIGHT OF THE SEDIMENT CONTROL LOG. 5. SEDIMENT CONTROL LOG SHALL BE REMOVED AT THE END OF CONSTRUCTION. IF DISTURBED AREAS EXIST AFTER REMOVAL, THEY SHALL BE COVERED WITH TOP SOIL, SEEDED AND MULCHED OR OTHERWISE STABILIZED IN A MANNER APPROVED BY THE LOCAL JURISDICTION. (DETAILS ADAPTED FROM TOwN OF PARKER. COLORADO. jEFFERSON COUNTY, COLORADO, DOUGLAS COUNTY, COLORADO, AND CITY OF AURORA, COLORADO, NOT AVAILABLE IN AUTOCAD) NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. November 2010 Urban Drainage and Flood Control District SCL-5 Urban Storm Drainage Criteria Manual Volume 3 Brush Barrier (BB) SC-4 Description A brush barrier is a perimeter sediment control constructed with stacked shrubs, tree limbs, and bushy vegetation that has been cleared from a construction area. Brush barriers reduce sediment loads by intercepting and slowing sheet flow from disturbed areas. Appropriate Uses A brush barrier is an appropriate BMP at sites where there is adequate brush from .•'' the clearing and grubbing of the construction site to construct an effective brush barrier. Brush barriers are typically used at the toe of slopes and Photograph BB-1. Brush barrier constructed with chipped wood. should be implemented in combination Photo courtesy of EPA. with other BMPs such as surface roughening and reseeding. Brush barriers should be considered short-term, supplemental BMPs because they are constructed of materials that naturally decompose. Brush barriers are not acceptable as a sole means of perimeter control,but they may be used internally within a site to reduce slope length or at the site perimeter in combination with other perimeter control BMPs for multi-layered protection. Brush barriers are not appropriate for high-velocity flow areas. A large amount of material is needed to construct a useful brush barrier; therefore, alternative perimeter controls such as a fabric silt fence may be more appropriate for sites with little material from clearing. Design and Installation The drainage area for brush barriers should be no greater than 0.25 acre per 100 feet of barrier length. Additionally,the drainage slope leading down to a brush barrier must be no greater than 3:1 and no longer than 150 feet. To construct an effective brush barrier,use only small shrubs and limbs with diameters of 6 inches or less. Larger materials(such as a tree stump)can create void spaces in the barrier,making it ineffective. The brush barrier mound should be at least 3 feet high and 5 feet wide at its base. In order to avoid significant movement of the brush and improve effectiveness,a filter fabric can be placed over the top of the brush pile,keyed in on the upstream side,and anchored on the downstream side. On the upgradient side,the filter fabric cover should be buried in a trench 4 inches deep and 6 inches wide. Brush Barrier Functions Erosion Control Moderate Sediment Control Moderate Site/Material No November 2010 Urban Drainage and Flood Control District BB-1 Urban Storm Drainage Criteria Manual Volume 3 SC-4 Brush Barrier (BB) Maintenance and Removal Inspect the brush barrier for voids where concentrated flow or erosion is occurring. Voids in the brush barrier should be filled with additional brush. Accumulated sediment should be removed from the uphill side of the barrier when sediment height reaches one-third of the height of the barrier. If filter fabric is used,inspect the filter fabric for damage;replace and properly secure it, as needed. Once the upstream area has been vegetated or stabilized,the brush barrier should be removed and the underlying area revegetated. 1313-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Rock Sock (RS) SC-5 Description A rock sock is constructed of gravel 00 that has been wrapped by wire mesh or � a geotextile to form an elongated cylindrical filter. Rock socks are A typically used either as a perimeter - - control or as part of inlet protection. - _ When placed at angles in the curb line, rock socks are typically referred to as curb socks. Rock socks are intended to _ trap sediment from stormwater runoff that flows onto roadways as a result of construction activities. Appropriate Uses = Photograph RS-1. Rock socks placed at regular intervals in a curb Rock socks can be used at the perimeter line can help reduce sediment loading to storm sewer inlets. Rock of a disturbed area to control localized socks can also be used as perimeter controls. sediment loading. A benefit of rock socks as opposed to other perimeter controls is that they do not have to be trenched or staked into the ground; therefore,they are often used on roadway construction projects where paved surfaces are present. Use rock socks in inlet protection applications when the construction of a roadway is substantially complete and the roadway has been directly connected to a receiving storm system. Design and Installation When rock socks are used as perimeter controls,the maximum recommended tributary drainage area per 100 lineal feet of rock socks is approximately 0.25 acres with disturbed slope length of up to 150 feet and a tributary slope gradient no steeper than 3:1. A rock sock design detail and notes are provided in Detail RS-1. Also see the Inlet Protection Fact Sheet for design and installation guidance when rock socks are used for inlet protection and in the curb line. When placed in the gutter adjacent to a curb,rock socks should protrude no more than two feet from the curb in order for traffic to pass safely. If located in a high traffic area,place construction markers to alert drivers and street maintenance workers of their presence. Maintenance and Removal Rock socks are susceptible to displacement and breaking due to vehicle traffic. Inspect rock socks for damage and repair or replace as necessary. Remove sediment by sweeping or vacuuming as needed to maintain the functionality of the BMP,typically when sediment has accumulated behind the rock sock to one-half of the sock's Rock Sock height. Functions Once upstream stabilization is complete,rock socks and Erosion Control No accumulated sediment should be removed and properly disposed. Sediment Control Yes Site/Material Management No November 2010 Urban Drainage and Flood Control District RS-1 Urban Storm Drainage Criteria Manual Volume 3 SC-5 Rock Sock (RS) o RS IY2" (MINUS) CRUSHED ROCK ENCLOSED IN WIRE MESH 1Y2" (MINUS) CRUSHED ROCK ENCLOSED IN WIRE MESH WIRE TIE ENDS f 4" TO 6" MAX AT 10" ON BEDROCK OR GROUND SURFACE CURBS, OTHERWISE ll HARD SURFACE, 2" C-10" DEPENDING IN SOIL ON EXPECTED SEDIMENT LOADS ROCK SOCK SECTION ROCK SOCK PLAN ANY GAP AT JOINT SHALL BE FILLED WITH AN ADEQUATE AMOUNT OF 0N" (MINUS) CRUSHED ROCK AND WRAPPED WITH ADDITIONAL WIRE MESH SECURED TO ENDS OF ROCK ROCK SOCK, REINFORCED SOCK. AS AN ALTERNATIVE TO FILLING JOINTS TYP BETWEEN ADJOINING ROCK SOCKS WITH CRUSHED ROCK AND 12" 12" ADDITIONAL WIRE WRAPPING, ROCK SOCKS CAN BE OVERLAPPED (TYPICALLY 12-INCH OVERLAP) TO AVOID GAPS. .Y GRADATION TABLE SIEVE SIZE MASS PERCENT PASSING SQUARE MESH SIEVES ROCK SOCK JOINTING NO. 4 2 100 1 90 - 100 j1' 20 - 55 -34" 0 - 15 3,j" 0 - 5 ROCK SOCK INSTALLATION NOTES MATCHES SPECIFICATIONS FOR NO. 4 COARSE AGGREGATE FOR CONCRETE 1. SEE PLAN VIEW FOR: PER AASHTO M43. ALL ROCK SHALL BE -LOCATION(S) OF ROCK SOCKS. FRACTURED FACE, ALL SIDES. 2. CRUSHED ROCK SHALL BE 1Y2" (MINUS) IN SIZE WITH A FRACTURED FACE (ALL SIDES) AND SHALL COMPLY WITH GRADATION SHOWN ON THIS SHEET (1,¢" MINUS). 3. WIRE MESH SHALL BE FABRICATED OF 10 GAGE POULTRY MESH, OR EQUIVALENT, WITH A MAXIMUM OPENING OF Y2", RECOMMENDED MINIMUM ROLL WIDTH OF 48" 4, WIRE MESH SHALL BE SECURED USING "HOG RINGS" OR WIRE TIES AT 6" CENTERS ALONG ALL JOINTS AND AT 2" CENTERS ON ENDS OF SOCKS. 5. SOME MUNICIPALITIES MAY ALLOW THE USE OF FILTER FABRIC AS AN ALTERNATIVE TO WIRE MESH FOR THE ROCK ENCLOSURE. RS- 1 . ROCK SOCK PERIMETER CONTROL RS-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Rock Sock (RS) SC-5 ROCK SOCK MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. ROCK SOCKS SHALL BE REPLACED IF THEY BECOME HEAVILY SOILED, OR DAMAGED BEYOND REPAIR. 5. SEDIMENT ACCUMULATED UPSTREAM OF ROCK SOCKS SHALL BE REMOVED AS NEEDED TO MAINTAIN FUNCTIONALITY OF THE BMP, TYPICALLY WHEN DEPTH OF ACCUMULATED SEDIMENTS IS APPROXIMATELY J� OF THE HEIGHT OF THE ROCK SOCK. 6. ROCK SOCKS ARE TO REMAIN IN PLACE UNTIL THE UPSTREAM DISTURBED AREA IS STABILIZED AND APPROVED BY THE LOCAL JURISDICTION. 7. WHEN ROCK SOCKS ARE REMOVED, ALL DISTURBED AREAS SHALL BE COVERED WITH TOPSOIL, SEEDED AND MULCHED OR OTHERWISE STABILIZED AS APPROVED BY LOCAL JURISDICTION. (DETAIL ADAPTED FROM TOWN OF PARKER, COLORADO AND CITY OF AURORA, COLORADO. NOT AVAILABLE IN AUTOCAD) NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. NOTE: THE DETAILS INCLUDED WITH THIS FACT SHEET SHOW COMMONLY USED, CONVENTIONAL METHODS OF ROCK SOCK INSTALLATION IN THE DENVER METROPOLITAN AREA THERE ARE MANY OTHER SIMILAR PROPRIETARY PRODUCTS ON THE MARKET. UDFCD NEITHER NDORSES NOR DISCOURAGES USE OF PROPRIETARY PROTECTION PRODUCTS; HOWEVER, IN THE EVENT PROPRIETARY METHODS ARE USED, THE APPROPRIATE DETAIL FROM THE MANUFACTURER MUST BE INCLUDED IN THE SWMP AND THE BMP MUST BE INSTALLED AND MAINTAINED AS SHOWN IN THE MANUFACTURER'S DETAILS. November 2010 Urban Drainage and Flood Control District RS-3 Urban Storm Drainage Criteria Manual Volume 3 Inlet Protection (IP) SC-6 Description Inlet protection consists of permeable barriers installed installed around an inlet to - - filter runoff and remove sediment prior to entering a storm drain inlet. Inlet protection can be constructed from rock -� socks,sediment control logs, silt fence, block and rock socks, or other materials approved by the local jurisdiction. Area inlets can also be protected by over-excavating around the inlet to form a sediment trap. Appropriate Uses Install protection at storm sewer inlets that are operable during construction. Photograph IP-1. Inlet protection for a curb opening inlet. Consider the potential for tracked-out sediment or temporary stockpile areas to contribute sediment to inlets when determining which inlets must be protected. This may include inlets in the general proximity of the construction area,not limited to downgradient inlets. Inlet protection is not a stand-alone BMP and should be used in conjunction with other upgradient BMPs. Design and Installation To function effectively,inlet protection measures must be installed to ensure that flows do not bypass the inlet protection and enter the storm drain without treatment. However, designs must also enable the inlet to function without completely blocking flows into the inlet in a manner that causes localized flooding. When selecting the type of inlet protection,consider factors such as type of inlet(e.g., curb or area, sump or on-grade conditions),traffic, anticipated flows,ability to secure the BMP properly, safety and other site-specific conditions. For example,block and rock socks will be better suited to a curb and gutter along a roadway, as opposed to silt fence or sediment control logs,which cannot be properly secured in a curb and gutter setting,but are effective area inlet protection measures. Several inlet protection designs are provided in the Design Details. Additionally, a variety of proprietary products are available for inlet protection that may be approved for use by local governments. If proprietary products are used, design details and installation procedures from the manufacturer must be followed. Regardless of the type of inlet protection selected,inlet protection is most effective when combined with other BMPs such as curb socks and check dams. Inlet protection is often the last barrier before runoff enters the storm sewer or receiving water. Design details with notes are provided for these forms of inlet Inlet Protection protection: (various forms) Functions IP-1. Block and Rock Sock Inlet Protection for Sump or On-grade Erosion Control No Inlets Sediment Control Yes IP-2. Curb(Rock) Socks Upstream of Inlet Protection, On-grade Site/Material Management No Inlets November 2010 Urban Drainage and Flood Control District IP-1 Urban Storm Drainage Criteria Manual Volume 3 SC-6 Inlet Protection (IP) IP-3. Rock Sock Inlet Protection for Sump/Area Inlet IP-4. Silt Fence Inlet Protection for Sump/Area Inlet IP-5. Over-excavation Inlet Protection IP-6. Straw Bale Inlet Protection for Sump/Area Inlet CIP-1. Culvert Inlet Protection Propriety inlet protection devices should be installed in accordance with manufacturer specifications. More information is provided below on selecting inlet protection for sump and on-grade locations. Inlets Located in a Sump When applying inlet protection in sump conditions, it is important that the inlet continue to function during larger runoff events. For curb inlets,the maximum height of the protective barrier should be lower than the top of the curb opening to allow overflow into the inlet during larger storms without excessive localized flooding. If the inlet protection height is greater than the curb elevation,particularly if the filter becomes clogged with sediment,runoff will not enter the inlet and may bypass it,possibly causing localized flooding,public safety issues, and downstream erosion and damage from bypassed flows. Area inlets located in a sump setting can be protected through the use of silt fence,concrete block and rock socks(on paved surfaces), sediment control logs/straw wattles embedded in the adjacent soil and stacked around the area inlet(on pervious surfaces), over-excavation around the inlet, and proprietary products providing equivalent functions. Inlets Located on a Slope For curb and gutter inlets on paved sloping streets,block and rock sock inlet protection is recommended in conjunction with curb socks in the gutter leading to the inlet. For inlets located along unpaved roads, also see the Check Dam Fact Sheet. Maintenance and Removal Inspect inlet protection frequently. Inspection and maintenance guidance includes: ■ Inspect for tears that can result in sediment directly entering the inlet, as well as result in the contents of the BMP(e.g.,gravel)washing into the inlet. ■ Check for improper installation resulting in untreated flows bypassing the BMP and directly entering the inlet or bypassing to an unprotected downstream inlet. For example, silt fence that has not been properly trenched around the inlet can result in flows under the silt fence and directly into the inlet. ■ Look for displaced BMPs that are no longer protecting the inlet. Displacement may occur following larger storm events that wash away or reposition the inlet protection. Traffic or equipment may also crush or displace the BMP. ■ Monitor sediment accumulation upgradient of the inlet protection. IP-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Inlet Protection (IP) SC-6 ■ Remove sediment accumulation from the area upstream of the inlet protection,as needed to maintain BMP effectiveness,typically when it reaches no more than half the storage capacity of the inlet protection. For silt fence,remove sediment when it accumulates to a depth of no more than 6 inches. Remove sediment accumulation from the area upstream of the inlet protection as needed to maintain the functionality of the BMP. ■ Propriety inlet protection devices should be inspected and maintained in accordance with manufacturer specifications. If proprietary inlet insert devices are used, sediment should be removed in a timely manner to prevent devices from breaking and spilling sediment into the storm drain. Inlet protection must be removed and properly disposed of when the drainage area for the inlet has reached final stabilization. November 2010 Urban Drainage and Flood Control District IP-3 Urban Storm Drainage Criteria Manual Volume 3 SC-6 Inlet Protection (IP) I A SEE ROCK SOCK DESIGN ROCK DETAIL FOR JOINTING ROCK SOCKS ifi" CINDER SOCKS 16" CINDER _ BLOCKS BLOCKS FLOW Y U-1 2"x4" WOOD STUD MIN CURB INLET 2"x4" WOOD - SECTION A - STUD IP- 1 . BLOCK AND ROCK SOCK SUMP OR ON GRADE INLET PROTECTION BLOCK AND CURB SOCK INLET PROTECTION INSTALLATION NOTES 1. SEE ROCK SOCK DESIGN DETAIL FOR INSTALLATION REQUIREMENTS. 2. CONCRETE "CINDER" BLOCKS SHALL BE LAID ON THEIR SIDES AROUND THE INLET IN A SINGLE ROW, ABUTTING ONE ANOTHER WITH THE OPEN END FACING AWAY FROM THE CURB. 3. GRAVEL BAGS SHALL BE PLACED AROUND CONCRETE BLOCKS, CLOSELY ABUTTING ONE ANOTHER AND JOINTED TOGETHER IN ACCORDANCE WITH ROCK SOCK DESIGN DETAIL. MINIMUM OF TWO CURB SOCKS APPROX 30 DEG, BLOCK AND ROCK SOCK INLET PROTECTION(SEE DETAIL IP-1) CURB SOCK FLOW 5' MIN 3'-5' TYP. IP-2. CURB ROCK SOCKS UPSTREAM OF INLET PROTECTION CURB ROCK SOCK INLET PROTECTION INSTALLATION NOTES 1. SEE ROCK SOCK DESIGN DETAIL INSTALLATION REQUIREMENTS. 2. PLACEMENT OF THE SOCK SHALL BE APPROXIMATELY 30 DEGREES FROM PERPENDICULAR IN THE OPPOSITE DIRECTION OF FLOW. 3. SOCKS ARE TO BE FLUSH WITH THE CURB AND SPACED A MINIMUM OF 5 FEET APART. 4. AT LEAST TWO CURB SOCKS IN SERIES ARE REQUIRED UPSTREAM OF ON-GRADE INLETS. IP-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Inlet Protection (IP) SC-6 INLET GRATE I P SEE ROCK SOCK DETAIL FOR JOINTING ROCK SOCK IP-3. ROCK SOCK SUMPZAREA INLET PROTECTION ROCK SOCK SUMP/AREA INLET PROTECTION INSTALLATION NOTES 1. SEE ROCK SOCK DESIGN DETAIL FOR INSTALLATION REQUIREMENTS. 2. STRAW WATTLES/SEDIMENT CONTROL LOGS MAY BE USED IN PLACE OF ROCK SOCKS FOR INLETS IN PERVIOUS AREAS. INSTALL PER SEDIMENT CONTROL LOG DETAIL. INLET GRATE SF N � SILT FENCE (SEE SILT --SF� FENCE DESIGN DETAIL ) IP-4. SILT FENCE FOR SUMP INLET PROTECTION SILT FENCE INLET PROTECTION INSTALLATION NOTES 1. SEE SILT FENCE DESIGN DETAIL FOR INSTALLATION REQUIREMENTS. 2. POSTS SHALL BE PLACED AT EACH CORNER OF THE INLET AND AROUND THE EDGES AT A MAXIMUM SPACING OF 3 FEET. 3. STRAW WATTLES/SEDIMENT CONTROL LOGS MAY BE USED IN PLACE OF SILT FENCE FOR INLETS IN PERVIOUS AREAS. INSTALL PER SEDIMENT CONTROL LOG DETAIL. November 2010 Urban Drainage and Flood Control District IP-5 Urban Storm Drainage Criteria Manual Volume 3 SC-6 Inlet Protection (IP) SILT FENCE (LF AREA INLET SILT FENCE ECB 2:1 MAX 1 1� 1' MIN >3 AREA 2' MAX INLET } ECB 4' ROCK FILTER L CONCENTRATED FLOW OR ROCK SOCK (USE IF FLOW IS CONCENTRATED) IP-5. OVEREXCAVATION INLET PROTECTION OVEREXCAVATION INLET PROTECTION INSTALLATION NOTES 1. THIS FORM OF INLET PROTECTION IS PRIMARILY APPLICABLE FOR SITES THAT HAVE NOT YET REACHED FINAL GRADE AND SHOULD BE USED ONLY FOR INLETS WITH A RELATIVELY SMALL CONTRIBUTING DRAINAGE AREA 2. WHEN USING FOR CONCENTRATED FLOWS, SHAPE BASIN IN 2:1 RATIO WITH LENGTH ORIENTED TOWARDS DIRECTION OF FLOW. 3. SEDIMENT MUST BE PERIODICALLY REMOVED FROM THE OVEREXCAVATED AREA. 0 o a INLET GRATE 0 0 0 0 STRAW BALE (SEE STRAW o a BALE DESIGN DETAIL) e e e o 0 IP-6. STRAW BALE FOR SUMP INLET PROTECTION STRAW BALE BARRIER INLET PROTECTION INSTALLATION NOTES 1. SEE STRAW BALE DESIGN DETAIL FOR INSTALLATION REQUIREMENTS. 2. BALES SHALL BE PLACED IN A SINGLE ROW AROUND THE INLET WITH ENDS OF BALES TIGHTLY ABUTTING ONE ANOTHER. IP-6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Inlet Protection (IP) SC-6 GENERAL INLET PROTECTION INSTALLATION NOTES 1. SEE PLAN VIEW FOR: —LOCATION OF INLET PROTECTION. —TYPE OF INLET PROTECTION (IP.1, IP.2, IP.3, IP.4, IP.5, IP.6) 2. INLET PROTECTION SHALL BE INSTALLED PROMPTLY AFTER INLET CONSTRUCTION OR PAVING IS COMPLETE (TYPICALLY WITHIN 48 HOURS). IF A RAINFALL/RUNOFF EVENT IS FORECAST, INSTALL INLET PROTECTION PRIOR TO ONSET OF EVENT. 3. MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED INLET PROTECTION MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. SEDIMENT ACCUMULATED UPSTREAM OF INLET PROTECTION SHALL BE REMOVED AS NECESSARY TO MAINTAIN BMP EFFECTIVENESS, TYPICALLY WHEN STORAGE VOLUME REACHES 50% OF CAPACITY, A DEPTH OF 6" WHEN SILT FENCE IS USED, OR Y4 OF THE HEIGHT FOR STRAW BALES. 5. INLET PROTECTION IS TO REMAIN IN PLACE UNTIL THE UPSTREAM DISTURBED AREA IS PERMANENTLY STABILIZED, UNLESS THE LOCAL JURISDICTION APPROVES EARLIER REMOVAL OF INLET PROTECTION IN STREETS. 6. WHEN INLET PROTECTION AT AREA INLETS IS REMOVED, THE DISTURBED AREA SHALL BE COVERED WITH TOP SOIL, SEEDED AND MULCHED, OR OTHERWISE STABILIZED IN A MANNER APPROVED BY THE LOCAL JURISDICTION. (DETAIL ADAPTED FROM TOWN OF PARKER, COLORADO AND CITY OF AURORA, COLORADO, NOT AVAILABLE IN ALITOCAD) NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. NOTE- THE DETAILS INCLUDED WITH THIS FACT SHEET SHOW COMMONLY USED, CONVENTIONAL METHODS OF INLET PROTECTION IN THE DENVER METROPOLITAN AREA, THERE ARE MANY PROPRIETARY INLET PROTECTION METHODS ON THE MARKET. UDFCD NEITHER ENDORSES NOR DISCOURAGES USE OF PROPRIETARY INLET PROTECTION; HOWEVER, IN THE EVENT PROPRIETARY METHODS ARE USED, THE APPROPRIATE DETAIL FROM THE MANUFACTURER MUST BE INCLUDED IN THE SWMP AND THE BMP MUST BE INSTALLED AND MAINTAINED AS SHOWN IN THE MANUFACTURER'S DETAILS. NOTE: SOME MUNICIPALITIES DISCOURAGE OR PROHIBIT THE USE OF STRAW BALES FOR INLET PROTECTION. CHECK WITH LOCAL JURISDICTION TO DETERMINE IF STRAW BALE INLET PROTECTION IS ACCEPTABLE. November 2010 Urban Drainage and Flood Control District IP-7 Urban Storm Drainage Criteria Manual Volume 3 Sediment Basin (SB) SC-7 Description A sediment basin is a temporary pond built on a construction site to capture eroded or disturbed soil transported in storm runoff prior to discharge from the site. Sediment basins are designed to capture site runoff and slowly release it to allow time for settling of sediment prior to discharge. Sediment basins are often constructed in locations that will later be + modified to serve as post-construction stormwater basins. Appropriate Uses Most large construction sites(typically Photograph S13-1. Sediment basin at the toe of a slope. Photo greater than 2 acres)will require one or courtesy of WWE. more sediment basins for effective management of construction site runoff. On linear construction projects, sediment basins may be impractical; instead, sediment traps or other combinations of BMPs may be more appropriate. Sediment basins should not be used as stand-alone sediment controls. Erosion and other sediment controls should also be implemented upstream. When feasible,the sediment basin should be installed in the same location where a permanent post- construction detention pond will be located. Design and Installation The design procedure for a sediment basin includes these steps: ■ Basin Storage Volume: Provide a storage volume of at least 3,600 cubic feet per acre of drainage area. To the extent practical,undisturbed and/or off-site areas should be diverted around sediment basins to prevent"clean"runoff from mixing with runoff from disturbed areas. For undisturbed areas (both on-site and off-site)that cannot be diverted around the sediment basin,provide a minimum of 500 ft3/acre of storage for undeveloped(but stable) off-site areas in addition to the 3,600 ft3/acre for disturbed areas. For stable,developed areas that cannot be diverted around the sediment basin, storage volume requirements are summarized in Table S13-1. ■ Basin Geometry: Design basin with a minimum length-to-width ratio of 2:1 (L:W). If this cannot be achieved because of site space constraints,baffling may be required to extend the effective distance between the inflow point(s) and the outlet to minimize short-circuiting. Sediment Basins ■ Dam Embankment: It is recommended that Functions embankment slopes be 4:1 (H:V) or flatter and no steeper Erosion Control No than 3:1 (H:V)in any location. Sediment Control Yes Site/Material Management No November 2010 Urban Drainage and Flood Control District S13-1 Urban Storm Drainage Criteria Manual Volume 3 SC-7 Sediment Basin (SB) ■ Inflow Structure: For concentrated flow entering the basin,provide energy dissipation at the point of inflow. Table SB-1. Additional Volume Requirements for Undisturbed and Developed TributaryAreas Draining through Sediment Basins Additional Storage Volume(ft) Imperviousness % Per Acre of Tributary Area Undeveloped 500 10 800 20 1230 30 1600 40 2030 50 2470 60 2980 70 3560 80 4360 90 5300 100 6460 ■ Outlet Works: The outlet pipe shall extend through the embankment at a minimum slope of 0.5 percent. Outlet works can be designed using one of the following approaches: o Perforated Riser/Plate: Follow the design criteria for Full Spectrum Detention outlets in the EDB BMP Fact Sheet provided in Chapter 4 of this manual for sizing of outlet perforations with an emptying time of approximately 72 hours. In lieu of the well-screen trash rack,pack uniformly sized 1'/2-to 2-inch gravel in front of the plate. This gravel will need to be cleaned out frequently during the construction period as sediment accumulates within it. The gravel pack will need to be removed and disposed of following construction to reclaim the basin for use as a permanent detention facility. If the basin will be used as a permanent extended detention basin for the site, a well-screen trash rack will need to be installed once contributing drainage areas have been stabilized and the gravel pack and accumulated sediment have been removed. o Floating Skimmer: If a floating skimmer is used,install it using manufacturer's recommendations. Illustration S13-1 provides an illustration of a Faircloth Skimmer Floating OutletTM, one of the more commonly used floating skimmer outlets. A skimmer should be designed to release the design volume in no less than 48 hours. The use of a floating skimmer outlet can increase the sediment capture efficiency of a basin significantly. A floating outlet continually decants cleanest water off the surface of the pond and releases cleaner water than would discharge from a perforated riser pipe or plate. S13-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Sediment Basin (SB) SC-7 Illustration S13-1. Outlet structure for a temporary sediment basin-Faircloth Skimmer Floating Outlet. Illustration courtesy of J.W.Faircloth&Sons,Inc.,FairclothSkimmer.com. o Outlet Protection: Outlet protection should be provided where the velocity of now will exceed the maximum permissible velocity of the material of the waterway into which discharge occurs. This may require the use of a riprap apron at the outlet location and/or other measures to keep the waterway from eroding. o Emergency Spillway: Provide a stabilized emergency overflow spillway for rainstorms that exceed the capacity of the sediment basin volume and its outlet. Protect basin embankments from erosion and overtopping. If the sediment basin will be converted to a permanent detention basin, design and construct the emergency spillway(s) as required for the permanent facility. If the sediment basin will not become a permanent detention basin, it may be possible to substitute a heavy polyvinyl membrane or properly bedded rock cover to line the spillway and downstream embankment, depending on the height, slope, and width of the embankments. Maintenance and Removal Maintenance activities include the following: • Dredge sediment from the basin, as needed to maintain BMP effectiveness,typically when the design storage volume is no more than one-third filled with sediment. • Inspect the sediment basin embankments for stability and seepage. • Inspect the inlet and outlet of the basin,repair damage,and remove debris. Remove, clean and replace the gravel around the outlet on a regular basis to remove the accumulated sediment within it and keep the outlet functioning. • Be aware that removal of a sediment basin may require dewatering and associated permit requirements. • Do not remove a sediment basin until the upstream area has been stabilized with vegetation. November 2010 Urban Drainage and Flood Control District SB-3 Urban Storm Drainage Criteria Manual Volume 3 SC-7 Sediment Basin (SB) Final disposition of the sediment basin depends on whether the basin will be converted to a permanent post-construction stormwater basin or whether the basin area will be returned to grade. For basins being converted to permanent detention basins,remove accumulated sediment and reconfigure the basin and outlet to meet the requirements of the final design for the detention facility. If the sediment basin is not to be used as a permanent detention facility, fill the excavated area with soil and stabilize with vegetation. SB-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Sediment Basin (SB) SC-7 INLETS TO SEDIMENT BASIN SHALL ENTER AT FURTHEST DISTANCE TO OUTLET AND SHALL 1 TO 2 S B CONSIST OF A TEMPORARY SLOPE CRUSHED ROCK DRAIN RISER PIPE 6" PVC RIPRAP PAD = - o 3 g " L=2 x W MIN. HOLE BOTTOM LENGTH o `+ DIAMETER, 00 m HD 01 1 02 EL. 03.00 03 SPILLWAY 04 f SINGLE B 4" COLUMN TYp —1 OF FIVE 1 HOLES' SEDIMENT BASIN PLAN "EXCEPT WHERE THE HOLES EXCEED 1" EL. 01. DIAMETER, THEN UP TO TWO COLUMNS OF SAME SIZED HOLES MAY BE USED SCHEDULE 40 2' 4' PVC OR GREATER 4i � t2„ EL. 00.00 r v r ry r w 'ry 1 6" EXCAVATION 050=9" RIPRAP TYPE L. (SEE TABLE RIPRAP BEDDING MD-7, MAJOR } DRAINAGE, VOL. 1) 1 2" SECTION A CL 3. CREST LENGTH 3, EMBANKMENT MATERIAL II EL. 03.00 EL. 04.00 i AT CREST 3 D50=9" RIPRAP TYPE L (SEE TABLE MD-7, MAJOR DRAINAGE, VOLA) SECTION B SB- 1 . SEDIMENT BASIN November 2010 Urban Drainage and Flood Control District SB-5 Urban Storm Drainage Criteria Manual Volume 3 SC-7 Sediment Basin (SB) TABLE SB—1. SIZING INFORMATION FOR STANDARD SEDIMENT BASIN Upstream Drainage Basin Bottom Width Spillway Crest Hole Area (rounded to (yy) (ft) Length (CL), (ft) Diameter nearest acre), (ac) (HD), (in) 1 12 Y2 2 b2 2 21 3 '-i6 3 28 5 Y2 4 33 Y2 6 5 38 )/2 8 2Y32 6 43 9 2,32 " 7 47 Y4 1 1 2%2 8 51 12 23�2 9 55 13 % 10 58 Y4 15 17y16 11 61 16 3Yj2 12 64 18 1 13 67 Y2 19 1 K6 14 70 Yz 21 1 )6 15 73 Y4 22 1 '/16 SEDIMENT BASIN INSTALLATION NOTES 1. SEE PLAN VIEW FOR: —LOCATION OF SEDIMENT BASIN. —TYPE OF BASIN (STANDARD BASIN OR NONSTANDARD BASIN). —FOR STANDARD BASIN, BOTTOM WIDTH W, CREST LENGTH CL, AND HOLE DIAMETER, HD. —FOR NONSTANDARD BASIN, SEE CONSTRUCTION DRAWINGS FOR DESIGN OF BASIN INCLUDING RISER HEIGHT H, NUMBER OF COLUMNS N, HOLE DIAMETER HD AND PIPE DIAMETER D. 2. FOR STANDARD BASIN, BOTTOM DIMENSION MAY BE MODIFIED AS LONG AS BOTTOM AREA IS NOT REDUCED. 3. SEDIMENT BASINS SHALL BE INSTALLED PRIOR TO ANY OTHER LAND—DISTURBING ACTIVITY THAT RELIES ON ON BASINS AS AS A STORMWATER CONTROL, 4. EMBANKMENT MATERIAL SHALL CONSIST OF SOIL FREE OF DEBRIS, ORGANIC MATERIAL, AND ROCKS OR CONCRETE GREATER THAN 3 INCHES AND SHALL HAVE A MINIMUM OF 15 PERCENT BY WEIGHT PASSING THE NO. 200 SIEVE. 5. EMBANKMENT MATERIAL SHALL BE COMPACTED TO AT LEAST 95 PERCENT OF MAXIMUM DENSITY IN ACCORDANCE WITH ASTM D698. 6. PIPE SCH 40 OR GREATER SHALL BE USED. 7. THE DETAILS SHOWN ON THESE SHEETS PERTAIN TO STANDARD SEDIMENT BASIN(S) FOR DRAINAGE AREAS LESS THAN 15 ACRES. SEE CONSTRUCTION DRAWINGS FOR EMBANKMENT, STORAGE VOLUME, SPILLWAY, OUTLET, AND OUTLET PROTECTION DETAILS FOR ANY SEDIMENT BASIN(S) THAT HAVE BEEN INDIVIDUALLY DESIGNED FOR DRAINAGE AREAS LARGER THAN 15 ACRES. SB-6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Sediment Basin (SB) SC-7 SEDIMENT BASIN MAINTENANCE NOTES t. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. SEDIMENT ACCUMULATED IN BASIN SHALL BE REMOVED AS NEEDED TO MAINTAIN BMP EFFECTIVENESS, TYPICALLY WHEN SEDIMENT DEPTH REACHES ONE FOOT (I.E., TWO FEET BELOW THE SPILLWAY CREST). 5. SEDIMENT BASINS ARE TO REMAIN IN PLACE UNTIL THE UPSTREAM DISTURBED AREA IS STABILIZED AND GRASS COVER IS ACCEPTED BY THE LOCAL JURISDICTION. 6. WHEN SEDIMENT BASINS ARE REMOVED, ALL DISTURBED AREAS SHALL BE COVERED WITH TOPSOIL, SEEDED AND MULCHED OR OTHERWISE STABILIZED AS APPROVED BY LOCAL JURISDICTION. (DETAILS ADAPTED FROM DOUGLAS COUNTY, COLORADO) NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. November 2010 Urban Drainage and Flood Control District S13-7 Urban Storm Drainage Criteria Manual Volume 3 Sediment Trap (ST) SC-8 Description - Y Sediment traps are formed by excavating " r - an area or by placing an earthen embankment across a low area or drainage swale. Sediment traps are designed to capture drainage from disturbed areas less than one acre and allow settling of sediment. Appropriate Uses Sediment traps can be used in combination with other layers of erosion Photograph ST-l. Sediment traps are used to collect sediment-laden and sediment controls to trap sediment runoff from disturbed area.Photo courtesy of EPA Menu of BMPs. from small drainage areas(less than one acre) or areas with localized high sediment loading. For example, sediment traps are often provided in conjunction with vehicle tracking controls and wheel wash facilities. Design and Installation A sediment trap consists of a small excavated basin with an earthen berm and a riprap outlet. The berm of the sediment trap may be constructed from the excavated material and must be compacted to 95 percent of the maximum density in accordance with ASTM D698. An overflow outlet must be provided at an elevation at least 6 inches below the top of the berm. See Detail ST-1 for additional design and installation information. Maintenance and Removal Inspect the sediment trap embankments for stability and seepage. Remove accumulated sediment as needed to maintain the effectiveness of the sediment trap,typically when the sediment depth is approximately one-half the height of the outflow embankment. Inspect the outlet for debris and damage. Repair damage to the outlet, and remove all obstructions. A sediment trap should not be removed until the upstream area is sufficiently stabilized. Upon removal of the trap,the disturbed area should be covered with topsoil and stabilized. Sediment Trap Functions Erosion Control No Sediment Control Yes Site/Material Management No November 2010 Urban Drainage and Flood Control District ST-1 Urban Storm Drainage Criteria Manual Volume 3 SC-8 Sediment Trap (ST) ST RIPRAP, TYPE M (D50=12") TYP.SMALLER ROCK SIZE MAY BE ALLOWABLE FOR SMALLER TRAPS IF APPROVED BY LOCAL JURISDICTION TOP OF EARTHEN BERM 2 1 MAX. i 2 1 MAX FLOW - TRANSITION EXISTING B FLOW - CHANNEL INTO W SEDIMENT TRAP 2 1 MAX 2 1 MAX. L SEDIMENT TRAP PLAN 6" (CENTER OF RIPRAP 6" LOWER THAN ENDS 6" MINIMUM 12' MIN. 30" FREEBOARD SECTION A CHANNEL GRADE 1 6" 2' 6' MIN. FLOW - /RIPRAP, TYPE m (D50=12") TYP. MIN. SMALLER ROCK SIZE MAY BE ALLOWABLE FOR SMALLER TRAPS IF APPROVED BY LOCAL JURISDICTION SECTION Q ST- 1 . SEDIMENT TRAP ST-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Sediment Trap (ST) SC-8 SEDIMENT TRAP INSTALLATION NOTES 1. SEE PLAN VIEW FOR: —LOCATION, LENGTH AND WIDTH OF SEDIMENT TRAP. 2. ONLY USE FOR DRAINAGE AREAS LESS THAN 1 ACRE. 3 SEDIMENT TRAPS SHALL BE INSTALLED PRIOR TO ANY UPGRADIENT LAND—DISTURBING ACTIVITIES. 4. SEDIMENT TRAP BERM SHALL BE CONSTRUCTED FROM MATERIAL FROM EXCAVATION. THE BERM SHALL BE COMPACTED TO 95% OF THE MAXIMUM DENSITY IN ACCORDANCE WITH ASTM D698. 5. SEDIMENT TRAP OUTLET TO BE CONSTRUCTED OF RIPRAP, TYPE M (050=12") TYP.SMALLER ROCK SIZE MAY BE ALLOWABLE FOR SMALLER TRAPS IF APPROVED BY LOCAL JURISDICTION. 6 THE TOP OF THE EARTHEN BERM SHALL BE A MINIMUM OF 6" HIGHER THAN THE TOP OF THE RIPRAP OUTLET STRUCTURE. 7. THE ENDS OF THE RIPRAP OUTLET STRUCTURE SHALL BE A MINIMUM OF 6" HIGHER THAN THE CENTER OF THE OUTLET STRUCTURE. SEDIMENT TRAP MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. REMOVE SEDIMENT ACCUMULATED IN TRAP AS NEEDED TO MAINTAIN THE FUNCTIONALITY OF THE BMP, TYPICALLY WHEN THE SEDIMENT DEPTH REACHES Y2 THE HEIGHT OF THE RIPRAP OUTLET. 5. SEDIMENT TRAPS SHALL REMAIN IN PLACE UNTIL THE UPSTREAM DISTURBED AREA IS STABILIZED AND APPROVED BY THE LOCAL JURISDICTION. 6. WHEN SEDIMENT TRAPS ARE REMOVED, THE DISTURBED AREA SHALL BE COVERED WITH TOPSOIL, SEEDED AND MULCHED OR OTHERWISE STABILIZED IN A MANNER APPROVED BY THE LOCAL JURISDICTION. (DETAILS ADAPTED FROM DOUGL S COUNTY, COLORADO, NOT AVAILABLE IN AUTOCAO) NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. November 2010 Urban Drainage and Flood Control District ST-3 Urban Storm Drainage Criteria Manual Volume 3 Vegetated Buffers (VB) SC-9 Description = _ A. Buffer strips of preserved natural vegetation or grass help protect 49- waterways and wetlands from land disturbing activities. Vegetated buffers - improve stormwater runoff quality by - straining sediment,promoting infiltration, and slowing runoff velocities. Appropriate Uses Vegetated buffers can be used to Photograph VB-1. A vegetated buffer is maintained between the separate land disturbing activities and area of active construction and the drainage swale. Photo courtesy natural surface waters or conveyances. of wwE. In many jurisdictions, local governments require some type of setback from natural waterways. Concentrated flow should not be directed through a buffer; instead,runoff should be in the form of sheet flow. Vegetated buffers are typically used in combination with other perimeter control BMPs such as sediment control logs or silt fence for multi- layered protection. Design and Installation Minimum buffer widths may vary based on local regulations. Clearly delineate the boundary of the natural buffer area using construction fencing, silt fence,or a comparable technique. In areas that have been cleared and graded,vegetated buffers such as sod can also be installed to create or restore a vegetated buffer around the perimeter of the site. Maintenance and Removal Inspect buffer areas for signs of erosion such as gullies or rills. Stabilize eroding areas, as needed. If erosion is due to concentrated flow conditions, it may be necessary to install a level spreader or other technique to restore sheet flow conditions. Inspect perimeter controls delineating the vegetative buffer and repair or replace as needed. Vegetated Buffers Functions Erosion Control Moderate Sediment Control Yes Site/Material Management Yes November 2010 Urban Drainage and Flood Control District VB-1 Urban Storm Drainage Criteria Manual Volume 3 Chemical Treatment (CT) SC-10 Description Chemical treatment for erosion and ! sediment control can take several forms: °[,�� ="'='""=N- ms ��:eun: ,7teT [w..o •.�.. �lir 11 i 1. Applying chemicals to disturbed �, ��+• ����� �""��' U�I surfaces to reduce erosion(these uses , are discussed in the Soil Binders Fact Sheet). 2. Adding flocculants to sedimentation Y� ponds or tanks to enhance sediment removal prior. 3. Using proprietary barriers Or flow- Photograph CT-1. Proprietary chemical treatment system being through devices containing flocculants used on a construction site with sensitive receiving waters. Photo (e.g., "floc logs"). courtesy of WWE. The use of flocculants as described in No.2 and No.3 above will likely require special permitting. Check with the state permitting agency. See the Soil Binder BMP Fact Sheet for information on surface application of chemical treatments,as described in No. 1. Appropriate Uses At sites with fine-grained materials such as clays, chemical addition to sedimentation ponds or tanks can enhance settling of suspended materials through flocculation. Prior to selecting and using chemical treatments,it is important to check state and local permit requirements related to their use. Design and Installation Due to variations among proprietary chemical treatment methods, design details are not provided for this BMP. Chemical feed systems for sedimentation ponds, settling tanks and dewatering bags should be installed and operated in accordance with manufacturer's recommendations and applicable regulations. Alum and chitosan are two common chemicals used as flocculants. Because the potential long-term impact of these chemicals to natural drainageways is not yet fully understood,the state does not currently allow chemical addition under the CDPS General Stormwater Construction Discharge Permit. Additional permitting may be necessary,which may include sampling requirements and numeric discharge limits. Any devices or barriers containing chemicals should be installed following manufacturer's guidelines. Check for state and local jurisdiction usage restrictions and requirements before including these practices in the SWMP and implementing them onsite. Chemical Treatment Functions Erosion Control Moderate Sediment Control Yes Site/Material Management No November 2010 Urban Drainage and Flood Control District CT-1 Urban Storm Drainage Criteria Manual Volume 3 SC-10 Chemical Treatment (CT) Maintenance and Removal Chemical feed systems for sedimentation ponds or tanks should be maintained in accordance with manufacturer's recommendations and removed when the systems are no longer being used. Accumulated sediment should be dried and disposed of either at a landfill or in accordance with applicable regulations. Barriers and devices containing chemicals should be removed and replaced when tears or other damage to the devices are observed. These barriers should be removed and properly disposed of when the site has been stabilized. CT-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Construction Phasing/Sequencing (CP) SM-1 Description Effective construction site management to minimize erosion and sediment transport includes attention to construction phasing, scheduling, and sequencing of land disturbing activities. On most construction projects, erosion and sediment controls will need to be adjusted as the project progresses and should be documented in the SWMP. Construction phasing refers to disturbing only part of a site at a time to limit the potential for erosion from dormant parts of a site. Grading activities and construction are completed Photograph CP-1. Construction phasing to avoid disturbing the and soils are effectively stabilized on one entire area at one time. Photo courtesy of WWE. part of a site before grading and construction begins on another portion of the site. Construction sequencing or scheduling refers to a specified work schedule that coordinates the timing of land disturbing activities and the installation of erosion and sediment control practices. Appropriate Uses All construction projects can benefit from upfront planning to phase and sequence construction activities to minimize the extent and duration of disturbance. Larger projects and linear construction projects may benefit most from construction sequencing or phasing,but even small projects can benefit from construction sequencing that minimizes the duration of disturbance. Typically, erosion and sediment controls needed at a site will change as a site progresses through the major phases of construction. Erosion and sediment control practices corresponding to each phase of construction must be documented in the SWMP. Design and Installation BMPs appropriate to the major phases of development should be identified on construction drawings. In some cases,it will be necessary to provide several drawings showing construction-phase BMPs placed according to stages of development(e.g., clearing and grading,utility installation, active construction, final stabilization). Some municipalities in the Denver area set maximum sizes for disturbed area associated with phases of a construction project. Additionally,requirements for phased construction drawings vary among local governments within the UDFCD boundary. Some local governments require separate erosion and sediment control drawings for initial Construction Scheduling BMPs, interim conditions(in active construction), and final stabilization. Functions Erosion Control Moderate Sediment Control Moderate Site/Material Management Yes November 2010 Urban Drainage and Flood Control District CP-1 Urban Storm Drainage Criteria Manual Volume 3 SM-1 Construction Phasing/Sequencing (CP) Typical construction phasing BMPs include: ■ Limit the amount of disturbed area at any given time on a site to the extent practical. For example,a 100-acre subdivision might be constructed in five phases of 20 acres each. ■ If there is carryover of stockpiled material from one phase to the next,position carryover material in a location easily accessible for the pending phase that will not require disturbance of stabilized areas to access the stockpile. Particularly with regard to efforts to balance cut and fill at a site, careful planning for location of stockpiles is important. Typical construction sequencing BMPs include: ■ Sequence construction activities to minimize duration of soil disturbance and exposure. For example, when multiple utilities will occupy the same trench, schedule installation so that the trench does not have to be closed and opened multiple times. ■ Schedule site stabilization activities (e.g., landscaping, seeding and mulching, installation of erosion control blankets) as soon as feasible following grading. ■ Install initial erosion and sediment control practices before construction begins. Promptly install additional BMPs for inlet protection,stabilization,etc., as construction activities are completed. Table CP-I provides typical sequencing of construction activities and associated BMPs. Maintenance and Removal When the construction schedule is altered, erosion and sediment control measures in the SWMP and construction drawings should be appropriately adjusted to reflect actual"on the ground" conditions at the construction site. Be aware that changes in construction schedules can have significant implications for site stabilization,particularly with regard to establishment of vegetative cover. CP-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Construction Phasing/Sequencing (CP) SM-1 Table CP-1. Typical Phased BMP Installation for Construction Projects Project BMPs Phase ■ Install sediment controls downgradient of access point(on paved streets this may consist of inlet protection). ■ Establish vehicle tracking control at entrances to paved streets. Fence as needed. Pre- disturbance, 0 Use construction fencing to define the boundaries of the project and limit access to areas of Site Access the site that are not to be disturbed. Note: it may be necessary to protect inlets in the general vicinity of the site,even if not downgradient,if there is a possibility that sediment tracked from the site could contribute to the inlets. ■ Install perimeter controls as needed on downgradient perimeter of site(silt fence,wattles, etc). ■ Limit disturbance to those areas planned for disturbance and protect undisturbed areas within the site(construction fence,flagging,etc). ■ Preserve vegetative buffer at site perimeter. ■ Create stabilized staging area. ■ Locate portable toilets on flat surfaces away from drainage paths. Stake in areas susceptible to high winds. ■ Construct concrete washout area and provide signage. ■ Establish waste disposal areas. Site Clearing and Grubbing Install sediment basins. ■ Create dirt perimeter berms and/or brush barriers during grubbing and clearing. ■ Separate and stockpile topsoil,leave roughened and/or cover. ■ Protect stockpiles with perimeter control BMPs. Stockpiles should be located away from drainage paths and should be accessed from the upgradient side so that perimeter controls can remain in place on the downgradient side. Use erosion control blankets,temporary seeding,and/or mulch for stockpiles that will be inactive for an extended period. ■ Leave disturbed area of site in a roughened condition to limit erosion. Consider temporary revegetation for areas of the site that have been disturbed but that will be inactive for an extended period. ■ Water to minimize dust but not to the point that watering creates runoff. November 2010 Urban Drainage and Flood Control District CP-3 Urban Storm Drainage Criteria Manual Volume 3 SM-1 Construction Phasing/Sequencing (CP) Project BMPs Phase In Addition to the Above BMPs: • Close trench as soon as possible(generally at the end of the day). Utility And Use rough-cut street control or apply road base for streets that will not be promptly paved. Infrastructure Installation EProvide inlet protection as streets are paved and inlets are constructed. ■ Protect and repair BMPs,as necessary. • Perform street sweeping as needed. In Addition to the Above BMPs: ■ Implement materials management and good housekeeping practices for home building activities. Building Construction 0 Use perimeter controls for temporary stockpiles from foundation excavations. ■ For lots adjacent to streets, lot-line perimeter controls may be necessary at the back of curb. In Addition to the Above BMPs; Final Grading ' Remove excess or waste materials. ■ Remove stored materials. In Addition to the Above BMPs: Final ■ Seed and mulch/tackify. Stabilization Seed and install blankets on steep slopes. ■ Remove all temporary BMPs when site has reached final stabilization. CP-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Protection of Existing Vegetation (PV) SM-2 Description Protection of existing vegetation on a construction site can be accomplished - - through installation of a construction fence around the area requiring protection. In cases where upgradient areas are disturbed, it may also be necessary to • s install perimeter controls to minimize sediment loading to sensitive areas such as wetlands. Existing vegetation may be designated for protection to maintain a stable surface cover as part of construction phasing, or vegetation may be protected in areas designated to remain in natural condition under post-development conditions(e.g.,wetlands,mature trees, Photograph PV-1. Protection of existing vegetation and a sensitive riparian areas, open space). area. Photo courtesy of CDOT. Appropriate Uses Existing vegetation should be preserved for the maximum practical duration on a construction site through the use of effective construction phasing. Preserving vegetation helps to minimize erosion and can reduce revegetation costs following construction. Protection of wetland areas is required under the Clean Water Act,unless a permit has been obtained from the U.S. Army Corps of Engineers(USACE)allowing impacts in limited areas. If trees are to be protected as part of post-development landscaping, care must be taken to avoid several types of damage, some of which may not be apparent at the time of injury. Potential sources of injury include soil compaction during grading or due to construction traffic, direct equipment-related injury such as bark removal,branch breakage, surface grading and trenching, and soil cut and fill. In order to minimize injuries that may lead to immediate or later death of the tree,tree protection zones should be developed during site design, implemented at the beginning of a construction project, as well as continued during active construction. Design and Installation General Once an area has been designated as a preservation area,there should be no construction activity allowed within a set distance of the area. Clearly mark the area with construction fencing. Do not allow stockpiles,equipment,trailers or parking within the protected area. Guidelines to protect various types of Protection of Existing Vegetation existing vegetation follow. Functions Erosion Control Yes Sediment Control Moderate Site/Material Management Yes November 2010 Urban Drainage and Flood Control District PV-1 Urban Storm Drainage Criteria Manual Volume 3 SM-2 Protection of Existing Vegetation (PV) Surface Cover During Phased Construction Install construction fencing or other perimeter controls around areas to be protected from clearing and grading as part of construction phasing. Maintaining surface cover on steep slopes for the maximum practical duration during construction is recommended. Open Space Preservation Where natural open space areas will be preserved as part of a development, it is important to install construction fencing around these areas to protect them from compaction. This is particularly important when areas with soils with high infiltration rates are preserved as part of LID designs. Preserved open space areas should not be used for staging and equipment storage. Wetlands and Riparian Areas Install a construction fence around the perimeter of the wetland or riparian(streamside vegetation) area to prevent access by equipment. In areas downgradient of disturbed areas, install a perimeter control such as silt fence, sediment control logs, or similar measure to minimize sediment loading to the wetland. Tree Protection' ■ Before beginning construction operations, establish a tree protection zone around trees to be preserved by installing construction fences. Allow enough space from the trunk to protect the root zone from soil compaction and mechanical damage, and the branches from mechanical damage(see Table PV-1). If low branches will be kept,place the fence outside of the drip line. Where this is not possible,place fencing as far away from the trunk as possible. In order to maintain a healthy tree,be aware that about 60 percent of the tree's root zone extends beyond the drip line. Table PV-1 Guidelines for Determining the Tree Protection Zone (Source: Matheny and Clark, 1998; as cited in GreenCO and WWE 2008) Distance from Trunk(ft)per inch of DBH Species Tolerance to Damage Young Mature Over mature Good 0.5' 0.75' 1.0' Moderate 0.75' 1.0' 1.25' Poor 1.0' 1.25' 1.5' Notes: DBH= diameter at breast height(4.5 ft above grade); Young=<20% of life expectancy; Mature = 20%-80% of life expectancy; Over mature =>80% of life expectancy ■ Most tree roots grow within the top 12 to 18 inches of soil. Grade changes within the tree protection zone should be avoided where possible because seemingly minor grade changes can either smother 1 Tree Protection guidelines adapted from GreenCO and W WE(2008). Green Industry Best Management Practices(BMPs)for the Conservation and Protection of Water Resources in Colorado: Moving Toward Sustainability, Third Release. See www.greenco.org for more detailed guidance on tree preservation. PV-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Protection of Existing Vegetation (PV) SM-2 roots (in fill situations) or damage roots (in cut situations). Consider small walls where needed to avoid grade changes in the tree protection zone. ■ Place and maintain a layer of mulch 4 to 6-inch thick from the tree trunk to the fencing,keeping a 6-inch space between the mulch and the trunk. Mulch helps to preserve moisture and decrease soil compaction if construction traffic is unavoidable. When planting operations are completed,the mulch may be reused throughout planting areas. ■ Limit access,if needed at all, and appoint one route as the main entrance and exit to the tree protection zone. Within the tree protection zone, do not allow any equipment to be stored, chemicals to be dumped, or construction activities to take place except fine grading,irrigation system installation, and planting operations. These activities should be conducted in consultation with a landscaping professional, following Green Industry BMPs. ■ Be aware that soil compaction can cause extreme damage to tree health that may appear gradually over a period of years. Soil compaction is easier to prevent than repair. Maintenance and Removal Repair or replace damaged or displaced fencing or other protective barriers around the vegetated area. If damage occurs to a tree,consult an arborist for guidance on how to care for the tree. If a tree in a designated preservation area is damaged beyond repair,remove and replace with a 2-inch diameter tree of the same or similar species. Construction equipment must not enter a wetland area, except as permitted by the U.S.Army Corps of Engineers(USACE). Inadvertent placement of fill in a wetland is a 404 permit violation and will require notification of the USACE. If damage to vegetation occurs in a protected area,reseed the area with the same or similar species, following the recommendations in the USDCM Revegetation chapter. November 2010 Urban Drainage and Flood Control District PV-3 Urban Storm Drainage Criteria Manual Volume 3 Construction Fence (CF) SM-3 Description A construction fence restricts site access _ _ to designated entrances and exits, delineates construction site boundaries, ` and keeps construction out of sensitive areas such as natural areas to be a preserved as open space,wetlands and riparian areas. Appropriate Uses A construction fence can be used to delineate the site perimeter and locations within the site where access is restricted to protect natural resources such as Photograph CF-1. A construction fence helps delineate areas where existing vegetation is being protected. Photo courtesy of Douglas wetlands,waterbodies,trees, and other County. natural areas of the site that should not be disturbed. If natural resource protection is an objective,then the construction fencing should be used in combination with other perimeter control BMPs such as silt fence,sediment control logs or similar measures. Design and Installation Construction fencing may be chain link or plastic mesh and should be installed following manufacturer's recommendations. See Detail CF-I for typical installations. Do not place construction fencing in areas within work limits of machinery. Maintenance and Removal ■ Inspect fences for damage; repair or replace as necessary. ■ Fencing should be tight and any areas with slumping or fallen posts should be reinstalled. ■ Fencing should be removed once construction is complete. Construction Fence Functions Erosion Control No Sediment Control No Site/Material Management Yes November 2010 Urban Drainage and Flood Control District CF-I Urban Storm Drainage Criteria Manual Volume 3 SM-3 Construction Fence (CF) cF-cF cF PLASTIC CAP, TYP. OCF STUDDED STEEL TEE POST ORANGE RESINET 5' MIN CONSTRUCTION FENCE EXISTING OR APPROVED EQUAL F GRADE r 1' MIN. 10' MAX SPACING STUDDED STEEL TEE POST 4 MIN. CF- 1 . PLASTIC MESH CONSTRUCTION FENCE CONSTRUCTION FENCE INSTALLATION NOTES 1. SEE PLAN VIEW FOR: -LOCATION OF CONSTRUCTION FENCE. 2. CONSTRUCTION FENCE SHOWN SHALL BE INSTALLED PRIOR TO ANY LAND DISTURBING ACTIVITIES. 3. CONSTRUCTION FENCE SHALL BE COMPOSED OF ORANGE, CONTRACTOR-GRADE MATERIAL THAT IS AT LEAST 4' HIGH. METAL POSTS SHOULD HAVE A PLASTIC CAP FOR SAFETY. 4. STUDDED STEEL TEE POSTS SHALL BE UTILIZED TO SUPPORT THE CONSTRUCTION FENCE. MAXIMUM SPACING FOR STEEL TEE POSTS SHALL BE 10'. 5. CONSTRUCTION FENCE SHALL BE SECURELY FASTENED TO THE TOP, MIDDLE, AND BOTTOM OF EACH POST. CF-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Construction Fence (CF) SM-3 CONSTRUCTION FENCE MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. CONSTRUCTION FENCE SHALL BE REPAIRED OR REPLACED WHEN THERE ARE SIGNS OF DAMAGE SUCH AS RIPS OR SAGS. CONSTRUCTION FENCE IS TO REMAIN IN PLACE UNTIL THE UPSTREAM DISTURBED AREA IS STABILIZED AND APPROVED BY THE LOCAL JURISDICTION. 5. WHEN CONSTRUCTION FENCES ARE REMOVED, ALL DISTURBED AREAS ASSOCIATED WITH THE INSTALLATION, MAINTENANCE, AND/OR REMOVAL OF THE FENCE SHALL BE COVERED WITH TOPSOIL, SEEDED AND MULCHED, OR OTHERWISE STABILIZED AS APPROVED BY LOCAL JURISDICTION. NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. (DETAIL ADAPTED FROM TOWN OF PARKER, COLORADO. NOT AVAILABLE IN AUTOCAD) November 2010 Urban Drainage and Flood Control District CF-3 Urban Storm Drainage Criteria Manual Volume 3 Vehicle Tracking Control (VTC) SM-4 Description - _ - Vehicle tracking controls provide _ stabilized construction site access where �l _ vehicles exit the site onto paved public - - roads. An effective vehicle tracking control helps remove sediment(mud or dirt)from vehicles,reducing tracking onto _ - _ the paved surface. Appropriate Uses - Implement a stabilized construction entrance or vehicle tracking control where Photograph VTC-1. A vehicle tracking control pad constructed with frequent heavy vehicle traffic exits the properly sized rock reduces off-site sediment tracking. construction site onto a paved roadway. An effective vehicle tracking control is particularly important during the following conditions: ■ Wet weather periods when mud is easily tracked off site. ■ During dry weather periods where dust is a concern. ■ When poorly drained,clayey soils are present on site. Although wheel washes are not required in designs of vehicle tracking controls,they may be needed at particularly muddy sites. Design and Installation Construct the vehicle tracking control on a level surface. Where feasible, grade the tracking control towards the construction site to reduce off-site runoff. Place signage,as needed,to direct construction vehicles to the designated exit through the vehicle tracking control. There are several different types of stabilized construction entrances including: VTC-1. Aggregate Vehicle Tracking Control. This is a coarse-aggregate surfaced pad underlain by a geotextile. This is the most common vehicle tracking control, and when properly maintained can be effective at removing sediment from vehicle tires. VTC-2. Vehicle Tracking Control with Construction Mat or Turf Reinforcement Mat. This type of control may be appropriate for site access at very small construction sites with low traffic volume over vegetated areas. Although this application does not typically remove sediment from vehicles,it helps protect existing vegetation and provides a stabilized entrance. Vehicle Tracking Control Functions Erosion Control Moderate Sediment Control Yes Site/Material Management Yes November 2010 Urban Drainage and Flood Control District VTC-1 Urban Storm Drainage Criteria Manual Volume 3 SM-4 Vehicle Tracking Control (VTC) VTC-3. Stabilized Construction Entrance/Exit with Wheel Wash. This is an aggregate pad, similar to VTC-1,but includes equipment for tire washing. The wheel wash equipment may be as simple as hand-held power washing equipment to more advance proprietary systems. When a wheel wash is provided, it is important to direct wash water to a sediment trap prior to discharge from the site. Vehicle tracking controls are sometimes installed in combination with a sediment trap to treat runoff. Maintenance and Removal Inspect the area for degradation and replace aggregate or material used for a ` a ; stabilized entrance/exit as needed. If the - - area becomes clogged and ponds water, .� remove and dispose of excess sediment or replace material with a fresh layer of aggregate as necessary. With aggregate vehicle tracking controls, - ensure rock and debris from this area do not enter the public right-of-way. r Remove sediment that is tracked onto the i public right of way daily or more , = f +# frequently as needed. Excess sediment "fit in the roadway indicates that the stabilized construction entrance needs maintenance. Photograph VTC-2. A vehicle tracking control pad with wheel wash facility. Photo courtesy of Tom Gore. Ensure that drainage ditches at the entrance/exit area remain clear. A stabilized entrance should be removed only when there is no longer the potential for vehicle tracking to occur. This is typically after the site has been stabilized. When wheel wash equipment is used,be sure that the wash water is discharged to a sediment trap prior to discharge. Also inspect channels conveying the water from the wash area to the sediment trap and stabilize areas that may be eroding. When a construction entrance/exit is removed, excess sediment from the aggregate should be removed and disposed of appropriately. The entrance should be promptly stabilized with a permanent surface following removal,typically by paving. VTC-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Vehicle Tracking Control (VTC) SM-4 VTC 20 FOOT (WIDTH CAN BE LESS IF CONST. VEHICLES ARE PHYSICALLY CONFINED ON BOTH SIDES) SIDEWALK OR OTHER 50 FOOT (MIN.) PAVED SURFACE .46 - _ _ - _ .. -� 9" (MIN ) PUBLIC UNLESS OTHERWISE SPECIFIED ROADWAY BY LOCAL JURISDICTION, USE • CDOT SECT. #703. AASHTO #3 COARSE AGGREGATE OR 6" MINUS ROCK NON-WOVEN GEOTEXTILE FABRIC BETWEEN SOIL AND ROCK UNLESS OTHERWISE SPECIFIED BY LOCAL INSTALL ROCK FLUSH WITH JURISDICTION, USE CDOT SECT. #703, AASHTO OR BELOW TOP OF PAVEMENT #3 COARSE AGGREGATE OR 6" MINUS ROCK g„ (MIN.) -� 77 f NON-WOVEN GEOTEXTILE FABRIC COMPACTED SUBGRADE SECTION A VTC- 1 . AGGREGATE VEHICLE TRACKING CONTROL November 2010 Urban Drainage and Flood Control District VTC-3 Urban Storm Drainage Criteria Manual Volume 3 SM-4 Vehicle Tracking Control (VTC) TC WW DITCH TO CARRY WASH WATER TO SEDIMENT TRAP OR BASIN i PUBLIC ROADWAY / NOTE: WASH WATER MAY NOT CONTAIN CHEMICALS OR SOAPS WITHOUT OBTAINING A SEPARATE PERMIT WASH RACK 6'7" MIN. MA REINFORCED CONCRETE RACK j :v (MAY SUBSTITUTE STEEL CATTLE DRAIN SPACE GUARD FOR CONCRETE RACK) SECTION A VTC-2. AGGREGATE VEHICLE TRACKING CONTROL WITH WASH RACK VTC-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Vehicle Tracking Control (VTC) SM-4 VTC/ VTC/ CM TR DISTURBED AREA, CONSTRUCTION SITE, STABILIZED STORAGE AREA 107- MAX, OR STAGING AREA O O O EXISTING 12' MIN PAVED CONSTRUCTION MATS, WOVEN OR TRM ROADWAY 50' MIN 18" MIN pQ Q SPIKES OR STAKES TRM END OVERLAP WITH } �& SPIKES OR STAKES a CONSTRUCTION MATS, WOVEN o Q�p��Q �� OR TURF REINFORCEMENT STRAP oa G��o,�� MAT (TRM) CONNECTORS CONSTRUCTION MAT ENO d RESTRICT CONST. VEHICLE OVERLAP INTERLOCK WITH ACCESS TO SIDES OF MAT STRAP CONNECTORS z V 11 x T 20' OR AS REQUIRED TO ACCOMMODATE ANTICIPATED TRAFFIC (WIDTH CAN BE LESS IF CONST. VEHICLES ARE PHYSICALLY CONFINED ON BOTH SIDES) VTC-3. VEHICLE TRACKING CONTROL W/ CONSTRUCTION MAT OR TURF REINFORCEMENT MAT (TRM) November 2010 Urban Drainage and Flood Control District VTC-5 Urban Storm Drainage Criteria Manual Volume 3 SM-4 Vehicle Tracking Control (VTC) STABILIZED CONSTRUCTION ENTRANCE/EXIT INSTALLATION NOTES 1, SEE PLAN VIEW FOR —LOCATION OF CONSTRUCTION ENTRANCE(S)/EXIT(S). —TYPE OF CONSTRUCTION ENTRANCE(S)/EXITS(S) (WITH/WITHOUT WHEEL WASH, CONSTRUCTION MAT OR TRM). 2. CONSTRUCTION MAT OR TRM STABILIZED CONSTRUCTION ENTRANCES ARE ONLY TO BE USED ON SHORT DURATION PROJECTS (TYPICALLY RANGING FROM A WEEK TO A MONTH) WHERE THERE WILL BE LIMITED VEHICULAR ACCESS. 3. A STABILIZED CONSTRUCTION ENTRANCE/EXIT SHALL BE LOCATED AT ALL ACCESS POINTS WHERE VEHICLES ACCESS THE CONSTRUCTION SITE FROM PAVED RIGHT—OF—WAYS. 4. STABILIZED CONSTRUCTION ENTRANCE/EXIT SHALL BE INSTALLED PRIOR TO ANY LAND DISTUR8ING ACTIVITIES. 5 A NON—WOVEN GEOTEXTILE FABRIC SHALL BE PLACED UNDER THE STABILIZED CONSTRUCTION ENTRANCE/EXIT PRIOR TO THE PLACEMENT OF ROCK. 6. UNLESS OTHERWISE SPECIFIED BY LOCAL JURISDICTION, ROCK SHALL CONSIST OF DOT SECT. #703, AASHTO #3 COARSE AGGREGATE OR 6" (MINUS) ROCK. STABILIZED CONSTRUCTION ENTRANCE/EXIT MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE 4. ROCK SHALL BE REAPPLIED OR REGRADED AS NECESSARY TO THE STABILIZED ENTRANCE/EXIT TO MAINTAIN A CONSISTENT DEPTH. 5. SEDIMENT TRACKED ONTO PAVED ROADS IS TO BE REMOVED THROUGHOUT THE DAY AND AT THE END OF THE DAY BY SHOVELING OR SWEEPING. SEDIMENT MAY NOT BE WASHED DOWN STORM SEWER DRAINS. NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. (DETAILS ADAPTED FROM CITY OF BROOMFIELD. COLORADO. NOT AVAILABLE IN ALITOCAO) VTC-6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Stabilized Construction Roadway (SCR) SM-5 Description � A stabilized construction roadway is a temporary method to control sediment runoff,vehicle tracking, and dust from roads during construction activities. -'' Appropriate Uses Use on high traffic construction roads to minimize dust and erosion. Stabilized construction roadways are used instead of rough-cut street controls on roadways with frequent construction traffic. Photograph SCR-1. Stabilized construction roadway. Design and Installation Stabilized construction roadways typically involve two key components: 1) stabilizing the road surface with an aggregate base course of 3-inch-diameter granular material and 2) stabilizing roadside ditches, if applicable. Early application of road base is generally suitable where a layer of coarse aggregate is specified for final road construction. Maintenance and Removal Apply additional gravel as necessary to ensure roadway integrity. Inspect drainage ditches along the roadway for erosion and stabilize, as needed,through the use of check dams or rolled erosion control products. Gravel may be removed once the road is ready to be paved. Prior to paving,the road should be inspected for grade changes and damage. Regrade and repair as necessary. Stabilized Construction Roadway Functions Erosion Control Yes Sediment Control Moderate Site/Material Management Yes November 2010 Urban Drainage and Flood Control District SCR-1 Urban Storm Drainage Criteria Manual Volume 3 Stabilized Staging Area (SSA) SM-6 Description A stabilized staging area is a clearly designated area where construction equipment and vehicles, stockpiles,waste - bins, and other construction-related materials are stored. The contractor office trailer may also be located in this - - area. Depending on the size of the r construction site,more than one staging area may be necessary. Appropriate Uses Most construction sites will require a staging area,which should be clearly Photograph SSA-1. Example of a staging area with a gravel surface to designated in SWMP drawings. The layout Prevent mud tracking and reduce runoff. Photo courtesy of Douglas of the staging area may vary depending on County. the type of construction activity. Staging areas located in roadways due to space constraints require special measures to avoid materials being washed into storm inlets. Design and Installation Stabilized staging areas should be completed prior to other construction activities beginning on the site. Major components of a stabilized staging area include: ■ Appropriate space to contain storage and provide for loading/unloading operations, as well as parking if necessary. ■ A stabilized surface, either paved or covered,with 3-inch diameter aggregate or larger. ■ Perimeter controls such as silt fence, sediment control logs,or other measures. ■ Construction fencing to prevent unauthorized access to construction materials. ■ Provisions for Good Housekeeping practices related to materials storage and disposal,as described in the Good Housekeeping BMP Fact Sheet. ■ A stabilized construction entrance/exit,as described in the Vehicle Tracking Control BMP Fact Sheet, to accommodate traffic associated with material delivery and waste disposal vehicles. Over-sizing the stabilized staging area may result in disturbance of existing vegetation in excess of that required for the project. This increases costs, as well as requirements for long-term stabilization following the Stabilized Staging Area construction period. When designing the stabilized staging area, minimize the area of disturbance to the extent practical. Functions Erosion Control Yes Sediment Control Moderate Site/Material Yes November 2010 Urban Drainage and Flood Control District SSA-1 Urban Storm Drainage Criteria Manual Volume 3 SM-6 Stabilized Staging Area (SSA) Minimizing Long-Term Stabilization Requirements ■ Utilize off-site parking and restrict vehicle access to the site. ■ Use construction mats in lieu of rock when staging is provided in an area that will not be disturbed otherwise. ■ Consider use of a bermed contained area for materials and equipment that do not require a stabilized surface. ■ Consider phasing of staging areas to avoid disturbance in an area that will not be otherwise disturbed. See Detail SSA-1 for a typical stabilized staging area and SSA-2 for a stabilized staging area when materials staging in roadways is required. Maintenance and Removal Maintenance of stabilized staging areas includes maintaining a stable surface cover of gravel,repairing perimeter controls, and following good housekeeping practices. When construction is complete, debris,unused stockpiles and materials should be recycled or properly disposed. In some cases,this will require disposal of contaminated soil from equipment leaks in an appropriate landfill. Staging areas should then be permanently stabilized with vegetation or other surface cover planned for the development. SSA-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Stabilized Staging Area (SSA) SM-6 SF/CF SF/CF fl FF SSA � ONSITE U n CONSTRUCTION CONSTRUCTION VEHICLE TRAILERS PrARKING (IF NEEDED), CONSTRUCTION SITE ACCESS n N 1� 3° MIN. THICKNESS I I MATERIAL GRANULAR MATERIAL STABILIZED STORAGE CONSTRUCTION ' ENTRANCE (SEE cn DETAILS VTC-1 TO VTC-3) SF/CF SF/CF _--�__ SILT FENCE OR CONSTRUCTION FENCING AS NEEDED EXISTING ROADWAY SSA- 1 . STABILIZED STAGING AREA STABILIZED STAGING AREA INSTALLATION NOTES 1. SEE PLAN VIEW FOR —LOCATION OF STAGING AREA(S). —CONTRACTOR MAY ADJUST LOCATION AND SIZE OF STAGING AREA WITH APPROVAL FROM THE LOCAL JURISDICTION. 2. STABILIZED STAGING AREA SHOULD BE APPROPRIATE FOR THE NEEDS OF THE SITE. OVERSIZING RESULTS IN A LARGER AREA TO STABILIZE FOLLOWING CONSTRUCTION. 3. STAGING AREA SHALL BE STABILIZED PRIOR TO OTHER OPERATIONS ON THE SITE. 4, THE STABILIZED STAGING AREA SHALL CONSIST OF A MINIMUM 3" THICK GRANULAR MATERIAL. 5. UNLESS OTHERWISE SPECIFIED BY LOCAL JURISDICTION, ROCK SHALL CONSIST OF DOT SECT. #703, AASHTO #3 COARSE AGGREGATE OR 6" (MINUS) ROCK. 6. ADDITIONAL PERIMETER BMPs MAY BE REQUIRED INCLUDING BUT NOT LIMITED TO SILT FENCE AND CONSTRUCTION FENCING. STABILIZED STAGING AREA MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. ROCK SHALL BE REAPPLIED OR REGRADED AS NECESSARY IF RUTTING OCCURS OR UNDERLYING SUBGRADE BECOMES EXPOSED. November 2010 Urban Drainage and Flood Control District SSA-3 Urban Storm Drainage Criteria Manual Volume 3 SM-6 Stabilized Staging Area (SSA) STABILIZED STAGING AREA MAINTENANCE NOTES 5. STABILIZED STAGING AREA SHALL BE ENLARGED IF NECESSARY TO CONTAIN PARKING, STORAGE, AND UNLOADING/LOADING OPERATIONS. 6 THE STABILIZED STAGING AREA SHALL BE REMOVED AT THE END OF CONSTRUCTION THE GRANULAR MATERIAL SHALL BE REMOVED OR, IF APPROVED BY THE LOCAL JURISDICTION, USED ON SITE, AND THE AREA COVERED WITH TOPSOIL, SEEDED AND MULCHED OR OTHERWISE STABILIZED IN A MANNER APPROVED BY LOCAL JURISDICTION. NOTE: MANY MUNICIPALITIES PROHIBIT THE USE OF RECYCLED CONCRETE AS GRANULAR MATERIAL FOR STABILIZED STAGING AREAS DUE TO DIFFICULTIES WITH RE-ESTABLISHMENT OF VEGETATION IN AREAS WHERE RECYCLED CONCRETE WAS PLACED. NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. (DETAILS ADAPTED FROM DOUGLAS COUNTY, COLORADO. NOT AVAILABLE IN AUTOCAD) SSA-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Street Sweeping and Vacuuming (SS) SM-7 Description Street sweeping and vacuuming remove sediment that has been tracked onto - roadways to reduce sediment transport - into storm drain systems or a surface waterway. , Appropriate Uses s Use this practice at construction sites where vehicles may track sediment offsite onto paved roadways. Design and Installation Photograph SS-1. A street sweeper removes sediment and potential Street sweeping or vacuuming should be pollutants along the curb line at a construction site. Photo courtesy of conducted when there is noticeable Tom Gore. sediment accumulation on roadways adjacent to the construction site. Typically,this will be concentrated at the entrance/exit to the construction site. Well-maintained stabilized construction entrances,vehicle tracking controls and tire wash facilities can help reduce the necessary frequency of street sweeping and vacuuming. On smaller construction sites, street sweeping can be conducted manually using a shovel and broom. Never wash accumulated sediment on roadways into storm drains. Maintenance and Removal ■ Inspect paved roads around the perimeter of the construction site on a daily basis and more frequently, as needed. Remove accumulated sediment,as needed. ■ Following street sweeping,check inlet protection that may have been displaced during street sweeping. ■ Inspect area to be swept for materials that may be hazardous prior to beginning sweeping operations. Street Sweeping/Vacuuming Functions Erosion Control No Sediment Control Yes Site/Material Management Yes November 2010 Urban Drainage and Flood Control District SS-1 Urban Storm Drainage Criteria Manual Volume 3 Temporary Diversion Channel (TDC) SM-8 Description ` A temporary diversion channel divertsSv 1' water from a stream to allow for construction activities to take place k i underneath or in the stream. Diversion channels are often required during the +6 construction of detention ponds, dams, _ q in-stream grade control structures, 1 utility installation and other activities that require working in waterways. Appropriate Uses Temporary diversion channels vary with the size of the waterway that is Photograph TDC-1. Use of a temporary diversion channel(right side) being diverted. For large streams, a to enable installation of a grade control structure(left side). Photo temporary diversion may consist of courtesy of wwE. berms or coffer dams constructed in the stream to confine flow to one side of the stream while work progresses on the dry side of the berm. For smaller streams and often for construction of dams and detention basins, a temporary diversion channel may divert the entire waterway,as illustrated in Figure TDC-1. For very short duration projects(typically less than 4 weeks)during dry periods with low base flows, a pump and bypass pipe may serve as a temporary diversion. Whenever a temporary diversion is used,construction should be scheduled during drier times of the year if possible(October 1 through April 1),and construction in the waterway should progress as quickly as possible to reduce the risk of exceeding the temporary diversion channel capacity. Some construction activities within a waterway are very short lived,namely a few hours or days in duration,and are minor in nature. These are typically associated with maintenance of utilities and stream crossings and minor repairs to outfalls and eroded banks. In these cases, construction of temporary diversion channels can often cause more soil disturbance and sediment movement than the maintenance activity itself. If it can be reasonably determined based on area and duration of disturbance that channel work will result in less disturbance and movement of sediment than would be done through installation of a temporary diversion channel, it is reasonable to exempt these activities from the requirement to construct a temporary diversion. Design and Installation Temporary Diversion Channel sizing procedures typically include the following steps: ■ Using the tributary area,A(in acres), determine the design peak flow rate according to Figure TDC-2. Note: For long duration projects, or where the consequences of diversion failure warrant, a larger design flow may be necessary. Temporary Diversion Channel ■ Determine depth of flow, 1-foot maximum for flows Functions less than 20 cfs and 3 feet maximum for flows less Erosion Control Yes than 100 cfs. (Flows in excess of 100 cfs should be designed in accordance with the Major Drainage Sediment Control No chapter in Volume 1). 1 Site/Material Management No August 2011 Urban Drainage and Flood Control District TDC-1 Urban Storm Drainage Criteria Manual Volume 3 SM-8 Temporary Diversion Channel (TDC) ■ Determine channel slope based on existing and proposed site conditions. ■ Perform initial channel sizing calculations using Manning's Equation. Determine maximum permissible velocities based on lining material. ■ Determine the channel geometry and check the capacity using Manning's Equation and the"n"value given in Table TDC-1. The steepest side slope allowable for a temporary channel is two horizontal to one vertical (2:1),unless vertical walls are installed using sheet piling, concrete or stacked stone. Temporary diversion channels should have a minimum freeboard of 0.5 feet above the design water surface elevation. Figure TDC-2 may be used to estimate the design discharge for the sizing of temporary diversion channels and pipes. The curves in this figure were developed using annual peak flow data collected from 17 watersheds within the UDFCD boundary. These data were collected over extended periods of time (up to eleven years)and, as a result,provide a sound statistical basis for the figure. The data supporting Figure TDC-2 were taken during the high flood potential period of April through September. The values from Figure TDC-2 represent approximately the 95`h percentile event that can occur, on the average, any given year,which means that it is likely that about 95 percent of runoff peaks during an average year will be less than values from this chart. This may not be the case in wetter-than-average seasons. Figure TDC-2 provides estimated 2-year peak flow rates based on watershed imperviousness for small waterways (< 12 square miles). Because Figure TDC-2 was developed using data from small watersheds, it is not appropriate to extrapolate from this figure for larger,more complex watersheds.For larger waterways (e.g., South Platte River, Sand Creek,Bear Creek, etc.),including ones controlled by flood control reservoirs(e.g. Chatfield Dam, Cherry Creek Dam, etc.), site specific risk assessment may be necessary to evaluate the appropriate level of protection to be provided by the temporary diversion. It is also important to recognize that larger floods can and do occur. It is the responsibility of the designer and the contractor to assess their risk of having the temporary diversion being exceeded and to evaluate the damages such an event may cause to the project, adjacent properties and others. Consider larger capacity diversions to protect a project if it will require a temporary diversion for more than one year. Because temporary diversion channels typically are not in service long enough to establish adequate vegetative lining, they must be designed to be stable for the design flow with the channel shear stress less than the critical tractive shear stress for the channel lining material. This stability criterion applies not only to diversion channels,but also to the stream-side of berms when berms are used to isolate a work area within a stream. Unlined channels should not be used. Table TDC-1 gives Manning's "n" values for lining materials. Design procedures for temporary channels are described in detail in the Hydraulic Engineering Circular No. 15 published by the Federal Highway Administration. The methods presented in this Fact Sheet are greatly simplified and are based on information developed using the most commonly used erosion control materials. TDC-2 Urban Drainage and Flood Control District August 2011 Urban Storm Drainage Criteria Manual Volume 3 Temporary Diversion Channel (TDC) SM-8 Former Location of FLOW Stream Bank 1 1 VEHICULAR/EQUIPMENT STREAM CROSSING; ACCESS TO ORIGINAL STREAMBED ` l" PLACE FLOW RIPRAP AT TRANSITION _ / J •� FLOW BARRIER'DIVERSION (RIPRAP, SANDBAGS, JERSEY BARRIERS / J OR SHEET PILING) LOW ORIGINAL STREAM BED FLOW BARRIER FLOW `1 �� i IE1i`h _ Former Location of PLACE RIPRAP Al•� TRANSITION Stream Bank ��o Figure TDC-1. Typical Temporary Diversion Channel August 2011 Urban Drainage and Flood Control District TDC-3 Urban Storm Drainage Criteria Manual Volume 3 SM-8 Temporary Diversion Channel (TDC) 1000 - 900 Imp. = 60% 800 • 700 Imp. = 40% N 600 LL V 43.3% y 46.5%500 Imp. = 30% ... JJ L 400 ♦5 5.4/o �� 33.3% Imp. = 20% 300 200 o ' 10.1%� 15. 100 100 o � � +26.8% 0 4.3% 0 2 4 6 8 10 12 TRIBUTARY AREA (SQUARE MILES) Figure TDC-2. Temporary Diversion Facility Sizing Nomograph Based on 2-year Peak Flows- Denver Metropolitan and Adjacent Areas TDC-4 Urban Drainage and Flood Control District August 2011 Urban Storm Drainage Criteria Manual Volume 3 Temporary Diversion Channel (TDC) SM-8 Table TDC-1. Temporary Diversion Channel Design Criteria Manning's n for Manning's n for Manning's n for Lining Material Flow Depth Flow Depth Flow Depth 0ftto1.0ft 1.0ftto3.0ft 3.0ftto5.0ft Plastic Membrane 0.011 0.010 0.009 Straw or Curled Wood 0.035 0.025 0.020 Mats Riprap, Type VL 0.070 0.045 0.035 Riprap, Type L 0.100 0.070 0.040 Riprap, Type M 0.125 0.075 0.045 Notes: Use manufacturer's Manning's n when available. See the Major Drainage chapter of Volume 1 for riprap gradation. Erosion protection should extend a minimum of 0.5 feet above the design water depth. Maintenance and Removal Because temporary diversion channels are one of the most critical BMPs for work in waterways,they must be inspected and maintained frequently to remain in effective operating condition. Flow barriers should be inspected at the start and end of each workday and at any time that excess water is noted in dry work areas. The diversion channel itself should be inspected for signs of erosion,and the lining should be repaired or replaced if there are signs of failure. Check armoring at the diversion return point to the waterway,and add additional armoring if erosion is noted. Water should not be allowed to flow back through the natural stream until all construction is completed. After redirecting the flow through the natural channel,lining materials should be removed from the temporary diversion channel. The diversion channel should then be backfilled and stabilized. Points of tie-in to the natural channel should be protected with riprap sized in accordance with the Major Drainage chapter in Volume 1. August 2011 Urban Drainage and Flood Control District TDC-5 Urban Storm Drainage Criteria Manual Volume 3 SM-8 Temporary Diversion Channel (TDC) SILT FENCE, TYP (SEE SF DETAIL D FOR INSTALL4REREMENTS) ANCHOR TRENCH AT PERIMETER OF BLANKET 30 MIL MIN. W (VARIESAND AT OVERLAPPING PLASTIC OINTS WITH ADJACENT VD (VARIEROLLS OF BLANKET, BWSIMILAR TO ECB/TRM, BUT VARIES) NO STAKING INTERMEDIATE ANCHOR TRENCH AT / ONE-HALF ROLL-LENGTH SIMILAR TRANSVERSE ANCHOR TRENCHES ECB/TRM DETAIL, BUT NO AT PERIMETER OF BLANKET AND STAKING AT OVERLAPPING JOINTS WITH ADJACENT ROLLS OF BLANKET, SIMILAR TO ECB, BUT NO STAKING DC- 1 . PLASTIC LINED DIVERSION CHANNEL SILT FENCE, TYP (SEE SF DETAIL FOR STAKES (SEE DESIGN DETAIL EC-10) INSTALLATION REQUIREMENTS) EROSION CO4TRW (5'-0" MIN.) ANCHOR TRENCH AT BLANKET (ECB) OR PERIMETER OF BLANKET REINFORCED MAT AND AT OVERLAPPING (SEE EC (10" MIN.) JOINTS WITH ANY BW ADJACENT ROLLS OF (VARIES) BLANKET. (SEE DETAIL _ ECB/TRM) INTERMEDIATE ANCHOR TRENCH :AT �� TRANSVERSE ANCHOR TRENCHES AT ONE-HALF ROLL-LENGTH PERIMETER OF BLANKET AND AT (SEE ECB/TRM) OVERLAPPING JOINTS WITH ANY ADJACENT ROLLS OF BLANKET. (SEE ECB/TRM) DC-2. GEOTEXTILE OR MAT LINED DIVERSION CHANNEL SILT FENCE, TYP (SEE THICKNESS=2 x D50 W (5'-0" MIN.) SF FOR INSTALLATION REQUIREMENTS) D (10" MIN) 1j BW (VARIES) LINE WITH VL RIPRAP (D50 = 6") OR AS OTHERWISE CALLED FOR IN THE PLANS DC-3. RIPRAP LINED DIVERSION CHANNEL TDC-6 Urban Drainage and Flood Control District August 2011 Urban Storm Drainage Criteria Manual Volume 3 Temporary Diversion Channel (TDC) SM-8 CHANNEL DIVERSION INSTALLATION NOTES 1, SEE PLAN VIEW FOR: —LOCATION OF DIVERSION CHANNEL —TYPE OF CHANNEL (UNLINED. GEOTEXTILE OR MAT LINED, PLASTIC LINE, OR RIPRAP LINED). —LENGTH OF EACH TYPE OF CHANNEL. —DEPTH, D. WIDTH, W, AND BOTTOM WIDTH, BW —FOR RIPRAP LINED CHANNEL, SIZE OF RIPRAP, 050, SHALL BE SHOWN ON PLANS. 2. SEE DRAINAGE PLANS FOR DETAILS OF PERMANENT CONVEYANCE FACILITIES. 3. DIVERSION CHANNELS INDICATED ON THE SWMP PLAN SHALL BE INSTALLED PRIOR TO WORK IN DOWNGRADIENT AREAS OR NATURAL CHANNELS. 4. FOR GEOTEXTILE OR MAT LINED CHANNELS, INSTALLATION OF GEOTEXTILE OR MAT SHALL CONFORM TO THE REQUIREMENTS OF DETAIL EC8, FOR PLASTIC LINED CHANNELS, INSTALLATION OF ANCHOR TRENCHES SHALL CONFORM TO THE REQUIREMENTS OF DETAIL ECB. 5. WHERE CONSTRUCTION TRAFFIC MUST CROSS A DIVERSION CHANNEL, THE PERMITTEE SHALL INSTALL A TEMPORARY STREAM CROSSING CONFORMING TO THE REQUIREMENTS OF DETAIL TSC. DIVERSION CHANNEL MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION, MAINTENANCE OF BMPS SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. DIVERSION CHANNELS ARE TO REMAIN IN PLACE UNTIL WORK IN THE DOWNGRADIENT AREA OR NATURAL CHANNEL IS NO LONGER REQUIRED. IF APPROVED BY LOCAL JURISDICTION DIVERSION CHANNEL MAY BE LEFT IN PLACE. 5 IF DIVERSION CHANNELS ARE REMOVED, THE DISTURBED AREA SHALL BE COVERED WITH TOPSOIL, SEEDED AND MULCHED OR OTHERWISE STABILIZED IN A MANNER APPROVED BY LOCAL JURISDICTION. (DETAILS ADAPTED FROM DOUGLAS COUNTY, COLORADO) NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. August 2011 Urban Drainage and Flood Control District TDC-7 Urban Storm Drainage Criteria Manual Volume 3 Dewatering Operations (DW) SM-9 Description „ The BMPs selected for construction dewatering vary depending on site- _ u,. specific features such as soils, topography, anticipated discharge quantities, and discharge location. Dewatering typically involves pumping water from an inundated area to a BMP, = .+ and then downstream to a receiving waterway, sediment basin,or well- vegetated area. Dewatering typically involves use of several BMPs in - - +4 - sequence. Photograph DW-1. A relatively small dewatering operation using straw Appropriate Uses bales and a dewatering bag. Dewatering operations are used when an area of the construction site needs to be J dewatered as the result of a large storm event,groundwater,or existing ponding conditions. This can occur during deep excavation,utility trenching, and wetland or pond excavation. Design and Installation --- Dewatering techniques will vary , depending on site conditions. However, all dewatering discharges must be treated to remove sediment before discharging from the construction site. Discharging water into a sediment trap or basin is an acceptable treatment option. Water may Photograph DW-2. Dewatering bags used for a relatively large also be treated using a dewatering filter bag, dewatering operation. and a series of straw bales or sediment logs. If these previous options are not feasible due to space or the ability to passively treat the discharge to remove sediment,then a settling tank or an active treatment system may need to be utilized. Settling tanks are manufactured tanks with a series of baffles to promote settling. Flocculants can also be added to the tank to induce more rapid settling. This is an approach sometimes used on highly urbanized construction sites. Contact the state agency for special requirements prior to using flocculents and land application techniques. Some commonly used methods to handle the pumped water without surface discharge include land application Dewatering Operations to vegetated areas through a perforated discharge hose Functions (i.e.,the "sprinkler method")or dispersal from a water Erosion Control Moderate truck for dust control. Sediment Control Yes Site/Material Management Yes November 2010 Urban Drainage and Flood Control District DW-1 Urban Storm Drainage Criteria Manual Volume 3 SM-9 Dewatering Operations (DW) Dewatering discharges to non-paved areas must minimize the potential for scour at the discharge point either using a velocity dissipation device or dewatering filter bag. Design Details are provided for these types of dewatering situations: DW-1. Dewatering for Pond Already Filled with Water DW-2 Dewatering Sump for Submersed Pump DW-3 Sump Discharge Settling Basin DW-4 Dewatering Filter Bag Maintenance and Removal When a sediment basin or trap is used to enable settling of sediment from construction dewatering discharges, inspect the basin for sediment accumulation. Remove sediment prior to the basin or trap reaching half full. Inspect treatment facilities prior to any dewatering activity. If using a sediment control practice such as a sediment trap or basin, complete all maintenance requirements as described in the fact sheets prior to dewatering. Properly dispose of used dewatering bags, as well as sediment removed from the dewatering BMPs. Depending on the size of the dewatering operation, it may also be necessary to revegetate or otherwise stabilize the area where the dewatering operation was occurring. DW-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Dewatering Operations (DW) SM-9 LID WITH HOLE CUT DW FOR SUCTION LINE PUMP SUCTION LINE = PLASTIC 5—GALLON BUCKET WITH OR SUBMERSIBLE PUMP MANY 3/8" HOLES DRILLED CENTERED IN BUCKET IN SIDES BUCKET FILLED WITH AASHTO #3 GRAVEL (COOT SECT. 703, #3) DW- 1 . DEWATERING POND ALREADY FILLED WITH WATER LOWEST SUBGRADE ELEVATION TO BE DEWATERED PUMP SUCTION LINE OR LID WITH HOLE CUT 2 ' MIN. SUBMERSIBLE PUMP FOR SUCTION LINE - =- PLASTIC 5—GALLON BUCKET WITH 12" MIN, AROUND ON >" •; rs MANY 3/8" HOLES DRILLED IN SIDES ALL SIDES OF BUCKET AND BOTTOM 12" MIN. ' AASHTO #3 GRAVEL BELOW BUCKET (COOT SECT. 703, #3) DW-2. DEWATERING SUMP FOR SUBMERSED PUMP DEWATERING PUMP 4' MIN. DISCHARGE LINE SETTLING POND 12 SURFACE AREA, "A" MIN. 2' MIN. 1 SF PER 1 GPM A IN 12" STAKES TO Z RIPRAP 12,' MIN. SECURE END OF D50=6" DISCHARGE LINE L 12" MIN j 2' MIN. 2 X D50 a .� . ,� . 3 4' (MIN.) SQUARE MIN (12" MIN) - �.•, : f RIPRAP PAD TO STABILIZE FLOW PATH f Y RIPRAP DISSIPATE THE TO OUTFALL OR 050=6" ENERGY OF THE RECEIVING WATERS FLOW EXITING THE DISCHARGE LINE DW-3. SUMP DISCHARGE SETTLING BASIN SETTLING BASIN SECTION A November 2010 Urban Drainage and Flood Control District DW-3 Urban Storm Drainage Criteria Manual Volume 3 SM-9 Dewatering Operations (DW) VEGETATION SEDIMENT CONTROL LOG (SEE SCL-1 DETAIL) ROCK WILL BE INSTALLED, �} D AS NECESSARY, TO '•d r: PREVENT EROSION 0 y�K DISCHARGE PIPE FILTER BAG ON STRAW BALES OR ROCK PAD DW-4. DEWATERING FILTER BAG DEWATERING INSTALLATION NOTES 1. SEE PLAN VIEW FOR; —LOCATION OF DEWATERING EQUIPMENT. —TYPE OF DEWATERING OPERATION (DW-1 TO DW-4). 2. THE OWNER OR CONTRACTOR SHALL OBTAIN A CONSTRUCTION DISCHARGE (DEWATERING) PERMIT FROM THE STATE PRIOR TO ANY DEWATERING OPERATIONS DISCHARGING FROM THE SITE ALL DEWATERING SHALL BE IN ACCORDANCE WITH THE REQUIREMENTS OF THE PERMIT. 3 THE OWNER OR OPERATOR SHALL PROVIDE, OPERATE, AND MAINTAIN DEWATERING SYSTEMS OF SUFFICIENT SIZE AND CAPACITY TO PERMIT EXCAVATION AND SUBSEQUENT CONSTRUCTION IN DRY CONDITIONS AND TO LOWER AND MAINTAIN THE GROUNDWATER LEVEL A MINIMUM OF 2—FEET BELOW THE LOWEST POINT OF EXCAVATION AND CONTINUOUSLY MAINTAIN EXCAVATIONS FREE OF WATER UNTIL BACK—FILLED TO FINAL GRADE. DW-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Dewatering Operations (DW) SM-9 DEWATERING INSTALLATION NOTES 4, DEWATERING OPERATIONS SHALL USE ONE OR MORE OF THE DEWATERING SUMPS SHOWN ABOVE, WELL POINTS, OR OTHER MEANS APPROVED BY THE LOCAL JURISDICTION TO REDUCE THE PUMPING OF SEDIMENT, AND SHALL PROVIDE A TEMPORARY SEDIMENT BASIN OR FILTRATION BMP TO REDUCE SEDIMENT TO ALLOWABLE LEVELS PRIOR TO RELEASE OFF SITE OR TO A RECEIVING WATER. A SEDIMENT BASIN MAY BE USED IN LIEU OF SUMP DISCHARGE SETTLING BASIN SHOWN ABOVE IF A 4—FOOT—SQUARE RIPRAP PAD IS PLACED AT THE DISCHARGE POINT AND THE DISCHARGE END OF THE LINE IS STAKED IN PLACE TO PREVENT MOVEMENT OF THE LINE. DEWATERING MAINTENANCE NOTES 1. INSPECT BMPS EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPS AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPS IN EFFECTIVE OPERATING CONDITION INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPS HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE- 4 DEWATERING BMPS ARE REQUIRED IN ADDITION TO ALL OTHER PERMIT REQUIREMENTS. 5. TEMPORARY SETTLING BASINS SHALL BE REMOVED WHEN NO LONGER NEEDED FOR DEWATERING OPERATIONS. ANY DISTURBED AREA SHALL BE COVERED WITH TOPSOIL, SEEDED AND MULCHED OR OTHERWISE STABILIZED IN A MANNER APPROVED BY THE LOCAL JURISDICTION. NOTE MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. (DETAILS ADAPTED FROM DOUGLAS COUNTY, COLORADO, NOT AVAILABLE IN AUTOCAD) November 2010 Urban Drainage and Flood Control District DW-5 Urban Storm Drainage Criteria Manual Volume 3 Temporary Stream Crossing (TSC) SM-10 Description ` U T'y Where an actively flowing watercourse must be crossed regularly by construction vehicles, a temporary crossing should be provided. Three primary methods are available: ■ Culvert crossing ■ Stream ford ■ Temporary bridge Culvert crossings and fords are the most commonly used methods. Due to the expense associated with a temporary bridge,these are used primarily on long- Photograph TSC-1. A temporary stream crossing using culverts. term projects. Photo courtesy of Tom Gore. Appropriate Uses Construction vehicles shall be kept out of waterways to the maximum extent practicable. Use a temporary stream crossing when it is absolutely necessary to cross a stream on a construction site. Construct a temporary crossing even if the stream or drainageway is typically dry. Multiple stream crossings should be avoided to minimize environmental impacts. A permit is required for placement of fill in a waterway under Section 404 of the Clean Water Act. The local office of the U.S.Army Corps of Engineers(USAGE) should be contacted concerning the requirements for obtaining a 404 permit. In addition, a permit from the U.S. Fish and Wildlife Service (USFWS)may be needed if endangered species are of concern in the work area. Typically,the USFWS issues are addressed by a 404 permit,if one is required. The municipality of jurisdiction should also be consulted,and can provide assistance. Other permits to be obtained may include a floodplain development permit from the local jurisdiction. Design and Installation Design details are provided for these types of stream crossings: TSC-1. Culvert Crossing TSC-2. Ford Crossing TSC-3. Flume Crossing Temporary Stream Crossin Functions Erosion Control Yes Sediment Control Yes Site/Material Management No November 2010 Urban Drainage and Flood Control District TSC-1 Urban Storm Drainage Criteria Manual Volume 3 SM-10 Temporary Stream Crossing (TSC) A culvert crossing should be designed to pass at least the 2-year design flow. Use Figure DC-2 from the Temporary Channel Diversion Fact Sheet to determine the 2-year peak flow rate. Culvert sizing must account for the headwater and tailwater controls to properly size the culvert. For additional discussion on design of box culverts and pipes, see the Major Drainage chapter in Volume 1. The designer also needs to confirm that the riprap selected is appropriate for the conditions in the channel being crossed. When a ford must be used,namely when a culvert is not practical or the best solution,the ford should be lined with at least a 12-inch thick layer of Type VL(1350=6 inches) or Type L(D50=9 inches)riprap with void spaces filed with 1-1/2 inch diameter rock. Ford crossings are recommended primarily for crossings of ephemeral(i.e. intermittently,briefly flowing) streams. For a temporary bridge crossing,consult with a structural and/or geotechnical engineer for temporary bridge design or consider pre-fabricated alternatives. Maintenance and Removal Inspect stream for bank erosion and in-stream degradation. If bank erosion is occurring, stabilize banks using erosion control practices such as erosion control blankets. If in-stream degradation is occurring, armor the culvert outlet(s)with riprap to dissipate energy(see Outlet Protection Fact Sheet). If sediment is accumulating upstream of the crossing,remove excess sediment as needed to maintain the functionality of the crossing. Remove the temporary crossing when it is no longer needed for construction. Take care to minimize the amount of sediment lost into the stream upon removal. Once the crossing has been removed, stabilize the stream banks with seed and erosion control blankets. TSC-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Temporary Stream Crossing (TSC) SM-10 TSC LENGTH L CREST LENGTH CL A >5 � AVOID BANK EXCAVATION EXISTING _ '% ; IF POSSIBLE GRADE DEPTH D —} CULVERT (AS SPECIFIED) HEIGHT H J ^CULVERT DIAMETER CD CULVERT CROSSING SECTION 8' MIN 1J2" (MINUS) CRUSHED ROCK D50-12" TYP. RIPRAP 12" MIN. COVER 6" CULVERTS AS SPECIFIED FLOW f s���._ — -— — — >2 GEOTEXTILE FABRIC FOR MATERIAL SEPARATION GEOTEXTILE OR MAT SECTION A TSC- 1 . CULVERT CROSSING November 2010 Urban Drainage and Flood Control District TSC-3 Urban Storm Drainage Criteria Manual Volume 3 SM-10 Temporary Stream Crossing (TSC) LENGTH L CREST LENGTH CL >5 A >5 EXISTING CHANNEL GRADE AVOID BANK EXCAVATION IF POSSIBLE FORD CROSSING SECTION 8' MIN EXISTING CHANNEL GRADE >2 FLOW 1 -, 050-6" RIPRAP VOIDS FILLED 12" MIN WITH 1Y2" (MINUS) CRUSHED ROCK GEOTEXTILE OR MAT SECTION A TSC-2. FORD CROSSING TSC-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Temporary Stream Crossing (TSC) SM-10 TSC EXCAVATED UTILITY PROPOSED UTILITY TRENCH FLUME PIPE FLOW FLOW EMBANKMENT, TYP. EXISTING STREAM BANK FLUME CROSSING PLAN STABILIZED STREAM BANK EMBANKMENT, TYP. FLUME PIPE STREAM FLOW STREAM BOTTOM PROPOSED UTILITY EXCAVATED UTILITY TRENCH SECTION A TSC-3. FLUME CROSSING November 2010 Urban Drainage and Flood Control District TSC-5 Urban Storm Drainage Criteria Manual Volume 3 SM-10 Temporary Stream Crossing (TSC) TEMPORARY STREAM CROSSING INSTALLATION NOTES 1. SEE PLAN VIEW FOR: —LOCATIONS OF TEMPORARY STREAM CROSSINGS. —STREAM CROSSING TYPE (FORD, CULVERT, OR FLUME). —FOR FORD CROSSING LENGTH (L), CREST LENGTH (CL), AND DEPTH (D). —FOR CULVERT CROSSING: LENGTH (L), CREST LENGTH (CL), CROSSING HEIGHT (H), DEPTH (D), CULVERT DIAMETER (CD), AND NUMBER, TYPE AND CLASS OR GAUGE OF CULVERTS. 2. TEMPORARY STREAM CROSSING DIMENSIONS, D50, AND NUMBER OF CULVERTS INDICATED (FOR CULVERT CROSSING) SHALL BE CONSIDERED MINIMUM DIMENSIONS; ENGINEER MAY ELECT TO INSTALL LARGER FACILITIES. ANY DAMAGE TO STREAM CROSSING OR EXISTING STREAM CHANNEL DURING BASEFLOW OR FLOOD EVENTS SHALL BE PROMPTLY REPAIRED. 3. SEE MAJOR DRAINAGE CHAPTER FOR RIPRAP GRADATIONS. 4. WHERE FAILURE OF A STREAM CROSSING CAN RESULT IN SIGNIFICANT DAMAGE OR HARM IT MUST BE DESIGNED BY A STRUCTURAL ENGINEER. TEMPORARY STREAM CROSSING MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. REMOVE SEDIMENT ACCUMULATED UPSTREAM OF CROSSING AS NEEDED TO MAINTAIN THE FUNCTIONALITY OF THE CROSSING. 5. STREAM CROSSINGS ARE TO REMAIN IN PLACE UNTIL NO LONGER NEEDED AND SHALL BE REMOVED PRIOR TO THE END OF CONSTRUCTION. 6 WHEN STREAM CROSSINGS ARE REMOVED, THE DISTURBED AREA SHALL BE COVERED WITH TOPSOIL, SEEDED AND MULCHED AND COVERED WITH GEOTEXTILE OR OTHERWISE STABILIZED IN A MANNER APPROVED BY THE LOCAL JURISDICTION. NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. (DETAIL ADAPTED FROM DOUGLAS COUNTY, COLORADO AND CITY OF AURORA, COLORADO (Va. DSWC), NOT AVAILABLE IN AUTOCAD) TSC-6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Temporary Batch Plant (TBP) SM-11 Description Temporary batch plant management includes implementing multiple BMPs such as perimeter controls, concrete washout area, stabilized construction 71 access, good housekeeping, and other dti. practices designed to reduce polluted' " runoff from the batch plant area. Appropriate Uses - - -- Implement this BMP at temporary batch plants and identify the location of the batch plant in the SWMP. Photograph TBP-1. Effective stormwater management at temporary batch plants requires implementation of multiple BMPs. Photo Additional permitting may be required for courtesy of California Stormwater BMP Handbook. the operation of batch plants depending on their duration and location. Design and Installation The following lists temporary management strategies to mitigate runoff from batch plant operations: ■ When stockpiling materials, follow the Stockpile Management BMP. ■ Locate batch plants away from storm drains and natural surface waters. ■ A perimeter control should be installed around the temporary batch plant. ■ Install run-on controls where feasible. ■ A designated concrete washout should be located within the perimeter of the site following the procedures in the Concrete Washout Area BMP. ■ Follow the Good Housekeeping BMP, including proper spill containment measures,materials storage, and waste storage practices. ■ A stabilized construction entrance or vehicle tracking control pad should be installed at the plant entrance, in accordance with the Vehicle Tracking Control BMP. Maintenance and Removal Inspect the batch plant for proper functioning of the BMPs,with Temporary Batch Plants attention to material and waste storage areas, integrity of perimeter BMPs, and an effective stabilized construction Functions entrance. Erosion Control No Sediment Control No Site/Material Management Yes November 2010 Urban Drainage and Flood Control District TBP-1 Urban Storm Drainage Criteria Manual Volume 3 SM-11 Temporary Batch Plant (TBP) After the temporary batch plant is no longer needed,remove stockpiled materials and equipment,regrade the site as needed, and revegetate or otherwise stabilize the area. TBP-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Paving and Grinding Operations (PGO) SM-12 Description Manage runoff from paving and grinding operations to reduce pollutants enteringr� storm drainage systems and natural - r drainageways. Appropriate Uses Use runoff management practices during all paving and grinding operations such - — as surfacing,resurfacing, and saw cutting. Design and Installation Photograph PGO-1. Paving operations on a Colorado highway. Photo courtesy of CDOT. There are a variety of management strategies that can be used to manage runoff from paving and grinding operations: ■ Establish inlet protection for all inlets that could potentially receive runoff. ■ Schedule paving operations when dry weather is forecasted. ■ Keep spill kits onsite for equipment spills and keep drip pans onsite for stored equipment. ■ Install perimeter controls when asphalt material is used on embankments or shoulders near waterways, drainages,or inlets. ■ Do not wash any paved surface into receiving storm drain inlets or natural drainageways. Instead, loose material should be swept or vacuumed following paving and grinding operations. ■ Store materials away from drainages or waterways. ■ Recycle asphalt and pavement material when feasible. Material that cannot be recycled must be disposed of in accordance with applicable regulations. See BMP Fact Sheets for Inlet Protection, Silt Fence and other perimeter controls selected for use during paving and grinding operations. Maintenance and Removal Perform maintenance and removal of inlet protection and perimeter controls in accordance with their respective fact sheets. Promptly respond to spills in accordance with the spill Paving and Grinding Operations prevention and control plan. Functions Erosion Control No Sediment Control No Site/Material Management Yes November 2010 Urban Drainage and Flood Control District PGO-1 Urban Storm Drainage Criteria Manual Volume 3 Grass Buffer T-1 Description Ix �- Grass buffers are densely vegetated strips of grass designed to accept sheet ' flow from upgradient development. , Properly designed grass buffers playa key role in LID, enabling infiltration and - slowing runoff. Grass buffers provide filtration(straining)of sediment. =:s Buffers differ from swales in that they s- - are designed to accommodate overland - - sheet flow rather than concentrated or channelized flow. Site Selection Grass buffers can be incorporated into a wide range of development settings. Photograph GB-1. A flush curb allows roadway runoff to sheet flow Runoff can be directly accepted from a through the grass buffer. Flows are then further treated by the grass parking lot,roadway, or the roof of a swale. Photo courtesy of Muller Engineering. structure,provided the flow is distributed in a uniform manner over the width of the buffer. This can be achieved through the use of flush curbs, slotted curbs,or level spreaders where needed. Grass buffers are often used in conjunction with grass swales. They are well suited for use in riparian zones to assist in stabilizing channel banks adjacent to major drainageways and receiving waters. These areas can also sometimes serve multiple functions such as recreation. Hydrologic Soil Groups A and B provide the best infiltration Grass Buffer capacity for grass buffers. For Type C and D soils,buffers still serve to provide filtration(straining)although infiltration rates are Functions lower. LID/Volume Red. Yes WQCV Capture No Designing for Maintenance WQCV+Flood Control No Fact Sheet Includes Recommended ongoing maintenance practices for all BMPs are EURV Guidance No provided in Chapter 6 of this manual. During design the Typical Effectiveness for Targeted following should be considered to ensure ease of maintenance Pollutants3 over the long-term: Sediment/Solids Good ■ Where appropriate(where vehicle safety would not be Nutrients Moderate impacted), install the top of the buffer 1 to 3 inches below the Total Metals Good adjacent pavement so that growth of vegetation and Bacteria Poor accumulation of sediment at the edge of the strip does not Other Considerations prevent runoff from entering the buffer. Alternatively, a Life-cycle Costs Low sloped edge can be used adjacent to vehicular traffic areas. • Amend soils to encourage deep roots and reduce irrigation 3 Based primarily on data from the requirements, as well as promote infiltration. International Stormwater BMP Database (www.bmpdatabase.orgy. November 2010 Urban Drainage and Flood Control District G13-1 Urban Storm Drainage Criteria Manual Volume 3 T-1 Grass Buffer ■ Design and adjust the irrigation system(temporary or Benefits permanent)to provide water in amounts appropriate for the selected vegetation. Irrigation needs will change from ■ Filters (strains) sediment and month to month and year to year. trash. ■ Protect the grass buffer from vehicular traffic when using ■ Reduces directly connected this BMP adjacent to roadways. This can be done with a impervious area. (See Chapter 3 slotted curb (or other type of barrier) or by constructing a for quantifying benefits.) reinforced grass shoulder(see Fact Sheet T-10.5). ■ Can easily be incorporated into a Design Procedure and Criteria treatment train approach. The following steps outline the grass buffer design procedure ' Provides green space available and criteria. Figure GB-1 is a schematic of the facility and its for multiple uses including components: recreation and snow storage. 1. Design Discharge: Use the hydrologic procedures ' Straightforward maintenance described in the Runoff chapter of Volume 1 to determine requirements when the buffer is the 2-year peak flow rate (Q2) of the area draining to the protected from vehicular traffic. grass buffer. Limitations 2. Minimum Width: The width(W),normal to flow of the buffer,is typically the same as the contributing basin(see ■ Frequently damaged by vehicles Figure GB-1). An exception to this is where flows become when adjacent to roadways and concentrated. Concentrated flows require a level spreader unprotected. to distribute flows evenly across the width of the buffer. The minimum width should be: ■ A thick vegetative cover is needed for grass buffers to be W _ Q2 Equation GB-1 effective. 0.05 ■ Nutrient removal in grass buffers Where: is typically low. W = width of buffer(ft) ■ High loadings of coarse solids, Q2 =2-year peak runoff(cfs) trash, and debris require pretreatment. 3. Length: The recommended length(L),the distance along . Space for grass buffers may not the sheet flow direction, should be a minimum of 14 feet. be available in ultra urban areas This value is based on the findings of Barrett et al. 2004 in (lot-line-to-lot-line). Stormwater Pollutant Removal in Roadside Vegetated Strips and is appropriate for buffers with greater than 80% _ vegetative cover and slopes up to 10%. The study found that pollutant removal continues throughout a length of 14 feet. Beyond this length,a point of diminishing returns in pollutant reduction was found. It is important to note that shorter lengths or slightly steeper slopes will also provide some level of removal where site constraints dictate the geometry of the buffer. GB-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Grass Buffer T-1 4. Buffer Slope: The design slope of a grass buffer in the Use of Grass Buffers direction of flow should not exceed 10%. Generally, a minimum slope of 2% or more in turf is adequate to Sheet flow of stormwater through a facilitate positive drainage. For slopes less than 2%, grassed area provides some benefit in consider including an underdrain system to mitigate pollutant removal and volume nuisance drainage. reduction even when the geometry of the BMP does not meet the criteria 5. Flow Characteristics (sheet or concentrated): provided in this Fact Sheet. These Concentrated flows can occur when the width of the criteria provide a design procedure watershed differs from that of the grass buffer. that should be used when possible; Additionally,when the product of the watershed flow however,when site constraints are length and the interface slope(the slope of the watershed limiting,this treatment concept is normal to flow at the grass buffer) exceeds approximately still encouraged. one, flows may become concentrated. Use the following equations to determine flow characteristics: Sheet Flow: FL(SI) < 1 Equation G13-2 Concentrated Flow: FL(SI) > 1 Equation G13-3 Where: FL =watershed flow length(ft) SI =interface slope(normal to flow) (ft/ft) 6. Flow Distribution: Flows delivered to a grass buffer must be sheet flows. Slotted or flush curbing, permeable pavements, or other devices can be used to spread flows. The grass buffer should have relatively consistent slopes to avoid concentrating flows within the buffer. A level spreader should be used when flows are concentrated. A level spreader can be a slotted drain designed to discharge flow through the slot as shown in Photo G13-2. It could be an exfiltration trench filled with gravel,which allows water to infiltrate prior to discharging over a level concrete or rock curb. There are many ways to design and construct a level spreader. They can also be used in series when the length of the buffer allows flows to re- concentrate. See Figure G13-2 for various level spreader sections. Photograph GB-2. This level spreader carries concentrated flows into a slotted pipe encased in concrete to distribute flows evenly to the grass buffer shown left in the photo. Photo courtesy of Bill Wenk. November 2010 Urban Drainage and Flood Control District G13-3 Urban Storm Drainage Criteria Manual Volume 3 T-1 Grass Buffer Photos GB-3 and GB-4 show a level spreader that includes a basin for sedimentation. Concentrated flows enter the basin via stormsewer. The basin is designed to drain slowly — while overflow is spread evenly to the downstream vegetation. A small notch,orifice, or pipe can be used to ' drain the level spreader completely. r.. The opening should be small to encourage frequent flows to overtop the level spreader but not so small that it is frequently clogged. 7. Soil Preparation: In order to encourage establishment and long- term health of the selected vegetation, Photograph GB-3. This level spreader includes the added benefit of a it is essential that soil conditions be sedimentation basin prior to even distribution of concentrated flows properly prepared prior to from the roadway into the grass buffer. Photo courtesy of Bill Wenk. installation. Following site grading, poor soil conditions often exist. When possible,remove, strip, stockpile, and reuse on-site topsoil. ' If the site does not contain topsoil, the soils should be amended prior to vegetation. Typically 3 to 5 cubic yards of soil amendment(compost) per 1,000 square feet,tilled 6 inches into the soil is required in order for vegetation to thrive, as well as to enable infiltration of runoff. Additionally, inexpensive soil tests _ can be conducted to determine - -- required soil amendments. (Some local governments may also require proof of soil amendment in landscaped areas for water conservation reasons.) Photograph GB-4. Maintenance access is provided via the ramp located at the end of the basin. Photo courtesy of Bill Wenk. 8. Vegetation: This is the most critical component for treatment within a grass buffer. Select durable, dense, and drought tolerant grasses to vegetate the buffer. Also consider the size of the watershed as larger watersheds will experience more frequent flows. The goal is to provide a dense mat of vegetative cover. Grass buffer performance falls off rapidly as the vegetation coverage declines below 80%(Barrett et a1.2004). GB-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Grass Buffer T-1 Turf grasses such as Kentucky bluegrass are often selected due to these qualities'. Dense native turf grasses may also be selected where a more natural look is desirable. Once established,these provide the benefit of lower irrigation requirements. See the Revegetation chapter in Volume 2 of this manual with regard to seed mix selection,planting and ground preparation. Depending on soils and anticipated flows,consider erosion control measures until vegetation has been established. 9. Irrigation: Grass buffers should be equipped with irrigation systems to promote establishment and survival in Colorado's semi-arid environment. Systems may be temporary or permanent, depending on the type of vegetation selected. Irrigation application rates and schedules should be developed and adjusted throughout the establishment and growing season to meet the needs of the selected plant species. Initially,native grasses require the same irrigation requirements as bluegrass. After the grass is established, irrigation requirements for native grasses can be reduced. Irrigation practices have a significant effect on the function of the grass buffer. Overwatering decreases the permeability of the soil,reducing the infiltration capacity and contributing to nuisance baseflows. Conversely, under watering may result in delays in establishment of the vegetation in the short term and unhealthy vegetation that provides less filtering and increased susceptibility to erosion and rilling over the long term. 10. Outflow Collection: Provide a means for downstream conveyance. A grass swale can be used for this purpose,providing additional LID benefits. Construction Considerations Success of grass buffers depends not only on a good design and long-term maintenance,but also on installing the facility in a manner that enables the BMP to function as designed. Construction considerations include: ■ The final grade of the buffer is critical. Oftentimes, following soil amendment and placement of sod, the final grade is too high to accept sheet flow. The buffer should be inspected prior to placement of seed or sod to ensure appropriate grading. ■ Perform soil amending, fine grading, and seeding only after tributary areas have been stabilized and utility work crossing the buffer has been completed. ■ When using sod tiles stagger the ends of the tiles to prevent the formation of channels along the joints. Use a roller on the sod to ensure there are no air pockets between the sod and soil. ■ Avoid over compaction of soils in the buffer area during construction to preserve infiltration capacities. ■ Erosion and sediment control measures on upgradient disturbed areas must be maintained to prevent excessive sediment loading to grass buffer. 'Although Kentucky bluegrass has relatively high irrigation requirements to maintain a lush,green aesthetic,it also withstands drought conditions by going dormant. Over-irrigation of Kentucky bluegrass is a common problem along the Colorado Front Range,and it can be healthy,although less lush,with much less irrigation than is typically applied. November 2010 Urban Drainage and Flood Control District GB-5 Urban Storm Drainage Criteria Manual Volume 3 T-1 Grass Buffer W, Uj r�t•c C �'WA 71tR5,RED rLOW L1;Nc,TN 0\1\ PLAN RNhlt i I"T03' LIP WNERE,.. � u SUITABLEOA 1 v 7 LEVEL SPR€ADER IE— AMENDED S0I1-5� PROFILE Figure GB-1. Typical Grass Buffer Graphic by Adia Davis. G13-6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Grass Buffer T-1 CORRUGATED SLOTTED DRAIN PIPE GRASS BUFFER AGGREGATE BASE COURSE SECTION n LEVEL SPREADER FOR PIPE FLOWS �- PIPE AND HEADWALL BEYOND GRASS BUFFER =" /- SLOTTED CURB DRAIN PAN WITH CURBS SECTION 0 LEVEL SPREADER FOR PIPE FLOWS GRASS BUFFER UNDERDRAIN, SEE SECTION 5 (OR PROVIDE SMALL OPENING IN WALL) SECTION � LEVEL SPREADER FOR SURFACE FLOWS �' GRASS BUFFER UNDERDRAIN, SEE SECTION 5 (OPTIONAL) SECTION LEVEL SPREADER FOR SMALL SURFACE FLOWS CDOT CLASS C FILTER MATERIAL OR OTHER COMPATIBLE MATERIAL SUCH AS AASHTO #57 OR #67 CDOT VARIES, MIN 8" CLASS C ILTER 4" MATERIAL 1 PER TABLE SLOTTED PIPE PER TABLE GS-3' GS-2 1. SEE BMP FACT SHEET T-2, GRASS SWALE SECTION 'UNDERDRAIN ` Figure G13-2. Typical Level Spreader Details November 2010 Urban Drainage and Flood Control District GB-7 Urban Storm Drainage Criteria Manual Volume 3 Grass Swale T-2 Description ` Grass swales are densely vegetated trapezoidal or triangular channels with - ` low-pitched side slopes designed to convey runoff slowly. Grass swales have low longitudinal slopes and broad cross-sections that convey flow in a slow and shallow manner,thereby facilitating sedimentation and filtering(straining) while limiting erosion. Berms or check dams may be incorporated into grass swales to reduce velocities and encourage settling and infiltration. When using berms, an underdrain system should be provided. Grass swales are an integral part of the Low Photograph GS-1. This grass swale provides treatment of roadway Impact Development(LID) concept and runoff in a residential area. Photo courtesy of Bill Ruzzo. may be used as an alternative to a curb and gutter system. Site Selection Grass swales are well suited for sites with low to moderate slopes. Grass Swale Drop structures or other features designed to provide the same function as a drop structures (e.g., a driveway with a stabilized Functions grade differential at the downstream end)can be integrated into LIDNolume Red. Yes the design to enable use of this BMP at a broader range of site WQCV Capture No conditions. Grass swales provide conveyance so they can also be used to replace curb and gutter systems making them well suited WQCV+Flood Control No for roadway projects. Fact Sheet Includes EURV Guidance No DeSI nlri for Maintenance Typical Effectiveness for Targeted g g Pollutants Recommended ongoing maintenance practices for all BMPs are Sediment/Solids Good provided in Chapter 6 of this manual. During design,the Nutrients Moderate following should be considered to ensure ease of maintenance Total Metals Good over the long-term: Bacteria Poor Other Considerations ■ Consider the use and function of other site features so that the swale fits into the landscape in a natural way. This can Life-cycle Costs Low encourage upkeep of the area,which is particularly important 3 Based primarily on data from the in residential areas where a loss of aesthetics and/or function International Stormwater BMP Database can lead to homeowners filling in and/or piping reaches of (www.bmpdatabase.orQ). this BMP. November 2010 Urban Drainage and Flood Control District GS-1 Urban Storm Drainage Criteria Manual Volume 3 T-2 Grass Swale ■ Provide access to the swale for mowing equipment and Benefits design sideslopes flat enough for the safe operation of equipment. Removal of sediment and associated constituents through ■ Design and adjust the irrigation system(temporary or filtering(straining) permanent)to provide appropriate water for the selected vegetation. Reduces length of storm sewer systems in the upper portions of a ■ An underdrain system will reduce excessively wet areas, watershed which can cause rutting and damage to the vegetation during mowing operations. Provides a less expensive and more attractive conveyance ■ When using an underdrain,do not put a filter sock on the element pipe. This is unnecessary and can cause the slots or perforations in the pipe to clog. Reduces directly connected impervious area and can help Design Procedure and Criteria reduce runoff volumes. The following steps outline the design procedure and criteria Limitations for stormwater treatment in a grass swale. Figure GS-1 shows trapezoidal and triangular swale configurations. Requires more area than traditional storm sewers. I. Design Discharge: Determine the 2-year flow rate to be conveyed in the grass swale under fully developed Underdrains are recommended for conditions. Use the hydrologic procedures described in slopes under 2%. the Runoff Chapter in Volume 1. ■ Erosion problems may occur if not 2. Hydraulic Residence Time: Increased hydraulic designed and constructed residence time in a grass swale improves water quality properly. treatment. Maximize the length of the swale when possible. If the length of the Swale is limited due to site constraints,the slope can also be decreased or the cross-sectional area increased to increase hydraulic residence time. 3. Longitudinal Slope: Establish a longitudinal slope that will meet Froude number,velocity, and depth criteria while ensuring that the grass swale maintains positive drainage. Positive drainage can be achieved with a minimum 2% longitudinal slope or by including an underdrain system(see step 8). Use drop structures as needed to accommodate site constraints. Provide for energy dissipation downstream of each drop when using drop structures. 4. Swale Geometry: Select geometry for the grass swale. The cross section should be either trapezoidal or triangular with side slopes not exceeding 4:1 (horizontal:vertical),preferably flatter. Increase the wetted area of the swale to reduce velocity. Lower velocities result in improved pollutant removal efficiency and greater volume reduction. If one or both sides of the grass swale are also to be used as a grass buffer, follow grass buffer criteria. GS-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Grass Swale T-2 5. Vegetation: Select durable, dense, and drought tolerant grasses. Turf grasses, such as Kentucky bluegrass, are often selected due to these qualities'. Native turf grasses may also be selected where a more natural look is desirable. This will also provide the benefit of lower irrigation requirements, once established. Turf grass is a general term for any grasses that will form a turf or mat as opposed to bunch grass,which will grow in clumplike fashion. Grass selection should consider both short-term(for establishment) and long-term maintenance requirements, given that some varieties have higher maintenance Native grasses provide requirements than others. Follow criteria in the a more natural aesthetic Revegetation Chapter of Volume 2,with regard to seed and require less water mix selection,planting, and ground preparation. once established. 6. Design Velocity: Maximum flow velocity in the swale should not exceed one foot per second. Use the Soil Conservation Service(now the NRCS)vegetal retardance curves for the Manning coefficient(Chow 1959). Determining the retardance coefficient is an iterative process that the UD-BMP workbook automates. When starting the swale vegetation from sod, curve "D" (low retardance) should be used. When starting vegetation from seed,use the "E" curve(very low vegetal retardance). 7. Design Flow Depth: Maximum flow depth should not exceed one foot at the 2-year peak flow rate. Check the conditions for the 100-year flow to ensure that drainage is being handled without flooding critical areas, structures, or adjacent streets. Table GS-1. Grass Swale Design Summary for Water Quality Design Flow Maximum Maximum Maximum Froude Number Velocity Flow Depth 2-year event 0.5 1 ft/s 1 ft Use of Grass Swales Vegetated conveyance elements provide some benefit in pollutant removal and volume reduction even when the geometry of the BMP does not meet the criteria provided in this Fact Sheet. These criteria provide a design procedure that should be used when possible; however,when site constraints are limiting,vegetated conveyance elements designed for stability are still encouraged. Although Kentucky bluegrass has relatively high irrigation requirements to maintain a lush,green aesthetic,it also withstands drought conditions by going dormant. Over-irrigation of Kentucky bluegrass is a common problem along the Colorado Front Range. It can be healthy,although less lush,with much less irrigation than is typically applied. November 2010 Urban Drainage and Flood Control District GS-3 Urban Storm Drainage Criteria Manual Volume 3 T-2 Grass Swale 8. Underdrain: An underdrain is necessary for swales with longitudinal slopes less than 2.0%. The underdrain can drain directly into an inlet box at the downstream end of the swale,daylight through the face of a grade control structure or continue below grade through several grade control structures as shown in Figure GS-1. The underdrain system should be placed within an aggregate layer. If no underdrain is required,this layer is not required. The aggregate layer should consist of an 8-inch thick layer of CDOT Class C filter material meeting the gradation in Table GS-2. Use of CDOT Class C Filter material with a slotted pipe that meets the slot dimensions provided in Table GS-3 will eliminate the need for geotextile fabrics. Previous versions of this manual detailed an underdrain system that consisted of a 3-to 4-inch perforated HDPE pipe in a one-foot trench section of AASHTO#67 coarse aggregate surrounded by geotextile fabric. If desired,this system continues to provide an acceptable alternative for use in grass swales. Selection of the pipe size may be a function of capacity or of maintenance equipment. Provide cleanouts at approximately 150 feet on center. Table GS-2. Gradation Specifications for Class C Filter Material (Source: CDOT Table 703-7) Sieve Size Mass Percent Passing Square Mesh Sieves 19.0 mm(3/4") 100 4.75 mm(No. 4) 60— 100 300 µm(No. 50) 10—30 150 µm(No. 100) 0— 10 75 µm(No. 200) 0-3 Table GS-3. Dimensions for Slotted Pipe ' Pipe Diameter Slot Maximum Slot Slot 1 Open Area Length Width Centers' (per foot) 4" 1-1/16" 0.032" 0.413" 1.90 in 6" 1-3/8" 0.032" 0.516" 1.98 in' 'Some variation in these values is acceptable and is expected from various pipe manufacturers. Be aware that both increased slot length and decreased slot centers will be beneficial to hydraulics but detrimental to the structure of the pipe. GS-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Grass Swale T-2 9. Soil preparation: Poor soil conditions often exist following site grading. When the section includes an underdrain,provide 4 inches of sandy loam at the invert of the Swale extending up to the 2-year water surface elevation. This will improve infiltration and reduce ponding. For all sections, encourage establishment and long-term health of the bottom and side slope vegetation by properly preparing the soil. If the existing site provides a good layer of topsoil,this should be striped, stockpiled, and then replaced just prior to seeding or placing sod. If not available at the site,topsoil can be imported or the existing soil may be amended. Inexpensive soil tests can be performed following rough grading,to determine required soil amendments. Typically, 3 to 5 cubic yards of soil amendment per 1,000 square feet,tilled 4 to 6 inches into the soil is required in order for vegetation to thrive, as well as to enable infiltration of runoff. 10. Irrigation: Grass swales should be equipped with irrigation systems to promote establishment and survival in Colorado's semi-arid environment. Systems may be temporary or permanent, depending on the type of grass selected. Irrigation practices have a significant effect on the function of the grass swale. Overwatering decreases the permeability of the soil,reducing the infiltration capacity of the soil and contributing to nuisance baseflows. Conversely,under watering may result in delays in establishment of the vegetation in the short term and unhealthy vegetation that provides less filtering (straining) and increased susceptibility to erosion and riling over the long term. Construction Considerations Success of grass swales depends not only on a good design and maintenance,but also on construction NO practices that enable the BMP to function as designed. Construction considerations include: PA R K I N G ■ Perform fine grading, soil amendment, and seeding only after upgradient surfaces have been stabilized ON and utility work crossing the swale has been completed. SWALE ■ Avoid compaction of soils to preserve infiltration capacities. ■ Provide irrigation appropriate to the grass type. ■ Weed the area during the establishment of vegetation Photograph GS-2. This community used by hand or mowing. Mechanical weed control is signage to mitigate compaction of soils post- preferred over chemical weed killer. construction. Photo courtesy of Nancy styles. ■ Protect the swale from other construction activities. ■ When using an underdrain, ensure no filter sock is placed on the pipe. This is unnecessary and can cause the slots or perforations in the pipe to clog. November 2010 Urban Drainage and Flood Control District GS-5 Urban Storm Drainage Criteria Manual Volume 3 T-2 Grass Swale RESIDUAL CAPACITY FOR �--, LARGER FLOODS 1 P. 2—YR WSE 6" MI 4 MIN. V (2—YR)<1.0 FPS x c, W. y 4" (MIN) SANDY LOAM O 1" MIN 12" MIN BOTTOM WIDTH (W) GRADE CONTROL STRUCTURE BEYOND TRAPEZOIDAL SWALE SECTION N- RESIDUAL CAPACITY FOR 4 LARGER FLOODS r/. 12" MIN. 1 2—YR WSE 6� MIN 4 MIN. GRADE CONTROL STRUCTURE BEYOND O UNDERDRAIN AND SANDY LOAM RECOMMENDED FOR LONGITUDINAL SLOPES < 2.0%. 4" SLOTTED PIPE MEETING TABLE GS-3 WITH CDOT CLASS C FILTER 4" MIN. SANDY LOAM MATERIAL ALL AROUND OR PERFORATED HOPE Q 1" MIN. PIPE WITH AASHTO #67 ALL AROUND CONTAINED D (20YR) 1.0 FPS 12' IN. WITHIN GEOTEXTILE FABRIC. ASTM D4751—AOS US STD. SIEVE #50 TO #70, ASTM D4533 MIN. TRAPEZOIDAL TEAR STRENGTH 100 X 60 LBS, MINIMUM COE SPECIFIED OPEN AREA OF 4%. TRIANGULAR SWALE SECTION NTS CONCRETE COLLAR ENERGY GRADE CONTROL EXTEND GRADE CONTROL DISSIPATION__ STRUCTURE STRUCTURES INTO THE BANK A MIN. 0.5' ABOVE THE 2—YR WSE PROVIDE DOUBLE CLEANOUTS WITH WATER TIGHT CAPS ®150' O.C. USE 90' SWEEP OR (2) UNDERDRAIN 45- BENDS (OFFSET FROM SWALE CENTERLINE TO AVOID IMPEDING FLOW WHEN USING A TRIANGULAR ENSURE ACCESS TO OUTLET SECTION BY CLEAN OUT OR OTHER ACCESSIBLE STRUCTURE SWALE PROFILE NTS Figure GS-1. Grass Swale Profile and Sections Design Example The UD-BMP workbook, designed as a tool for both designer and reviewing agency is available at www.udfed.org. This section provides a completed design form from this workbook as an example. GS-6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Bioretention T-3 Description A BMP that utilizes bioretention is an j ! engineered, depressed landscape area designed to capture and filter or infiltrate ----= the water quality capture volume (WQCV). BMPs that utilize bioretention Q are frequently referred to as rain gardens _ or porous landscape detention areas (PLDs). The term PLD is common in the Denver metropolitan area as this manual - first published the BMP by this name in 1999. In an effort to be consistent with terms most prevalent in the stormwater industry,this document generally refers to the treatment process as bioretention and Photograph B-1. This recently constructed rain garden provides to the BMP as a rain garden. bioretention of pollutants,as well as an attractive amenity for a residential building. Treatment should improve as vegetation matures. The design of a rain garden may provide detention for events exceeding that of the WQCV. There are generally two ways to achieve this. The design can provide the Bioretention flood control volume above the WQCV water surface elevation, (Rain Garden) with flows bypassing the filter usually by overtopping into an inlet designed to restrict the peak flow for a larger event(or Functions events). Alternatively,the design can provide and slowly release LID/Volume Red. Yes the flood control volume in an area downstream of one or more WQCV Capture Yes rain gardens. WQCV+Flood Control Yes Fact Sheet Includes This infiltrating BMP requires consultation with a EURV Guidance No geotechnical engineer when proposed near a structure. A Typical Effectiveness for Targeted geotechnical engineer can assist with evaluating the suitability of Pollutants3 soils, identifying potential impacts,and establishing minimum Sediment/Solids Very Good' distances between the BMP and structures. Nutrients Moderate Total Metals Good Bacteria Moderate Other Considerations Terminology Life-cycle Costs' Moderate 'Not recommended for watersheds with The term bioretention refers to the high sediment yields(unless pretreatment is treatment process although it is also provided). frequently used to describe a BMP 3 Based primarily on data from the that provides biological uptake and International Stormwater BMP Database retention of the pollutants found in (www.bmpdatabase.org). stormwater runoff. This BMP is 4 Based primarily on BMP-REALCOST frequently referred to as a porous available at www.udfcd.org. Analysis landscape detention (PLD) area or based on a single installation(not based on the maximum recommended watershed rain garden. tributary to each BMP). November 2010 Urban Drainage and Flood Control District B-1 Urban Storm Drainage Criteria Manual Volume 3 T-3 Bioretention Benefits Site Selection Bioretention uses multiple treatment processes to remove Bioretention can be provided in a variety of areas within new pollutants, including developments,or as a retrofit within an existing site. This sedimentation, filtering, BMP allows the WQCV to be treated within areas adsorption, evapotranspiration, designated for landscape (see design step 7 for appropriate and biological uptake of vegetation). In this way,it is an excellent alternative to constituents. extended detention basins for small sites. A typical rain garden serves a tributary area of one impervious acre or less, Volumetric stormwater treatment although they can be designed for larger tributary areas. is provided within portions of a Multiple installations can be used within larger sites. Rain site that are already reserved for gardens should not be used when a baseflow is anticipated. landscaping. They are typically small and installed in locations such as: ■ There is a potential reduction of ■ Parking lot islands irrigation requirements by taking advantage of site runoff. ■ Street medians ■ Landscape areas between the road and a detached walk Limitations ■ Planter boxes that collect roof drains Additional design and construction steps are required for Bioretention requires a stable watershed. Retrofit placement of any ponding or applications are typically successful for this reason. When infiltration area near or upgradient the watershed includes phased construction, sparsely from a building foundation and/or vegetated areas, or steep slopes in sandy soils, consider when expansive(low to high another BMP or provide pretreatment before runoff from swell) soils exist. This is these areas reaches the rain garden. The surface of the rain discussed in the design procedure garden should be flat. For this reason,rain gardens can be section. more difficult to incorporate into steeply sloping terrain; however,terraced applications of these facilities have been In developing or otherwise erosive successful in other parts of the country. watersheds,high sediment loads can clog the facility. When bioretention(and other BMPs used for infiltration)are located adjacent to buildings or pavement areas,protective measures should be implemented to avoid adverse impacts to these structures. Oversaturated subgrade soil underlying a structure can cause the structure to settle or result in moisture-related problems. Wetting of expansive soils or bedrock can cause swelling,resulting in structural movements. A geotechnical engineer should evaluate the potential impact of the BMP on adjacent structures based on an evaluation of the subgrade soil, groundwater, and bedrock conditions at the site. Additional minimum requirements include: ■ In locations where subgrade soils do not allow infiltration,the growing medium should be underlain by an underdrain system. ■ Where infiltration can adversely impact adjacent structures,the filter layer should be underlain by an underdrain system designed to divert water away from the structure. ■ In locations where potentially expansive soils or bedrock exist,placement of a rain garden adjacent to structures and pavement should only be considered if the BMP includes an underdrain designed to divert water away from the structure and is lined with an essentially impermeable gcomembrane liner designed to restrict seepage. B-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Bioretention T-3 Designing for Maintenance Is Pretreatment Needed Recommended maintenance practices for all BMPs are in Chapter Designing the inflow gutter to 6 of this manual. During design,the following should be the rain garden at a minimal considered to ensure ease of maintenance over the long-term: slope of 0.5%can facilitate sediment and debris deposition ■ Do not put a filter sock on the underdrain. This is not prior to flows entering the BMP. necessary and can cause the BMP to clog. Be aware,this will reduce maintenance of the BMP, but ■ The best surface cover for a rain garden is full vegetation. Do may require more frequent not use rock mulch within the rain garden because sediment sweeping of the gutter to ensure build-up on rock mulch tends to inhibit infiltration and require that the sediment does not frequent cleaning or removal and replacement. Wood mulch impede flow into the rain handles sediment build-up better than rock mulch;however, garden. wood mulch floats and may clog the overflow depending on the configuration of the outlet,settle unevenly, or be transported downstream. Some municipalities may not allow wood mulch for this reason. ■ Consider all potential maintenance requirements such as mowing(if applicable)and replacement of the growing medium. Consider the method and equipment for each task required. For example, in a large rain garden where the use of hand tools is not feasible, does the shape and configuration of the rain garden allow for removal of the growing medium using a backhoe? ■ Provide pre-treatment when it will reduce the extent and frequency of maintenance necessary to maintain function over the life of the BMP. For example,if the site is larger than 2 impervious acres, prone to debris or the use of sand for ice control, consider a small forebay. ■ Make the rain garden as shallow as possible. Increasing the depth unnecessarily can create erosive side slopes and complicate maintenance. Shallow rain gardens are also more attractive. ■ Design and adjust the irrigation system(temporary or permanent)to provide appropriate water for the establishment and maintenance of selected vegetation. Design Procedure and Criteria The following steps outline the design procedure and criteria,with Figure B-1 providing a corresponding cross-section. 1. Basin Storage Volume: Provide a storage volume based on a 12-hour drain time. ■ Find the required WQCV(watershed inches of runoff). Using the imperviousness of the tributary area(or effective imperviousness where LID elements are used upstream),use Figure 3-2 located in Chapter 3 of this manual to determine the WQCV based on a 12-hour drain time. ■ Calculate the design volume as follows: V = [WQCV 12 ]A Equation B-1 Where: V= design volume(ft) November 2010 Urban Drainage and Flood Control District B-3 Urban Storm Drainage Criteria Manual Volume 3 T-3 Bioretention A =area of watershed tributary to the rain garden(ft2) 2. Basin Geometry: A maximum WQCV ponding depth of 12 inches is recommended to maintain vegetation properly. Provide an inlet or other means of overflow at this elevation. Depending on the type of vegetation planted,a greater depth may be utilized to detain larger(more infrequent)events. The bottom surface of the rain garden, also referred to here as the filter area, should be flat. Sediment will reside on the filter area of the rain garden;therefore, if the filter area is too small, it may clog prematurely. Increasing the filter area will reduce clogging and decrease the frequency of maintenance. Equation B-2 provides a minimum filter area allowing for some of the volume to be stored beyond the area of the filter(i.e., above the sideslopes of the rain garden). Note that the total surcharge volume provided by the design must also equal or exceed the design volume. Use vertical walls or slope the sides of the basin to achieve the required volume. Use the rain garden growing medium described in design step 3 only on the filter area because this material is more erosive than typical site soils. Sideslopes should be no steeper than 4:1 (horizontal:vertical). A >_ V(2/3) 1 foot Equation B-2 Where: V= design volume(ft) A =minimum filter area(flat surface area) (ft) The one-foot dimension in this equation represents the maximum recommended WQCV depth in the rain garden. The actual design depth may differ; however, it is still appropriate to use a value of one foot when calculating the minimum filter area. 3. Growing Medium: For partial and no infiltration sections,provide a minimum of 18 inches of growing medium to enable establishment of the roots of the vegetation(see Figure B-1). Previous versions of this manual recommended a mix of 85%sand and 15%peat(by volume). Peat is a material that typically requires import to Colorado and mining peat has detrimental impacts to the environment(Mazerolle 2002). UDFCD partnered with the University of Colorado to perform a study to find a sustainable material to replace peat. The study was successful in finding a replacement that performed well for filtering ability, clogging characteristics,as well as seed germination. This mixture consists of 85%coarse sand and a 15%compost/shredded paper mixture (by volume). The study used thin(approximately 1/4 inch)strips of loosely packed shredded paper mixed with an equal volume of compost. Based on conversations with local suppliers,compost Benefits of Shredded Paper in Rain Garden Growing Media ■ Shredded paper, similar to other woody materials,captures nutrients from the compost and slowly releases them as the paper decomposes. Compost alone will leach more nutrients than desired. ■ As the paper decomposes,nutrients stored in the material are available to the vegetation. ■ Paper temporarily slows the infiltration rate of the media and retains moisture,providing additional time for a young root system to benefit from moisture in the growing media. B-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Bioretention T-3 containing shredded paper is not an uncommon request, although not typically provided in the proportions recommended in this BMP Fact Sheet. Compost suppliers have access to shredded paper through document destruction companies and can provide a mixture of Class 1 compost and shredded paper. The supplier should provide the rain garden compost mixture premixed with coarse sand. On- site mixing is not recommended. Rain Garden Compost Mixture(by volume) ■ 50% Class 1 STA registered compost(approximate bulk density 1000 lbs/CY) ■ 50%loosely packed shredded paper(approximate bulk density 50 to 100 lbs/CY) When using diamond cut shredded paper or tightly packed paper,use the bulk densities provided to mix by weight. Rain Garden Growing Medium The supplier should premix the rain garden compost mixture(above)with coarse sand, in the following proportions,prior to delivery to the site: ■ 15%rain garden compost mixture described above(by volume) ■ 85%coarse sand(either Class C Filter Material per Table B-2 or sand meeting ASTM C-33) (by volume) Table 13-1 provides detailed information on Class 1 compost. Be aware,regular testing is not required to allow a compost supplier to refer to a product as a specific STA class. However,regular testing is required and performed through the United States Compost Council(USCC) Seal of Testing Assurance(STA)Program to be a STA registered compost. To ensure Class 1 characteristics, look for a Class 1 STA registered compost. Other Rain Garden Growing Medium Amendments The growing medium described above is designed for filtration ability, clogging characteristics, and vegetative health. It is important to preserve the function provided by the rain garden growing medium when considering additional materials for incorporation into the growing medium or into the standard section shown in Figure B-1. When desired, amendments may be included to improve water quality or to benefit vegetative health as long as they do not add nutrients,pollutants, or modify the infiltration rate. For example, a number of products, including steel wool, capture and retain dissolved phosphorus(Erickson 2009). When phosphorus is a target pollutant,proprietary materials with similar characteristics may be considered. Do not include amendments such as top soil, sandy loam, and additional compost. Full Infiltration Sections A full infiltration section retains the WQCV onsite. For this section, it is not necessary to use the prescribed rain garden growing medium. Amend the soils to provide adequate nutrients to establish vegetation. Typically, 3 to 5 cubic yards of soil amendment(compost)per 1,000 square feet,tilled 6 inches into the soil, is required for vegetation to thrive. Additionally, inexpensive soil tests can be conducted to determine required soil amendments. (Some local governments may also require proof of soil amendment in landscaped areas for water conservation reasons.) November 2010 Urban Drainage and Flood Control District B-5 Urban Storm Drainage Criteria Manual Volume 3 T-3 Bioretention Table B-1. Class 1 Compost Characteristic Criteria Minimum Stability Indicator(Respirometry) Stable to Very Stable Maturity Indicator Expressed as <4 Ammonia N/Nitrate N Ratio Maturity Indicator Expressed as < 12 Carbon to Nitrogen Ratio Maturity Indicator Expressed as 80+/80+ Percentage of Germination/Vigor pH—Acceptable Range 6.0—8.4 Soluble Salts—Acceptable Range (1:5 by weight) 0—5 mmhos/cm Seal of Testing Assurance(STA)/Test Testing and Test Report Submittal Requirement Methods for the Examination of Composting and Compost(TMECC) Equal or better than US EPA Class A Chemical Contaminants Standard,40 CFR 503.13,Tables I &3 levels PwI100ens Meet or exceed US EPA Class A standard, 40 CFR 503.32(a)levels i3-6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Bioretention T-3 Important Design Considerations 4. Underdrain System: Underdrains are often necessary The potential for impacts to adjacent and should be provided if infiltration tests show buildings can be significantly reduced percolation drawdown rates slower than 2 times the rate by locating the bioretention area at needed to drain the WQCV over 12 hours, or where least 10 feet away from the building, required to divert water away from structures as beyond the limits of backfill placed determined by a professional engineer. Percolation tests against the building foundation walls, should be performed or supervised by a licensed and by providing positive surface professional engineer and conducted at a minimum depth drainage away from the building. equal to the bottom of the bioretention facility. Additionally,underdrains are required where The BMP should not restrict surface impermeable membranes are used. Similar to the water from flowing away from the terminology used for permeable pavement sections,there buildings. This can occur if the top of are three basic sections for bioretention facilities: the perimeter wall for the BMP impedes flow away from the building. ■ No-Infiltration Section: This section includes an underdrain and an impermeable liner that does not Always adhere to the slope allow for any infiltration of stormwater into the recommendations provided in the subgrade soils. It is appropriate to use a no- geotechnical report. In the absence infiltration system when either of the following is of a geotechnical report,the following true: general recommendations should be followed for the first 10 feet from a o Land use or activities could contaminate building foundation. groundwater when stormwater is allowed to infiltrate, or 1) Where feasible,provide a slope of 10%for a distance of 10 feet away o The BMP is located over potentially expansive from a building foundation. soils or bedrock and is adjacent(within 10 feet)to structures. 2) In locations where non-expansive soil or bedrock conditions exist, ■ Partial Infiltration Section: This section does not the slope for the surface within 10 include an impermeable liner and,therefore;allows feet of the building should be at for some infiltration. Stormwater that does not least 5%away from the building infiltrate will be collected and removed by an for unpaved(landscaped) surfaces. underdrain system. 3) In locations where potentially ■ Full Infiltration Section: This section is designed to expansive soil or bedrock infiltrate all of the water stored into the subgrade below. conditions exist,the design slope Overflows are managed via perimeter drainage to a should be at least 10%away from downstream conveyance element. UDFCD recommends the building for unpaved a minimum infiltration rate of 2 times the rate needed to (landscaped) surfaces. drain the WQCV over 12 hours. 4) For paved surfaces, a slope of at When using an underdrain system,provide a control orifice least 2% away from the building is sized to drain the design volume in 12 hours or more (see adequate. Where accessibility Equation B-3). Use a minimum orifice size of 3/8 inch to requirements or other design avoid clogging. This will provide detention and slow release constraints do not apply,use an of the WQCV,providing water quality benefits and reducing increased minimum design slope impacts to downstream channels. Space underdrain pipes a for paved areas(2.5%where non- maximum of 20 feet on center. Provide cleanouts to enable expansive soil or bedrock maintenance of the underdrain. Cleanouts can also be used to conditions exist). conduct an inspection(by camera) of the underdrain system to November 2010 Urban Drainage and Flood Control District B-7 Urban Storm Drainage Criteria Manual Volume 3 T-3 Bioretention ensure that the pipe was not crushed or disconnected during construction. Calculate the diameter of the orifice for a 12-hour drain time using Equation B-3 (Use a minimum orifice size of 3/8 inch to avoid clogging.): D12 hour drain time — F T-1y0.41 Equation B-3 Where: D =orifice diameter(in) y =distance from the lowest elevation of the storage volume (i.e., surface of the filter)to the center of the orifice(ft) V =volume(WQCV or the portion of the WQCV in the rain garden) to drain in 12 hours(ft3) In previous versions of this manual,UDFCD recommended that the underdrain be placed in an aggregate layer and that a geotextile(separator fabric)be placed between this aggregate and the growing medium. This version of the manual replaces that section with materials that,when used together, eliminate the need for a separator fabric. The underdrain system should be placed within an 6-inch-thick section of CDOT Class C filter material meeting the gradation in Table B-2. Use slotted pipe that meets the slot dimensions provided in Table B-3. Table B-2. Gradation Specifications for CDOT Class C Filter Material (Source: CDOT Table 703-7) Sieve Size Mass Percent Passing Square Mesh Sieves 19.0 mm(3/4") 100 4.75 mm(No. 4) 60— 100 300 µm(No. 50) 10—30 150 µm(No. 100) 0— 10 75 µm(No. 200) 0 -3 B-8 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Bioretention T-3 Table B-3. Dimensions for Slotted Pipe Pipe Diameter Slot 1 Maximum Slot Slot 1 Open Areal Length Width Centers (per foot) 4" 1-1/16" 0.032" 0.413" 1.90 in' 6" 1-3/8" 0.032" 0.516" 1.98 in2 1 Some variation in these values is acceptable and is expected from various pipe manufacturers. Be aware that both increased slot length and decreased slot centers will be beneficial to hydraulics but detrimental to the structure of the pipe. 5. Impermeable Geomembrane Liner and Geotextile Separator Fabric: For no-infiltration sections, install a 30 mil(minimum) PVC geomembrane liner,per Table B-5, on the bottom and sides of the basin, extending up at least to the top of the underdrain layer. Provide at least 9 inches (12 inches if possible) of cover over the membrane where it is attached to the wall to protect the membrane from UV deterioration. The geomembrane should be field-seamed using a dual track welder,which allows for non-destructive testing of almost all field seams. A small amount of single track and/or adhesive seaming should be allowed in limited areas to seam around pipe perforations,to patch seams removed for destructive seam testing, and for limited repairs. The liner should be installed with slack to prevent tearing due to backfill, compaction, and settling. Place CDOT Class B geotextile separator fabric above the geomembrane to protect it from being punctured during the placement of the filter material above the liner. If the subgrade contains angular rocks or other material that could puncture the geomembrane,smooth-roll the surface to create a suitable surface. If smooth-rolling the surface does not provide a suitable surface, also place the separator fabric between the geomembrane and the underlying subgrade. This should only be done when necessary because fabric placed under the geomembrane can increase seepage losses through pinholes or other geomembrane defects. Connect the geomembrane to perimeter concrete walls around the basin perimeter, creating a watertight seal between the geomembrane and the walls using a continuous batten bar and anchor connection (see Figure B-3). Where the need for the impermeable membrane is not as critical,the membrane can be attached with a nitrile-based vinyl adhesive. Use watertight PVC boots for underdrain pipe penetrations through the liner(see Figure B-2). November 2010 Urban Drainage and Flood Control District B-9 Urban Storm Drainage Criteria Manual Volume 3 T-3 Bioretention Table B-4. Physical Requirements for Separator Fabric' Class B Property Elongation Elongation Test Method <50%2 > 50%2 Grab Strength,N(lbs) 800 (180) 510(115) ASTM D 4632 Puncture Resistance,N(lbs) 310(70) 180 (40) ASTM D 4833 Trapezoidal Tear Strength,N(lbs) 310(70) 180 (40) ASTM D 4533 Apparent Opening Size,mm ASTM D 4751 (US Sieve Size) AOS <0.3mm(US Sieve Size No. 50) Permittivity, sec-1 0.02 default value, ASTM D 4491 must also be greater than that of soil Permeability, cm/sec k fabric>k soil for all classes ASTM D 4491 Ultraviolet Degradation at 500 50% strength retained for all classes ASTM D 4355 hours ' Strength values are in the weaker principle direction 2 As measured in accordance with ASTM D 4632 Table B-5. Physical Requirements for Geomembrane Thickness Property 0.76 mm Test Method (30 mil) Thickness,%Tolerance ±5 ASTM D 1593 Tensile Strength,kN/m(lbs/in)width 12.25 (70) ASTM D 882,Method B Modulus at 100%Elongation,kN/m(lbs/in) 5.25 (30) ASTM D 882,Method B Ultimate Elongation, % 350 ASTM D 882,Method A Tear Resistance,N(lbs) 38 (8.5) ASTM D 1004 Low Temperature Impact, °C(°F) -29 (-20) ASTM D 1790 Volatile loss,%max. 0.7 ASTM D 1203,Method A Pinholes,No.Per 8 m2(No.per 10 sq.yds.)max. 1 N/A Bonded Seam Strength, %of tensile strength 80 N/A B-10 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Bioretention T-3 6. Inlet/Outlet Control: In order to provide the proper drain time,the bioretention area can be designed without an underdrain(provided it meets the requirements in step 4)or the outlet can be controlled by an orifice plate. Equation B-3 is a simplified equation for sizing an orifice plate for a 12-hour drain time. 7. How flow enters and exits the BMP is a function of the overall drainage concept for the site. Inlets at each rain garden may or may not be needed. Curb cuts can be designed to both allow stormwater into the rain garden as well as to provide release of Photograph B-2. The curb cut shown allows flows to enter this stormwater in excess of the WQCV. rain garden while excess flows bypass the facility.Note:trees are not recommended inside a rain garden Roadside rain gardens located on a steep site might pool and overflow into downstream cells with a single curb cut, level spreader,or outlet structure located at the most downstream cell. When selecting the type and location of the outlet structure, ensure that the runoff will not short-circuit the rain garden. This is a frequent problem when using a curb inlet located outside the rain garden for overflow. For rain gardens with concentrated points of inflow,provide for energy dissipation. When rock is used,provide separator fabric between the rock and growing medium to minimize subsidence. 8. Vegetation: UDFCD recommends that the filter area be vegetated with drought tolerant species that thrive in sandy soils. Table B-6 provides a suggested seed mix for sites that will not need to be irrigated after the grass has been established. All seed must be well mixed and broadcast, followed by hand raking to cover seed and then mulched. Hydromulching can be effective for large areas. Do not place seed when standing water or snow is present or if the ground is frozen. Weed control is critical in the first two to three years, especially when starting with seed. Do not use conventional sod. Conventional sod is grown in clay soil that will seal the filter area, greatly reducing overall function of the BMP. Several successful local installations have started with seed. Designing for Flood Protection Provide the WQCV in rain gardens that direct excess flow into to a landscaped area providing the flood control volume. Design the flood control outlet to meter the major event(100-year event) and slowly release the difference in volume between the EURV and the WQCV. (This assumes that the runoff treated by the rain gardens is routed directly into the outlet or infiltrates.) Providing treatment in this manner will reduce inundation in the landscaped area to a few times per year, resulting in an area better suited for multipurpose uses. November 2010 Urban Drainage and Flood Control District B-11 Urban Storm Drainage Criteria Manual Volume 3 T-3 Bioretention When using an impermeable liner, select plants with diffuse(or fibrous)root systems,not taproots. Taproots can damage the liner and/or underdrain pipe. Avoid trees and large shrubs that may interfere with restorative maintenance. Trees and shrubs can be planted outside of the area of growing medium. Use a cutoff wall to ensure that roots do not grow into the underdrain or place trees and shrubs a conservative distance from the underdrain. 9. Irrigation: Provide spray irrigation at or above the WQCV elevation or place temporary irrigation on top of the rain garden surface. Do not place sprinkler heads on the flat surface. Remove temporary irrigation when vegetation is established. If left in place this will become buried over time and will be damaged during maintenance operations. Irrigation schedules should be adjusted during the growing season to provide the minimum water necessary to maintain plant health and to maintain the available pore space for infiltration. B-12 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 EPS E GROUP NORTHERN APPENDIX C LANDSCAPE PLAN NORTHERNENGINEERING.COM 970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY APPENDIX EPS E APPENDIX D PERMITS GROUP NORTHERN NORTHERNENGINEERING.COM 1 970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY APPENDIX EPS E INSPECTIONGROUP NORTHERN APPENDIX E • NORTHERNENGINEERING.COM 970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY APPENDIX STORM WATER MANAGEMENT PLAN Engines Energy Conversions Lab INSPECTION TABLE BMP Name/Desc. Date Erosion Control Measures Effective Brief Revision Description Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) 1 STORM WATER MANAGEMENT PLAN Engines Energy Conversions Lab INSPECTION TABLE BMP Name/Desc. Date Erosion Control Measures Effective Brief Revision Description Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes(w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) 2 STORM WATER MANAGEMENT PLAN Engines Energy Conversions Lab INSPECTION TABLE BMP Name/Desc. Date Erosion Control Measures Effective Brief Revision Description Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes(w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) 3 STORM WATER MANAGEMENT PLAN Engines Energy Conversions Lab INSPECTION TABLE BMP Name/Desc. Date Erosion Control Measures Effective Brief Revision Description Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes(w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) 4 STORM WATER MANAGEMENT PLAN Engines Energy Conversions Lab INSPECTION TABLE BMP Name/Desc. Date Erosion Control Measures Effective Brief Revision Description Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes(w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) 5 STORM WATER MANAGEMENT PLAN Engines Energy Conversions Lab INSPECTION TABLE BMP Name/Desc. Date Erosion Control Measures Effective Brief Revision Description Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes(w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) 6 STORM WATER MANAGEMENT PLAN Engines Energy Conversions Lab INSPECTION TABLE BMP Name/Desc. Date Erosion Control Measures Effective Brief Revision Description Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes(w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) 7 STORM WATER MANAGEMENT PLAN Engines Energy Conversions Lab INSPECTION TABLE BMP Name/Desc. Date Erosion Control Measures Effective Brief Revision Description Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes(w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) 8 STORM WATER MANAGEMENT PLAN Engines Energy Conversions Lab INSPECTION TABLE BMP Name/Desc. Date Erosion Control Measures Effective Brief Revision Description Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes(w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) 9 STORM WATER MANAGEMENT PLAN Engines Energy Conversions Lab INSPECTION TABLE BMP Name/Desc. Date Erosion Control Measures Effective Brief Revision Description Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes(w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) 10 STORM WATER MANAGEMENT PLAN Engines Energy Conversions Lab INSPECTION TABLE BMP Name/Desc. Date Erosion Control Measures Effective Brief Revision Description Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes(w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) Yes No Yes (w/Rev) 11 EPS E GROUP NORTHERN APPENDIX F CONTRACTOR INSERTS L v 11 NORTHERNENGINEERING.COM 970.221.4158 SWMP:WILLOX FARMS FORT COLLINS I GREELEY APPENDIX a) NORTH ° wool A e 40 0 40 80 120 Feet (IN FEET)9S' 99k499 — 49�3 = = = = = = = _ _ _ _ =499 —490990-= = — — — s3�— - - -WEST WILLOX LANE --� - - - - - - - - F — i — 1 inch 40 ft. a _- __ ____- _- - _ -- _ - °� - - WEST WILLOX LANE MATCH LINE - SEE THIS SHEET LEFT EC1 --------------- N ■ I\J \ \ � I I I IIY \I nl x lu i I �\ /PROPOSED 2' \ —I \ \ \ 4984 / \\ \\ 1 / c O CONCRETEP N � I T III I \ I I ` ACKELSON CONNIE A. 603 \�� \\\\ \ ^� co J I ( � �\\\i\� I I / I II I� / > KAFKA, AMY I I I' I \ I \- W WILLOX LANE, \ I� W WILLOX LANE, r 1 < I .� I I I I J , J il t >> \ —Ir 1�)///I l L J I �� I I I00 I • LLI , � _ , c w J Sq/ �� J i i I �, \\\ CJ fJ r�,�\jig I I i \ 9 I ( I SOFT \ NT S v i �� \\��v I / I I Sal GOLD PARK I w w ST Fpy , IIJ \\\ /I HICKORY TREET \ Q,- l I I KEYMAP o•�_ NTS Q Dry O N O N i(n L � - - � I \ \ � --- �, \ \\ \\ � � / � I I i III LEGEND: L � �a �.� oa)o-� �°`�o Oar ,a I I G =� � Eo =Lz� TZ � o I I PROPOSED STORM SEWER L o �o c ° �' o\rn 1 PROPOSED CONTOUR 93 o \ \ I 1 0Lo_ 1 \ / \ r v w PROPOSED 4' �� \ \ / I O I - - - a c c m a rn 1 1 I EXISTING CONTOUR —4953- - - - - - o c o o a CONCRETE PAN � \ / 'o c c o ` c w/7"CURBS \� \ PROPOSED SWALE a m ___________________ L L O Q�L (�L 1 / / / I 1 1 QI �li PROPOSED CURB&GUTTER 1 V/ I PROPERTY BOUNDARY 3 ��� I I I I r 0� 0 PROPOSED 2 1 ( — x 1 0 / / \I t I LIMITS OF DISTURBANCE �LOa CONCRETE PAN I [M — ' 1 C2 o x L -_ PROPOSED 4' I I — — /I^ L. j I t 1 _ - t \I 4J�' 'j /I I I t I SILT FENCE SF— CONCRETES'F �a 1 Wm PAN _ N w/7"CURBS - - I - - � 1 1 `-1 I / / I 1� IW oc� C3 c Z x / I I WATTLE DIKE W z - — —I I 1I\II 0 U H ROCK SOCK R$ — \ — —I— — — sg PEREZ DANIEL A. o 4987_ .-_ I I I 400 HICKORY STREET 149 ` ��'� \\ 1 \ 1 I o �\ . . 9p19 � 1`J'� CONCRETE WASH AREA CWA — — MOLLER STREET \\ \ \ J � — — _ I I S�� �\\\ \ ( / / / / VEHICLE TRACKING CONTROL PAD J \ lam _ /)wow _ INLET PROTECTION �Jp z cnl ' / �� / / / ',�� - -� \ \ \ \ IN� PITT, JEAN III I --i i r \ I / I / \ \I PROPOSED 4' I � � J 11 / // �9 / \ \ \ \ �,/ I I rn o � BALE OUTLET PROTECTION— I' / _ IIII �/ / _ _1 M BOP 1522 WOOD LANE, I I 1 -' \ 1` 1 CONCRETE PAN I / // // I J u //// / \ \ J/ \ \ 00 \ 0 w/7"CURBS I V r � ,/i / IIJ II / _ \ I \\ \ / sF I -- I I I �c, � / I//�/^>/ IIJ I / \ \= —I \I 1\ \ \\ \ \ a �� // / I .T/ I \ I : 1► I /� /�/ I)�/rt\ \�—/\ / \\ \\ ` \ �� l V/ rir \ \ N lo I li /i _ , A 1 o Q o 1//�( / / //)/ \ \ ® III \ \ ( I I 0o z F I , o I �//I j///�/ //// \ \ I I \ \ Nd- / / MULCH MU I-\ Q /// � II Q � �. _ / o \� \I //// /// /�// - - - - - - 00 �:- IZQ LL `\ J,o � II ! ///�/ �`�`; �� 1 \ \I / / \\ I / // II ��/ /� � �� .� ' \ I \ BENCHMARK/BASIS OF BEARING: � ` ,�- I jai /ii t 11 \ )`// / /I \ I _ / I �- I PROJECT DATUM: NAVD88 o m 0 ) �// // / WOOD ` �� N — _ = =I 1 �jll ///( - - - I / I L I^ U w t -I-- rill \ _ � — — // \ \ /rl, lli/// DUCK -�, \ / I1 / / I / POND 1 \ \ / \ \ \ / I / City of Fort Collins Benchmark NO. 9-07. o r- N Q I I I /� Rs I / Southeast corner of Shields ST. and Willox Lane on the South east wingwall of rn o m o m a. SAINT GRACE 8 I - — I �/ I _ \ 3 GBP LLC \ I \ / of the bridge over an irrigation ditch. ° , v / /�, v 1 \ 1 1434 WOOD LANE, T \ STREET- \ „ / / \\ \ I / \� JI ELEV.=4999.15 / � -\\ I-\ �,- - - - - ��- - � `� / --�_ --_ _ NGS Benchmark V-401. _ - -`�- -_- - - - - _ — In Fort Collins, at the unction of U.S. 287 and Bristlecone Drive, 59.4 meters , �,�- i \ - - J I -�. (194.9 ft) east of the north bound lanes of the highway, 14.7 I ' \ \�I I III I laP �// i� _- - - - - - - - - - - ===-Y=- -���- � - �i� - - - ` _ - - - meters (48.2ft) North of the center of the drive, and 1.1 meters (3.6 ft) north `� \ \ \ \ s - - - -. - `-- —I WCKORY STREET _,ter — — — — J J I _ ~ `--�_— �; L -� _ - \ _ - - _ - of a utility pole and powerline crossing the drive, Note--access to the datum is / / _ through a 5-inch logo cap. I � I .' � .'. �� i - J I \ I I - � L - -1 : d / I\ / - - - � / - - - III �..'` / � � ° L.L N (/ I .�: . . � � ELEV.=4977.81 PEREZ DANIEL A. - 11 � -- � - - - _ - �`O : 4s 4 0HICKORYSTREET149 ` � - - - - - j_•:.:.` - - s I Please Note: This plan set is using NAVD88 for a vertical datum. Surrounding developments have used NGVD29 Unadjusted for their vertical O o; 5 :LL` it �� � I �� I �/ I III I I �� III I� I l< �I datums. PROPOSED 2' CONCRETE PAN li i I If NGVD29 Unadjusted Datum is required for any purpose, the following OD equation should be used: a NGVD29 Unadjusted = NAVD88- 3.18' 8s ,► / / $� / I Z ~ S� O l � Basis of Bearings 878 S5 / ke$5 I Assuming the North line of the Northeast Quarter of the Northwest Quarter of - - I I -- � Section 2, Township, 7 North, Range 69 West of the 6th P.M., as bearing Q U ILI ---------7-- - x - - (117 ----------------------------- _ _9 ------------------------- __ \- - x North 89°33'13" East. LL uu)i a I/IIII IIII '�\ — ' ��98� / \\ Z IIIII►I Illy _ - - ✓ � \ \ GENERAL NOTES: X I I I I �� \ — — SOFT GOLD PARK + \ \ O O O4 a II.I II-I lilil t �� � 1. CONTRACTOR SHALL IMMEDIATELY STABILIZE ALL DISTURBED SLOPES BY CRIMP N FUTURE CITY OF FORT COLLINS I / \ \\\ I \ \ J x g N PARKS DEPT. IRRIGATION LINE \ \ / — \ / J C/ MULCHING OR SIMILAR METHODS. N (TO BE DESIGNED BY OTHERS) �\�, � —_— I v I TABLE OF CONSTRUCTION SEQUENCE AND BMP APPLICATION \�4s 2. SWMP ADMINISTRATOR: o¢ \� \ 49 22 i 1 \ \\ \=4SY' \\\ \ // \ Contact Project: WILLOX FARMS Company n/ W ' LLL CONSTRUCTION PHASE MOBILIZATION DEMOLITION GRADING UTILITIES FLAT WORK VERTICAL LANDSCAPE DEMOBILIZATION Address L.L w a `�I I I ��h \ 111 L \ I INSTALLATION INSTALLATION INSTALLATION Phone 1 1 Z m I ICI III a I I \�\\ IiII // I \ L X BEST MANAGEMENT PRACTICES(BMPS) W I�IIIII I / L LL LL I 3. CONTRACTOR TO PROVIDE VEHICLE TRACKING CONTROL FOR CONCRETE o J V t°a \\\ J%/ II —� / O I I I\1 I STRUCTURAL"INSTALLATION" WASHOUT AREA IF ACCESS IS OFF PAVEMENT. r 1 z z l x I V a N pQ — — I 1 I Silt Fence Barriers J \�,I I \\\\\ 4. REFER TO THE Final Drainage Report dated April 12,2024 BY NORTHERN 3 O p I II I IIII I \\\ //I \ -�sr9 I 1 I Concrete Washout Area' ENGINEERING FOR ADDITIONAL INFORMATION. W Z O III II II IIII 1 \ \\\� a/i/ 8¢\ Vehicle Tracking Pad" 5. DEVELOPER/CONTRACTOR SHALL RECEIVE A PERMIT THROUGH THE PARKS DEPARTMENT PRIOR TO COMMENCEMENT OF ANY CONSTRUCTION WORK.THIS o W co IIIIII III III !\ \ Dt`r ` 1 1\ I I I Straw Wattles' PERMIT WILL INCLUDE ALL REQUESTED DETAILS AND INFORMATION REGARDING I W IIII IIII IIII \ \ III \ I I z o Q III Inlet Protection' Any prior inlets that cou d use protecting THE USE OF THE PARK PROPERTY FOR ALL CONSTRUCTION WORK AND o ^ t II \ ■ ■�� ■ ■ ■ ■ ■ ■ ■ I ACTIVITY, DATES OF CONSTRUCTION, DETAILS RESTORATION PLANS, ETC. 3 u Rock Socks` Any prior in ets that cou d use protecting CALL UTILITY NOTIFICATION CENTER OF Q N F MATCH LINE - SEE THIS SHEET RIGHT All Temporary BMPs to be Removed once Construction is Complete COLORADO a I co a ro Vegetative , Temporary Seeding Planting Anytime the site will sit dormant longer t an 30 ays Mulching/Sealant Anytime the sz1zite will sit dormant longer t an 30 as Sheet c� z o Permanent Seeding Planting Know what's below. ~ EC4 o Call before you dig. Sod Installation CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU Rolled Products:Netting/Blankets/Mats Anytime the site wil sit dormant longer t an 30 ays DIG,GRADE,OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES. ##of 64