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HomeMy WebLinkAboutSNOW RIDGE APARTMENTS - FDP240003 - SUBMITTAL DOCUMENTS - ROUND 2 - Stormwater Management Plan� I NORTHERN ENGINEERING STORMWATER MANAGEMENT PLAN SNOW RIDGE APARTMENTS FORT COLLINS, COLORADO APRIL 3, 2024 Project Number: 2047-0a1 NORTHERNENGiNEERING.COM 970.221.4158 FORT COLLINS' GREELEY April 3, 2024 City of Fort Collins Stormwater Development Review 700 Wood Street Fort Collins, CO 80521 RE: STORMWATER MANAGEMENT PLAN SNOW RIDGE APARTMENTS To Whom It May Concern: Northern Engineering Services, Inc. is pleased to submit this Stormwater Management Plan for the Snow Ridge Apartments 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 (�a I�e fi(le�-i� b�� ���� �� �i�cc, l, and the Certification No. for this SDP is (t�_I�e fillecl_on b�;�eo � ��it�e_�i. The Permit Certification is effective beginning;i_o be fil.le�? i_i I��� per_n�u{_tE;,_.;, and initial certification expires (�o be (illed-in bv �ermittee;l. A copy ofthe issuance cover letter can be found in Appendix D ofthis document !;io be filled-on b��eu rriitteel. 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 ofthe SWMP Administrator and/orthe 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. C���-- Jacob O'Banion, EI Project Engineer � Amanda Poincelot Project Manager NORTHERNENGINEERING.COM � 970.221.4158 FORT COLLINS � GREELEY SWMP: SNOW RIDGE APARTMENTS 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 .................................................................................................................................2 1.4 EXISTING TOPOGRAPHIC AND SOIL DATA ..............................................................................................2 1.5 RECEIVING WATERS .................................................................................................................................3 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 ............................................................................................4 3.1 OBJ ECTIVES .............................................................................................................................................4 3.2 SMWPAVAILABILITY .................................................................................................................................4 3.3 DEFINITIONS ............................................................................................................................................4 3.4 ADDITIONAL PERMITTING .......................................................................................................................4 4.0 ENVIRONMENTAL IMPACT ............................................................................................4 5.0 POTENTIAL POLLUTION SOURCES .................................................................................5 5.1 DISTURBED AND STORED SOILS .............................................................................................................5 5.2 VEHICLE TRACKING OF SEDIMENT ..........................................................................................................6 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 ...............................................................................................................7 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 .........................................................................9 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 ....................................................................................10 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 SWMPADMINISTRATOR .........................................................................................................................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 NORTHERNENGINEERING.COM � 970.221.4158 SWMP: SNOW RIDGEAPARTMENTS FORT COLLINS � GREELEY 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 PERMITAND 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 � 970.221.4158 SWMP: SNOW RIDGEAPARTMENTS FORT COLLINS � GREELEY 1.0 PROJECT DESCRIPTIONS AND NATURE OF CONSTRUCTION 1.1 EXISTING SITE DESCRIPTION A replat of Tract A, Brookfield First Replat, located in the northeast Quarter of Section 4, Township 6 North, Range 68 West of the 6th Principal Meridian, City of Fort Collins, County of Larimer, State of Colorado. More specifically it is 8.34-acres of land Ya mile south of east Harmony Road, bound on the east by Cinquefoil Lane, on the west by Brookfield Drive, and the south by Precision Drive. � ,r �`;�. ._ , � f '� �' t i• �� , %+� r , ` � � � ..�'1' �:, . � ...� � . t..•� . � � _.!� � ' . .. NER 1509 � " � �.��,,,, S�r�.�.� � . . ��� � � �i . -��`� .« --, . � �' ,� � - � .���;=,.� �� .� � . � ,, .:�� ,. � �'� � , �`., .�. . +,•,V. • � �' - -. , ��► � '� ! �, ', � , � �. ,� "'.t` ?f • '� � , ,. } Y.' . �,. - � � a+�. • , . . ' ; � , ,.�I. ,. '� _, � � �•"`+ . �-� . ` J �r , �. �� ��� ■ � Figure 1- Vicinity Map 1.2 NATURE OF CONSTRUCTION ACTIVITY 1 - A - t _' 2 �} � ��f ;•, , �- � �� w w � � � � 0 J W i � � . ;,� .� i" , � �� f . -. 'r � � � The project includes the construction of an 8-unit complex. Consisting of a conversion of the existing residential structure to a 2-unit complex and the addition of (3) 2-unit interconnected structures. Other proposed improvements include a new drive isle consisting of concrete and permeable pavers, new sidewalks and new landscaping, a mailroom with bike storage, outdoor bike parking, trash enclosure, and a patio common area. Standard water quality, LID, and all associated storm infrastructure will be provided with this project. Detention will be provided on-site in the Pond on the east side of site. Utilities will be installed with the construction of Snow Ridge Apartments. NORTHERNENGINEERING.COM � 970.221.4158 SWMP: SNOW RIDGEAPARTMENTS FORT COLLINS � GREELEY 1 � 21 1.3 SITE DISTURBANCE The site disturbance will occur across roughly 0.72 acres. It is recommended that existing site condition photos be taken prior to the demolition. CALCULATIONS CHART TOTAL DISTURBED PROJECT AREA 0.72 ACRES TOTAL "ONSITE" AREA OF DISTURBANCE 0.67 ACRES TOTAL "OFFSITE" AREA OF DISTURBANCE 0.05 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 "'35% DENSITY EXISTING SOILTYPE C APPROX. GROUNDWATER DEPTH 17 FEET NUMBER OF PHASES W/ PROJECT N/A TOTAL VOLUME OF IMPORTED (+) / EXPORTED (-) MATERIALS CUB. YD. TOTAL AREA OF STOCKPILING OF FILL OR BORROW AREAS OFF SITE SQ� FEET STEEPEST SLOPE 5:2 H:V DISTANCE FROM A RIPARIAN AREA OR SENSITIVE AREA N/A FEET 1.4 EXISTING TOPOGRAPHICAND 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 PLS Corporation in July 2023. A NRCS Custom Soil Resource Report of the property indicates that the soil on site is composed entirely of Altvan-Satanta loams with slopes of 3- 9 percent. Altvan-Satanta loam is considered well drained and is hydrologic Soil Group B. NRCS indicates a wind erodibility rating of 5(of a scale of 1 to 8, 1 is most susceptible to erosion), and as such this site does has a median to low potential for wind erosion. NRCS indicates an erosion factor, K, of 0.28 (range of 0.02-0.69, 0.69 being more susceptible to sheet and rill erosion). As such, this site has a moderate susceptibility to sheet and rill erosion. The existing groundcover consists of grass with tree cover, a residential structure, and an asphalt driveway. The existing on-site runoff of the western two thirds of the property generally drains from the east-to-southwest where it sheet flows to the adjacent properties to the south and west. The existing on- site runoff of the eastern third of the property generally drains from the west-to-east across moderately flat grades (e.g., <6.00%) onto Shields Street. From there, the drainage continues to Prospect Road, and is received by the New Mercer Canal. NORTHERNENGINEERING.COM � 970.221.4158 FORT COLLINS � GREELEY SWMP: SNOW RIDGE APARTMENTS 2 � 21 1.5 RECEIVING WATERS The Snow Ridge Apartments will have two outfall locations. The majority of the site will be released from the detention pond on the east side of the site to the flow line of South Shields Street. A small portion of flow will maintain existing flow patterns discharging southwest via sheet flow to the flow line of South Shields Street. Another small portion of the site will discharge southwest of the site maintaining historic drainage patterns. From there, the drainage continues to Prospect Road, and is received by the New Mercer Canal. 1.6 EXISTING SITE CONDITIONS AND VEGETATION The existing groundcover consists of grass with tree cover, a residential structure, and an asphalt driveway. The remainder of the site is comprised of grass. There is not a significant amount of grade change on the site. It is highly recommended that pre-construction photos be taken to clearly document vegetative conditions priorto any disturbance activities. 1.7 EXISTING GROUNDWATER Groundwater depth was measured onsite in September 2023 by Soillogic Inc. within various borings (see attached Subsurface Exploration Report). At the time of ineasurement (September 14, 2023), groundwater depth was approximately 17' 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 of the existing asphalt pavement within the existing driveway, the removal of approximately 530 sf of the existing residential building, the removal of a portion of the existing sidewalk along South Shields Street, the removal of existing concrete around the existing residential building, and the removal of some existing fence and trees on the site. Saw cuts will be made and asphalt will be removed for utility tie ins on South Shields Street. 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 and water quality pond will commence. Next, utility installation including sanitary sewer service, water service, fire service, electric service, and storm sewer. Construction ofthe proposed buildings is expected to begin once the storm sewer is in place. New curb/gutter, water quality pavers, drive paving, and sidewalks are expected to begin after the foundations ofthe buildings are in place and will coincide with building construction. The final stages of site construction will be fine grading of the areas mentioned above, and the 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. NORTHERNENGINEERING.COM � 970.221.4158 FORT COLLINS � GREELEY SWMP: SNOW RIDGE APARTMENTS 3 � 21 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 Snow Ridge Apartments in Fort Collins, C0. 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 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 inethods, 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 ofthis 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. NORTHERNENGINEERING.COM � 970.221.4158 SWMP: SNOW RIDGEAPARTMENTS FORT COLLINS � GREELEY 4 � 21 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 "N0." 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. • 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 0.72 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 stock pile 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). NORTHERNENGINEERING.COM � 970.221.4158 SWMP: SNOW RIDGEAPARTMENTS FORT COLLINS � GREELEY 5 � 21 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 and east 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-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 There is not anticipated to be a significant amount of export leaving the site. 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 NORTHERNENGINEERING.COM � 970.221.4158 SWMP: SNOW RIDGEAPARTMENTS FORT COLLINS � GREELEY 6 � 21 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. 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 features 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 nearby to hang a hose after filling to catch drips, and to scoop up any dirt that 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 ofthe 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 NORTHERNENGINEERING.COM � 970.221.4158 FORT COLLINS � GREELEY SWMP: SNOW RIDGE APARTMENTS 7 � 21 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 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. Pre mixed 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 NORTHERNENGINEERING.COM � 970.221.4158 FORT COLLINS � GREELEY SWMP: SNOW RIDGE APARTMENTS 8 � 21 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 covercontrol). 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. 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. 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 Manual) 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. NORTHERNENGINEERING.COM � 970.221.4158 SWMP: SNOW RIDGEAPARTMENTS FORT COLLINS � GREELEY 9 � 21 • 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. A spill 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 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 in the event that 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 2023 by Soilslogic, Inc., ground water levels indicate that it may be present during construction activities at approximately 17' deep. If encountered, dewatering activities may be required. Groundwater has in most excavations mixed with the dirt and as NORTHERNENGINEERING.COM � 970.221.4158 SWMP: SNOW RIDGEAPARTMENTS FORT COLLINS � GREELEY 10 � 21 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 ifthey are to be infiltrated on site. Ifthe 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. 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: Company: Phone: E-mail: (to be filled in by permittee) (to be filled in by permittee) (to be filled in by permittee) (to be filled in by permittee) 6.2 OWNER INFORMATION Name: Matthew Deault Company: MMD Built LLC Phone: (303) 931-9295 E-mail: 6.3 BEST MANAGEMENT PRACTICES (BMPS) FOR STORMWATER POLLUTION PREVENTION Beginning from mobilization, and throughout the entire construction ofthe 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 contractorto implement modifications as directed. NORTHERNENGINEERING.COM � 970.221.4158 FORT COLLINS � GREELEY SWMP: SNOW RIDGE APARTMENTS 11 � 21 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 BMPs that may be appropriate for the site that have not specifically been mentioned in the report. 6.4 STRUCTURAL PRACTICES FOR EROSION AND SEDIMENT CONTROL Structural BMPs are physical devices that are implemented to prevent erosion from happening orto 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 forthe 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) 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) for additional clarification. Sediment Control Log - aka "Straw Wattles" (Phase I) 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 prior to 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 perpendicular to flow every 4" of elevation difference. Refer to the Erosion Control Plan (Sheets EC1- EC3) for additional clarification. NORTHERNENGINEERING.COM � 970.221.4158 SWMP: SNOW RIDGEAPARTMENTS FORT COLLINS � GREELEY 12 � 21 Vehicle Tracking Control Pads (Phase I) 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 priorto any land disturbing activity (demolition - as necessary, stockpiling, stripping, grading, etc.). Location ofvehicle 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. 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 ofthe vehicle tracking pad is at the east entrance of the project site. Refer to the Erosion Control Plan (Sheets EC1- EC2) for additional clarification. Inlet Protection (Phase I & II) 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 fortears 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 (Sheets 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, induding 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. NORTHERNENGINEERING.COM � 970.221.4158 FORT COLLINS � GREELEY SWMP: SNOW RIDGE APARTMENTS 13 � 21 Concrete Washout Area (Phase II) 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 of 400 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. 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 Ripley Design. 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. NORTHERNENGINEERING.COM � 970.221.4158 SWMP: SNOW RIDGEAPARTMENTS FORT COLLINS � GREELEY 14 � 21 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 Ripley Design. Stockpile Management (Phases I-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 side of the stockpile should be identified. BMPs such as surface roughening, temporary seeding, mulching, erosion control blankets, or soil binders should be used to stabilize the stockpile su rface. 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 asneeded. 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 ofthe SWMP Administrator. Mulching (Phase I-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 Ripley Design. 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 NORTHERNENGINEERING.COM � 970.221.4158 SWMP: SNOW RIDGEAPARTMENTS FORT COLLINS � GREELEY 15 � 21 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 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. StreetSweeping 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/Vehide 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 NORTHERNENGINEERING.COM � 970.221.4158 SWMP: SNOW RIDGEAPARTMENTS FORT COLLINS � GREELEY 16 � 21 Phase II - Infrastructure Stage; BMPs for utility, paving, and curb installation Phase III - Vertical Construction Stage; BMPs for individual building construction. Phase IV - Permanent BMPs and final site stabilization. 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. Table 1- Preliminary Permit and Construction Schedule TASK BEGINNING ENDING DATE BMP-PHASE OF DATE DEVELOPMENT" Development Construction Permit Issued by City of Fort Collins Jul. 2024 Aug. 2024 I Overlot Grading (Demolition) Jul. 2024 Aug. 2024 I Utility Installation Au . 2024 Sept. 2024 II Paving and Vertical Construction Sept. 2024 Apri12025 III Final Stabilization April 2025 June 2025 IV 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 for the 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, orthe potential for, pollutants enteringthe 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. NORTHERNENGINEERING.COM � 970.221.4158 FORT COLLINS � GREELEY SWMP: SNOW RIDGE APARTMENTS 17 � 21 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 ofthis 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. NORTHERNENGINEERING.COM � 970.221.4158 FORT COLLINS � GREELEY SWMP: SNOW RIDGE APARTMENTS 18 � 21 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 of the State of Colorado (which indude 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. NORTHERNENGINEERING.COM � 970.221.4158 SWMP: SNOW RIDGEAPARTMENTS FORT COLLINS � GREELEY 19 � 21 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 PRAI RI E 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" NORTHERNENGINEERING.COM � 970.221.4158 SWMP: SNOW RIDGEAPARTMENTS FORT COLLINS � GREELEY 20 � 21 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 Partnershi� Boulder 9.0 REFERENCES 1. Drainage Report for Snow Ridge Apartments, Northern Engineering, April 3rd, 2024 (NE Project No. 2047-001) 2. City of Fort Collins Landsca�e 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) ofthe 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. NORTHERNENGINEERING.COM � 970.221.4158 FORT COLLINS � GREELEY SWMP: SNOW RIDGE APARTMENTS 21 � 21 NORTHERNENGINEERING.COM � 970.221.4158 SWMP: SNOW RIDGEAPARTMENTS FORT COLLINS � GREELEY APPENDIX T U O C � � � U � U � � -p �� � N N � � � "� N N � N .� � N N�� U�++ N t}q O U N b�A o z�� 9 �� W z�� � N�, � p O t0 — �� � � � � � � -p C T 'O �-p b�0 �O � N O O 00 � � ' � � C 'N Q'— V1 � � N � �-.� � � N 47 > N i � N � � � N O C c6 T N O� C � n � � C N d � � W � @ C @ � W � W � a � � 5 W � Q J � C9 Z a a � X l� 0 _ � � � � � � � l..L� � � � � � � � r � W � � � J w � � � � � �� � � � � � � � � � � � � � � � Z A�ii 2 �3 z � � � _ � Z � � � g � � tiL W t� i3 ffi Z � � � � � � ~ N WO �N � U Q \ z Z LJ O J � � � Q d\- U � � O (n U � Q �- m Z � H � � � m � � Z w Z Q �O O� tnm Q� �o w � � N � Q � � � �— z w � � � Q � Q w C� � � � O Z � J Q � Z Z Q J � J O � � Z O U Z O V � O � W Sheet EC 1 8 of 22 0 �o �� 00 <� W � 0 0 < � c� v �o �� � �$ N � o a N p u N 0 0 0 � r a � � < W � J a � Z � � o = a }^ J � a � W X -a�� X � I � O � ^ 3 µ / N Oy o � t� v° � o N � � I a W . z i� � a . � � � X C9 � � O <� a� I I I /! 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PERCENT OF PROJECT AREA EXPOSED �� ��\ �--- /� --�---5033—' —�--_ _���� `�\ �� \\ ; EST. PERCENTVEGETATIVECOVER � � EXISTING SOIL TYPE i \ � � � _ _ i � � — — � � �� \\ \ � � � �� ' � APPROX. GROUNDWATER DEPTH � � � — — — — l � � � � � � � � i / NUMBER OF PHASES W/ PROJECT I�—/�_____— �—�--------------5032—�__\—_-- I �� �� � \\ �1---- �--� , �� TOTALVOLUMEOFIMPORTED(+)/EXPORTED(-)MATERIALS �— � \ � TOTAL AREA OF STOCKPILING OF FILL OR BORROW AREAS OFF ��i ---�` ------so3�—__ �—r � \ �� ��--_--^��� �i %�� SITE I \\�� \�`---- �J��� \� \� --___ �--- /- � -------------- - STEEPESTSLOPE � — - - � ----------------- ��---_ �_ � � _ _ _ _ _ _ _ - - �- - - - - - — _ _ _ _ _ _ _ � __ � _ — � � � DISTANCE FROM A RIPARIAN AREA OR SENSITIVE AREA � I I � 0.72 0.67 0.05 N/A N/A N/A 100% ^'35% 0 N/A 5:2 V/A ACRES ACRES ACRES ACRES DENSITY FEET CU B. YD. SQ. FEET H:V FEET NORTH 20 0 20 40 60 Feet ( IN FEET ) � �„�h - �n r+ LEGEND: PROPOSED STORM SEWER PROPOSED CONTOUR EXISTING CONTOUR PROPOSED SWALE LIMIT OF DISTURBANCE PROPOSED CURB & GUTTER PROPERTY BOUNDARY SILT FENCE m�i��r��.�r�a ROCK SOCK RIPRAP CONCRETE WASH AREA VEHICLE TRACKING CONTROL PAD INLET PROTECTION BALE OUTLET PROTECTION SLOPE DRAIN SEDIMENT TRAP BALE INLET PROTECTION EROSION CONTROL FABRIC 93 ----4953----- ------------------- LOD —SF— SF � -\ -� �i � RS �� RP CWA VTC O IP � BOP � SD ST �g BiP EF CITY OF FORT COLLINS UPLAND MIX SEED GENERAL NOTES: 1. CONTRACTOR SHALL IMMEDIATELY STABILIZE ALL DISTURBED SLOPES BY CRIMP MULCHING OR SIMILAR METHODS. 2. SWMP ADMINISTRATOR: Contact Company Address Phone 3. CONTRACTOR TO PROVIDE VEHICLE TRACKING CONTROL FOR CONCRETE WASHOUT AREA IF ACCESS IS OFF PAVEMENT. 4. NO MUD OR DEBRIS IS ALLOWED ON CITY STREETS. IF ANY DOES OCCUR, CONTRACTOR SHALL SWEEP AND CLEAN IMMEDIATELY. 5. REFER TO THE FINAL DRAINAGE REPORT, DATED APRIL 3, 2023 BY NORTHERN ENGINEERING FOR ADDITIONAL INFORMATION. 6. PAVER SYSTEM IS TO BE CONSTRUCTED AS PART OF THE LAST SEQUENCE OF CONSTRUCTION TO MINIMIZE POTENTIAL FOR SEDIMENTATION. 7. FINAL STABILIZATION TO BE DONE IN ACCORDANCE WITH THE FINAL LANDSCAPE PLAN. CALL UTILITY NOTIFICATION CENTER OF COLORADO / • Know what's belOw. Ca�� before you dig. CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU DIG, GRADE, OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES. 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W Sheet EC2 9 of 22 r— — — — — — — — 0 � ,o � � I v 'o �� $ � I ! a � U W w < Z � 0 5 a � W X -a�� X � I � O � ^ 3 µ / N Oy o � t� v° � o N � � I a W . z i� � a . � � � X C9 � � O < � a � � I I r--� i / � � I / I / / � / � i I i �---- -- / � / 1 I / � I / j I / 1 / � / 1 ' � � � I ; / � / I � 1 ( ( , � � � � � ; �� � I � ; I �/ 1 � Q I � � I I � j ,_ _ —. . � � i ' __ _ i � '' � / � �� � PROPOSED SIC , � /� �� � � � / � 1 � / ' � < � i I\ � ; > i � � ' i \ � ; � \ \ � � � ; , i -__ � � , � � \ ; � � I I � I I � I / � I I � / I / I / I ; � � I � � I / I / � I ��� � � /�___— � � I / ' /�� I i // //-- �/ / - / , I / /� � / I � / ,� / i i I i/ I i i \ ' � � ' � � � \ � � � � � � � � � �� � 1� �s ������ � —�---_ . _\/ � \ I I,. � \ � �� \� I , � i � � �I � i � � I L I \ � ��--- � � � � � �e=-- / � \ � ��— i /�1� � / \ \ � \ � � � / � i� � / // OFFSITE CONTOURS PROVIDED i �, / � � � \ � FOR REFERENCE ONLY �5036� , � i � � I � � I� � ` � � / % � � i � / � � ��-- ; \� �,\1 1� � \`,.—'� I � I � I 1 / � • ` � f � � 1 i � / � I � ' , � � � � i I / � 1 , I � I / � � � i � i � I 1 � � � _ � � � / 5036� 1 \ \ _ — — — � / I I I I I � / I 1 � I � \�/ I ` , i 1 � i ; ��\\ I 1 f . � _ � � I I I � � � I 1 i �� -- -- -- - -- - -- � -- \�-��_ � 1 I �� I �--- �------- ------, - �-- - -, - - - - � I 1 \�� / I � 1 ;I �� — �p35i---J I � I � �/,� I \ i � �� -- � _ `_ �— — �� � —___ -- t i� \ I ``/ � I ` �I � � . J I � i ` �l t \ � — \ � 1 `\ � i _ _ _ � / I� — — � �� \ � � i � � — � � � l CALCULATIONS CHART �� � �� � _ _ � � � � � � TOTAL DISTURBED PROJECT AREA � � � � — — — — _ � � � ` � ! TOTAL "ONSITE" AREA OF DISTURBANCE \ � � \ � � _ _ _ _ _ _ _ _ -so3a� i r � \ �� �l \\ ' TOTAL "OFFSITE" AREA OF DISTURBANCE �� �� \� \ ,� � `� � � � � � � � I TOTAL STORAGE/STAGING AREA � � \ � — -� / � � � � � � � � , TOTAL HAUL ROADS AREA � � \ � i � � I � �� A CONSTRUCTION VEHICLE TRAFFIC AREA � � ��' ' �� I I � �� EST. PERCENT OF PROJECT AREA EXPOSED �� ��\ �--- /� --�---5033—' —�--_ _���� `�\ l� \\ , EST. PERCENTVEGETATIVECOVER � � � EXISTING SOIL TYPE i � � � _ _ i � � — — — � � �� \\ \ � � � � � ' � APPROX. GROUNDWATER DEPTH i � � — — — — — l � � � � � � � � NUMBER OF PHASES W/ PROJECT � — — — — — —soaz— _ _ \ I /� �� � \ � � ' — — � , , �� TOTAL VOLUME OF IMPORTED (+) / EXPORTED (-) MATERIALS I � — � � — — — �` — — — — — � — — — — TOTAL AREA OF STOCKPILING OF FILL OR BORROW AREAS OFF ��� ��` ----5031---�� _--�—r/ �� \� � ��--�-- \ � / / � � — ^ � — �i SITE � \���� \��----� /—����`_ \� \�— -----------------\ — ' STEEPESTSLOPE — - - � --------------- ��---" _ _ - - � �.- - - - - - — _ _ � _ _ � _ _ — � � � DISTANCE FROM A RIPARIAN AREA OR SENSITIVE AREA I I I � 0.72 0.67 0.05 N/A N/A N/A 100% ^'35% 17 N/A 5:2 V/A ACRES ACRES ACRES ACRES DENSITY FEET CU B. YD. SQ. FEET H:V FEET NORTH 20 0 20 40 60 Feet ( IN FEET ) L E G E N D: � inch = 20 ft. PROPOSED STORM SEWER PROPOSED CONTOUR 93 EXISTING CONTOUR — — — —4953— — — — — PROPOSED SWALE ------------------- LIMIT OF DISTURBANCE �oD PROPOSED CURB & GUTTER PROPERTY BOUNDARY � ` � � SILT FENCE m�i��r��.�r�a ROCK SOCK RIPRAP CONCRETE WASH AREA VEHICLE TRACKING CONTROL PAD INLET PROTECTION BALE OUTLET PROTECTION SLOPE DRAIN SEDIMENT TRAP —SF— SF � -\ -� �i � RS �� RP CWA VTC O IP � BOP � SD ST BALE INLET PROTECTION � BIP EROSION CONTROL FABRIC EF CITY OF FORT COLLINS UPLAND MIX SEED GENERAL NOTES: 1. CONTRACTOR SHALL IMMEDIATELY STABILIZE ALL DISTURBED SLOPES BY CRIMP MULCHING OR SIMILAR METHODS. 2. SWMP ADMINISTRATOR: Contact Company Address Phone 3. CONTRACTOR TO PROVIDE VEHICLE TRACKING CONTROL FOR CONCRETE WASHOUT AREA IF ACCESS IS OFF PAVEMENT. 4. NO MUD OR DEBRIS IS ALLOWED ON CITY STREETS. IF ANY DOES OCCUR, CONTRACTOR SHALL SWEEP AND CLEAN IMMEDIATELY. 5. REFER TO THE FINAL DRAINAGE REPORT, DATED APRIL 3, 2023 BY NORTHERN ENGINEERING FOR ADDITIONAL INFORMATION. 6. PAVER SYSTEM IS TO BE CONSTRUCTED AS PART OF THE LAST SEQUENCE OF CONSTRUCTION TO MINIMIZE POTENTIAL FOR SEDIMENTATION. 7. FINAL STABILIZATION TO BE DONE IN ACCORDANCE WITH THE FINAL LANDSCAPE PLAN. CALL UTILITY NOTIFICATION CENTER OF COLORADO / , Know what�s below. Call before you dig. CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU DIG, GRADE, OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES. T U O C � � � U � U i � —p �� � N N � � � � � a`�i `�n ? m . � � a`�i N�� U� N t}q O U pp N �3 � T N Q O@ W z� � �� @�� � -p C T -o ��°�° o o a� o 0 o�n � � � n �'N Q' a`ni �'> m �' � v� m� m � N O C c6 T N O� C � n ao -a � a� a � °° w�@�@�W � �� z � �� w � � � � W � � �` � 2 �3 �� J � W � W = �- z � � �� � � � ���� �� - � � � � g � � � � � _ � � � � > � � � � � � ~ N WO O (� W N � Q U M L�.j N z Z �\ Q II �� 0o cvi�:— �Q � m Z >- �o �� m� � zw zQ c� o O� v>m ao �o w � � N � Q � � U) I� Z W � � � Q � Q w � � � � � z v J z Q � � J O � J � � z Z� u.. 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PROPOSED STORM SEWER PROPOSED CONTOUR 93 EXISTING CONTOUR — — — —4953— — — — — PROPOSED SWALE ------------------- LIMIT OF DISTURBANCE �oD PROPOSED CURB & GUTTER PROPERTY BOUNDARY � ` � � SILT FENCE m�i��r��.�r�a ROCK SOCK RIPRAP CONCRETE WASH AREA VEHICLE TRACKING CONTROL PAD INLET PROTECTION BALE OUTLET PROTECTION SLOPE DRAIN SEDIMENT TRAP —SF— SF � -\ -� �/ � RS �� RP CWA VTC O IP � BOP � SD ST BALE INLET PROTECTION � BIP EROSION CONTROL FABRIC EF CITY OF FORT COLLINS UPLAND MIX SEED GENERAL NOTES: 1. CONTRACTOR SHALL IMMEDIATELY STABILIZE ALL DISTURBED SLOPES BY CRIMP MULCHING OR SIMILAR METHODS. 2. SWMP ADMINISTRATOR: Contact Company Address Phone 3. CONTRACTOR TO PROVIDE VEHICLE TRACKING CONTROL FOR CONCRETE WASHOUT AREA IF ACCESS IS OFF PAVEMENT. 4. NO MUD OR DEBRIS IS ALLOWED ON CITY STREETS. IF ANY DOES OCCUR, CONTRACTOR SHALL SWEEP AND CLEAN IMMEDIATELY. 5. REFER TO THE FINAL DRAINAGE REPORT, DATED APRIL 3, 2023 BY NORTHERN ENGINEERING FOR ADDITIONAL INFORMATION. 6. PAVER SYSTEM IS TO BE CONSTRUCTED AS PART OF THE LAST SEQUENCE OF CONSTRUCTION TO MINIMIZE POTENTIAL FOR SEDIMENTATION. 7. FINAL STABILIZATION TO BE DONE IN ACCORDANCE WITH THE FINAL LANDSCAPE PLAN. CALL UTILITY NOTIFICATION CENTER OF COLORADO / , Know what�s below. Call before you dig. CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU DIG, GRADE, OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES. T U O C � � � U � U i � —p �� � N N � � � � � a`�i `�n ? m . � � a`�i N�� U� N t}q O U pp N �3 � T N Q O@ W z� � �� @�� � -p C T -o ��°�° o o a� o 0 o�n � � � n �'N Q' a`ni �'> m �' � v� m� m � N O C c6 T N O� C � n ao -a � a� a � °° w�@�@�W � �� z � �� w � � � � W � � �` � 2 �3 �� J � W � W = �- z � � �� � � � ���� �� - � � � � g � � � � � _ � � � � > � � � � � � ~ N WO O (� W N � Q U M L�.j N z Z �\ Q II �� 0o cvi�:— �Q � m Z >- �o �� m� � zw zQ c� o O� v>m ao �o w � � N � Q � � U) 1 Z W � � � Q � Q w C� � � � � z v J z Q � � J � U� � � ` � � Z� �U � z O VJ O � W Sheet DYN r� �----- NORTHERNENGINEERING.COM � 970.221.4158 SWMP: SNOW RIDGEAPARTMENTS FORT COLLINS � GREELEY APPENDIX 0 `v 0 � � 0 � E M a I 0 N N `v � � < U iii � � 5 SIGN TO INDICATE THE co . B ,�. CONTAIN WASTE CONCRETE OR HARD SURFACE, GROUND SURFACE 4" TO 6" MAX AT CURBS, 2" IN SOIL OTHERWISE 6"-10" DEPENDING ON EXPECTED SEDIMENT LOADS ROCK SOCK SECTION ROCK SOCK PLAN 1�" (MINUS) CRUSHED ROCK � RS ENCLOSED IN WIRE MESH WIRE TIE ENDS� 0" ON BEDROCK ^NY GAP AT JOINT SHALL BE FILLED WITH AN ADEQUATE �OUNT OF 1�" (MINUS) CRUSHED ROCK AND WRAPPED TH ADDITIONAL WIRE MESH SECURED TO ENDS OF ROCK =1NFORCED SOCK. AS AN ALTERNATIVE TO F�LLING JOINTS =TWEEN ADJOINING ROCK SOCKS WITH CRUSHED ROCK AND )DITIONAL WIRE WRAPPING, ROCK SOCKS CAN BE /ERLAPPED iTYPICALLY 12-INCH OVERLAPi TO AVOID GAPS. ROCK � CURB AND NOTES: i. CONCRETE WASHOUT AREA SHALL BE INSTALLED PRIOR TO ANY CONCRETE PLACEMENT ON SITE. 2. VEHICLE TRACKING CONTROL IS REQUIRED IF ACCESS TO CONCRETE WASHOUT AREA IS OFF PAVEMENT. 3. SIGNS SHALL BE PLACED AT THE CONSTRUCTION ENTRANCE, AT THE WASHOUT AREA, AND ELSEWHERE AS NECESSARY TO CLEARLY INDICATE THE LOCATION OF THE CONCRETE WASNOUT AREA TO OPERATORS OF CONCRETE TRUCKS AND PUMP RIGS. 4. THE CONCRETE WASHOUT AREA SHALL BE REPAIRED AND ENLARGED OR CLEANED OUT AS NECESSARY TO MAINTAIN CAPACITY FOR WASTED CONCRETE. 5. THE CONCRETE WASHOUT SHOULD BE EMPTIED WHEN HALF OF TOTAL NOLDING CAPACITY HAS BEEN REACHED. 6. AT THE END OF CONSTRUCTION, ALL CONCRETE SHALL BE REMOVED FROM THE SITE AND DISPOSED OF AT AN ACCEPTED WASTE SITE. 7. WHEN TNE CONCRETE WASHOUT AREA �S REMOVED, THE DISTURBED AREA SHALL BE SEEDED AND MULCHED OR OTHERWISE STABIUZED IN A MANNER ACCEPTED BY THE CITY. 8. LOCATION OF CONCRETE WASHOUT AREA ON SHEET EC1 IS CONCEPTUAL ONLY. FINAL LOCATION TO BE DETERMINED IN THE FIELD AT CONTRACTOR'S DISCRETION. CWA CONCRETE WASHOUT AREA � RUNOFF _ N �. � TUBULAR MARKER MINIMUM 12" WtRE ENCLOSED 1 7/2" WASHED ROCK GRADATION TABLE MASS PERCENT SIEVE SIZE PASSING SQUARE MESH SIEVES N0.4 2" 100 1-i l2" 90-100 1" 20-55 3!4" 0-15 3l8" 0-5 MATCHES SPECIFICATIONS FOR NO. 4 COARSE AGGREGATE FOR CONCRETE PER AASHTO M43. ALL ROCK SHALL BE FRACTURED FACE, ALL SIDES ROCK SOCK INSTALLATION NOTES 7. SEE PLAN VIEW FOR: - LOCATION (S) OF ROCK SOCKS. 2. CRUSHED ROCK SHALL 8E 1�" (MINUS) IN SIZE WITH A FRACTURED FACE (ALL SIDES) AND SHALL COMPLY WITH GRADATION SNOWN ON THIS SNEET (1#° MINUS). 3. WIRE MESH SHALL BE FABRICATED OF 10 GAGE POULTRY MESH, OR EQUIVALENT, WITH A MAXIMUM OPENING OF �", RECOMMENDED MINIMUM ROLL WIDTH OF 48". 4. WIRE MESH SHALL BE SECURED USING "HOG RINGS" OR WIRE TIES AT 6" CENTERS ALONG AL� JOINTS AND AT 2" CENTERS ON ENDS OF SOCKS. 5. SOME MUNICIPALITIES MAY A�LOW THE USE OF FILTER FABRIC AS AN ALTERNATIVE TO WIRE MESH FOR THE ROCK ENCLOSURE. ROCK SOCK INSTALLATION NOTES: 1. VEHICLE TRACKING CONTROL PAD SHALL BE LOCATED AT EVERY ACCESS POWT TO THE CONSIRUCTION SITE. 2. A SIGN SHALL 8E PLACED NEXT TO THE VEHICLE TRACKING CONTROL PAD TO DESIGNATE THE LOCATiON AS THE CONSIRUCTION ENIRANCE/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 8E USED. THE STONES SHALL BE A MINIMUM OF 3" AND A MAXIMUM OF 6" DIAMETER. THE STONES SHALL HAVE A SPECIFIC GRAVITY OF AT LEAST 2.6. CONTROL OF GRADATION WILL BE BY VISUAL INSPECTION. 4. ANY CRACKED OR DAMAGED CURB AND GUTTER AND SIDEWALK SHALL BE REPLACED BY CONTRACTOR. 5. ALTHOUGH NOT NORMALLY USED, THE CITY RESERVES THE RIGHT TO REQUIRE VEHICLE TRACKING CONTROL WITN A TEMPORARY CATTLE GUARD AND/OR WHEEL WASH FACILITIES AT SITES WHERE TRACKING ONTO PAVED AREAS BECOMES A SIGNIFICANT PROBIEM AS DE7ERMINED 8Y THE CITY INSPECTOR. 6. IF VEHICLE TRACKWG 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 CONIRACTOR SHALL BE RESPONSIBLE FOR OBTAINING A WATER SOURCE AND CONSTRUC1lNG A WASHWATER SEDIMENT TRAP. MAINTENANCE NOTES: 7. CONTRACTOR SHALL WSPECT VEHICLE TRACKING CONTROL PAD DAILY. ROCK SURFACE SHALL BE CLEAN AND LOOSE ENOUGH TO RUT SLIGHTLY UNDER WHEEL LOADS AND CAUSE LOOSE ROCK TO DISLODGE MUD FROM TIRES. WHEN ROCK BECOMES COMPACTED OR FILLED WITH SEDIMENT SO THAT THE EFFECTNENESS OF THE PAD IS DIMINISHED, CONTRACTOR SHALL RIP, TURN OVER, OR OTHERWISE LOOSEN ROCK, PLACE ADDITIONAL NEW ROCK, OR REPLACE WITH NEW ROCK AS NECESSARY TO RESTORE EFFECTIVENESS. 2. SEDIMENT AND OTHER MATERIAL SPILLED, DROPPED OR TRACKED ONTO PAVED SURFACES SHALL BE REMOVED IMMEDIATELY OR BY THE END OF EACH WORKING DAY. 3. VEHICIE TRACKING CONIROL PAD SHALI BE REMOVED AT THE END OF CONSTRUCTION. THE AREA SHOULD BE TOPSOILED, SEEDED, CRIMPED, AND MULCHED OR OTHERWISE STABILIZED. 4. IF VEHICLE WHEEL WASH FACILITIES ARE REQUIRED, CONTRACTOR SHALL INSPECT VEHICLE TRACKING CONTROL AND WFiEEL WASH FACILIIIES DAILY. ACCUMULATED SEOIMENTS SHALL BE REMOVEO FROM THE PAD SURFACE. 5. ACCUMULATED SEDIMENT IN THE WASHWATER/SEDIMENT TRAP SHALL BE REMOVED WHEN THE SEDIMENT REACHES AN AVERAGE DEPTH OF 12-INCHES. i- 50' MIN. -' NO MATERIALS INCLUDING 2x4'S, PIPES, DIRT, GRAVEL OR ASPHALT, SHALL BE PLACED IN GUTTER TO FACILITATE MOUNTING CURB; HOWEVER, CURB MAY BE CUT DOWN TO A HEIGHT OF 2" OR HIGHER FOR EASIER ACCESS AND REPIACED AT PROJECT COMPLETION. OTHER ACCESS DEVICES MAY BE USED AS ACCEPTED BY THE C�TY. SECTION A 3" - 6" ROCK 20' MIN. VTC VEHICLE TRACKING PAD SILT FENCE NOT TO SCALE (TWO LPER BALE) STRAW BALES STAKE TWINE COMPACTED BACKFILL � � � � � / � //�� � , \ I' � i` �/ II i STORM� W�� � i / � UU GENERAL NOTES: �6 MIN � 1. INSPECT, REPAIR, AND REPLACE, (IF NECESSARY) THE FlL'lERS AfTER EACH STORM EVENT. PLAN I��UIyxNIPPI ir � - II � 2. ALL BAlES MUST BE REPlACEO AFfER 12 S E C T I O N G- G MONTHS UNlE55 APPROVAL IS GRANTE� BY iHE ENGINEERING DIVISION FOR LONGER USE. 3. STRAW 8ALE5 SHAW BE TRENCHED INTO THE GROUNO A MINIMUM OF 3". ECTION Q O P u EXTEND UP SLOPE AS NECESSARY TO PREVENT WATER ENTRY FROM BEHIND STRAW BALES BALE OUTLET PROTECTION IV W1 NOTES: iNsrn��a-rioN: PERVIOUS INSTALLATION WHEN INSTALLING RUNNING LENGTHS OF WATTLES, BUTT THE SECOND WATTLE TIGHTLY AGAINST THE FIRST, DO NOT OVERLAP TNE ENDS. STAKE F�� THE WATTLES AT EACH END AND FOUR FOOT ON CENTER. FOR EXAMPIE: 3'-4' A 25 FOOT WATTLE USES 6 STAKES A 20 FOOT WATTLE USES S STAKES �- A 12 FOOT WATTLE USES 4 STAKES /�!� STAKES SHOULD BE DRIVEN THROUGN THE MIDDLE OF THE WATTLE. LEAVING 2- 3 WCHES OF THE STAKE PROTRUDING ABOVE THE WATTLE A � �� � //� �/�, HEAVY SEDIMENT LOAD WILL TEND TO PICK THE WATTLE UP AND COULD � �� '- PULL IT OFF THE STAKES IF THEY ARE DRIVEN DOWN TOO LOW. IT MAY BE .� \` ; �� �' NECESSARY TO MAKE A HOLE IN THE WATTLE WITH A PICK END OF YOUR . � ADJACENT ROLLS SHALL TIGHTLY ABUT MADDOX IN ORDER TO GET THE STAKE THROUGH THE STRAW. WHEN � 4 -� �� ' STRAW WATTLES ARE USED FOR FLAT GROUND APPLICATIONS, DRNE THE i�% \ . � � STAKES STRAIGHT DOWN; WHEN INSTALLING WATTLES ON SLOPES, DRIVE ��/ ,` � � � I�`/ 1� THE STAKES PERPENDICULAR TO THE SLOPE. �;; ��� • � -� � / m� /' / DRIVE THE FIRST END STAKE OF THE SECOND WATTLE AT AN ANGLE ,��\'. , / TOWARD THE FIRST WATTLE IN ORDER TO HELP ABUT THEM TIGHTLY N/ %/� � .�� ( TOGETHER. IF YOU HAVE DIFFICULTY DRIVING THE STAKE INTO EXTREMELY �� �,°� /� �,'� -�.. � . ,;R\, r > /� HARD OR ROCKY SLOPES, A PILOT BAR MAY BE NEEDED TO BEGW THE �f� \��,( \���� ��-, � STAKE HOLE � ��% `' , . ,. � . /,. . ��,,�. �_- � � - ---- 1"x 1" WOOD STAKES - - � - - 18"-24" � . � w, a w2 ws-ra��ATioN NorEs: WATTLES - DETAIL A yy � 1. THE LOCATION AND LENGTH OF WATTLE IS DEPENDENT ON THE CONDITIONS OF EACH SITE. � 2. WATTIES SHALL BE INSTALLED PRIOR TO ANY IAND-DISTURBING ACTIVITIES. 3. WAT(LES SHALL CONSIST OF STRAW, COMPOST, EXCELSIOR, OR COCONUT FIBER. 4. NOT FOR USE IN CONCENTRATED fLOW AREAS. 5. THE WATTLES SHALL BE TRENCHED INTO THE GROUND A MINIMUM OF TWO (2) INCHES. 6. WATTLES SHALL BE INSTALLED PER MANUFACTURERS SPECIFICATIONS. 7. ON SLOPES, WATTLES SHOULD BE INSTALLED ON CONTOUR WITH A SLIGHT DOWNWARD ANGLE AT THE END OF THE ROW IN ORDER TO PREVENT PONDING AT THE MID SECTION. 8. RUNN WG LENGTHS OF WATTLES SHOULD BE ABUTiED FIRMLY TO ENSURE NO LEAKAGE AT THE ABUTMENTS. 9. SPACING - DOWNSLOPE: VERTICAL SPACING FOR SLOPE INSTALLATIONS SHOULD BE DETERMINED BY SITE CONDITIONS. SLOPE GRADIENT AND SOIL TYPE ARE THE MAIN FACTORS. A GOOD RULE OF THUMB IS: 1:1 SLOPES = 10 FEET APART 2:1 SLOPES = 20 FEET APART 3:1 SLOPES = 30 FEET APART 4:1 SLOPES = 40 FEET APART, ETC. HOWEVER, ADJUSTMENTS MAY HAVE TO BE MADE FOR THE SOIL TYPE: FOR SOFT, LOAMY SOILS - ADJUST THE ROWS CLOSER TOGETHER; FOR HARD, ROCKY SOILS - ADJUST THE ROWS FURTHER APART. A SECONDARY WATTLE PLACED BEHIND THE ABUTMENT OF TWO WATTLES IS ENCOURAGED ON STEEP SLOPES OR WHERE JOINTS HAVE FAILED IN THE PAST. 1Q STAKING THE CITY RECOMMENDS USING WOOD STAKES TO SECURE THE WATfLES. 1/2" TO 5/8" REBAR IS ALSO ACCEPTABLE. BE SURE TO USE A STAKE THAT IS LONG ENOUGH TO PROTRUDE SEVERAL INCHES ABOVE THE WATTLE: 18" IS A GOOD LENGTH FOR HARD ROCKY SOIL FOR SOFT LOAMY SOIL USE A 24" STAKE. IF THE BEHIND THE INLET IS NOT STABILIZED, A BMP SHOUL USED TO PREVENT SEDIMENT FROM ENTERING THE T LIP OF GU'f'rER SED DEPOSITION IMPERVIOUS INSTALLATION EXISTING OR PROPOSEDINLET _ END ALL ABUT TIGHTLY T CK OF CURB TOP BACK CURB FLOW LINE � � � � STORM WATER LINE � /� � ZONE SIDEWALK TOP BACK FLOW LINE � � LIP OF GUTTER \ WEIGHTED WATTLE AT 45 DEG. TO CURB W4 NOTES: 1. NUMBER OF WATTLES� 2. TUBULAR MARKERS SH 3. CITY RECOMMENDS ALL / WEIGHTED WATTLE � CURB INLET WATTLE PROTECTION SETUP W3 WATTLE MAINTENANCE NOTES: 1. THE CONTRACTOR SHALL INSPECT WATTLES EVERY TWO WEEKS AND AFTER ANY SIGNIFICANT STORM EVENT AND MAKE REPAIRS OR REMOVE SEDIMENT ACCUMULATED BEHIND WATTLE AS NECESSARY. 2. SEDIMENT ACCUMULATED BEHIND WATTLE SHALL BE REMOVED WHEN THE SEDIMENT HAS ACCUMULATED TO ONE HALF THE DIAMETER OF THE WATTLE. 3. WATTLES SHALL REMAIN IN PLACE UNTIL THE UPSTREAM DISTURBED AREA IS STABILIZED AND IS ACCEPTED BY THE CITY. TUBULAR MARKER W2 NOTES: � 4"-6" ABOVE WATTLE AFTER BAILING WIRE OR NYLON ROPE IS ATTACHED. STAKES WSTALLATION: NEED TO BE TAMPED UNTIL WIRE/ROPE IS STAKES SHOULD BE DRIVEN ACROSS FROM EACH OTNER � SNUG WITH WATTLE. AND ON EACH SIDE OF THE WATTLE LEAVING 4"-6" OF � STAKE PROTRUDING ABOVE THE WATTLE. BAILING WIRE OR NYLON ROPE SHOULD BE TIED TO THE STAKES ACROSS THE WAl"rlE STAKES SHOULD THEN BE DRIVEN UNTIL THE BAILING WIRE OR NYLON ROPE IS SUFFICIENTLY SNUG TO THE WATTLE. WHEN INSTALLING RUNNING LENGTHS OF WATTLES, TO � PREVENT SHIFTING, BUTT THE SECOND WATTLE TIGHTLY AGAINST THE FIRST, DO NOT OVERLAP THE ENDS. STAKES SHOULD BE DRIVEN 1 FT FROM END, ACROSS FROM AND � I I ON EACH SIDE OF WATTLE LEAVING 4'-6" OF STAKE ��� P R O T R U D I N G A B O V E T H E W A T T L E. B A I L I N G W I R E O R 1"x 1" WOOD STAKES NYLON ROPE SHOULD BE TIED TO STAKES IN AN HOUR GIASS FORMATION (FRONT TO BACK OF WATTLE "A", 18"-24" ACROSS TO FRONT OF WATTLE B", ACROSS TO BACK AND I i I BACK TO FRONT OF WATTLE "A"). STAKES SHOULD THEN BE � �� DRIVEN IN UNTIL BAILING WIRE OR NYLON ROPE IS SUFFICIENTLY SNUG TO THE WATTLE. � W2 NOTE� � ONLY WATTLES MADE WITH COCONUT FIBERS SHALL BE USED WNEN INSTALLATION COMES IN CONTACT WITH A WATER BODY. 1' 2� ^ TYP. BAILIN('i WIRE OR NYLON ROPE 1' 1' � ENDS OF ADJACENT WATTLES SHALL BE TIGHTLY ABU'f?ED TO PREVENT SEDIMENT BYPASS WATTLES - DETAIL B W2 W3, W4 8 WS NOTES: 1. WHEN USING STRAW WATTLE, THE STRAW WATTLE MUST NAVE A WEIGHTED CORE. 2. ALL PRODUCTS SHALL BE WSTALLED PER THE MANUFACTURER'S SPECIFICATIONS. 3. OTHER PRODUCTS MAY BE USED IN PLACE OF WEIGHTED WAT�LES UPON � WRITTEN APPROVAL FROM THE CITY. NOTE: A COPY OF DETAILS AND SPECIFICATIONS WIIL NEED TO BE INCORPORATED �NTO THE SWMP. END SHALL ABUT TIGHTLY TO BACK OF CURB EXISTING OR SEDIMENT PROPOSEO INLET DEPOSITION ZONE - END SHALL TIGHTLY ABUT TO _ _ _ _.. _ _ BACK OF CURB 4' MAX. � � STORM WATER LINE SEDIMENT POSITION ING SHOULD BE DETERMINED BY THE SLO D SITE CONDITIONS. � THE REQUIREMENTS OF MANUAL ON UNIFOR FFIC CONTROL DEVICES (MUTCD) AT LEAST 3 CHECKDAMS WHEN USING THIS SETU . CURBSIDE CHECKDAMS SETUP W4 WATTLE INSTALLATION DETAIL WEIGHTED WATTLE SIDEWALK SIDEWALK CULVERT/CHASE/PAN END SHALL TIGHTLY ABUT TO BACK OF CURB LIP OF GUTTER TOP BACK CURB ,- FLOW LINE CONCRETE CHASE/TRICKLE CHANNEL SETUP W5 o � t� v° � o N � � I a W . z i� � a . � � � X C9 � � O < � a � CALL UTILITY NOTIFICATION CENTER OF COLORADO • / Know what�s below. Call before you dig. CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU DIG, GRADE, OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES. /j�/� PERIMCTCR JOINTANCHOR EF UNDISTURBE�/ ///ff�\\ ANCHOR TRENCH,TVP. SOIL I�TRENCH, TVP. � TOP OF � CHANNELBANK � � � � TVPE OF BLANKET FlS INDICATED IN PLAN VIEW. IN ALL OISTURBE� AREAS OF STREAMS AND DRAINAGC GHF�NNE�S TO UEPTH "D" ABOVE CHANNEL INVERT. BLANKET SHALL GENERALLV BE ORIENTED PARALLEL TO FLOW DIRECTION. STAKING PATTERN SHALL MATCH BLANKET TVPE. AT PIPE OUTLET AREAS OF STREAMS AND DRAINAGE CHANNELS - DETAIL A PERMANUFACTURERSPEC.ORTVPF20H'iSTAKING TYPEOF6LANKET. (MATCH SPECIFIED BIANKET TVPE) SEE THE STAKING INOICATE� IN PLAN VIEW PATTERNS=ETAIL ON NE T SHEET � THE BLANKET SHALL "�n" BE EXTENOEO TO THE TOP OF CHHNNEL >3 � ' � �` � O ' PLRIMETER r,onnpncreo F SUBGRA�E �NCNORTRENCH,TVP. JOINT ANCHOR TRENCH, P/P. IN DIVERSION DITCH OR SMALL DITCH DRAINAGE WAY - DETAIL B STAGGER BLANKETSHALLBE OVERLAPS 100°aSTRAWMIN. pVERLAPPINGJOINT.SEE DLTFliL ON THIS SHEET OIVERSION DITCH TYPICALLV AT / TOP OF SLOPE ■Q � � � PERMANUFACTURERSPEC. ,� a � OH IYPE 1 STAKING SEE p � � THESTAKINGPATTERN PERIMETERFlNCHOFiN[NCFi� DETAILONNEXTSHEET SEE DETFIL ON THIS SHEET OUTSIDE OF STREAMS AND DRAINAGE CHANNELS - DETAIL C ANCHOR DETAILS EROSION CONTROL BLNNKE�,(�'�.) �r�P r �... -� MIN. � rva. j�'� / 1 i SIN LE EOGE // � \ �srnKE m'P.i \ COMPACTED BNCKFILL (ttP.) PERIMETER ANCHOR TRENCH � ss -;__� � ;;`s�-� TWO EDGES OF TWO ADJACENT ROLLS JOINTANCHORTRENCH � r ,�_� ,.,� �,�lI�L00PFROM V MIDDLEOF ao�� INTERMEDIATE ANGHOR TRENCH FL _�I��. o,v�.----��= � � (' ...... :...:... OVERLAPPING JOINT 3"MiN � � � WOOD STAKEO0.DETAIL ROLL WIDTH W" (TVP.) 1/2.�W�� I � �y irz•w� r-�y- PERIMETERANCHOR ��2 W � TRENCH OR JOINT � � �* ANCHORTRENCH,TVP. t a � 12 ��W - � # � IM I �rr�w° } . STRAW-COCONUT - k � ' I STAKING PATTERNS c coNuroaexce� iorz STRAW , tcFcnioN v�e�EusEiHEncctvtna�EsinHN� nnEUN nssHowrvneo�t 1. SEE PLAN VIEW FOR: - lOCA710N OF PERIMEIER OF EROSION CON7ROl BLANKET. -'fYPE OF BLANKET (S7RAW, S1RAW-COCO NUT, COCONUT, OR IXC�.SIOR). - AREA 'A'IN SQUARE YARDS OF EACH TYPE OF BLANKET. 2. ALl ER�SION CONIROL BLANKEfS AND NETIiNG SHALL BE MADE OF 100[ NA'NRAI. AN� 810DEGRADABLE MA7ERIAL; NO PLASTIC IX2 OhiER SYNTHEfIC MAIERIAI, EYEN IF PHOTO DEGRADABLE, 91ALL BE ALLOWED. 3. IN AREAS WFiERE EROSION CONIROL BLANKET IS 9i0WN ON iHE PlANS, 7HE PERMITiEE SHALL PIACE TOPSOIL AND PERFORM FlNAL GRAOING, SURFACE PREPARATION, AND SEEDING BE10W 'THE �mING AND MULCHING, SUBqiADE SHALL BE SM007H AND MOIST PWOR TO BLANKET INSTALLAiION AND iHE BIANKEf SHALL. BE IN FULL CONTACT N7TH SUBGRADE, NO GAPS OR VOIDS SHALL DOST UN�ER iHE BIANKET. 4. PEPoMEfQt ANCHOR iR�iCH SFiALL BE USED AT W751DE PEftiMEfQt OF ALL BLANKEf AREAS. 5. JOINT ANCHOR 7ftENCH SHALL BE USED TO JOIN ROLL.S OF BLANKEfS TOGEh1ER (LIXJpNDINALLY AND iRANSVERSEl.'� FOR ALL BLANKEfS IXCEPT S7RAW, WiICH MAY USE AN OVERLAPPMG JOINT. 8. IN7ERAIEDIA7E ANCHOR 7RENCH SHALL BE U�D AT SPAGNG OF ONE-HALF 7HE ROLL LENG7H FOR COCONUT AND IXCELSIOR BLANKETS. 7. 1HE O�ERLAPPMG JdNT DETAIL SHALL 8E USED TO JdN ROLLS OF BLANI�IS TOGEIHER FOR BLANKE'15 ON5LOPES. B. MATERIAL �EqFlCATI0N5 OF EROSION CON7ROL BLANI�T SNALL CONFORM TO TABLE BELOW. 9. ANY AREAS OF SEEDING AND MULqiING DISTURBFD IN 7HE PROCESS OF INSTAWNG ER0.S10N CANiROL BLANKEf SHALL 8E RE-SEEOED AND MULCHm. 10.DETAILS ON OESIGN PUNS FOR MAJOR DRAINAGE-WAY STABILIZATION X7LL GO�ERN IF DIfFERENT FROM ONES SHOWN HERE. rvvE cocoNur sranN ExcE�sio CONTEM CONTE T CONTENT NETTING MIN. STRAW' � 100% DOUBLE/NATURAL -�- 1 30% MIN. ]p% MHX. - �OUBLE/NFTURAI. 5 GOCONUiU i00% �OUBLE/NATURAL E(:ELSIOF 100% �OU6LE/NHTURNL Foa oursioE oF siaEaMs nr�o oaai�uacE cHnNNE�s F120SON CON7ROL BLANKE? MA�NTENANCE NO'fES 7. 7HE CONSTRUC710N SIiE OPERATOR �IALL INSPECT EROSION CONTRIX. BIANKEfS WEEKIY, WRING AND AFfEft ANY STORM EI�NT ANO MAKE REPAIRS AS NE�SSARY. 2 EROSION CON'iROL BLWKE� IS TO BE LEFT IN PLACE UNLESS REWESTED TO BE REAIO�FD BY'iFiE TOWN. 3. ANY EROSION CON7ROL BLANKET PULLED WT, TORN, OR O7HERN7� DAMAI;ED 9iALL BE RE-INSTALLID. ANY SUBIXiADE AREAS 80.0W 7HE BIANKET iHAT HA�E ERODED TO CREATE A VOID UNOER 1HE BLANKEf, OR THAT REMNN DEVDID OF ptASS SHALL BE REPAIRED. RE-SEEDm AND MULCHm AND THE FR090N l�N7ROL BtANKEf RONSTALLED. EROSION CONTROL BLANKET T U O C � � � U � U i � -p �� � N N � `° � � a`�i '�n ? m .� � a`�i N�� U� N t}q O U pp N �3 � T N Q O@ W z� � a � � � � � -p C T 'O �-p b�0 �O � N O O 00 � � ' � � C 'N Q'- �n � '� m � n .b0 �n � m a> > a� �� v� a� � � N O C c6 T N O� C � n ao -a � a� a � °° w � `° � @ " w � �� � � �� w � � � � � � � � 2 � �� J � W � l..Ll = �� � � � � � � � �� � � � 1.�1 = � J � � g � � � � � ut _ � � � Z � � � � � � � � ~ � � N �N � U Q M L�.j Q O �� Qa �� Q d- U \ � 0 �% Z � Q i- m Z � � O � � m O � Z w Z Q i.� o o� in�' ao � � w �' � N � Q � � V ! � Z W � � � � � � W V � � � � Z v / v / � � � W � J O � � Z O U Z O v / O � W Sheet E C4 11 of 22 ROCK SOCK JOINTING �2" MIN. � 6° MIN. � Fl-�� � 6° MIN. ■ Develop Site Plan ■ Obtain Site Survey, Hydrology and Soils Information • Prepare SWMP Representative Phases: ■ Clearing and Grubbing ■ Rough Grading ■ Road Construction • Utility and Infrastracture Installation ■ Vertical Construction (Buildings) ■ Final Grading • Revegetate Site • Activate Post Construction BMPs (e.g., convert sediment basin to extended detention basin) ■ Remove Temporary BMPs ■ Obtain Stormwater Construction Permits (State and Local) • Obtain Other Relevant Permits (e.g., 404 , Floodplain, Dewatering) Management Practices: ■ Phase Construction Activities to Minimize Disturbed Area at a Given Time • Sequence Contruction within Phases to Avoid Idle Disturbed Areas • Install, Inspect and Proactively Maintain BMPs Appropriate for Each Phase of Construction • Maintain and Update SWMP as Construction Progresses • Closeout State and Local Stormwater Permits Figure 7-2. Construction Stormwater Management November 2010 Urban Drainage and Flood Control District 7-13 Urban Storm Drainage Criteria Manual Voluine 3 Chapter 7 Construction BMPs Construction BMPs Table 7-2. Overview of Construction BMPs 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 Modcrate No Compost Blankets and Filter Berms Yes Moderate No RolledFrosion Control Products Yes No No Temporary Slope Drains Yes No No Temporary Outlet Protection Yes Moderate No Rough Cut Street Control Yes Moderate No Farth Dikes / Drainage Swales Yes Moderate No Terracing Yes Moderate No Check Dams Yes Moderate No Streambank Stabiliration Yes No No Wind Ni-osion / llust Control Yes No Moderate Sediment Control BMPs Silt Fence No Yes No Sediment Control Log Modcrate Yes No StrawBale Barrier No Moderate No Brush Barrier Moderate Moderate No Rock Sock (perimeter control) No Yes No Inlet Protection (vai-ious forms) No Yes No Sediment Basins No Yes No S ediment Traps No Yes No Vegetative Buffers Moderate Yes Yes Chemical Treatment Moderatc Ycs No Materials Management Concrete Washout Area No No Yes Stockpile Management Yes Yes Yes Good Houskeeping (mulYiple practices) No No Yes Site Management and Other Specific Practices Construction Phasing Moderatc Moderate Yes Protection of F�isting 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 I3atch Plants No No Yes Paving andGrinding Operations No No Yes 7-14 UrUan Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Voluine 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 rougheni��g creates variations in the soil surface that help to minimize wind and water erosioil. Depending on the technique used, surface roughening may also help establish conditions favorable to establishment of vegetation. Appropriate Uses Surface roughening can be used to provide temporary stabilization of disturbed areas, such as when � :.�,. - ' �� x���`,_, f �� " L ��r��l� �_f'� ✓�. � ��� � � . • /✓ r �'� y��f��t _ � revegetation cannot be immediately established due to seasonal planting limitatio��s. 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 lieavy 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 perfarmed either after final grading or to temporarily stabilize an area during active construction that may be inactive fior 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 Coniro] No Site/Material Management No November 2010 Urban Drainage and Flood Control District SR-1 Urban Starm Draiilage Criteria Manual Volume 3 Photograph SR-1. Surface roughening via imprinting for temporary stabilization. EC-1 Surface Roughening (SR) Maintenance and Removal Care should be taken not to drive vehicles ar equipment over areas that have been surface roughened. Tire tracks will smooth the rougl�ened 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 condirion. 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 � 2�� T� 4" DEEP FOR LOW SLOPES (LESS THAN 3:1) SR November 2010 Urban Drainage and Flood Control District SR-3 Urban Starm Draiilage Criteria Manual Volume 3 SR-1. SURFACE ROUGHENING FOR STEEP SLOPES (3:1 OR STEEPER) SR-2. SURFACE ROUGHENING EC-1 Surface Roughening (SR) SURFACE ROUGHENING INSTALLATION NOTES 1. SEE PLAN VIEW FOR: -LOCATION(S) OF SURFACE ROUGHENING. 2. SURFACE ROUGHENING SHALL BE PROVIOEO PROMPTLY AFTER COMPLETION OF FINISHED GRADING (FOR AREAS NOT RECEIVING TOPSOIL) OR PRIOR TO TOPSOIL PLACEMENT OR ANY FORECASTEQ RAIN EVENT. 3. AREAS WHERE BUILDING FOUNDATIONS, PAVEMENT, OR S00 WILL BE PLACED WITHOUT DELAY IN THE CONSTRUCTION SEQUENCE, SURFACE ROUGHENING IS NOT REQUIRED. 4. DISTURBED SURFACES SHALL BE ROUGHENEO USING RIPPING OR TILLING EQUIPMENT ON THE CONTOUR OR TRACKING UP ANO DOWN A SLOPE USING EQUIPMENT TREADS. 5. A FARMING DISK SHALL NOT 8E USED FOR SURFACE ROUGHENING. SURFACE ROUGHENING MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, ANO MAINTAIN THEM IN EFFECTIVE OPERATING CONOITIQN. 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, ANO PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS ANO CORRECTivE ME�,SURES SHou�� BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACE UPON DISCOVERY OF THE FAILURE. 4. VEHICLES ANO EQUIPMENT SHALL NOT BE �RIVEN 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 ADAPiEO fROM TOWN OF PARKER, COLORADO, NOT AVAILABLE IN RUTOCAO) NaTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH OETAIL SHOULD 8E USEO 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 Temparary 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 �� �� . �� •• - '`. ti't � 3� �.}�� � _ . ;, .. r v ���';,.� Q�� 1 s, aF"* �1-•l�s'� � � ��^ . , -f� ;�, Ki h� � .�1t�, ` � _ �1�-. rr� e. X. ' .�. !!1'f�1 ; ;� ` ,��.: �^' �i��.� � �F�r.. � •�.'. � _ .. Wl�en the soil surface is disturbed and Photograph TS/PS -l. Equipment used to drill seed. Photo courtesy of will remaii� 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 ju�-isdictional requirements for seeding and teinporary 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 vegetarion. Overlot �rading can result in loss of topsoil, resulting in poor quality subsoils at the ground surface that have low nutrient value, little organic matter content, few soil microorganisms, rooring restrictions, and conditions less conducive to infiltration of precipitation. As a result, it is typically necessary to provide stockpiled topsoil, compost, or other Temporary and Permanent Seeding Functions Erosion Control Yes Sediment Control No Site/Material Management No Noveinber 2010 Urban Drainage and Flood Control District TS/PS-1 Urban Starm Draiilage 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 i�nportant resource to be utiliaed for vegetation establishment, due to its wat�er-holding capacity, struct�ure, texture, organic matter content, biological activity, and nlitrient content. The rooting depth of most native grasses in the semi-arid Denver metropolitan area is 6 to 18 inches. At a minimum, tl�e upper 6 inches of topsoil should be stripped, stockpiled, and ulrimately respread across areas that will be revegetated. Where topsoil is not available, subsoils should be amended to provide an appropriate plant-growth medium. Organic nlatter, such as well digested coinpost, can be added to improve soil cl�aracteristics conducive to plant growth. Other treatments can be used to adjust soil pH conditio��s when needed. Soil testing, which is typically inexpensive, should be completed to determine and oprimize the types and amouilts of ainendments that are required. If the disturbed ground surface is compacted, rip or rototill the surface prior to placi�lg 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 nar 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 temparary vegetative cover on disturbed areas which will not be paved, built upon, or fully landscaped ar 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 ii1 Table TS/PS-1. 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 perforined promptly (typically within 14 days) after reaching final grade. Each site will have different characteristics and a landscape professiona] ar the local jurisdiction should be contacted to determine the most suitable seed mix far a specific site. In lieu of a specific recommendation, one of the perennial grass lnixes appropriate for site conditions and growth season listed ii� Table TS/PS-2 can be used. The pure live seed (PLS) rates of application recommei�ded 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 seedinixes at 0.25, 0.5 and 1 pound PLS/acre, respectively. In riparian zones, planting root stock of such species as American plum (Prunu�s am.ericana), woods rose (Rosa woodsii), plains cottonwood (Populus sargentii), and willow (Populus spp.) may be considered. O» non-topsoiled upland sites, a legume such as Ladak alfalfa at 1 pound PLS/acre can be included as a source of nitrogen far 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 perenni�l 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 suminer months, as well. See Table TS/PS-3 for appropriate seeding dates. Table TS/PS-L Minimum Drill Seeding Rates for Various Temporary Annual Grasses Pounds of Planting Speciesa 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 1/z 5. Millet Warm 3- 15 '/z - 3/a 6. Sudangrass Warm 5-10 '/z - 3/a 7. Sorghum Warm 5-10 1�2 - 3�4 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 � Successful seeding of an»ual grass resiilt�ing in adequate plant growth will ustially produce enough dead-plant residue to provide protecrion 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 limitarions 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. e 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, ar 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 Starm Draiilage Criteria Manual Volume 3 EC-2 Temporary and Permanent Seeding (TS/PS) Table TS/PS-2. Minimum Drill Seeding Rates for Perennial Grasses Common" Botanical Growth Growth Seeds/ Pounds of Name '.Vame Seasonb Form Pound PLS/acre Alakali Soil Seed Mix Alkali sacaton S��orobolus airoir/es Coo1 Bunch 1,750,000 0.25 Basin wildrye EI>>meds crnereus Cool Bunch 165,000 2.5 Sodar streambank wheatgrass �lgropyron ripariiem 'Sodar�' Cool Sod 170,000 2.5 Jose ta11 wheatgrass Agro��yron elongatum Jose' Cool Bunch 79,000 7.0 An�iba western wheatgrass Agropyron smitl�rr 'Arr•iba' Cool Sod 1] 0,000 5.5 Total 17.75 Fertile Loamy Soil Seed Mix Ephriam crested wheatgrass �ST�°L�?'��on cristaturn Cool Sod 175,000 2.0 'Ephriam' Dura] hard fesc�ue Festuca orina 'duriuscula' Cool Bunch 565,000 1.0 Lincoln smooth brome Bronrus iraermi.r leyss Cool Sod 130,000 3.0 Zrnt�oln' Sodar streambank wheatgrass Agr•o��yron riparium 'Sodar-' Cool Sod 170,000 2.5 Airiba westem wheatgrass Agropvror� smithii Arriba' Cool Sod 110,000 7.0 Total 15.5 High Water Table Soil Seed Mix Meadow foxtail Alopecu��us pratensis Cool Sod 900,000 0.5 Redtop A�rostis alba Wa��m Open sod 5,000,000 0.25 Reed canarygrass Phalm•is a�•u�idinucea Cool Sod 68,000 0.5 Lii�coln smooth brome Bromus inermi.c leys,s Cool Sod 130,000 3.0 'Lincoln' Pathfinder switchgrass Puraicum virgatun� Warm Sod 389,000 1.0 'Path fitzcter, �Igropyron elongatttm Alkar tall wheatgrass Alkm-' Cool Bunch 79,000 5.5 Total 10.75 Transition Turf Seed Mix` Ruebens Canadian biuegrass Poa compre,ssa 'Ruehens' Cool Sod 2,500,000 0.5 Dural hard fescue Fe,stuca o>>ina 'dw�ii�scula' Cool Bunch 565,000 1.0 Citation perennial ryegrass Goldum perenne 'Citalion' Cool Sod 247,000 3.0 Lincoln smooth brome Bromus rnermis leyss Cool Sod 130,000 3.0 'Li�uoh:' Total 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 Crowth Seeds/ Pounds of Name Name Scason�' Form Pound PLS/acre Sandy Soil Seed Mix Blue grama Bouteloua gi-acili.r Wa� Sod-forming 825,000 0.5 bunchgrass Camper litYle bluestem Scl�izachyrium scopar•ium Wa� Bunch 240,000 1.0 'Camper' Prairie sandreed Calarnorilfa longifolia Wann Open sod 274,000 1.0 Sand dropseed SUorobolus cr_��ptandrus Cool Bunch 5,298,000 0.25 Vaughn sideoats grama Bouteloua curtipendula Warm Sod 191,000 2.0 'Vuughn' Arriba western wheatgrass ngropyron srnitliii '�lrriha' Cool Sod 110,000 5.5 Total 10.25 Heavy Clay, Rocky Foothill Seed Mix Ephriam crested wheatgrass`� ��r°Pyrorr cristazum Cool Sod 175,000 1.5 'Ephriam' Oahe Intermediate wheatgrass ��'�opyron inteT•medium Cool Sod 115,000 5.5 'Ouhe' Vaughn sideoats grama� Bouteloua cw-tipe�zdula �Iarni Sod 191,000 2.0 'Vt,ughn' Lineoln smooih brome Bro»�us inermi.r ley,ss Cool Sod 130,000 3.0 'Lincoln' Arriba western wheatgrass Agropyron ,smithii 'An-ibu' 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 }�ercent if the seeding is done using a Brillion Drill or is applied through hydraulic seeding. Hydraulic seeding may be subsrituted for drilling only where slopes are steeper than 3: I. 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 h-ansirion turf seed rates should be doubled. `� Crested wheatgrass should noY be used on slopes steeper than 6H to 1V. ` Can substitute 0.5 lbs PLS oP blue grama for the 2.0 lbs PLS of Vaughn sideoa[s grama. Noveinber 2010 Urban Drainage and Flood Control District TS/PS-5 Urban Starm Draiilage 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 Jamiary 1—March 15 ✓ ✓ March 16—April 30 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 ✓ ✓ Mulch Cover seeded areas with mulch or an appropriate rolled erosion control product to p�-omote 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 Monitar and observe seeded areas to identify areas of poar growth or areas Chat 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 germi»ate or remain bare after the first growing season. Seeded areas may require irrigation, patticularly 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) Description Soil binders include a broad range of treatments tl�at cail be applied to exposed soils for temporary stabilization to reduce wind and water erosion. Soil binders may be applied alone oi• as tackifiers in co»junction with mulching and seeding applications. Ack-n�owledgement: This BMP Fact Sheet has been adapted fi�om the 2003 California Stormwater Quality Association (CASQA) Stormwater BMP Han�lbook: Construction (www.cabmpha�dbooks.com.). Appropriate Uses �� ' }, � .' � , :1._j _ e" � '� � EC-3 I_� �` -^ � ' 1, .. i ��..�, - r _ � "-�' � .,: 'f 1 j - - w-� �r` �� -- � t,. _. , r Photograph SB-l. Tackifier being applied to provide temporary soil stabilization. Photo courlesy of Douglas County. Soil binders can be used for shart-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 pennanent seeding has occurred. Prior to selecting a soi] 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 painCed surfaces. Soil binders should not be used in vehicle or pedesirian 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 funcrion 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 guidance below are provided for general reference. Follow the manufacturer's instructions for application rates and procedures. Soil Binders Functions Erosion Control Yes Sediment Control No Site/Material Mana ement Moderate November 2010 Urban Drainage and Flood Control District SB-1 Urban Starm Draiilage 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 Existing Vegetation Good Poor Poor Poor Photodegraclable/ Photodegradable/ Mode of Degradation Biodegradable Biodegradable Chemically Chemically Degradable Degradable Specialized Application Water Truck or Water Truck ar Water Truck or Water Truck or Hydraulic Hydraulic Equipment Hydraulic Mulcher Hydraulic Mulcher Mulcher Mulcher Liyuid/Powder Powder Liquid Liquid/Powder Powder Yes, but Yes, but dissolves on Surface Crusting dissolves on Yes Yes rewetting rewetting Clean Up W ater W ater W ater W ater Erosion Control Varies Varies Varies 4,000 to 12,000 Application Rate lbs/acre Typ. SB-2 Urban Drainage and Flood Control District November 2010 Urbail Storm Drainage Criteria Manual Voluine 3 Soil Binders (SB) Factors to consider when selecting a soil binder generally include: EC-3 ■ 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 factar. ■ Soil types and surface materials: Fines and moisture content are key properties of surface materials. Consider a soil binder's ability to penetrate, likelihood ofi 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 miniinized 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 1 1 to 15 Ibs per 1,000 gallons. Recommended minimum application rates are provided in Table SB-2. Table SB-2. Application Rates for Guar Soil Stabilizer Slo e (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 ofi plantago seeds that is applied as a wet slurry to the surface of the soil. lt dries to form a fiirm but rewettable membrane that binds soil particles together but permits germiilation and growth of seecl. Psyllium requires 12 to 18 hours drying time. Application rates should be from 80 to 2001bs/acre, with enough water in solution to allow for a uniform slurry t�ow. Starch: Non-ionic, cold-water soluble (pre-gelatinized) granular cornstarcll. The material is mixed with water and applied at the rate of ] 50 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 applicarion cures to a water insoluble binding and cementing agent. For soil erosion control applicat�io»s, the emulsion is diluted and should be applied as follows: o For clayey soil: 5 parts water Co 1 part emulsion November 2010 Urban Drainage and Flood Control District SB-3 Urban Starm Draiilage Criteria Manual Volume 3 EC-3 o For sandy soil: 10 parts water to 1 part emulsion Soil Binders (SB) 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 oti 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 ar animal life, non-flammable, should provide surface soil stabilization for various soil types without inhibiting water infiltrarion, 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 MethacrylaYes and Acrylates: This material consists of a tackifier/sealer that is a liquid polymer of inethacrylates and acrylates. It is an aqueous 100 percent acrylic emulsion blend of 40 percent solids by volume that is free froin styrene, acetate, vinyl, ethoxylated surfactants ar 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 far erosion control at rates that are determined by slope �radient, as summarized in Table SB-3. Table SB-3. Application Rates for Copolymers of Sodium Acrylates and Acrylamides Slo e H: V Flat to 5:1 5:1 to 3:1 2:2 to 1:1 A lication 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 tlowable solid. When used as a stand-alone stabiliaer, it is diluted at a rate of 1 1 lb/1,000 gal. of water and applied at the rate of S.O lb/acre. ■ Hydrocolloid Polymers: Hydrocolloid Polymers are various coinbinations 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 protecrive crust on the soil surface. It is composed of high purity gypsum that is ground, calcined and processed into calcium sulfate hemihydrat�e 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. SB-4 Urban Drainage and Flood Control District November 2010 Urbail Storm Drainage Criteria Manual Voluine 3 Soil Binders (SB) Installation EC-3 After selectiilg an appropriate soil binder, the untreated soil sLirface must be prepared befare applying the soil binder. The untreated soil surface must� contain sufficient ��noisture to assist the agent in achieving uniform distribution. In general, the following steps should be followed: ■ Follow manufacturer's written recommendarions far applicarion rates, pre-wetring of application area, and cleaning of equipment afiter 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, exisring 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 tune 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 03 gal/yd' ar 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/yd�. 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. Noveinber 2010 Urban Drainage and Flood Control District SB-5 Urban Starm Draiilage 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 mat�ing repairs. Most binders biodegrade after exposure to sun, oxidation, heat and biological organisms; therefore, removal of the soi] binder is not typically required. SB-6 Urban Drainage and Flood Control District November 2010 Urbail Storm Drainage Criteria Manual Voluine 3 Mulching (MU) EC-4 Description Mulching consists of evenly applying straw, hay, shredded wood mulch, bark or compost to disturbed soils and securing the mulch by crimping, tackifiers, netting or other ineasures. Mulching helps reduce erosion by protecting bare soil from rainfall impact, increasing infiltration, and reduciilg ruiloff. Altllough 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. Mulch can be applied either using standard mechanical dry application methods or using hydromulching eyuipment that hydraulically applies a slurry of water, wood fiber mulch, and often a tackifier. Appropriate Uses � � ,� n r� � ,' �'� 4 �1 I Y r � .{ :—r L�. ��1,``�n,�� . ..ti�1? � r � •. l.� . .:, � +. "' � . t'� . � , � � w . N� ,� � �{ �, � , � Y\ � M .�•A� � ��� lar ,+ �,�. �,�,��i �i�, . , � `` ,r�N� ,:' 1 �� ,� ► �r.��:� �� '��,y„"'+�j�11►R��,������, . ��� .�1� .� , � �;.� r �'�,��:�' ; Y .,:;.. �r ��;� � �� � �4Z��' �' * � t' �f;,yl. l,r.r,. �'�'� � i ; . � � � �- �: w , ��ta�T �: ,l� � � � , ��,�� ,� � , i_� v+�' � 7� �.» �i ' ,+' � � { � : ����1�y _���' �� t `F��� 4 �i,� f 'L �My'�� � . � 7 j,' ;' '�.�'q� f �: :-"' `t�, ����'`�1 1 � �p�,, �j . ti � ,,, -, . , �� 1� ;1, 4 �►�, � .: ,��•C���` `�+ i •. . , ,� � - �'1 .�� �• 4 i 7 4�.`L•�"I-�i� f1�Y� r.� ��� i �� y'•` q ,:i � �� `'�,�''��'�y �-'.t.�,�,� � ��, �' . . � ., �,, ., �:,�+'' �' �k''' ,;, � � `, y �. .." +,._ �� . . � �,� � �1 ',�V h�l+�`1� ,(� 1: ���V . Y�'�wj� h�'�, ,� '�,-�;, � � �, � ,X•� ,•:A► 'i� �+ •��;�� ��.�����'��.� ���-• ,a �r �" ����"� :%�' `���.' �.rE�=.��W►I.; y�.'� �� � ��1:� �'� 'y ..� ,�1�a; M, i i �� ', �,�i �.+.e `,�r+�� ;�. +�}'',v�. �'� . ,� ✓��� � 4:.- *�� r� �: " 'y tiI� j ww ,�y.. - y�;1 y:: r' �''. ���;� ?• ��, �a,. ' �� `� � b �". '"� t,�, �'� � �'W �. � �x` � ,� :�� j � ' � , : '��,► �,� • • � 1:�1�� ��, � ''�t;�.� "�y, '�� ;�►'.�'�d�'�;�'' ;� '•�:. � '� .'.�,, �:.��,ut,,,%�`�; :►�!' ,,�`, s�.�� '1i'�i11► ;�LC�'_'�'L'�!.�'! �'�4'�t-'�.`�.�#!�i�� Photograph MU-1. An area that was recently seeded, mulched, and crimped. 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 pro�nptly 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 inay not be allowed near waterways. Do »ot 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 equipme»t typically compacts the soil. A variety of mulches can be used effectively at coilstructioil sites, including the following types: Mulch Functions Erosion Control Yes Sediment Control Moderate Site/Materia] Management No Noveinber 2010 Urban Drainage and Flood Control District MU-1 Urban Starm Draiilage Criteria Manual Volume 3 EC-4 Mulching (MU) ■ Clean, weed- and seed-free, ]ong-stemmed grass hay (preferred) or cerea] 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 far 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 criinping or with tl�e aid of tackifiers or nets. Anchoring with a crimping implement is preferred, and is the recommended method for areas flaiter than 3:1. Mechanical crimpers must be capable of tucking the long mulch fibers into the soil to a depth of 3 inches withoLit cutting them. An agricultural disk, while not an ideal subsritute, nlay work if the disk blades are dull or blunted and set vertically; however, the frame may have to be weighted to afford proper soi] 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, waCerways and existing vegetation should be avoided. ■ Erosion control mats, blankets, ar nets are recommended to help stabilize steep slopes (generally 3:1 and steeper) and waterways. Depending on the product, these may be useci alone or in conjuncrion with grass or straw mulch. Normally, use of these products will be restricted to relatively small areas. Biode�radable 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 p�-ovides 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 temparary or permanent stabilization. The rock mulch layer should be thick enough to provide full coverage of eaposed soil on the area it is applied. Maintenance and Removal After mulching, the bare ground surface should not be inore 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 _ . .. .�_.- ,.: �' � ., . - ' N ,` �.� 1.: �i � , C,. �_ r � �'71l"• A compost blanket is a layer of compost uniformly applied to the soil in disturbed areas to control erosioil, facilitate revegetation, and retain sediment resulting from sheet-fi7ow runoff. A compost filter berm is a dike of compost or a compost product that is placed perpendicular to runoff to control erosion in disturbed areas and retain sediment. Compost berms can be placed at regular intervals to t�elp reduce the formation of rill and gully erosion when a compost blanket is stabilizing a slope. 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 concei�trated flows. � — � � ' . r � , - -....r-'�'- � -. � �^b '1_ �W Compost provides an excellei�t source of nutrients for plant photograph CB-1. Applicarion of a composr growth, and should be co�lsidered far use i�1 areas that will be blanker to a disrurbect area. Phoro courtesy of permanently vegetated. Catcrans. Design and Installation See Detail CB-1 far design details and notes. Do not place compost in areas where it can easily be transported into drainage pathways or waterways. When using a coinpost blanket on a slope, berms should be installed periodically to reduce the potential for coilcentrated flow and rilling. Seeding should be completed before an area is composted or incorporated into the compost. Compost qualiiy is an important consideration when selecting compost blankets or berms. Representaiive 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. Composring 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 cotnpost should be used. Compost Blankets and Berms Functions Erosion Control Yes Sediment Control Moderate Site/Material Management No Noveinber 2010 Urban Drainage and Flood Control District CB-1 Urban Starm Draiilage 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 iilstall 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 reinoval and spot applicarion 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. Coinpost blankets and berins biodegrade and do not typically require removal following site stabilization. CB-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Compost Blanket and Filter Berm (CB) EC-5 _ � — — — _ � — — � 0_ �1' MIN CB 15� MAk � CLASS 1 COMPOST FILTER BERM 1" TO 3" THICK (2" TYP.) STA CERTIFIED CLASS t COMPOST BLANKET PROPER SOIL PREPARATION `�-��`, AND SURFACE RQUGHENING 1LT WHEN APPROPRIATE 2.5 TABLE CB— 1. CLASS 1 COMPOST PARAMETERS CHARACTERISTIC MINIMUM STABILITY INDICATOR STABLE T� VERY STABLE SOLUBLE SALTS MAXIMUM 5 mmhos/cm PH 6.Q — 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 TQ 20:1 NITROGEN RATIO TESTEO FOR CLOPYRALID YES/NEGATIVE RESULr 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 UNOER COLORADO DEPARTMENT OF REQUIREMENT PUB�IC HEALTH AND ENVIRONMENT, HAZARDOUS MATERIALS ANO WASTE MANAGEMENT DIVISION RISK FACTaR RELATING TO PLANT LOW GERMINATION AND HEALTH CB-1. COMPOST BLANKET AND COMPOST FILTER BERM November 2010 Urban Drainage and Flood Control District CB-3 Urban Starm Draiilage 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 COMPaST FILTER BERM(S). -LENGTH OF CflMPOST FILTER BERM(S). 2. COMPOST BERMS ANQ BLANKETS MAY 8E USEO IN PLACE OF STRAW MULCH OR GEOTEXTILE FABRIC IN AREAS WHERE ACCESS TO LANDSCAPING IS DIFFICULT DUE TO LANDSCAPING OR OTHER aBJECTS 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 WIOE. 5. FILTER BERMS SHALL BE APP�IED BY PNEUMATIC BLOWER OR BY HAND. 6. FILTER BERMS SHALL ONLY BE UTILI2ED IN AREAS WHERE SHEET fLOYJ 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 SUPPLEMENTEO BY CaMPOST. A THIN 0.5-INCH LAYER MAY BE USED. 8. SEEDING SHALL BE PERFORMED PRIOR TQ 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. COMPaST 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 i0 MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTEO 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 REGRADEO AS NECESSARY IF RILLING IN THE COMPOST SURFACE OCCURS. (OEiNLS AOAPTED fROM ARAPAMOE COUNiY, COLORA00, NOT AVAILABLE IN AUTOCRD) NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UOFCD STANOARD DETAILS. CONSULT WITH LOCAL JURISOICTIONS AS TO WHICH DETAIL SHOULO 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 Rolled Erosion Control Products (RECPs) ii�clude a variety of temporary ar permanently installed manufactured products designed to control erosion aild enhance vegetation establishment and survivability, particularly on slopes and in channels. Far 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 _� .�, :,�== �'�I *►y�;. � ,« ��.�_ � �._�.. �I_�il� r_ • _ ,�, " . - *`:� . ' - _ . w . � - _ 1 s :�: ..... =? �� `y, r �, _ y,-�. ,�,,,�'.. � �- -:a ��� .c+�c�'xs�.,sf Y� � zr `�"' �,�.��^a �.,..._ ": '-_'''„ �s�. r�<� � �_��'�� �=� .�;�L''�_ �`..:� �� v� .J� s-�-.�,e <.:._�4. of biodegradable natural materials Photograph RECP-1. Erosion control blanket protecting the slope from (e.g., Stl"aW, COCOriut f1b21'� C1n b0 uSOCl. 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 ]imits of matiire natural vegetation. Appropriate Uses RECPs can be used to control erosion in conjunction with revegetation efforts, providin� 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 erosioil control products accarding 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 ilatural or polymer yarns woven into a inatrix, 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 mechanically, structurally or chemically bound together to form a continuous matrix to provide erosion coiltrol and facilitate vegetation establishment. ECBs can be further differentiated into rapidly degrading single-net and double-net types or slowly degrading types. Rolled Erosion Control Products Functions Erosion Control Yes Sediment Control No Site/Material Mana ement No Noveinber 2010 Urban Drainage and Flood Control District RECP-1 Urban Starm Draiilage 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 tibers, filaments, neCs, wire mesh, and/or other elements, processed into a permanent, three- dimensional matrix of sufficient thickness. TRMs, which may be suppleinented with degradable components, are designed to impart immediate erosion protection, enhance vegetation establishment and provide long-term functionality by permanently reinforcing vegetation ducing 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-l. ECTC Standard Speci�cation 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 Factor''S Max. She ar Gradient Stress ' ' Mulch Control Nets 5:1 (H:V) �0.10 @ 0.25 Ibs/ft� 5 lbs/ft 5:1 (12 Pa) (0.073 kN/m) Netless Rolled z Erosion Control 4:1 (H:V) �0.10 @ O.S lbs/ft 5 lbs/ft Blankets 4:1 (24 Pa) (0.073 kN/m) Up to 12 months Single-net Erosion <0.15 @ 1.5 Ibs/ft� SO lbs/ft Control Blankets & 3:1 (H:V) 3:1 (72 Pa) (0.73 kN/m) Open Weave Textiles Double-net Erosion 2.1 �H:V� <0.20 @ 1.75 lbs/ft� 75 lbs/ft Control Blankets 2:1 (84 Pa) (1.09 kN/m) <0.10 @ 0.25 Ibs/ft� 25 lbs/ft Mulch Cont��ol Nets 5:1 (H:V) 5:1 (12 Pa) (0.36 kN/m) 24 months Erosion Control Blankets & Open <0.25 @ 2.00 lbs/ft� 1001bs/ft Weave Textiles L5:1 (H:V) 1.5:1 (96 Pa) (1.45 kN/m) 24 months (slowly degrading) Erosion Control 2 Blankets & Open 1:1 (H:V) �0.25 @ 2.25 lbs/ft 125 Ibs/ft 36 months Weave Texriles 1:1 (108 Pa) (1.82 kN/m) * C Factor and shear stress for mulch control nettings must be obtained with nettin� used in conjlinction with pre-applied mulch material. (See Section 5.3 of'Chapter 7 Const�uction BMPs,f'or- mof�e infof-mation on the C Factor.) � Minimum Average Roll Values, Machine direction using ECTC Mod. ASTM D 5035. � C Factor calculated as ratio of soil loss from RECP protected slope (tested at specified or b eater gradient, H:V) to ratio of soil loss from unprotected (control) plot in large-scale testing. � Required minimum shear stress RECP (unvegetated) can sustain witl�out physical damage or excess erosion (> 12.7 mm (0.5 in) soil loss) during a 30-minute flow event in large-scale testing. 4 The permissible shear stress levels established far each perfarmance category are based on historical experience with products characterized by Manning's roughness coefficients in the range of 0.01 - 0.05. s Acceptable large-scale test methods may iilclude ASTM D 6�59, or other independent testing deemed acceptable by the engineer. �' 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 Starm Draiilage 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 Counci12005) Product Type Slope Channel Applications Applications Maximum Maximum Minimum Gradient Shear Stress4'S Tensile � Strength ` TRMs with a minimum thickness of 0.5:1 (H:V) 6.O lbs/ft� (288 Pa) 1251bs/ft (1.82 0.25 inches (6.35 mm) per ASTM D kN/m) 6525 and UV stability of 80°Io per ASTM D 4355 (500 hours z 1501bs/ft (2.19 exposure). 0.5:1 (H:V) 8.O lbs/ft (384 Pa) kN/m) 0.5:1 (H:V) 10.0 lbs/ft� (480 Pa) 1751bs/ft (2.55 kN/m) ' Far TRMs containing degradable components, all property values must be obtained on the non- degradable portion of the matting alone. � Minimum Average Roll Values, machine direction only far tensile strength determination using ASTM D 6818 (Supersedes Mod. ASTM D 5035 for RECPs) � Field conditions with high loading and/ar 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, ar other independent testing deemed acceptable by the engineer. Design and Installation RECPs should be installed according to manufacturer's specifications and �uidelines. Regardless of the type of product used, it is impartant 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 insta]]ation and maintenance challenges and generally take a long time to biodegrade. Some local jurisdictions have had favorable experiences using biodegradable stakes. Tl�is BMP Fact Sheet provides design details far several commonly used ECB applications, including: ECB-1 Pipe Outlet to Drainageway ECB-2 Small Ditd� 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 ihe design details according to these factors: ■ ECB type ■ Slope or channel type Far 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 ofi erosion contro] blankets and other RECPs includes: Check far 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 reinoval. 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. Noveinber 2010 Urban Drainage and Flood Control District RECP-5 Urban Starm Draiilage Criteria Manual Volume 3 EC-6 UNDISTURBED SOIL � _ j� M . j ,� - �'._� = �-- Rolled Erosion Control Products (RECP) PERIMETER ANCHOR TRENCH, TYP ECB JOINT ANCHOR TOP OF TRENCH, TYP. /- CHANNEL BANK r / ANCHOR DETAILS GEOTEXTILE IFABRIC OR MAT, TYP. � I� 3" MIN, TYP. � I �, 6 �MIN, I TYPE OF ECB AS INDICATED IN PLAN VIEW. INSTALL IN � ALL DISTURBED AREAS OF STREAMS AND DRAINAGE CHANNELS TO DEPT 0 ABOVE CHANNEL INVERr. ECB SHALL GENERALLY BE ORIENTED PARALLEL TO FLaW DIRECTION {I.E. LONG DIMENSIONS OF BLANKET PARALLEL TO FLOWLINES} STAKING PATTERN SHALL MATCN ECB ANO/OR CHANNEL TYPE. ECB-1 . PIPE OUTLET TO DRAINAGEWAY JOINT ANCHOR TRENCH. TYP. 6.. / TOPSOIL � M. � �� NPE OF ECB, INDICATED IN PLAN VIEW V�� SINGLE EDGE `� STAKE, TYP. COMPACTED BACKFILL, TYP. PERIMETER ANCHOR TRENCH TWO EDGES OF TWO ADJACENT ROLLS JOINT ANCHOR TRENCH � � LOOP FROM EC8 SHALL MIODLE OF EXTEND TO THE ROLL TOP OF THE CHANNEL INTERME�IATE ANCHOR TRENCH r � PERIMETER ANCHOR FLOW �� �` 6� � TRENCH, TYP. COMPACTED SUBGRADE STAKING PATTERN PER MANUFACTURER SPEC. OR PATTERN BASED aN ECB AND/OR CHANNEL TYPE (SEE STAKING OVERLAPPING JOINT PATTERN DETAIL) ECB-2. SMALL DITCH OR DRAINAGEWAY � �-- 3" MIN. , 2,� 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) f.�i�CKd� =iPl� 7F�3.�1 DIVERSION DITCH NPICALLY AT TOP OF SLOPE OVERLAPPING J�IN7 EC-6 STAKING PATTERN PER MANUFACTURER SPEC. aR PATTERN BASEO aN ECB AND/OR SLOPE TYPE (SEE STAKING PATTERN DETAIL) \CPERIMETER ANCHOR TRENCH ECB-3. OUTSIDE OF DRAINAGEWAY ROLL PERIMETER WIDTH ANCHOR W, TYP. TRENCH OR JOINT, TYP. 3' 6' �o —� — Yz w I STRAW �w — �o kz H' g' o 0 0 �3 STRAW—COCONUT I°I v�w °—� ° -- � w 4 � -j o o � 1 ° T2, COCONUT OR EXCELSIOR STAKING PATTERNS BY ECB TYPE 3��i f� Yz W 2� 0 0 3' --' .�— y+ 'N 4' o 0 6' q � y� W 6' � o W o _ � y� w I---I Y4 w 'o 0 0 0 4:1-3:1 3:1 -2:1 2:1 AND STEEPER SLOPES 2 SLOPES �SLOPES 4' o'bo �� w 4'� o00 �Y2 W � o00 000� L2' 20" f-- 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 Starm Draiilage Criteria Manual Volume 3 EC-6 Rolled Erosion Control Products (RECP) EROSION CONTROL BLANKET INSTALLATION NOTES 1. SEE PLAN VIEW FOR: —LOCA710N OF ECB. —TYPE OF ECB (STRAW, STRAW—COCONUT, COCONUT, OR EXCELSIOR). —AREA, A, IN SQUARE YARQS OF EACH TYPE OF ECB. 2. 100% NATURAL AND 810DEGRADABLE MATERIALS ARE PREFERRED FOR RECPs, ALTHOUGH SOME JURISOICTIONS MAY ALLOW OTHER MATERIALS IN SOME APPLICATIONS. 3. IN AREAS WHERE ECBs ARE SHOWN ON THE PLANS, THE PERMITTEE SHALL PIACE TOPSOIL AND PERFORM FINAL GRADING, SURFACE PREPARATION, AND SEEDING AND MULCHING. SUBGRADE SHALL BE SMOOTH AND MOIST PRIDR TO EC6 INSTALLATION AND THE EC8 SHALL BE IN FULL CONTACT WITH SUBGRADE. NO GAPS OR V�IDS SHALL EXIST UNDER THE BLANKET. 4. PERIMETER ANCHOR TRENCH SHALL BE USED A�ONG THE OUTSIDE PERIMETER OF ALL BLANKET AREAS. 5. JOINT ANCHOR TRENCN SHALL 8E USED TO JOIN ROLLS OF ECBs TOGETHER (LONGITUDINALLY AND TRANSVERSELY) FOR ALL ECBs EXCEPT STRAW WHICH MAY USE AN aVERLAPPING JOINT. 6. INTERMEDIATE ANCHOR TRENCH SHALL 8E USED AT SPACING OF ONE—HALF ROLL LENGTH FOR COCONUT AND EXCELSIOR ECBs. 7. aVERLAPPING JOINT DETAIL SHALL BE USEO TO JOIN ROLLS OF ECBs TOGETHER FOR ECBs ON SLOPES. 8. MATERIAL SPECIFICATIONS OF ECBs SHALL CONFORM TO TABLE ECB-1. 9. ANY AREAS OF SEEOING 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 EC8-1. ECB MATERIAL SPECIFICATIONS �,PE COCONUT STRAW EXCELSIOR RECOMMENDED CONTENT CONTENT CONTENT NETTING"* STRAW — 100% _ DOUBLE/ NATURAL S7RAW— 30% MIN 70% MAX DOUBLE/ COCONUT NATURAL COCONUT 100% — _ DOUBLE/ NATURAL EXCELSIOR _ _ �QQ% DOUBLE/ NATURAL "STRAW ECBs MAY ONLY BE USED OUTSI�E OF STREAMS AND ORAINAGE CHANNEL. "•ALTERNATE NETTING MAY BE ACCEPTABI.E IN SOME JURISOICTIONS 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 ERaSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREOUENT 08SERVATIONS 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 O7HERWISE DAMAGED SHALL BE REPAIRED OR REINSTALLED. ANY SUBGRADE AREAS BELOW THE GEOTEXTILE THAT HAVE ERODEO TO CREATED A VOID UNDER THE BLANKET, OR THA7 REMAIN DEVOID OF GRASS SHALL 8E REPAIRED, RESEEDED AND MULCHED AND THE ECB REINSTALLED. NOTE: MANY JURISDICTIONS HAVE BMP DE7AILS THAT VARY FROM UOFCD STANDAR� DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH OETAIL SHOULD BE USED WHEN OIFFERENCES ARE NOTEO. �DETAILS ADAPTED FROM DOUClAS COUNTY, COLORA00 ANO 70WN OF PARKER COLORADO, NOT AVAILABIE IN AUTOCAD) Noveinber 2010 Urban Drainage and Flood Control District RECP-9 Urban Starm Draiilage Criteria Manual Volume 3 Temporary Slope Drains (TSD) EC-7 Description A temporary slope drain is a pipe ar culvert used to convey water down a slope where there is a high potential for erosion. A drainage chailnel or swale at the top of the slope rypically directs upgradient runoff to the pipe entrance for conveyance down the slope. The pipe outlet must be equipped with outlet protection. -. :_, . . . �.- � � ' �� .,� � =�- ' .. I, .,� •.,1 � i�'.. - =��= ' : . ",`",,:� :� _���� _. _� : ,� ' .� _ • ` ;=��: _ - ., _` �a_ . _}. 1 � �� � � . ._ r..�,.^ . � � �~ _ �I� d ^ . � �, • � •`.��� � �� -�'^, � : ,r , �' � ��V�� 7�"_'1� � . ��u1K � : �iwir�:,. � .. . . ... .� . r . .. ' - - ... Photograph TSD-1. A temporary slope drain installed to convey runoff down a slope during construction. Photo courtesy of the City oP 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 fram 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 anchared by burying it with adequate cover or by using an anchor system to secure it to the ground. The discharge froin the slope drain must be directed to a stabilized outlet, temporary or pernlanent channel, and/or sedimentation basin. See Detail TSD-1 for additional sizing and design information. Temporary Slope Drains Functions Erosion Control Yes Sediment Control No Site/Material Management No Noveinber 2010 Urban Drainage and Flood Control District SD-1 Urban Starm Draiilage 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 ihe 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 coinpromised the depth of cover. Slope drains should be removed when no longer needed or just prior to installation of pennanent 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, inulched or otherwise stabilized as required by the loca] jurisdiction. SD-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Voluine 3 Temporary Slope Drains (TSD) EC-7 • PIPE MUST BE ANCHORED WITH SOIL OR OTHER SUITABLE ANCHOR RIPRAP � i _ r-t ;=t;;�t_ 2xD50 MIN RIPRAP �`J � BEDDING 6x 0 { MIN 12" MIN (TOP COMPACTED OF PIPE TO TOP EMBANKMENT A OF EMBANKMENT, BERM � CHECK HEA�WATER DEPTH) � 1�� � � SCH 40 PIPE D= 12" (MIN) PLASTIC PIPE, HEAVY CANVAS STOCK, RIPRAP LINED TRENCH, OR GEOMEMBRANE LINED TRENCH TEMPORARY SLOPE DRAIN PROFILE 12" MW COVER (CHECK HEAOWATER DEPTH COMPACTED ANO PROVIDE FOR ARMORED �VERFLOW EMBANKMENT BERM � FOR EVENTS EXCEEDING DESIGN STORM) UNDISTURBEO OR COMPACTED SOIL y 1 ! / SECTION A D (10" MIN) ,a ,=� . _ - - .a"- -:� - �I �� ��� � .1�f `�!_;M M . . � . 2xD50 '""' RIPRAP MIN TERMINATION OF RIPRAP LINED SLOPE DRAIN GEOMEMBRANE LINED SLOPE DRAIN 30 MIL (MIN) IMPERMEABLE PERIMETER ANCHOR GEOMEMBRANE TRENCH, SEE ECB D{10" MIN) , �� 4xD MIN TERMINATION OF GEOMEMBRANE LINED SLOPE DRAIN TSD-1 . TEMPORARY SLOPE DRAIN PROFILE PERIMETER ANCHOR TRENCH, SEE ECB 30 MIL (MIN) Ih4PERMEABLE ._ GEOMEMBRANE COMPACTED�- l / � EMBANKMENT BERM UNDIS7URBED OR COMPACTEO SOIL November 2010 Urban Drainage and Flood Control District SD-3 Urban Starm Draiilage Criteria Manual Volume 3 EC-7 Temporary Slope Drains (TSD) SLOPE DRAIN INSTALLATION NOTES 1. SEE PLAN VIEW FOR: —LOCA710N AND LENGTH OF SLOPE DRAIN —PIPE OIAMETER, D, AND RIPRAP SIZE, D50. 2. SLOPE DRAIN SHALL 8E 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 INDICATEO 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 OESIGN HEADWATER DEPTH. 6. RIPRAP PAD SHALL 8E PLACED AT SLOPE DRAIN OUTFALL. 7. ANCHOR PIPE 8Y COVERING WITH SOIL OR AN ALTERNATE SUITABLE ANCHOR MATERIAL. SLOPE DRAIN MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, ANO MAINTAIN THEM IN EFFECTIVE OPERATING CONOITION. 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 ANO CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHIY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. INSPECT INLET AND OUTLET POINTS AFTER SrORMS FOR CLOGGING OR EVIDENCE OF OVERTOPPING. BREACHES IN PIPE OR OTHER CONVEYANCE SHALL BE REPAIRED AS SOON AS PRACTICABLE IF 08SERVED. 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 TQ THE END OF CONSTRUCTION. WHEN SLOPE DRAINS ARE REMOVED, THE DISTURBED AREA SHALL BE COVERED WITH TOP SOIL, SEEDED, MULCHED OR OTHERWISE STABILI2ED IN A MANNER APPROVED 8Y THE LOCAL JURISOICTION. (DETAIL ADAPTEO fROM OOUGLAS COUNTY, COLORADO ANO THE CITY OF COLORADO SPRINCS, COLORADO, NOT AVAILABLE IN AUiOCAD) NQTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD 8E USED WHEN DIFFERENCES ARE NOTED. SD-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Voluine 3 Temporary Outlet Protection (TOP) EC-8 Description Outlet protection l�elps to reduce erosion immediately downstream of a pipe, culvert, slope drain, rundown or other conveyance with concentrated, high- velocity flows. Typical outlet protection consists of riprap or rock aprons at the conveyance outlet. Appropriate Uses Outlet protection should be Lised when a �_�� .�__ ,�,..�� : �,, . ... �. _ . _��- _ a�- � .� _ . - � �`�'. :: . 4 ; .-;� �+���. _- �'� .. - _,.o; .r .. �'L - ti,�..:31 •sv'3i'�-.: - I I; � � .�� ;-�.: � _ -�!4'�' � �. t � �- �� � -_ ..- � �' � �i►� � ' ���.- _ � � F � ��r �� = _-�... w _ � . `�� �'_sr `_ � -`.�1..�.c = � � �-1���" - � � � ��.� '�` •�~ 9+�� ...�� �� .- _ .�Y � � -i'� .�l �-�r� ` ` - �{� �� _ --� , ,� -- _ � r� j � �- � � . � : � . �,d .� ' ��. , '%"�� ��s..��`� ^'1" , �'���'' :�- � - l _ ��.. �� !.f : _.1i�_'-�' . ._� '�- �,._ conveyance discharges onto a disturbed area where there is potenrial far accelerated Photograph TOP-1. Riprap outle� protection. erosion due to concentrated flow. OuTlet protection should be provided where the velociry at the clilvert 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 constsuction (the drainage area may cl�ange 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. Wl�en sedime��t accumulation is noted, check that upgradient BMPs, including inlet protection, are in effective operating condirion. Outlet Protection Functions Erosion Control Yes Sediment Control Moderate Site/Material Management No Outlet protection may be removed once the pipe is no longer draining an upstream area, or once the downstreain area has been sufficiently stabilized. If the drainage pipe is permanent, outlet protection can be left in place; however, permanent outlet protection should be designed and constructed in accordance with the requirements of the Mcrjor-Drainage chapter of Volume 2. November 2010 Urban Drainage and Flood Control District TOP-1 Urban Starm Drainage Criteria Manual Volume 3 EC-8 Temporary Outlet Protection (TOP) _.��:���} R-��_ tt-ij�ti�v ix��i.'y'�''i'j� .:4 7 : ^. �. y. ^:,. 3(C Do) TEMPORARY OUTLET PROTECTION PLAN I Lo Q� D= 2 x D50 1 � NON-WOVEN GEOTEXTILE � KEY IN TO 2 x D50 AROUND PERIMETER SECTION A TABLE OP-1. TEMPORARY OUTLET PROTECTION SIZING TABLE PIPE RIPRAP D50 DIAMETER, OISCHARGE, APRON DIAMETER Do Q(CFS) LENGTH, La MIN {INCHES� ��� {INCHES� 8 2.5 S 4 5 10 6 12 S 10 4 10 13 6 10 10 6 18 20 16 9 30 23 12 40 26 16 30 16 9 24 40 26 9 50 26 12 60 30 16 OP-1. TEMPORARY OUTLET PROTECTION EXTEND RIPRAP TO HEIGHT OF CULVERT OR NORMAL CHANNEL DEPTH. WHICHEVER IS LESS OP TOP-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Voluine 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. OETAII. IS INTENDED FOR PIPES WITH SLOPE S 10%. ADDITIONAL EVALUATION OF RIPRAP SIZING AND OUTLET PROTECTION DIMENSIaNS REQUIRED FOR STEEPER SLOPES. 3. TEMPORARY OU7LET PRaTECT10N INFORMATION IS FOR OUTLETS INTENOED TO BE UTILIZED LESS THAN 2 YEARS. TEMPORARY OUTLET PROTECTION INSPECTION ANO 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 ERaSION, 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 LOCA� JURISOICTIONS AS TO WHICH DETAIL SHOULD 8E USED WHEN DIFFERENCES ARE NOTED. (DEiAILS ADAPTED FROM AURORA, COLORADO AND PREVIOUS VERSION OF VOLUNE 3, NOT AVAILABLE IN AUTOCAD) November 2010 Urban Drainage and Flood Control District TOP-3 Urban Starm 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 ar used fior construction access. These temporaiy berms intercept sheet flow and divert runoff from the roadway, and control erosion by minimizing concentration ofi flow and reducing runoff velocity. Appropriate Uses Appropriate uses include: ■ Temporary dirt construction roadways that have not received roadbase. r��t� .�..�.�=�► �_�=:! �A �ri�� ��� _ 3 . ;.:- � .% � ,� 't�t ,. . :.;��.� x� _—. . - _ ' :,'ti-=�'�:,'��� �� _ — --;s.,r:-,. �. �� . . -- . � �:�� . � : _ '. - .-!� -- ¢ ' .��� - :::, _ �. = .. _�.. .::;�, � • •. ;s; .� . - , � �: :. -. • .��.Y,F:.��fi. . ""� "'��� : 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 co»ce»tratin� and eroding the soil. These controls consist of runoff ban-iers that are constructed at intervals along the road. These barriers are installed perpendicular to the longitudina] 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 far 400 feet froin 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 infarmation. Maintenance and Removal I�Zspect street controls for erosion and stabiliry. If rills are farming 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 pavmg. Erosion Control Yes Sediment Control Moderate Site/Material Manageinent No Noveinber 2010 Urban Drainage and Flood Control District RCS-1 Urban Starm Draiilage Criteria Manual Volume 3 EC-9 Rough Cut Street Control (RCS) �� EXCAVATEO ROADBED CL� I- SPACING 200' MAXIMUM (SEE TABLE RCS-2) STREET SLOPE X _ SEE TABLE RCS-1 RCS W = 1/2 ROADBED WIDTH 8' MINIMUM SPACING FOR VEHICLE PASSAGE GEOTEXTILE SOCK(S) FILLED WITH / CRUSHED ROCK OR COMPACTEQ J EARTHEN BERM(S} ROUGH CUT STREET CONTROL PLAN PL FL'_-�._ '�__ i� c.m� i r a.�:z.n.� :� a.� SECTION A .-� ;�� ,-:;�:, _'�?. � �}-�= 12" TO 18" � ����� � ��. �l� TABLE RCS-1 W (FT) X (FT) 20-30 5 31 - 40 7 41-50 g 51-60 10.5 61-70 12 SECTION B w F� GEOTEXTILE SOCK{S) FILLED WITH CRUSH ROCK OR COMPACTED EARTHEN BERM{S) = 12° TO 18" � ?-, r; ->, -.r� ' TABLE RCS-2 LONGITUDINAL SPACING {FT) STREET SLOPE {%) <2 NOT TYPICALLY NEEDED 2 200 3 200 4 150 5 100 6 50 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 CONTRaL INSPECTION AND MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONOITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND A�WAYS WITHIN 24 HOURS) FOLLOWING A STORM THA7 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 AOAPiED fROM AURORA, COLORADO, NOT AVAILABLE IN AUTOCAD) NOTE: MANY JURISDIC710NS HAVE BMP OETAILS THAT VARY FROM u�Fco srarvoaRo oEr,a��s. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. Noveinber 2010 Urban Drainage and Flood Control District RCS-3 Urban Starm Draiilage 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 coiltrol 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 rypically used to control the flow path of runoff at a construction site by diverting runoff around areas prone to erosion, such as steep slopes. Earth dikes and drainage swales may also be constructed as temporary conveyance features. This will direct runoff to additional sediment control treatment BMPs, such as sediment traps or basins. Design and Installation _. , - q .; ��,�y( _ i I���� � c2.=.r _ !� � ';i. '�.;.~�..` .� ��`Y+ _"�i-__ 1�� �r' , N�����}'j• `�� ? , t� t'�� . ..,� � fi �`' 3'„�— � �� . F , �',•��� �#i„E„-.�s,� - � •.-- _ - ��_,', '� : ���. '• "'� �: ° ' . :::"9't. . +�_- ''�i• � _t-a��'1!t�..��,_��N ��i ,' r Y �rY,�. ��;-!t'� � .. . �� ` �:� _ h� �� ; ;� < ��=� - . ,�,:_, , :, -'+�. : ti. �� :: ��'�.``� '.r -�}��w�' s�;�..s� 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 ar a small chamlel upslope of the berm to convey the diverted water. Temporary diversion dikes can be constructed by excavation of a V-shaped trencl� 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 inid-slope of a disturbed area to iiltercept runoff and reduce the effective slope length. Depending on the project, either an earth dike or drainage swa need far cut on the project, then an excavated drainage swale may be better suited. When the project is primarily fill, then a conveyance constructed using a benn may be the better option. All dikes or swales receiving runoff from a disturbed area should direct stormwater to a sediment control BMP such as a sediment trap or basin. e may be more appropriate. If there is a Earth Dikes and Drainage Swales Functions Erosion Control Yes Sediment Control Moderate Site/Material Mana ement No Noveinber 2010 Urban Drainage and Flood Control District ED/DS-1 Urban Starm Draiilage Criteria Manual Volume 3 Photograph ED/DS-]. Example of an earth dike used to divert flows at a construc[ion site. Photo courtesy of CDOT. 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 severa] 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 v-ea immediately followiilg reinoval by revegetation or other permanent stabilization method approved by the local jurisdiction. ED/DS-2 Urban Drainage and Flood Control District November 2010 Urbail Storm Drainage Criteria Manual Voluine 3 Earth Dikes and Drainage Swales (ED/DS) EC-10 " M �� � ir- ED-1 . COMPACTED UNLINED EARTH DIKE FORMED BY BERM TRANSVERSE FLOW �^ �"` TO�ALE �-- �� '^ � EXISTING GRADE 15" MIN. >3 >3 DS-1. COMPACTED UNLINED EXCAVATED SWALE r�w >3 � �3 r� �3 � EXISTING GRADE 15�� MIN DS-2. COMPACTED UNLINED SWALE FORMED BY CUT AND FILL W (5' MIN. GEOTEXTILE OR MAT (SEE ECB) INTERMEOIATE ANCHOR TRENCH AT ONE-HALF ROLL LENGTH (SEE ECB) ED/ DS TRANSV SE �� �` FLOW TO SWALE � EXISTING GRADE STAKES (SEE ECB) D (10" MIN.) ANCHOR TRENCH AT PERIMETER OF BLANKET AND AT OVERLAPPING JOINTS WITH ANY ADJACENT ROLLS OF BLANKET {SEE ECB) TRANSVERSE ANCHOR TRENCHES AT PERIMETER OF BLANKET AND AT OVERLAPPING JOWTS 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 Starm Draiilage Criteria Manual Volume 3 EC-10 Earth Dikes and Drainage Swales (ED/DS) 30 MIL MIN. THICKNESS NO W (5' MIN.) � ` STAKING �u (�u MIN.f ANCHOR TRENCH AT PERIMETER OF BLANKET AND AT OVERLAPPING JOINTS WITH ANY ADJACENT ROLLS OF BLANKET, INTERMEDIATE ANCHOR � � � SIMILAR TO ECB, 8UT 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, 8UT NO STAKING DS-4. SYNTHETIC LINED SWALE THICKNESS=2 X D50 �, W(5' MIN. - --� D {10" MIN.) - > ,;,, -`I;i LINE WITH AASHTO #3 ROCK (CDOT SECT. 703, j%3) OR RIPRAP CALLED FOR IN THE PLANS I�I.�.�:�1,:7_\��I\I���.y�1%1�� EARTH DIKE AND DRAINAGE SWALE INSTALLATION NOTES 1. SEE SITE PLAN FOR: - LOCATION OF DIVERSION SWALE - TYPE OF SWALE (UNUNED, COMPACTED AND/OR LWED). - LENGTH OF EACH SWALE. - DEPTH, D, AND WIOTH, 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 DIVERSIQN SWALES EXCEEDING 2-YEAR FLOW RATE OR 10 CFS. 3. EARTH DIKES AND SWALES INDICA7ED 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 ACCOR�ING Ta ASTM D698. 5. SWALES ARE TO DRAIN TO A SEDIMENT CONTRO� BMP. 6. FOR LINED DITCHES, INSTALLATION OF ECB/TRM SHALL CONFORM TO THE REQUIREMENTS OF THE ECB DETAIL. 7. WHEN CONSTRUCTION TRAFFIC MUSr CROSS A DIVERSIaN SWALE, INSTALL A TEMPORARY CULVERT WITH A MINIMUM DIAMETER OF 12 INCHES. ED/DS-4 Urban Drainage and Flood Control District November 2010 Urbail Storm Drainage Criteria Manual Voluine 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 ERaSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREOUENT 08SERVATIONS 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 TOP501L, SEEDED AND MULCHED OR OTHERWISE STABILIZED IN A MANNER APPROVED BY LOCAL JURISDICTION. (DETPIL ADAPTED fROM OOUGL4S COUNTY, COLORADO ANO THE CITY OF COLORPDO SPRINCS, COLORADO, NOT AVAILABLE IN AUiOCAD) 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. Noveinber 2010 Urban Drainage and Flood Control District ED/DS-5 Urban Starm Draiilage 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 se�ments. Terraces shorten the uninterrupted flow lengths on steep slopes, helping to reduce the development of rills and gullies. Retaining walls, gabioils, cribbing, deadman anchars, rock-filled slope mattresses, and other types of soil retention systems can be used in Y�- . - � - _ •:= - � � r �, a w �'".�!'h �< - �,_ I�?.� �{,, _...���. � �� �� �Fv.� -'Y.�. �''4;'�'.'! -�. ' � -- `�;•�' .. _ � .����� ` r��� � ��, -. �.� �• -�,� '�-�r, - �,�-�-�• �- �. 4 � r�t�f�i11�' r � i•%• ,� �. +..�.,�.,. �'�J.. .. ""'+`�;i ; teiTaCing. Photograph TER-1. Use of a terrace to reduce erosion by controlling slope length on a long, steep slope. Pl�oto courtesy of Douglas Appropriate Uses c°u"`�. Terracing techniques are most typically used to control erosion on slopes that are steeper than 4: l. Design and Installation Design details with notes are provided in Detail TER-1. The type, number, and spaciiig 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 far 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 fina] configuration and terraces are removed. Due to the steepness of the slope, once terraces are graded, erosion control blankets or other stabilization measures are rypically required. If tei7aces are permanent, vegetation should be established on slopes ancl terraces as soon as practical. Terracing Functions Erosion Control Yes Sediment Control Moderate Site/Material Mana ement No Noveinber 2010 Urban Drainage and Flood Control District TER-1 Urban Starm Draiilage Criteria Manual Volume 3 EC-11 Terracing (TER) �--� � � TER W (8' MIN.) EXISTING -� � � GRADE "H" VARIES �� (15' MAX.) ~ `~- SEE GRADING PLAN '` � �� � FINISHED 1� ` GRADE � 3% MIN., �� 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. GRAOE TERRACES TO DRAIN BACK TO SLOPE AT A MINIMUM OF 3% GRADE. TERRACING MAINTENANCE NOTES 1. INSPECi BMPs EACH WORKDAY, ANO MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BA�Ps AS SQON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE ERQSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT 08SERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTNE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHOULO BE DOCUMENTEO THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIArED UPON DISCOVERY OF THE FAILURE. 4. RILL EROSION OCCURRING ON TERRACEO SLOPES SHALL BE REPAIRED, RESEEDEO, MULCHED OR SiABIL12ED 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 ADAPTEO FRON OOUGLAS COUNTY, COLORA�O ANO TOWN OF PARKER, COLORA00, NOT AVAILABLE IN AUTOCA�) NOTE: MANY JURISDIC710NS HAVE BMP DETAIIS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE N07ED. TER-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Check Dams (CD) EC-12 Description , � >, � a ` '' _ ��tr � � � 9- k r I�dd `.s - ,:.� Check dams are temparary grade control �' --�=-•r� ''� ����`�'� � structures placed in drainage channels to �"__ limit ihe erosivity of stormwater by ��` � -� �� _ reducing flow velocity. Check dams are �ti�, �� �' �� � � � ��,;�� typically coilstructed from rock, gravel ='� � � �������„ -: a -".-��,,,, � -- pit .1 �I,Y� � :�, u`fi,�-'� i r. � f 7'' :�,��� f'�+w.:^m �� �""1.�ti bags, sand bags, or sometimes, '���t�;;;���� :_?��� r f��= �: :x.: proprictary devices. Reinforced check � � �;�� s �� ,.- _ '' " �' �.,�-�r� - , dams are typically constructed from rock X+�} �i� `� � �'„°y �'�' �" �� , .n f .. 1, and wire abion. Althou h tl�e rimar � A �� �� ' � ���'`� � `�'°`� �� > `'` �� �- � g g P Y t,x ,, �k , � � � h �. . , [l . .� ��W � function of check dams is to reduce the ,,;: �; � �-=�.r t � iY velocity of concentrated flows, a secondary benefit is sediment trapping upstream of the siructure. Appropriate Uses Photograph CD-1. Rock check dains in a roadside ditch. Photo courtesy of WWE. Use as a grade control for temporary drainage ditches or swales unril final soil stabilization measures are established upstream and downstream. Check dams can be used on mild or moderately steep slopes. Check dains may be used uildei• the following conditions: ■ As temporary grade control facilities along waterways until final stabilizaTion is established. ■ Along permanent swales that need protectioi� prior to installation of a non-erodible lining. ■ Along temparary 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 l�and. Do not dump rocks into the drainage chaimel. Where multiple check dams are used, the top of the lower dain should be at the same elevation as the toe ofi the upper dam. Wl�en reinforced check dains are used, install erosion control fal prevent erosion on the upstream and downstream sides. Each section of the dam should be keyed in to reduce the potential for washout ar undermining. A rock apron upstream and downstream of the dam may be necessary to further control erosion. �ric under and around t11e check dam to Check Dams Functions Erosion Control Yes Sediment Control Moderate Site/Material Management No Noveinber 2010 Urban Drainage and Flood Control District CD-1 Urban Starm Draiilage Criteria Manual Volume 3 EC-12 Check Dams (CD) Design details with notes are provided for the following rypes of check dams: ■ Rock Check Dams (CD-1) ■ Reinforced Check Dams (CD-2) Sediment control logs may also be used as check dains; 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 lh of the crest height. Remove accumulated sediinent priar 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 ]ocation in accordance with the standard specifications. Check dams constructed in pennanent swales should be removed when perennial grasses have become established, or immediately prior to installation of a non-erodible lining. All of the rocic 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) COMPACTED J BACKFILL, ( TYP. ) LENGTH, L CREST LENGTH, CL SECTION 3 (NP.) SECTION D q ��, 6„ � MIN��) 1' 6" '�� � (MIN) CHANNEL GRADE UPSTREAM AND DOWNSTREAM 2 1� TOP OF CHECK DAM EC-12 CD CHECK DAM ELEVATION VIEW 2' 6' CHANNEL � � GRADE �, 6„ FLOW � MIN. 1 � MIN. 050 = 12" RIPRAP, NPE M OR TYPE L D50= 9" (SEE TABLE MD-7, MAJOR DRAINAGE, VOL. 1 FOR GRADATION) EXCAVATION TO NEAT LINE, AVOID aVER-EXCAVATION, (TYP. ) SECTION A FLOW � I I CHANNEL GRADE — � -� -� � -e ,y��y..�,, � -� .� .-� 1' MIN. -� ''� Y�r�r-�Yy r� r��.�� r��f=i' EXCAVATION TO NEAT � 1., :.; Y Y� Y�' f w� �,� w� Y Y, �'`'�� LINE, AVOID OVER-EXCAVATION 050 = 12" RIPRAP, TYPE M OR �NP�� TYPE � D50=9" (SEE T'ABLE MD-7, MAJOR DRAINAGE, VOL. 1 FOR GRADATION) SECTION B SPaCiNG BETwEEN CHECK DAMS SUCH THaT �-, .-.�.:,� q A AND B ARE EQUAL ELEVATION _ -: �•`i�-, Yy= t''-!'. . � `lM1�'^�'(-l�r� ='` -i. � '� B ��_.i�_:.�: Yy .,t_.�, _��; _. �l J� � �� �" �� �' � ~ i` ' -V Y - CHANNEL GRADE � % { � `� � � .`� , ..+ y.:y..: . PROFILE ��`�'�``�``{" �j� CD-1. CHECK DAM November 2010 Urban Drainage and Flood Control District CD-3 Urban Starm Draiilage Criteria Manual Volume 3 EC-12 . � �„ ► � •► .. Check Dams (CD) 1. SEE PLAN VIEW FOR: —LOCA710N OF CHECK �AMS. —CHECK DAM TYPE (CHECK OAM 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 PRIQR 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 (�50 9"). 4. RIPRAP PAD SHALL BE TRENCHED INTO THE GROUND A MINIMIUM OF 1'. 5. THE ENOS OF THE CHECK DAM SHALL 8E A MINIMUM OF 1� 6" HIGHER THAN THE CENTER OF THE CHECK DAM. CHECK DAM MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKOAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE Of BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS P0551BLE (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 OOCUMENTE� 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 REMOVEO 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 ANO APPRaVED BY THE LOCAL JURISOICTION. 6. WHEN CHECK DAMS ARE REMOVED, EXCAVATI�NS SHALL BE FILLED WITH SUITABLE COMPACTEO BACKFILL. DISTURBED AREA SHALL BE SEEDEO AND MULCHED AND COVERED WITH GEOTEXTILE OR OTHERWISE STA8ILIZED IN A MANNER APPROVED BY THE LOCAL JURISDICTION. (DETAlLS ADAPTEO FROM OOUGLAS 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 OIFFERENCES ARE NOTED. CD-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Check Dams (CD) � �� ALTERNATIVE TO STEPS ON BANKS ABOVE CREST: DEFORM GABIONS AS NECESSARY TO ALIGN TOP OF GABIONS wITH GROUNO SURFACE: AVOiO GAPS BETwEEN GABiOrvS MAX. STEP HEIGHT i'6" 1� <4 1 �6�� MIN EC-12 RCD COMPACTED � L� ROCK FILLED GABION BACKFILL HOG RINGS MIN. BURY SECURED TO (TYP) DEPTH 1'6" AOJACENT GABION REINFORCED CHECK DAM ELEVATION VIEW 3' D50=6" RIPRAP ��� ENCLOSEO IN GA810N 1 6'� ,: �-� `���t-' �,6�, 6„ MIN. FLOW � ` :_ � MIN - - � � + -� :-� i �6�� , � � CHANNEL GRADE { COMPACTED BACKFILL r'� ���-- GEOTEXTILE 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 (D). 2. CHECK DAMS INDICATED ON THE SWMP SHALL BE INSTALLED PRIOR TO AN UPSTREAM LAND-DISTURBING ACTIVITIES. 3. REINFORCED CHECK DAMS, GABIONS SHA�L HAVE GALVANIZED TWISTED WIRE NETTING WITH A MAXIMUM OPENING DIMENSION OF 4}�" AND A MINIMUM WIRE THICKNESS OF 0.10��. WIRE "HOG RINGS" AT 4" SPACING OR OTHER APPROVEO MEANS SHALL 8E USED AT ALL GA810N 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 CREST LENGTH, CL Noveinber 2010 Urban Drainage and Flood Control District CD-5 Urban Starm Draiilage Criteria Manual Volume 3 EC-12 . .: � . . •_,, ,_ ► ►_. • Check Dams (CD) 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 (ANO ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AN� PERfORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY r0 MAINTAIN BMPs IN EFFECTIVE OPERATWG CONOITION. INSPECTIONS ANO CORRECTNE MEASURES SHOULO 8E DOCUMENTED THOROUGH�Y. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. SEDIMENT ACCUMULATED UPSTREAM Of REINFaRCED CHECK DAMS SHALL BE REM�VED AS NEEDED TO MAINTAIN THE EFFECTIVENESS OF BMP, TYPICALLY wHEN THE UPSTREAM SEDIMENT DEPTH IS WITHIN Y� THE HEIGHT OF THE CREST. 5. REPAIR OR REPLACE REINfORCEO CHECK DAMS WHEN THERE ARE SIGNS OF DAMAGE SUCH AS HOLES IN THE GA810N OR UNOERCUTTING. 6. REINFORCED CHECK DAMS ARE TO REMAIN IN PLACE UNTIL THE UPSTREAM DISTURBED AREA IS STABILIZED AND APPROVED BY THE LOCAL JURISDICT�ON. 7. WHEN REINFORCED CHECK DAMS ARE REMOVED, ALL DISTURBED AREAS SHALL BE COVEREO WITH TOPSOIL, SEEDED ANO MULCHEO, AND COVERED WITH A GEOTEXTILE BLANKET, OR OTHERWISE STABILIZED AS APPROVED BY LOCAL JURISDICTION. {DETFUL AOAPTEO fROM DOUGLAS COUNTY, COLORA00 AND CITY OF AURORA, COLORA00, NOi AVAILABLE IN AUTOCAD) NOTE: MANY JURISD�CTIONS HAVE BMP DETAILS THAT VARY FROM UOFCD STANDARD DETAI�S. CONSU�T WITH LOCA� 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) Description Streambank stabilization involves a combination of erosion and sediment control practices to protect streams, ba»ks, and in-stream habitat from 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, temparary diversions, dewatering operations and bioengineering practices such as brush ]ayering, live staking and fascines. .,� T���`�\s r "'�in*;� '� ,�- ;�. � _� � '.,t'4,�_' �J' . - �i �'�; r _� . ' —�`--- 1.. ��i _ _�--:- , � Appropriate Uses _ a , � � EC-13 : ��. � �--..a,�� �'"'�'-, .•- ,► 3'� ��T ' � ;r�'' ►s-" ,.'!� r : �;, "+ '` � / :r � � - .�. _-�� . � . ' Photograph SS-l. Sh�eambank stabilizatio� using geotexriles following installation oP a permanent in-stream grade confrol 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 stabiliry 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 construcrion streambank stabilization: ■ Protect existing ve�etation along the stream bank in accordance with the Vegetated Buffiers 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. Ii� 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 Che stream. Use rolled erosion control products, temporary or permanent seeding, or other appropriate measures. ■ Ensure all point discharges entering the stream are adequately armored with a velocity dissipation device and appropriate outlet protection. See individual design details and notes for the various BMPs referenced in this practice. Additional information on bioengineering techniques for stream stabilization can be Streambank Stabilization Functions Erosion Control Yes Sediment Control No Site/Material Management No Noveinber 2010 Urban Drainage and Flood Control District SS-1 Urban Starm Draiilage Criteria Manual Volume 3 EC-13 Streambank Stabilization (SS) found in the Major Urainage chapter of Volume 1 and additional guidance on BMPs far working in waterways can be found in UDFCD's Best Manngement Practices for• Constru�ctior2 in Wnterways Ti�aining Mantral. Maintenance and Removal Inspect BMPs protecting the stream for damage on a daily basis. Maintaiil, 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 inats). For BMPs that are not to remain in place as a part of fii�al stabilization such as silt fence and other temparary measures, BMPs should be removed when all land disturbing activities have ceased and areas have been penn�nently stabilized. SS-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Wind Erosion/Dust Control (DC) Description Wind erosion and dust control BMPs help to keep soil particles from entering the air as a result of ]and 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 sllould be used. For construction roadways, road watering and stabilized surfaces should be considered. Appropriate Uses EC-14 �,~�� •�� �_ � srf� Si �? �^ , -+�.. 4 � i�.y�� ��� � -; ='�r-_, �� - t. � ,'�:�� •,,t�F� _.a . .'. ` `. \ F � - . :�.: - .'�.. ' C ti' ti {� , � r.'\ !.� � r�' i. ' _ � '�ti5r.��.A�',�F+":�1�'� • ' � s i' � , • - � • :�-. :,,:,; �t�..;. � �.: ;��. . ` . '-, :� ;�. , '-.. , _ �.'. y � - ; � � f�.y . ; 4,, .~' iS, i;��+\��_ :4•�'N J'� r'�.�.�vi�. .�!` �t: _- ; �s:.� �• ,..,. _,i�."� j, � �� Photograph DC-1. Water truck used for dust suppression. Pl�oto courtesy of Douglas County. 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 consti•uction 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 Co 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 farm a bond between soil particles keeping them grounded. Chemical treatments may require additional pennitting 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 miniinum across the constrl�ction site. ■ Wind fences can be installed oi1 site to reduce wind speeds. Install fences perpendicular to the prevailing wind direction for maximum effectiveness. Maintenance and Removal When using an irrigation/sprinkler control system to aid in dust control, be careful not to overwater. Overwatering will cause construction vehicles to track mud off-site. Wind Erosion Control/ Dust Control Functions Erosion Control Yes Sediment Control I�10 Site/Material Management Moderate November 2010 Urban Drainage and Flood Control District DG1 Urban Starm Draiilage Criteria Manual Volume 3 Concrete Washout Area (CWA) Description Concrete waste management involves designating and properly mailaging a specific area of the construction site as a concrete washout area. A concrete washout area can be created using one of several approaches designed to receive wash water from washing of tools and coi�crete 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. Appropriate Uses .. �� .. - � �,... r„-- F � �� ,,t ' J,hx IYf�...A �,)rbr� i�w t .'. � 1 _. . . . . , . d:•�� " . ,�p ° , r �. .+�', ., . , s r ;� �t` , �'; ` , ? `- t� t:' ' ���,:'� • , i�r,�. � t� "' 'l�,r ,;�,<:�' �\> f':. ! ' "�! t ,�;' •� . x. ' .. ,� . �� - 1 - . iu ru-�� ",� ; � �=, � � �'���,�� ���; �� �R . � � �, � � �, Photograph CWA-1. Example of concrete washout area. Note gravel tracking pad for access and sign. Concrete washout areas must be designated on all sites that will generate concrete wash wlter or liquid concrete waste from onsite concrete mixing or concrete delivery. Because pH is a pollutant of concern for washout activiries, 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/co��tainment must be used. The following manageme��t 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 ar starmwater runoff. Concrete washout areas may be lined ar unlined excavated pits in the ground, com�nercially manufactured prefabricated washout containers, or aboveground holding areas co»structed 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 Functions Erosion Control No Sediment Control No Site/Material Management Yes Do not locate an unlined washout area within 400 feet of any natural drainage pathway or waterbody or within 1,000 feet of any wells or drinking water sources. Even far lined concrete washouts, it is advisable to locate the facility away from waterbodies and drainage paths. If site constraints make these Noveinber 2010 Urban Drainage and Flood Control District CWA-1 Urban Starm Draiilage Criteria Manual Volume 3 �u Nu �� 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 starage 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 vendars. 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 tl�at adequate signage is provided and in good repair and that the washout area is being used, as opposed to washout in non-designated areas ofi the site. Remove concrete waste in the washout area, as needed to maintain BMP funcrion (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. 3 *�� . �.' r , ���� ' . .� ' : ''r` :� .� ., , . w,_. : � - ;� : � Rf� � �S� � l�� /- � �i' ': 1 . ` :' � '. � «ya -.� � �� .. �,y.�. _ . ' tiw"a:��+iF/�a '��"�!` F �►.. . � ��. . 3 .r�s� � f.� '•� ��,�p: � „ .� ' �, ' ' t � .,��'2-` _ �� `.a� �.. L_+. s `s',.'� ." : a'�p►_'r. ti � Photograph CWA-2. Prefabricated concrete washout. Photo cow-tesy of CDOT. , _. �r _� .� �,�,�i,�,l�}.�3`j - ' , - � ! CbHCRETE `.� - .1�'��- ,ti � r ' �- .�WA.`.'u;;itt '• ti� _ - ` ' 1 J h y � ' �. � ..h�. .�.s;o• S : �' ?�- ^ �•�°�.L —'`! ;<. 9�. . — �- _ . _ . �_ . ' . . ,s � �. ��-.�� C�}� - , - =•,t ��s�'�'_ �'' ' �' Photograph CWA-3. Earthen concrete washout. Pholo cow-tesy of CDOT. CWA-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Concrete Washout Area (CWA) � 12" TYP >4 1� iu ru-�� CWA VEHICLE TRACKING CONTROL (SEE VTC DETAIL) OR OTHER STABLE SURFACE IY�.3.9[�71� - -� - - - �� �3� MIN. _J� UNDISTURBED OR � >3 >3 COMPACTED SOIL VEHICLE TRACKING S X 8 MIN. CON7ROL (SEE VTC SECTION A DETAIL � CWA-1 . CONCRETE WASHOUT AREA CWA INSTALLATION NOTES 1. SEE PLAN VIEW FOR: -CWA INSTALLATION LOCATION. 2. DQ 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 LINEO A80VE GROUND STORAGE ARE SHOULD BE USEO. 3. THE CWA SHALL BE INSTALLED PRIOR TO CONCRETE PLACEMENT ON SITE. 4. CWA SHALL INCLU�E A FLAT SUBSURFACE PIT THAT IS AT LEAST 8' BY S' SLOPES LEADING OUT OF THE SUBSURFACE PIT SHALL BE 3:1 OR FLATTER. THE PIT SHALL BE AT LEAST 3' OEEP. 5. BERM SURROUNDING SIDES AND BACK OF THE CWA SHALL HAVE MINIMUM HEIGHT OF 1'. 6. VEHICLE TRACKING PAD SHALL BE 5LOPE0 2% TOWARDS THE CWA. 7. SIGNS SHALL BE PLACEO 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 Starm Draiilage Criteria Manual Volume 3 CONCRETE WASHOUT AREA PLAN � COMPACTED BERM AROUND � rHE PERIMETER 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 (ANO ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE ERaSION, AND PERFORM NECESSARY MAIN7ENANCE. 2. FREQUENT 08SERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS ANO CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGNLY. 3. 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 WA7ER, 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 DISTURBE� AREA WITH TOP SOIL, SEED AND MULCH OR OTHERWISE STABILIZED IN A MANNER APPROVED BY THE LOCAL JURISDICTION. (DETAIL ADAPTED fROM OOUGLAS COl1NTY, COLORADO AN� THE CITY aF PARKER, COLORA00, NOT AVAILABLE IN AUTOCAD). NOTE: MANY JURISDICriONS HAVE BMP OETAILS THAT VARY FROM UDFCO 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 coustrucrion site. Special attention should be given to stockpiles in close proximity to natural or manmade storm systems. Design and Installation ,.. �:'��,� ,-,. 1 � � �4➢ �r'y" � ,^�I t .t = �a1�3 Y `fs-�'^. ^W. . ., . t� � �� � �� r�yfiw� ,,�� �^ . 34�, � s �s'.r� '' � " -_ -2 < ,�' d�+ �. `�' ' ._ ' � ' ^ � ". : .,... _� "' '�. i._ ' _•i�� ���� w �. e -.��9. f �� y,-' . pl.y.'��'.' '!-f�sci� � -.t - -, � - �i:, . . :. ax - '? L � s�E .��• tl`� � � ��` : � � � ' �` �- - '� _ �� k ..�y I�� ' A . . ��.T s.,� l��t 6�. 'ay�,��--� _ � ,- +�ti �_ �. k��itQ� y�S�z. ..� : �i � � �, {/ ,, . � _ _ � � ., � ; 1�. � �f.�.i. ` . �� �Lr \'Y 'i� Y .,. R�k,�i w , z �.� :x, ,�•� �..-t�s�`: �.,�, 7 _� � _itr �'�'-" s _'i„ ,� � :� ,R'.' _-= - '��" `y -'' �,.. . � -�e � # � g I ar ti� �� - �^ i b-' 'W �'E � � �r; ,�"'� �. i� � ` . �`� i tt + :y 5�� ;�� � � y � : �; .. � � � ,, ` �. .-� a, .rs �'L'� a->s. 4 ...�_ _ .':t� � _.s �.. .... - -. . � ..., -�e�`s`-,s�t`ira'- -n V%: : _ . _ . r Photograph SP-1. A topsoil stocl.pile that has been partially revegetated and is protected by silt fence perimeter control. Locate stockpiles away from all drainage system components inclLiding storm sewer inlets. Where practical, choose stockpile locarions that that will remain undisturbed for the longest period of time as the phases of construction progress. Place sedimei�t 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, temparary seeding and mulching, erosion control blankets, ar 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, andJar 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 far guidance when staging ii1 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 Iilspect perimeter controls and inlet protection in accordance with their respective BMP Fact Sheets. Wl�ere seeding, inulch and/or soil binders are used, reseeding or reapplication of soil binder may be necessary. When temparary removal of a perimeter BMP is necessary to access a stockpile, ensure BMPs are reinstalled in accordance with their respective design detail section. Stock ile Mana ement Functions Erosion Control Yes Sediment Control Yes Site/Material Management Yes Noveinber 2010 Urban Drainage and Flood Control District SP-1 Urban Starm Draiilage 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 %� �� h � f •` J �� � / � / \ � \ � � � \ � � 1 SP / � SILT FENCE (SEE SF DETAIL FOR � / INSTALLATION REQUIREMENTS) � STOCKPILE PROTECTION PLAN MAXIMUM 1�/ SILT FENCE (SEE SF DETAIL FOR INSTALLATION REQUIREMENTS) 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 ACCOROANCE WITH THEIR RESPECTIVE DESIGN DETAILS. SILT FENCE IS SHOWN IN THE STOCKPILE PROTECTION DETAILS; HOWEVER, OTHER TYPES OF PERIMETER CONTROLS INCLUDING SEOIMENT 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 FACTaRS. 3. STABILIZE THE STOCKPILE SURFACE WITH SURFACE ROUGHENING, TEMPORARY SEEDING AND MULCHING, EROSION CONTROL BLANKETS, OR SOIL BINDERS. SOILS STOCKPILED FOR AN EXTENOED PERIOD (TYPICALLY FOR MORE THAN 60 DAYS) SHOULO BE SEE�ED ANO 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 30-6fl DAYS). 4. FOR TEMPORARY STOCKPILES ON THE INTERIOR PORTION OF A CONSTRUCTION SITE, WHERE OTHER OOWNGRAOIENT 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 Starm Draiilage 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 (ANO ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE ERaSION, AND PERFORM NECESSARY MAIN7ENANCE. 2. FREQUENT 08SERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS ANO CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGNLY. 3. 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. (DE7NLS ADAPTEO FROM PARKER, COLORA00, N07 AVNLABLE 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 NOiED. SP-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Stockpile Management (SP) MM-2 0 ORANGE SAFETY C�NE TARP ANCHOR � � RQAD CL � ROADWAY � I A PaLY LINER BERM � m � m m POLY TARP � POLY TARP 6' MAX. SSA— � R SOIL/LANDSCAPE MATERIAL 6" PVC PIPE FOR DRAINAGE IN FLOWLINE CURB LINE TARP ANCHOR (CINDER BLOCK, OR 5 GALLON BUCKET OF WATER) POLY LINER BERM MATERIAL `� (TRIANGULAR SILT DIKE, 6"MIN. � SEDIMENT CONTROL LOG, 6' MAX., MUST NOT 6" PVC PIPE ROCK SOCK, OR OTHER BE LOCATED WITHIN WRAPPED MATERIAL) A DRIVE LANE SP-2. MATERIALS STAGING IN ROADWAY MATERIALS STAGING IN R�ADWAYS INSTALLATION N�TES 1. SEE PLAN VIEW FOR -LOCATION OF MATERIAL STAGING AREA(S). -CONrRACTOR MAY ADJUST LOCATION AND SIZE OF STAGING AREA WITH APPROVAL FROM THE LOCAL JURISOICTION. 2. FEATURE MUST BE INSTALLEO PRIOR TO EXCAVATION, EAR7HWORK OR DELIVERY OF MATERIALS, 3. MATERIALS MUST BE STATIONEO ON THE POLY LINER. ANY INCIDENTAL MATERIALS DEPOSITED ON PAVEQ SECTION OR ALONG CURB LINE MUST BE CLEANED UP PROMPTLY. 4. POLY LINER AND 7ARP COVER SHOULD BE OF SIGNIFICANT THICKNESS TO PREVENT DAMAGE OR LOSS OF INTEGRITY. 5. SANO BAGS MAY BE SUBSTITUTED TO ANCHOR THE COVER TARP OR PROVIDE BERMING UNOER THE BASE LINER. 6. FEa,TURE IS NOT iNTENDE� FOR uSE wiTH WET MATERIAL THAT WILL BE DRAINING AND/OR SPREADING OUT QN THE POLY LINER OR FOR DEMOLITION MATERIALS. 7. THIS FEATURE CAN BE USED FOR: —UTILITY REPAIRS. —WHEN OTHER STAGING LOCATIONS AND OPTIONS ARE LIMITEO. —OTHER LIMITED APPLICATION AND SHORT DURATION STAGING. Noveinber 2010 Urban Drainage and Flood Control District SP-5 Urban Starm Draiilage 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 (ANO ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE ERaSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT 08SERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS ANO CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGNLY. 3. 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 JURISDIC710NS 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 AOAPiEO 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 housekeepin� practices to prevent poll�ution associated with solid, liquid and hazardous construction-related materials and wastes. Stormwater Manageme»t Plans (SWMPs) should clearly specify BMPs 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 Pollution Prevent Plan (EPA 2007). Appropriate Uses =--- � ` �n �� r,;s ;' �i . , a�� �__ -- _�-' � ' �=�i...�_ �_ � � �_ _ - � � .�-.'. . � � ����`� : �� s • 4� ^r`.,:. ' <. " � , :. � ,. �. - . ��:�. _. � `- •_� Photographs GH-1 and GH-2. Proper materials storage and secondary containment for fuel tanks are important good housekeeping practices. Photos cour[esy 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 aild transport of pollutatlts 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 far llazardous or toxic materials, such as paiilts, 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 o Designate trash and bulk waste-collection areas on- site. Good Housekeeping Functions Erosion Control No Sediment Control No Site/Material Mana ement Yes Noveinber 2010 Urban Drainage and Flood Control District GH-1 Urban Starm Draiilage 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 �way from streets, gutters, watercourses, and storm drains. Waste- collection areas (dumpsters, and sucl�) are often best located near construction site entrances to minimize traffiic on disturbed soils. Consider secondary containment around waste collection areas to minimize the likelihood of contaminated discharges. o Empty wasie 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 aild contamination of starinwater. o Maintain clean restroom facilities and empty portable toilets regularly. o Where possible, provide secondary containment pans under partable 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 unmediately. 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 haaardous waste-collection areas on-site. o Place all hazardous and toxic material wastes in secondary containment. Photograph GH-3. Locate �ortable toilet lacilities on level surfaces away from waferways and s[orm drains. Photo courtesy of WWE. GH-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Voluine 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 SWMP 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 stared 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 ancl subcontractars 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 ihe staging area into sub-areas designated far vehicles, equipment, or stockpiles. Construction entrances and exits should be clearly marked so that delivery vehicles enter/eXit through stabilized areas with vehicle [racking controls (See Vehicle Tracking Control Fact Sheet). o Provide starage in accardance with Spill Protection, Control and Countermeasures (SPCC) 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, con�osion, support or foundation failure, or other signs of deterioration and tested for soundness. o Reuse and recycle construction materials when possible. Designate Conerete 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 far concrete washout areas on- site, designaie 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 fi•om 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, ar stucco is part of the consri-uction 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 Starm Draiilage 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 si�ns. Ensure that signage remains in good repair. o Provide adequate containment far 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. Coilcrete wash water can be highly polluted. It should not be discharged to any surface water, storm sewer system, or allowed to infiltrate into fl�e 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. Implemenc practices to prevent conCamination of surface and groundwater from equipment and vehicle wash water. Representative pracrices include: o Educate employees and subcontractors on proper washing procedures. o Use off-site washing facilities, when available. o Clearly inark the washing areas and inform workers that all washing inust 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 Voluine 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 tliat clear and concise spill cleanup procedures are provided and posted for areas in which spills may potenrially occur. When developing a spill preve»tion 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 froin leaving the site. o Provide proper handlin� and safety procedures for each rype of waste. Keep Material Safety Data Sheets (MSDSs) for chemical used on site with the SWMP. o Establish an education program for employees and subcontractars 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 tream�ent facilities to reqLiest 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 ancl 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. Noveinber 2010 Urban Drainage and Flood Control District GH-5 Urban Starm Draiilage Criteria Manual Volume 3 MM-3 Good Housekeeping Practices (GH) Spill Prevention, Control, and Countermeasure (SPCC) Plan Construcrion 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 faciliry is subject to this rule if it is a non-transportation-related facility that: ■ Has a Cotal storage capacity greater than 1,320 gallons or a coinpletely buried storage capacity greater than 42,000 gallons. ■ Could reasonably be expected to discharge oil in quantiries that may be harmful to navigable waters of the United States and adjoining sl�orelines. Furthennore, 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.gov/oilspill/spcc.htm. Reporting Oil Spills In the event of an oil spill, contact the National Respoizse Center toll free at 1-800-424- 8802 far assistance, or for more details, visit their website: www.nrc.usc .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 inanageinent 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 penn�nent stabilization when the areas are no longer being used far 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 pracrices; 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 Voluine 3 Silt Fence (SF) Description A silt fence is a woven geotexrile fabric 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 ofi a disturbed area to accept sheet flow. ■ Along the perimeter of a receiving water such as a stream, pond or wetland. ■ At the perimeter of a construction site. Design and Installation SC-1 � � � � i � , t:;. . `, ' "�, / ,�,� ' � � � p` .. , .,` � '' ��'� + �� r �� �� ,� �,��� . � 4.� iti�'"1� . , - . , � .-:�. . �t .. t ' d - ' + t' �.���',�� _ � . ....� , . . . � ,,, �;,�,::,�, � �� ��,� , ,� �;. _ . — � .��'� �_-. r�:o: �- - _ _ - . - _ ,+ �' 1 i J ! . : r '.� � � �" � � : �, _. .. .. , _ - �., r ' � �. , � ,Y,;,� _ r. �.�'��i.-�y � _: .ss.�. .��.._�:�.-� " � �- . 3 � �� � � �"� *� �t�, "� ,.� � �4` . r:.r �-'�' _ ,�,�� -� �` ..s �"� .� -� ,� � _ __ � �,�- � - ~ �. ,�--�- �;..e„4,.. �°-n.�- �yc' "�: �- 3; .:a. �. dv ..��c .-. � _ . �..a._ ._ �. �= � _ � �—:�. Photograph SF-1. Silt fence creates a sec�iment barrier, forcing sheet Ilow runoff ro evaparate or infiltrate. Silt fence should be installed along the contour of slopes so that it intercepts sheet flow. The maximum recom�nended tributary drainage area per 1001ineal 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: l. Longer and steeper slopes require additional measures. This recommendarion 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"7-hook" installation may be appropriate io force runoff to pond and evaporate or infiltrate in multiple areas rather than concentrate and cause erosive condirions parallel to tl�e 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 groiuld and the fabric. Silt fence must meet ihe minimum allowable strength requiremei�ts, 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 Mana ement No Noveinber 2010 Urban Drainage and Flood Control District SF-1 Urban Starm Draiilage Criteria Manual Volume 3 SC-1 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 replacin� the damaged section with a new section. Sediment accumulated behind silt fence should be removed, as needed to maintain BMP effectiveness, rypically before it reaches a depth of 6 inches. Silt fence may be removed when the upstream area has reached final stabilization. Silt Fence (SF) . '`, �: . ; f . ���=.a�� �.;�;:;� ��i:." . .4� � . ��: . , f +-y.,t' � x�._ ,..W . � :x� ,� t" � .._� , o*:*- ���'... r��:.. *'- - �,:. , _ r� . _ � � _ �Y ,s �, .:��tr ,�.� . . �n"a:.. . 'iM. � � titi � . • l ..� J �r � , ::. � ' � � : y � ,`��. ,,� , a , � .'�'�-�' � , . _ ,� 4 .a . ,. '.� r,. r,�?` ,".,; -r,_ ? _. _ _ Photograph SF-2. When silt fence is not installed along the contour, a"J-hook" installation may be appropriate to ensure thaf the BMP does not create concentrated flow parallei 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) �_�_� SILT FE� GEOTEXT COMPACI BACKF F� W ---�, EXISTING � _� ` GROUND s" Mir AT LEAST 10" OF SILT FENCE "TAIL'� SHALL BE BURIED SILT FENCE ,Y2.,X,�„ (RECOMMENDED) WOODEN "ENCE POST WITH 10' MAX �PACING 36 -48" - TYP� SC-1 SF POSTS SHALL OVERLAP AT JOINTS SO THAT NO GAPS EXIST IN SILT FENCE POSTS SHALL BE JOINED AS SHOWN, THEN ROTATED 180 DEG. THICKNESS OF GEOrEXTILE HAS IN DIRECTION SHOWN ANO DRIVEN BEEN EXAGGERATE�, TYP INTO THE GROUND SECTION A SF-1 . SILT FENCE November 2010 Urban Drainage and Flood Control District SF-3 Urban Starm Draiilage Criteria Manual Volume 3 SC-1 Silt Fence (SF) SILT FENCE INSrALLATION NOrES 1. SILT FENCE MUST BE PLACED AWAY FROM THE TOE OF THE SLOPE TO ALLOW FOR WATER PaNDING. 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 P�NDING AND �EPOSITIaN. 2. A UNIFORM 6" X 4" ANCHOR TRENCH SHALL 8E EXCAVATED USING TRENCHER OR SILT FENCE INSTALLATION OEVICE. NO ROAO GRADERS, BACKHOES. OR SIMILAR EQUIPMENT SHALL BE USED. 3. COMPACT ANCHOR TRENCH BY HAND WITH A"JUMPING JACK'� OR BY WHEEL RaLLING. COMPACTIQN 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 SILr FENCE A�ONG A CONTOUR, THE SILT FENCE SHOULD 8E TURNED PERPENDICULAR TO THE CONTOUR TO CREATE A'�J—HOOK." THE "J—HOOK" EXTENOING PERPENDICUTAR TO THE CONTOUR SHOULD 8E OF SUFFICIENT LENGTH TO KEEP RUNaFF FROM FLOWING AROUND THE END OF THE SILT FENCE {TYPICALLY 10' — 20'). 7. SILT FENCE SHALL 8E 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 DOCUMENTEO 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 ACCUMULATEO 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 PIACE UNTIL THE UPSTREAM DISTURBED AREA IS STABIIIZED ANO APPROVED BY THE LOCAL JURISOICTION, OR IS REPLACEO 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 AVWLABLE 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 NOTEO. 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 woodeil stake. Sedimei7t control logs are also often referred to as "straw wattles." They are used as a sediment barrier to iiltercept 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 d�eck dams in small drainage ditches. (Sediment control logs are not intended for use in channels with high flow velocities.) ■ On disturbed slopes to shorten flow lengths (as an erosion control). .� ,, , � �: i =�. `_ , . « - �.' �4"�`el....� * s ' ' � ; y.� �. ' " � . - . . ,� ` a',,�. . ,�� =y�A�:':�j '�`' `�V �17�. �,T� � : �,� _ . - . � .-=�. -�.,:-�.`�'�-->s�: . . � �_ �.� - -- .,,r�,�,�,.4....R++. : �y -. �- '. _ ..� -.-r -. , . ..-�.',.RW _ . •. ' ."]: . . _ _ y ; � "1► ._ � . Y� _ �.. - _ = � �; �,�.,>;..� r` � , ' �. ,, - -%"�` �e. �'�i _ � r •� _ �c�'�, �lRj r J - � � ��� .ia"+ �r � . - . s-. �. x . �`S'a.�a2� 'y'_-- . . ' �� ' _ - . ' F �' . g� �� -" �� _ : .� a ''1" `�'"� -='i ,��� ` s ,.� ���,. � �,, ,ser _; t - . � : � �32� -�� �' - `�s �.``�•��"`� �','�� s� � _ -�w � � -=• �:> � f��, e„� � +�e � t - . i���L s _ i . r- _ ", • . Photographs SCL-1 and SCL-2. Sediment control logs used as 1) a perimeler contro] around a soil stockpile; and, 2) as a"J-hook" perimeter control at the corner of a conscruction site. ■ 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 erosioil aild 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 alon� the contour, is approximately 0.25 acres with a disturbed slope lengih of up to 150 feet and a tributary slope gradient no steeper than 3: l. Longer and steeper slopes require additional measures. This recommendation only applies to sediment control logs installed along the contour. When installed far other uses, sucl� as perimeter control, it should be installed in a way that will not produce concentrated flows. For example, a"7-hook" Sediment Control Lo installation may be appropriate to force runoff to pond and Functions evaporate or infiltrate in multiple areas rather than concentrate and cause erosive conditions parallel to the BMP. Erosion Control Moderate Sediment Control Yes Site/Material Management No November 2010 Urban Drainage and Flood Control District SCL-1 Urban Starm Draiilage Criteria Manual Volume 3 . .. � -- .: _ _ . SC-2 Sediment Control Log (SCL) Although sediment contro] 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, rypically 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 lo�s 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 rypically recommended when used in perimeter control, inlet protection aiid 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 - Sa-Sq, - SC�- 1�" x 1�" x 18" (MIN) WOODEN STAKE SCL 9" DIAMETER {MIN) } SEDIMENT CONTROI. I.OG L 3�� 4' MAX. CENTER (TYP.) 6" i'3 DIAM. � FLOW � OF SCL OIAM. �j�i�i,,� ���/� NOTE: LARGER (TYP.) � SC� ��i���iyi ; : pIAMETER SEDIMENT ��!���y'�" CONTROL LOGS MAY � NEED TO BE ����������� �������/,���i�!%!%��i�i�!i��i✓i����r;��/:\�i�!i�!i�!i�!iv�(i'��!X�iY� EM BEOOED OEEPER. SEDIMENT CONTROL LOG � CENTER STAKE IN CONTROL LOG COMPACTED EXCAVATED 3�� 9" DIAMETER (MIN) TRENCH SOIL � SEDIMENT CONTROL LOG FLOW r � DIAM. SCL (TYP.) f 6„�J f SECTION A 9" DIAMETER (MIN) SEDIMENT CONTROL LOG 12" OVERLAP (MIN.) 1J�i" x 115" x 18" (MINI SEDIMENT CONTROL LOG JOINTS SCL-1. SEDIMENT CONTROL LOG November 2010 Urban Drainage and Flood Control District SCL-3 Urban Starm Draiilage Criteria Manual Volume 3 SC-2 Sediment Control Log (SCL) COMPACTE� EXCAVATED TRENCH SOIL FLOW ----.�. 3� � CENTER STAKE IN CONTROL LOG 9" DIAMETER tMIN) \ � SEDIMENT CONTROL LOG \� PLACE LOG AGAINST BACK OF CURB Y3 DIA�1. SCL {TYP.) 6" MIN. SCL-2. SEDIMENT CONTROL LOG AT BACK OF CURB CENTER STAKE � IN CQNTROL LOG 3�� 9" DIAMETER (MIN) 1 SEGIMENT CONTROL LOG TREE LAWN (TYPICAL) Ya DIAM. SCL {TYP.) �-- CURB FLOW - i, � w�,�,� �� ,.. . . .. . . _ .. . i; i .-%i�� . � : , �� -�: "% : ��.s�i��; _ MIN��` ���-7:�� ���.��'- �: � ��� ��fN�'K". ; �, , ,:�� ,. � , � ,�:- �, >��. � SCL-3. SEDIMENT CONTROL LOG AT SIDEWALK 1NITH TR E E LA1N N STAKING AT 4 MAX. ON CENTER (TYP.) VERTICAL SPACIN� VARIES DEPENDING ON SLOPE j� �, ., /\\ ��;�" -;�< ',`.�.'��.;� ,-. '�>> .�;�; ��; ;�. . �i�;:. � ��' \i/ '� � � -- . � �\ ., � � � �� �''� CONTINUOUS SCL :� ; �� : �� � � , ; , � ��� � ; , AT PERIMETER OF ��;; /, �,=� � ; '- �� , � � . _��;� CONSTRUCTION SITE SCL-4. SEDIMENT CONTROL LOGS T� 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 INSrALLATION NOTES 1. SEE PLAN VIEW FOR LOCATION AND LENGTH OF SEDIMENT CONTROL LOGS. 2. SEDIMENT CONTROL LOGS rHAT ACT AS A PERIMETER CONTROL SHALL BE INSTALLED PRIOR TO ANY UPGRADIENT LAND-DISTUR8ING ACTIVITIES. 3. SEDIMENT CONTROL LOGS SHALL CONSIST OF STRAW, COMPOST, EXCELSIOR OR CaCONUT FIBER, AND SHALL BE FREE OF ANY NOx10US WEED SEEDS OR DEFECTS INCLUDING RIPS, HOLES AND OBVIDUS WEAR. 4. SEDIMENT CONTRaL LOGS MAY BE USED AS SMALL CHECK OAMS IN OITCHES AND SWALE5. 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 ANO/OR DESIRABLE (SHORT TERM INSTALLATION WITH DESIRE NOT TO DAMAGE LANDSCAPE) A LESSER TRENCHING DEPTH MAY BE ACCEPTABLE WITH MORE RaBUST STAKING 6. THE UPHILL SIQE OF THE SEDIMENT CONTROL LOG SHALL BE BACKFILLED WITH SOIL THAT IS FREE OF ROCKS AND DEBR15. 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 OQ NOT SPECIFY SPACING, STAKES SHA�L BE PLACED ON 4' CENTERS AND EMBEODED 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 CONTRaL 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 ERaSI�N, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTNE 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. SEOIMENT ACCUMULATED UPSTREAM OF SEDIMENT CONTROL LOG SHALL BE REMOVED AS NEEOEO TO MAINTAIN FUNCTIONALITY OF THE BMP, TYPICALL.Y WHEN OEPTH OF ACCUMULATEO SEOIMENTS IS APPROXIMATELY 1� OF THE HEIGHT OF THE SEDIMENT CONTROL LOG. 5. SEDIMENT CONTROL LOG SHALL BE REMOVED AT THE END OF CONSTRUCTION. IF DISTUR6ED 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 PDAPTEO fROM TOWN Of PARKER, COLORADO, JEFFERSaN COUNTY, COLORA00, DOUGLAS COUNN, COLORA00, AND CI7Y OF AURORA, COLORADO, NOT AVAILABLE IN AUTOCAD) NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCO 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 Starm Draiilage Criteria Manual Volume 3 Brush Barrier (BB) Description A brush ban�ier is a perimeter sediment coiltrol 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 tlow 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 should be implemented in combination with other BMPs such as surface SC-4 . . � �� 4 �. . . .. � _ .t ' �. .',a;%. � • �f �. � ���x ,�:.. " �= , `��� ;� ., , ,-i � .s� �..� p x �:y � �- ;,,� � � .,��'•; ,� � M:.� �"� ,Y r �. y"'. � �;,��� ��`���"'�,- � 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 conirol, but they may be used inten�ally 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 ainount of material is needed to co»struct a L�seful 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 bai�rier must be no greater than 3:1 and no longer than 150 feet. To construct an effective brush bariier, 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 inound 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 Noveinber 2010 Urban Drainage and Flood Control District BB-1 Urban Starm Draiilage Criteria Manual Volume 3 Photograph BB-l. Brush batrier constructed with chipped wood. Photo courtesy of EPA. SC-4 Maintenance and Removal Brush Barrier (BB) Inspect the brush barrier for voids where concentrated flow ar 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 ofi 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. BB-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Rock Sock (RS) Description A rock sock is constructed of gravel that has been wrapped by wire mesh or a geotextile to form an elongated cylindrical filter. Rock socks are 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 Rock socks can be used at the perimeter of a disturbed area to control localized SC-5 Photograph RS-l. Rock socks placed at regular intervals in a curb line can help reciuce sediment loading to storm sewer inlets. Rock 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 systein. Design and Installation Wl�en rock socks are used as perii�neter controls, the maximum recommended tributary drainage area per 1001ineal feet of rock socks is approximately 0.25 acres witl� disturbed slope lengtl� 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. lnspect rock socks for damage and repair ar replace as necessary. Remove sediment by sweeping or vacuuming as needed to maintain the functionality of the BMP, rypically when sediment has accumulated behind the rock sock to one-half of the sock's Rock Sock height. Once upstream stabilization is complete, rock socks and accumulated sediment should be removed and properly disposed. Functions Erosion Control No Sediment Control Yes Site/Material Mana ement No Noveinber 2010 Urban Drainage and Flood Control District RS-1 Urban Starm Drainage Criteria Manual Volume 3 SC-5 `.Y;:y�� .. .�. �'.s'.�.:'y�'. lY�" (MINUS) CRUSHED ROCK :LaSED iN wiRE MESH WIRE TIE ENDS ! L 0" ON BEDROCK OR HARD SURFACE, 2" IN SOIL `- GROUND SURFACE ROCK SOCK SECTION Rock Sock (RS) RS 1J�" {MINUSj CRUSHED ROCK ENCLOSED IN WIRE MESH 4" TO 6" MAX AT CURBS, OTHERWISE 6"-10" DEPENDING ON EXPECTEO SEDIMENT LOADS ROCK SOCK PLAN ANY GAP AT JOINT SHALL BE FILLED WITH AN AOEQUATE AMOUNT OF 1N�" (MINUS) CRUSHED ROCK ANO WRAPPED WITH ADDITIONAL WIRE MESH SECURED TO ENDS OF ROCK ROCK SOCK, REINFORCE� S�CK. AS AN ALTERNATIVE TO FILLING JOINTS nP BETWEEN ADJOINING ROCK SOCKS WITH CRUSHEO ROCK AND 12" 12" ADDITIONAL WIRE WRAPPING, ROCK SOCKS CAN BE OVERLAPPED {TYPICALLY 12-INCH OVERLAP) TO AVOID GAPS. ��� ,��n!� ROCK SOCK JOINTING ROCK SOCK INSTALLATION NOTES 1. SEE PIAN VIEW FOR: -LOCATION(S) OF ROCK SOCKS. GRADATION TABLE SIEVE SIZE MASS PERCENT PASSING SQUARE MESH SIEVES N0. 4 2 100 �kz�. 90 - 100 1 �� 20 - 55 ��" 0 - 15 3�.� � - 5 MATCHES SPECIFICATIQNS FOR N0. 4 COARSE AGGREGATE FOR CONCRETE PER AASHTO M43. ALL ROCK SHALL BE FRACTUREO FACE, ALL SIOES. 2. CRUSHED ROCK SHALL 8E tY2" (MINUS) IN 51ZE WITH A FRACTUREO FACE (ALL SIDES) ANO SHALL COMPLY WITH GRADATION SHOWN ON THIS SHEET {1J¢" MINUS). 3. WIRE MESH SHALL BE FABRICATED OF 10 GAGE POULTRY MESH, QR EQUIVA�ENT, WITH A MAXIMUM OPENING OF 1�", 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 RaCK 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) :• . • u: ► ►:. ►+ SC-5 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 ERaSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREOUENT 08SERVATIONS 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 8E REPLACED IF THEY BECOME HEAVILY SOILED, OR DAMAGED BEYOND REPAIR. 5. SEDIMENT ACCUMULATED UPSTREAM �F ROCK SOCKS SHALL BE REMOVED AS NEEDED TO MAINTAIN FUNCTIQNALITY OF THE BMP, TYPICALLY WHEN DEPTH OF ACCUMULATED SEDIMENTS IS APPROXIMATELY k� �F THE HEIGHT OF THE ROCK SaCK. 6. RaCK SOCKS ARE TO REMAIN IN PLACE UNTIL 7HE UPSTREAM OISTURBED AREA IS STABILIZED AND APPROVED BY THE LOCAL JURISDICTION. 7. WHEN ROCK SOCKS ARE REMOVEO, ALL OISTUR6ED AREAS SHALL BE COVERED WITH TOPSOIL, SEEDED AND MULCHED OR OTHERWISE STABILIZED AS APPROVED BY LOCAL JURISDICTION. (DETML ADAPTED fROM TOWN OF PARKER, COLORADO AND CITY OF AURORA, COLORADO, NOT AVAILABLE IN AUTOCA�) NOTE: MANY JURISDICTIONS HAVE BMP OETAILS THAT VARY FROM UDFCO STANDARD DETAILS. CONSULT WITH L�CAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. NOTE: THE DETAILS INCLUDED WITH THIS FACT SHEET SHOW COMMONLY USED, CONVENTIONAL METH005 OF ROCK SOCK INSTALLATION IN THE DENVER METROPOLITAN AREA. THERE ARE MANY OTHER SIMILAR PROPRIETARY PROOUCTS ON THE MARKEf. 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 INCLUOED IN THE SWMP AND THE BMP MUST 8E INSTALLED AND MAINTAINED AS SHOWN IN THE MANUFACTURER�S DETAILS. Noveinber 2010 Urban Drainage and Flood Control District RS-3 Urban Starm Drainage Criteria Manual Volume 3 Inlet Protection (IP) Description Inlet protection consists of permeable barriers installed around an inlet to filter runoff and remove sediment prior to entering a storm drain inlet. Inlet protection can be constructed froin rock socks, sediment control logs, silt fence, block and rock socks, or other materials approved by the local jurisdiction. Area ii�lets 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. Consider the potential for tracked-out SC-6 �....,�� �-;.�,L..�"""�W._. _..�.. �.�. _ —' — �;;,,� .«.;,-----""' -- �'"'YtlE'� `..-�, . � w�,.:�--'f�,��-�"--* sediment or temporary stockpile areas to contribute sediment to inlets when determining which inlets must be protected. This may include inlets in the general proximiCy 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 Chat tlows do not bypass the inlet protection and enter the storm drain without treatment. However, designs �nust also enable the inlet to function without compleT�ely blocking flows into the inlet in a manner tl�at causes localized flooding. When selecting the type of inlet protection, consider factars such as type of inlet (e.g., curb or area, sump or on-grade conditions), traffic, anticipated ilows, 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 �utter 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 stonn sewer ar receiving water. Inlet Protection (various forms) Functions Erosion Control No Sediment Control Yes Site/Material Management No Design details with notes are provided for these forms of inlet protection: IP-1. Block and Rock Sock Inlet Protection for Sump or On-grade Inlets IP-2. Curb (Rock) Socks Upstream of Inlet Protection, On-grade Inlets Noveinber 2010 Urban Drainage and Flood Control District IP-1 Urban Starm Draiilage Criteria Manual Volume 3 Photograph IP-1. lnlet prolection for a curb opening inlet. SC-6 1P-3. Rock Sock Inlet Protection for Sump/Area Inlet IP-4. Silt Fence Ii11et Protection for Sump/Area Inlet IP-5. Over-excavation Inlet Protection IP-6. Straw Bale Inlet Protectioil for Suinp/Area Inlet CIP-1. Culvert Inlet Protection Inlet Protection (IP) Propriety inlet protection devices should be installed in accordance with manufacturer specifications. More information is provided below on selecting inlet protection far sump and on-grade locations. Inlets Located in a Sump When applying inlet protection in sump conditions, it is important that the inlet contirnie 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 overtlow 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 swnp 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 Che 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 Cl�eck 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 i»let. ■ 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 sedimei�t 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 upsiream 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 accwr�ulates to a depth of no more than 6 inches. Remove sediment accumulat�ion from the area upstream of the inlet protectioi� 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 Starm Draiilage Criteria Manual Volume 3 SC-6 ��� � IP SEE ROCK SOCK �ESIGN ROCK DETAIL FOR JOINTING ROCK SOCKS 16" CINDER 16" CINDER SOCKS _ BLOCKS BLOCKS ;�` �` - '�` FLOW - ' _ � ",� 0 � , = 2"x4' WOOD STUD '-+:.'�.: �?-%=J � :�. ;.:.Y � ..,� 1' 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 INLEr PROTECTION INSTALLATION NOTES 1. SEE ROCK SOCK DESIGN DETAIL FOR INSTALLATION REQUIREMENTS. 2. CONCRETE "CINDER" BLOCKS SHALL 8E 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 rwo cuRa � SOCKS APPROX 30 DEG. BLOCK AND ROCK SaCK INLET ^ 0 � � s CURB SOCK �(? PROTECTION(SEE DETAIL IP-1) FLOW --- �, .=� :y,] � \-� =-'t`=�] � ' Runi I z'_�' IP-2. CURB ROCK SOCKS UPSTREAM OF INLET PROTECTION CURB ROCK SOCK INLET PROTECTION INSTALLATION NOTES 1. SEE ROCK SOCK OESIGN OETAIL INSTALLATION REQUIREMENTS. 2. PLACEMENT OF THE S�CK SHALL BE APPROXIMATELY 30 DEGREES FROM PERPENDICULAR IN THE OPPOSITE OIRECTION OF FLOW. 3. SOCKS ARE TO 8E FLUSH WITH THE CURB AND SPACEO A MINIMUM OF 5 FEET APART. 4. AT LEAST TWO CURB SOCKS IN SERIES ARE REQUIRED UPSTREAM OF ON-GRADE INLETS. Inlet Protection (IP) IP-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Inlet Protection (IP) ;� 7r i �_ ROCK SOCK =T GRATE SC-6 IP SEE ROCK SOCK DETAIL FOR JOINTING IP-3. ROCK SOCK SUMPfAREA INLET PROTECTION ROCK SOCK SUMP/AREA INLET PROTECTION INSTALLATIaN NOTES 1. SEE ROCK SOCK DESIGN DETAIL FOR INSTALLATION REQUIREMENTS. 2. STRAW WATTLES/SEOIMENT CONTROL LOGS MAY 8E U5ED IN PU�,CE OF ROCK SOCKS FOR INLETS IN PERVIOUS AREAS. INSTALL PER SEOIMENT CONTROL LOG DETAIL. � SF� ��� � SFJ '"" rT GRATE SILT FENCE (SEE SILT FENCE DESIGN DETAIL ) IP-4. SILT FENCE FOR SUMP INLET PROTECTION SILT FENCE INLET PROTECTI�N 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 LaG DETAIL. Noveinber 2010 Urban Drainage and Flood Control District IP-5 Urban Starm Draiilage Criteria Manual Volume 3 SC-6 SHEET FLOW Inlet Protection (IP) ��� ��� C�7 1�1 I�� SILT FENCE AREA INLET SILT % FENCE ECB �� 2:1 MAX IP 1� 1' MIN - �3 AREA 2' MAX { ECB INLET 4 ROCK FILTER L CONCENTRATED FLOW OR ROCK SOCK (USE IF FLOW IS CONCENTRATED) IP-5. OVEREXCAVATION INLET PROTECTION OVEREXCAVATION INLEr PROTECTION INSTALLATION N�TES 1. THIS FORM OF INLET PROTECTION IS PRIMARILY APPLICABLE FOR SITES THAT HAVE NOT YET REACHED FINAL GRA�E 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 DIRECTIQN OF FLOW. 3. SEDIMENT MUST BE PERIODICALLY REMOVED FROM THE OVEREXCAVATED AREA. 0 0 0 o INLET GRATE o a STRAW BALE (SEE SiRAW BALE DESIGN OETAIL) IP-6. STRAW BALE FOR SUMP INLET PROTECTION STRAW BALE BARRIER WLET PROTECTIQN INS7ALLATION 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) , ► :: ► •:. •► ► .. ,• 1. SEE PLAN VIEW FOR: —LOCATION OF INLET PROTECTION. —TYPE OF INLET PROTECTION (IP.1, IP.2, IP.3, IP.4, IP.S, IP.6) SC-6 2. INLET PROTECTION SHALL BE INSTALLED PROMPTLY AFTER IN�ET CONSTRUCTION OR PAVING IS COMPLETE (TYPICALLY WITHIN 48 HOURS). IF A RAINFALL/RUNOFF EVENT IS FORECAST, INSTA�L INLET PROTECTION PRIOR TQ 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 08SERVATIONS ANO MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CaNDIT10N. INSPECTIONS AND CORRECTNE MEASURES SHOULD 8E DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATEO 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 b" WHEN SILT FENCE IS USEO, OR Yti OF THE HEIGHT FOR STRAW BALES. 5. INLET PROTECTION IS TO REMAIN IN PLACE UNTIL THE UPSTREAM DISTURBED AREA IS PERMANENTLY STABIUZED, UNLESS THE LOCAL JURISDICTION APPRaVES EARLIER REMOVAL OF INLET PROTECTION IN STREETS. 6. WHEN INLET PROTECTION AT AREA INLETS IS REMOVEO, THE DISTURBED AREA SHALL BE COVERED WITH TOP SOIL, SEEDED ANO MULCHED, OR OTHERWISE STABILIZED IN A MANNER APPROVED BY THE LOCAL JURISDICTION. �DETAIL P,�APTEO fROM TOWN OF PaRKER, COLORA00 AN� CIN Of AURORA, COLORallO, NOT AVAILABLE IN AUTQC.40) NOTE: MANY JURISDICTIONS HAVE 8MP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISOICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. NOTE THE DETAILS INCWDED WITH THIS FACT SHEET SHOW CaMM�NLY USED, C�NVENTIONAL METHODS OF INLET PROTECTION IN THE DENVER METROPOLITAN AREA. THERE ARE MANY PROPRIETARY INLET PROTECTION METHODS ON THE MARKET. UOFCD 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 INCLUOED 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 IN�ET PROTECTION. CHECK WITH LOCAL JURISOICTION TO DETERMINE IF STRAW BALE INLET PRQTECTION IS ACCEPTABLE. November 2010 Urban Drainage and Flood Control District IP-7 Urban Starm Draiilage Criteria Manual Volume 3 Sediment Basin (SB) 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. Sediinent basins are designed to capture site runoff and slowly release it to allow tiine for settling of sediment prior to discharge. Sediment basins are often constructed in locarions that will later be modified to serve as post-construction starmwater basins. Appropriate Uses Most large construction sites (typically �reater than 2 acres) will require one or more sediment basins for effective SC-7 �r ;. , �, �. � ;��y .s - � y'� � � ��> - F . ,.�� a ,. � 'W� At � , t� '. y `� � . :, �, "*� ,. � � � � �.�� � ,�a � S , , ��„ y .�; , .::� ��'_ � ��r p li�r � y : ' r.. �- _ �� +�''.����e � �'"�' � ( .�.�, ��� - �' �, q�-�� , `' i ""' . `. �' �„ �t �v� '� '� � ��� �' �' � �'' `� � 'tC•,i � �r . ��Mt_�f `�� �� �d�t*� r y� t;� r ' j ..� :� Ik.. iJk 4. � � � ) 4 � �` — , F � � }� ,S, ' �lK = i � ; ... , ." �i . � tir �' "�' � `� � � : '�-�.`�'' t i �, �,�3 �. •�' > ,,,¢ s i �'f.`�t . _ i y. � ; � ',�.1k' *. . ,- .. �+ i�r • �. �= r'�� � -:t� ` �"� � �. C.� ��5 ',k` . �""` ��-..;�=:.�` "'�`'`.s Vtc {' � � k , , � f� 3 : . �.� - + s .,�A.� '_ �e �ar,,�=� �i�• � ,, �yl � y�. 4:T S�� . v c r,,,,,ty..ya �_•�i�= 1 f ' 4��4 �'.v�y �: ��;,;.� sR;,� . � , . : � F wR:� � . ' ; . '� � �.. 1 $�> i.. ��� � � � � -:� � � % �. � �� Lt ,� i . . � � a 5M � '..l %'}�1� +�.� r�Mwrt�. •.— . . "� Y� . •� r— ..�.�� � yr,� �•�,— .- a» ^�''5-��• ,r��;, . q 4:; , $ �r _.. ,� , .. �� y �,i _��� �� .,", ,rn'� "'WNCwW,- � �.":�` � .. sd... c.. � .�� . �► -. 4 . �) . _;.�i .. '�� �i!��." a'� ^ ' . . ' Photograpl� SB-l. Sediment basin at the toe of a slope. Photo courtesy of WWE. mana�ement of construction site runoff. On linear construction projects, sediment basins may be impractical; instead, sediment traps or other combinations of BMPs may be inare appi-opriate. 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 ft�/acre of storage far undeveloped (but stable) off-site areas in addition to the 3,600 ft�/acre far disturbed areas. For stable, developed areas that cannot be diverted around the sediment basin, storage volume requirements are summarized in Table SB-1. Basin Geometry: Design basiil witl� a minimum length-to-width rario of 2:1 (L:W). If this cannot be achieved because of site space coi�straints, baffling in�y 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 embankment slopes be 4:1 (H:V) or f7atter and no steeper than 3:1 (H:V) in any location. Functions Erosion Control No Sediment Control Yes SiCe/Material Management No November 2010 Urban Drainage and Flood Control District SB-1 Urban Starm Draiilage Criteria Manual Volume 3 SC-7 Sediment Basin (SB) ■ Inflow Structare: 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 (ft3) Im erviousness % Per Acre of Tributar Area Undevelo ed 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 exteild through the emb�nkment 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 oLitlets in the EDB BMP Fact Sl�eet 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 siaed l�/z - to 2-inch gravel in front of the plate. This gravel will need to be cleaned out frequently during the construction period as sediment accuinulates within it. The gravel pack will need to be removed and disposed of following construction to reclaiin tl�e basin far use as a permanent detention facility. If the basin will be used as a permanent extended detention basin far the site, a well-screen trash rack will ileed to be installed once coiltributiilg 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 ma�lufacturer's recommendations. Illustration SB-1 provides an illustration of a Faircloth Skimmer Floating OutletTM, one of the more commonly used floating skimmer ouilets. A skimmer sho�ild 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 ouflet continually decants cleanest water off the surface of the pond and releases cleaner water than would discharge from a perforated riser pipe or plate. SB-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Sediment Basin (SB) SC-7 Illustration SB-1. Outle[ structure for a temporary sedirnent basin - Faircloth Skimmer Floafing Outlel. Illustration courtesy of J. W. Faircloth & Sons, Inc., FairclothSkimmer.com. o Outlet Protection: Outlet protection should be provided where the velocity of flow will exceed the maximum permissible velociry 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 �neasures to keep the waterway from eroding. o Emergency Spillway: Provide a stabilized einergency overflow spillway foi• rainstonns that exceed the capacity of che sediment basin volume and its outlet. Protect basin emba»kments from erosion and overtopping. If the sediment basin will be converted to a pennanent detention basin, design and construct the emergency spillway(s) as required for the permailent facility. If the sediment basin will not become a permane»t 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 ihe basin, as needed to maintain BMP effectiveness, rypically when the design storage volume is no �nore 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 olitlet 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 pernut 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 Starm Draiilage 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 starmwater basin ar whether tl�e basin area will be returned to grade. Far basins being converted to perinanent detention basins, remove accumulated sediment and reconfigure the basin and outlet to meet the requirements of the final design far 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) �� � �� I 7I1:71»\�l HOLE DIAMETER, HD � � �, � EL. 03.00 � a SINGLE 4" COLUMN Typ OF FIVE HOLES• , SCHEDULE 40 PVC OR GREATER INLETS TO SEDIMENT BASIN 5HALL ENTER AT FURTHE57 DISTANCE TO QUTLET ANO SHALL CONSIST OF A TEMPORARY SLOPE DRAIN Y� o a � 3 � L=2 x W MIN. � BOTTOM LENGTH � 01 J2 J3 )4 C�l ��7����,1�i1�1�1�,��,�,, SPILLWAY «EXCEPT WHERE THE HOLES EXCEED 1" DIAMETER, THEN UP T� TWO COLUMNS OF SAME SIZED HOLES MAY BE USED � 4� � —� '/ l;� i� \�1 —�12 4 "��:Y _:1 -: �<_� � . � — 1� 1<���"������=. EL 00.00 � v "� ;�-� " " ;. � � 4. Y-� ``,i � � �6,� EXCAVATION D50=9" RIPRAP Y { �` ��` � ` TYPE L. (SEE TABLE RIPRAP BEODING MD-7, MAJ�R DRAINAGE, VOL. 1) 12" SECTION A CL raccr i rti�ru EMBANK MAT SC-7 , �� Ta 2�� S B CRUSHED ROCK �RISER PIPE r- 6" PVC Noveinber 2010 Urban Drainage and Flood Control District SB-5 Urban Starm Draiilage Criteria Manual Volume 3 (SEE TABLE MD-7, MAJOR ORAINAGE, VOL.1) SECTION B SB-1 . SEDIMENT BASIN SC-7 Sediment Basin (SB) 7ABLE SB-1. SIZING INFORMATION FOR STANDARD SEOIMENT BASIN Upstream Drainage Basin Bottom Width Spillwoy Crest Hoie Areo {rounded to �yy�, {ft) Length (CL), {ft) Diameter nearest acre), (ac) (HD), (in) , , z y2 2 9r32 2 21 3 '�is 3 28 5 Yz 4 33 Yz 6 9/s 5 38 S'z 8 2Yss 6 43 9 23`s2 7 47 Y4 11 ZS/32 8 51 12 27/32 9 55 13 �/8 10 58 i's 15 ��g 1 1 fi 1 16 3y�2 12 64 18 1 13 67 1� 19 1 1f 6 � 4 7p }� 2 t 1 ifi 15 73 ya 22 1 3/s SEOIMENT BASIN INSTALLATION NOTES SEE PIAN VIEW FOR: —LOCATION OF SEDIMENT BASIN. —TYPE OF BASIN (STANDARD BASIN OR NONSTANDARD BASIN�. —FOR STAN�ARD BASIN, BOTTOM WIDTH W, CREST LENGTH CL, AND HOLE DIAMETER, HD. —FaR NONSTANDARD BASIN, SEE CONSTRUCTION DRAWINGS FOR �ESIGN OF BASIN INCLUOING RISER HEIGHT H, NUMBER OF COLUMNS N, HOLE DIAMETER HD AND PIPE DIAMETER �. 2. FaR STANDARD BASIN, BOTTOM DIMENSION MAY BE MOOIFIED AS LONG AS BOTTOM AREA IS NOT REDUCED. 3. SEDIMENT BASINS SHALL 8E INSTALLED PRIOR TO ANY OTHER LANO—OISTURBING ACTIVITY THAT RELIES ON ON BASINS AS AS A STaRMWATER CONTROL. 4. EMBANKMENT MATERIAL SHALL CONSIST OF SOIL FREE OF DEBRIS, ORGANIC MATERIAL, AND ROCKS OR CONCRETE GREATER THAN 3 INCHES ANO SHALL HAVE A MINIMUM OF 15 PERCENT BY WEIGHT PASSING THE N0. 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 STANDARO SEOIMENT BASIN(S) FaR 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 DESIGNEO FOR ORAINAGE 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 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 (ANO ALWAYS WITH�N 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 DOCUMENTE� THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATEO UPON DISCOVERY OF THE FAILURE. 4. SEDIMENT ACCUMULATED IN BASIN SHALL BE REMOVE� AS NEEDED TO MAINTAIN BMP EFFECTIVENESS, TYPICALLY WHEN SEDIMENT DEPTH REACHES ONE FOOT {I.E., T4Wa 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 SEOIMENT BASINS ARE REMOVEO, ALL DISTURBED AREAS SHALL BE COVEREO WITH TOPSOIL, SEEDED AND MULCHED OR OTHERWISE STABILIZED AS APPROVEO 8Y LOCAL JURISDICTION. (DETAIIS ADAPTEO FROM �OUGLAS COUNTY, COLORA�O) 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 SB-7 Urban Starm Draiilage Criteria Manual Volume 3 Sediment Trap (ST) SC-8 Description Sediment traps are farmed by excavating an area or by placing an earthen embankment across a low area or draina�e swale. Sediment traps are designed to capture drainage from disturbed areas less than one acre and allow settli��g of sediment. Appropriate Uses Sediment traps can be used in - — - ,� � � � y�= � � . t.-` �5� r�r. i�, . �;�:* i`� � , ,,t. .. •� ~� _'.YrT�_.� 4. -- ti�t:• 1`��♦ _ _ . n - - i'.. �rt.i�r �� ��. �. � : ? • t �r"'�'''y.i _ l _.4 . `�� h''S ��� _ 4 >rj, �- �•' �..,i . �9� -S ti�.^�` :1Y1 S r• � �.��y 1;,�'� i. ..�1 ,r ,:. - �• � .��' 'S . . �� ",•�1'/. � � �,,f � t ' s �• ''� . 1 � � � � ,�' � : r ., ... � r C . � ���' � � Y t�.. » K �1 f �� V �r ��y� ya� ``��� ,./' � � • I` r" �y: �'i�tii!{/,( �: .�t� � .�.1 ' . �...•' +j-b��.' �=�',�J^tiJ ��- ���,� " . ' . � �p .s� . ���^s� t� � ...�f, y?�!�V.� Jv�{-%j�1�'(� � ;: t ff�P�'!��.�.0 ir `� 'r� 5F ' . •t� '�'" � �r'.3� :�. � . . _ _ . � �� Cot7lbltlaf1011 With OtheT layel'S Of etOslOn photograph ST-1. Sediinent traps are useci to collect sediinent-laden arid Sedlm0l7t COri1TO1S t0 tI'ap SOdlmerit runo�ff from disturbed area. Photo courtesy oP EPA Menu of BMPs. from small drainage areas (less than one acre) or areas with localized hi�h sediment loading. For example, sediment traps are often provided in conjuncrion 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 benn. See Detai] ST-1 for additional design and installation informatioil. Maintenance and Removal Inspect the sediment trap embankments fior 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 ihe 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/Materia] Management No November 2010 Urban Drainage and Flood Control District ST-1 Urban Starm Draiilage Criteria Manual Voluine 3 SC-8 Sediment Trap (ST) :�; FLOw �- RIPRAP, TYPE M(D50=12") TYP.SMALLER ROCK SIZE MAY BE ALLOWABLE FOR SMALLER TRAPS IF APPROVED BY LOCAL JURISDICTION TOP OF EARTHEN BERM A 2.1 MAX. 2: 1 MAX. `` ' :-'�= -� -Y,t' %� ':4 - �.�: �, - __ TRANSITION EXISTING g �, � 'r ��- CHANNEL INT� w � - - j-1 .'-7� ��-1� : �t �. SEDIMENT TRAP ' :' �1 _, ` �'�! . r i .�d , 2: � Mfix. -; : { ;�1 . ;�� ;� 2:1 MAX. L SEDIMENT TRAP PLAN 6" (CENTER OF RIPRAP 6" LOWER THAN ENDS 6" MINIMUM 12' MIN. 30' FREEBOARD � � f - � � - l � :��� w� :���� SECTION A � �6,� MIN. � f ? FLOW � CHANNEL GRADE � 8 J RIPRAP, TYPE M(D50=12") TYP. MIN. SMALLER ROCK SIZE MAY 8E ALLOWABLE FOR SMALLER TRAPS IF APPROVED BY LOCAL JURISDICTION SECTION B ST-1. SEDIMENT TRAP ST F�ow �- 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. aNLY U5E FOR DRAINAGE AREAS LESS THAN 1 ACRE. 3. SEDIMENT TRAPS SHALL 8E INSTALLED PRIOR TO ANY UPGRA�IENT LAND-DISTURBING ACTIVITIES. 4. SEDIMENT TRAP BERM SHALL BE CONSTRUCTED FROM MATERIAL FROM EXCAVATION. THE BERM SHALL 8E COMPACTED TO 95� OF THE MAXIMUM DENSITY IN ACCORDANCE WITH ASTM D698. 5. SEDIMENT TRAP OUTLET TO BE CaNSTRUCTED OF RIPRAP, TYPE M(D50=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 &" 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 WORKOAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONOITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SaON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAr CAUSES SURFACE ERaSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREOUENT 08SERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHOULO 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 QEPTH REACHES J� rHE HEIGHT OF THE RIPRAP our�ET. 5. SEDIMENT TRAPS SHALL REMAIN IN PLACE UNTIL THE UPSTREAM DISTURBED AREA IS STABILIZED ANO APPROVED 8Y THE LOCAL JURISDICTION. 6. WHEN SEDIMENT TRAPS ARE REMOVED, THE DISTURBE� AREA SHALL BE COVERED WITH TOPSOII., SEEDEO ANO MULCHED OR OTHERwISE STABILIZEO IN A MANNER APPROvED BY THE LOCAL JURISDICTION. (DETAILS aOAPiEO fROM OOUGIAS COUNTY, COLORADO, NOi AVAILABLE IN AUTOCAD� NQTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FR�M UDFCD STANDARO DETAILS. CONSULT WITH L�CAL JURISDICTIONS AS T4 WHICH DETAIL SH�ULD BE USED WHEN DIFFERENCES ARE NOTED. November 2010 Urban Drainage and Flood Control District ST-3 Urban Starm Draiilage Criteria Manual Voluine 3 Vegetated Buffers (VB) SC-9 Description Buffer strips of preserved natural vegetation or grass help protect waterways and wedands from land disturbing activities. Vegetated buffiers improve stormwater ruiloff quality by straining sediment, promoting infiltration, and slowing runoff velocities. Appropriate Uses Vegetated buffers can be used to separate land disturbing acrivities and natural surface waters or conveyances. nrr.�:�. �? �- ... . '�_���� - ��, k;r�' '� �.`� � � � � �,r.s ,I "�M �, �.;,;.. �'' ��Y' D�yI.. 't��N' �`��1.. � f. '��, .,� . .� 4- li`k�� J � ,a'rj� ��,}�—'LLw — , ..;�::� �'�� r�r---� � � � - - � - - -�._ Photograph VB-1. A vegetated buffer is maintained beYween the area of acYive construction and the drainage swale. Photo courtesy of WWE. In many jurisdictions, loca] 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. Vegeiated 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 delinearing the vegetative buffer and repair or replace as needed. Vegetated Buffers Functions Erosion Control Moderate Sediment Control Yes Site/Material Management Yes Noveinber 2010 Urban Drainage and Flood Control District VB-1 Urban Starm Draiilage Criteria Manual Volume 3 Chemical Treatment (CT) Description Chemical treatment far erosion and sediment control can take several forms 1. Applying chemicals to disriirbed surfaces to reduce erosion (these uses are discussed in the Soil Binders Fact Sheet). 2. Adding flocculants to sedimentation ponds or tanks to enhance sediment removal prior. SC-10 ����: � ii :• If;; �:iti' S'It14:1111_ 1 .�t!'�il.�ti�;!'f}�i�i9ll�.:11�� ..,., _ u � � �� �e� En: �-u,����j I r�i�I�l��ir�l��'—''�la. ���� 1 ,—�,a _ • �1�1���,lR�� �ql� J _ _.. . . f . • ���� � M►'• - , .._ ,. r ,� � I - ` � l i a ' .� - �!�►�� �' � !, t� .,,� ��"�;� � ., � � t � � . 4 '� � � .� q�" � ''. .. ._\\ \l� `t I �rNY1U�,.....\\i�\\���\;�� �� � �.l`'. ��� ., � H.. _� -- '�—� — 3. USing pTOpI'letat'y bat'riers OI' tlow- Photograph CT-1. Proprietary chemical treatment system being �hCOUgl1 deVlCes COnta1171ng �OCCul111ts used on a construchon site with sensitive receiving waters. Photo courtesy of WWE. (e.g., "floc logs ). 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 t1occulation. Prior to selecting and using cheinical 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, t�he 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 dischar�e limits. Any devices or barriers containing chemicals should be installed following manufacturer's guidelines. Check for state and local jurisdiction usage restrictions and requirements befare including these practices in the SWMP and implementing them onsite. Chemical Treatment Functions Erosion Control Moderate Sediment Control Yes Site/Material Mana ement No November 2010 Urban Drainage and Flood Control District CT-1 Urban Starm Draiilage Criteria Manual Volume 3 SC-10 Maintenance and Removal Chemical Treatment (CT) Chemical feed systems for sedimentation ponds ar 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 ofi 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 Voluine 3 Construction Phasing/Sequencing (CP) SM-1 Description Effective construction site mana�ement 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. ,e - " : :b: _ j� �. e„ : .� � +'� ,�- -�--,� �- �$ - _ � -,� � ._ � �-- _ - _ r..,,,��- ��' _."-:-`-:�-.-=- — _ y - _ . Construction phasing refers to ��.,;�,� ���_ ..-.��._ � � �!' -� ''�'_ _�'I disturbing only part of a site at a time to ' � �� �� limit the potential for erosion from ��- � _, :;_ m� _= r� dormant parts of a site. Grading ��'r�� ��� -a _ activities and construction are completed Photograph CP-1. Consrruction phasing to avoid disrurbing tl�e a11d 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 consiruction 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 ininimizes 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 developmeilt should be idenrified on construction drawings. In some cases, it will be necess�ry to provide several dr�wings showing construction-phase BMPs placed according to stages of development (e.g., clearing and grading, utiliry installation, active construction, fiilal stabilization). Some municipalities in the Denver area set maximutn sizes for disturbed area associated with phases of a construction project. Additionally, requirements far phased construction drawings vary among local governments within the UDFCD boundary. Some local governments reyuire separate erosion and sediment control drawings far initial Construction Scheduling BMPs, interim conditions (in active construction), and final stabilization. Functions Erosion Control Moderate Sediment Control Moderate Site/Material Mana�ement Yes November 2010 Urban Drainage and Flood Control District CP-1 Urban Starm Draiilage 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 tl�e extent pracrical. 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 seyuencing BMPs include: ■ Sequence construction activities to ininimize duration of soil disturbance and exposure. Far 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 befare construction begins. Promptly install additiona] BMPs for inlet protection, stabilization, etc., as construction activities are completed. Table CP-1 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 construcrion drawin�s should be appropriately adjusted to ref7ect acttial "on the ground" condirions at the construction site. Be aware that changes in construction schedules can have sigilifica�lt iinplications for site stabiliaation, 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 Phase Pre- ■ disturbance, ■ Site Access Site Clearing and Grubbing BMPs 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. Use construction fencing to define tl�e boundaries of the project and limit access to a�-eas of 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. ■ 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. Stocl��iles 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/ar mulch for stockpiles that will be inactive for an extended period. � Leave disturbed area of site in a roughened condition to limit erosion. Consider temparary 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 tl�at watering creates runoff. November 2010 Urban Drainage and Flood Control District CP-3 Urban Starm Draiilage 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). Utiliry And ' Use rough-cut street control or apply road base for streets that will not be promptly paved. Infrastructure lnstallation ' Provide 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 BM Ps: ■ Implement materials management and good housekeeping practices for home building activities. Building Construction . Use perimeter controls for teimporary stockpiles from foundation excavarions. ■ For lots adjacent to streets, lot-line perimeter controls may be necessary at the back of curb. In Addition to the Above BMPs: Fina] Grading ' Remove excess or waste materials. ■ Remove stored materials. In Addition to the Above BMPs: ■ Seed and mulch/tackify. Final 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 coilstruction site can be accomplished through installation of a construction fence around the area requiring protection. In cases where upgradient areas ai•e disturbed, it may also be necessary to install periineter controls to minimize sediment loading to sensitive areas such as wetlands. Existing vegetarion may be designated for protection to maintain a stable surface cover as part of construction phasing, or vegetation nlay be protected in areas desigi�ated to remain in natural condition under post-development conditions (e.g., wetlands, mature trees, riparian areas, open space). Appropriate Uses t -.�4 r� '�—�' z� �' ��'���� �' � �-'� `� .-� . ,� - � .` - .� r�. ;r� ��t�'���� . � , ' '�, N 9 . �1 � , ' ' . , _ - � - � � _`rJ. Photograph PV-1. Protection of existing vegetation and a sensilive area. Photo courtesy of CDOT. Existing vegetation should be preserved for the maximum practical durarion on a const�uction 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, uilless a permit has been obtained from the U.S. Army Corps of Engineers (USACE) allowing impacts in li�mited areas. If trees are to be protected as part of post-developinent landscaping, care must be taken to avoicl several types of damage, some of which may not be apparent at the time of injury. Potential sources of injury include soil compaction duri»g gradii�g or due to construction traffic, direct equipment-related injury such as bark reinoval, branch breakage, surface grading and trenching, and soil cut and filL In order to minimize injuries that may lead to immediate ar 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 fenci��g. Do not allow stockpiles, equipment, trailers or parking within the protected area. Guidelines to protect various types of existing vegetation follow. Protection of Existing Vegetation Functions Erosion Control Yes Sediment Control Moderate Site/Materia] Management Yes November 2010 Urban Drainage and Flood Control District PV-1 Urban Starm Draiilage Criteria Manual Volume 3 SM-2 Protection of Existing Vegetation (PV) Surface Cover During Phased Construction Install construction fencing or other periineter controls arouild areas to be protected from cleariilg and grading as part of construction phasing. Maintaining surface cover on steep slopes far the maxiinum pracrical duration during construcrion 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 co»struction 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 Protectionl Before beginning construction operations, establish a tree protection zone around trees to be preserved by installin� 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 arder 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 matu�re Good 0.5' 0.75' 1.0' Moclerute 0.75' 1.0' 1.25' Poo�- 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°Io 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 � Tree Protecfion guidelines adapied from GreenCO and WWE (2008). Gr�een Irzdu,shy Best Management Practice,c (BMPs) for the Co��se�-vation and Protection of Water Resources in Colorado: Mo��ing Towm-d Sustainabiliry. Third Release. See www. greenco.org for more detai]ed guidance on tree preservaYion. 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 equipir�ent to be stored, chemicals to be dumped, or construction activiries 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 dainaged beyond repair, remove and replace with a 2-inch diameter tree of the same or similar species. Construction equipment must not eilter a wetland area, except as pennitted by the U.S. Army Corps of Engineers (USACE). Inadvertent placement of till 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 ar similar species, following the recommendations in the USDCM Revegetation chapter. November 2010 Urban Drainage and Flood Control District PV-3 Urban Starm Draiilage Criteria Manual Volume 3 Construction Fence (CF) Description A construction fence restricts site access to designated eiltrances and exits, delineates cons[ruction site boundaries, and keeps construction out of sensitive areas such as natural areas to be 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 wetlands, waterbodies, trees, and other natural areas of the site that should not be disturbed. SM-3 �r,:.: � � .�--� - � ,- ,� . - ,, d ��i r , � � � w _ . _ �.,. ��-y . �: � ��i �� . _ � . � � ,-�� ' ,. �'=� `�� �� � .H � ��._�1'`+�����i� ���•y: �� � ��,�` �f �+ .q y}�, , 'r'' � ; i . t ,` � ! .:a t���Y Y ' !. 4 :J'' �� . � � ' . v4r' ,/ � , � � , � � �'�.�• � , . �; ,�. � �,,;� : , F' e �i i��''� � � �; �� ,, , 1, � ' +' �' � • .� � � 1 '� y : 'v � , Photograph CF-l. A construction fence helps delineate areas where existing vegetation is being protected. Photo courtesy of Douglas County. 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 ar plastic mesh and should be installed following manufaciurer's recommendations. See Detail CF-1 for typical installarions. Do not place construction fencing in areas within work limits of machinery. Maintenance and Removal [nspect 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-1 Urban Starm Draiilage Criteria Manual Volume 3 SM-3 CF — CF — CF Construction Fence (CF) oi nc�rir rno rvo n r CONSTRUCTION FENCE INSTALLATION NOTES 1. SEE PLAN VIEW FOR: -LOCATION OF CONSTRUCTION FENCE. 2. C�NSTRUCTION FENCE SHOWN SHALL BE INSTALLED PRIOR TO ANY LAND DISTURBING ACTIVITIES. 3. CONSTRUCTION FENCE SHALL BE COMPOSED OF ORANGE, CONTRACTOR-GRADE MATER�AL THAT IS AT LEAST 4' HIGH. METAL POSTS SHOULD HAVE A PLASTIC CAP FOR SAFETY. 4. STUODED STEEL TEE POSTS SHALL 8E 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, MIDD�E, AND BOTTOM OF EACH POST. CF-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 CF-1. PLASTIC MESH CONSTRUCTION FENCE Construction Fence (CF) ,• ., , ,:, • SM-3 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 ERaSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREOUENT 08SERVATIONS 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. CQNSTRUC710N FENCE IS TO REMAIN IN PLACE UNTIL THE UPSTREAM DISTURBED AREA IS STABIL12ED AND APPROVEO BY THE LOCAL JURIS�ICTION. 5. WHEN CONSTRUCTION FENCES ARE REMOVED, ALL DISTURBED AREAS ASSaCIATED WITH THE INSTALLATION, MAINTENANCE, AND�OR REMOVAL OF THE FENCE SHALL BE COVEREO WITH TOPSOIL, SEEDED AND MULCHED, OR OTHERWISE STABILIZED AS APPROVED BY LOCAL JURISDICTION. NOTE: MANY JURISDIC710NS HAVE 8MP OETAILS THAT VARY FROM UDFCO STANDARD DETAILS. CONSULT WITH LOCAL JURISOIC710NS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. (DETAIL ADAPTED FROM TOWN OF PARKER. COLORADO, NOT AVAILABLE IN AUiOCAD) November 2010 Urban Drainage and Flood Control District CF-3 Urban Starm Draiilage Criteria Manual Volume 3 Vehicle Tracking Control (VTC) SM-4 Descr iption Vehicle tracking controls provide stabilized construcrion site access where 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 frequent heavy vehicle traffic exits the construction site onto a paved roadway. An :a.�F.�,�"� _ �''� _. . a,� �4� -. e- w.` • � "; - • - •' � � - � � -� ' 'P. " y` . �i- - n,1 � . r. � '- � , f i c - � . ' _ "� ��'� �t, �j ��.,• � .., �^ �� ���+�. .:y T y �, . . - �[. � �� ' y - �J � \ � \ ` � � M � 1 . . - • t � ^1��� t�`���•.Y� T�� t� ��y��ae' -� �'���~ r '� 'M1i`it -:+'S�(� ay'r� �, ���1`- � �� ���� ♦ �1I���� ���_ ' .=�jti'Ay �%1� t i�.a�.,� � _ i�'_'�' . � w�. v� �'i'`- .� _ +c�* Photograph VTC-l. A vehicle tracking conCrol pad consfructed wit�h properly sized rock reduces off-site sediment tracking. effective vehicle iracking control is particularly impartant during the following conditions: ■ Wet weather periods w11en 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 ii� designs of vehicle tracking controls, they may be needed at particularly �nuddy 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 ihrough 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 sedinlent froin vehicles, it helps protect existing vegetation and provides a stabilized entrance. Vehicle Tracking Control Functions Erosion Control Moderate Sediment Conirol Yes Site/Material Management Yes November 2010 Urban Drainage and Flood Control District VTG1 Urban Starm Draiilage 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 inare advance proprietary systems. When a wheel wash is provided, it is important to direct wash water to a sediment trap priar to discharge from the site. Vehicle tracking controls are somerimes 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 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 t11e public right-of-way. Remove sediment tl�at is tracked onto the public right of way daily or more frequently as needed. EXcess sediment in the roadway indicates that the stabilized construction entrance needs mamtenance. Ensure that drainage ditches at the entrance/exit area remain clear. - ���ci��.� . � � -as�. : � ., � :;� � . +� �,� � : ��� • R / � rY��� »�..� t t� '��r,�� �. � ' .�t� ...�r.`r'�"_ . !e. �' A stabilized entrance should be removed only when there is no longer ihe 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 dischai•ge. Also inspect channels conveying the water from the wash area to Che 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 Photograph VTG2. A vehicle tracking control pad with wheel wash facility. Photo courtesy of Tom Gore. Vehicle Tracking Control (VTC) SM-4 �_x •�t�x z�r %�.2`-i� °�-!: +,� vTc 20 FOOT (WIDTH CAN BE LESS IF CONST. VEHICLES ARE PHYSICALLY CONFINED ON BOTH SIOES) SIDEWALK OR QTHER PAVED SURfACE J � ��.-_e�c _ . y .•-t }-i .l'�..'� � -t r� � µ�'_� � ��.. µ�:��fJ��.. '� ��� ,.{_. � ' � PUBLIC RaADwnY 50 FOOT (MIN. UNLESS OTHERWISE SPECIFIED BY LOCAL JURISDICTION, USE COOT SECT. /J703, AASHTO #3 \ COARSE AGGREGATE OR 6" MINUS ROCK '.Y�'."�..Y.;�-`w " �"�� � , r. r Y _e,._r � . , �:�_ -j 1 . -f �f -�l � . ti '1 -t I , �: K� Y ��_ Y f-� , �� � � � t�c 4 � Y . 'Y :.,�a � �" y'� .'"y� ..1 .._{ �...�_ - . H �{ �1 .� -1 -{ � -( � �� L p �-,1.,.,{- : ti .. '� ,r ,r . '����-���'-+.."�y; _, _t :< 1 � T 9" (MIN.) � Y � � :-{ 2 � � . 1 .-{ '. 44 _'.{.. _'- ' _ " " -..i -I.` - :. NON-WOVEN GEaTEXTILE FABRIC BETWEEN SOIL AND ROCK INSTALL ROCK FLUSH WITH aR BELOW TOP OF PAVEMENT UNLESS OTHERWISE SPECIFIED BY LOCAL JURISOICTION, USE COOT SECT. #703. AASHTO #3 COARSE AGGREGATE r 9" (MIN.) � � NON-WOVEN GEOTEXTILE FABRIC VTC-1. AGGREGATE VEHICLE TRACKING CONTROL November 2010 Urban Drainage and Flood Control District VTC-3 Urban Starm Draiilage Criteria Manual Volume 3 COMPACTED SUBGRADE -� SECTION A SM-4 Vehicle Tracking Control (VTC) �� . <<,:�- �_a ;� . , .. PUBLIC ROADW/ NOTE: WASH WATER MAY NOT CONTAIN CHEMICALS OR SOAPS WITHOUT OBTAINING A SEPARATE PERMIT 7" MIN. <, ,. •'=`�. %'-c� '�. -t. •"-� `=,. � � "-� � '� `�+ •'' i. .. .. . , _. v- �. - a a.....,. . r.. _ REINFORCEO CONCRETE RA�K Y���� 1�� t� ��� �� (MAY SUBSTITUTE STEEL CATTLE DRAIN SPACE GUARO FOR CONCRETE RACK) SECTION A VTC-2. AGGREGATE VEHICLE TRACKING CONTROL WITH WAS H RAC K VTC-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 TC WW ' DITCH TO CARRY wASH wATER TO Vehicle Tracking Control (VTC) SM-4 t 0% MAX�� EXISTING PAVED ROADwAY �TC/ VTC/ CM TR DISTURBED AREA, CONSTRUCTION SITE, STABILIZED STORAGE AREA OR STAGING AREA CONSTRUCTION MATS, WOVEN OR TRM Rt►l r a � a a 0 � 0 w > a c� z F � x w O�,�O � Q�Q,O ��C'� .�P'� ti� ��� �G ��� � � J`�� JG J�'�� 18�� MIN SPIKES OR STAKES TRM END OVERLAP WITH SPIKES OR STAKES Q„O c�'� ��,��� CONSTRUCTION MATS, WOVEN Q p��� F. OR TURF REINFORCEMENT STRAP \ �'��G'��� �MAT (TRM) CONNECTORS � �. � �.��.--�----.� CONSTRUCTION MAT END RESTRICT CONST. VEHICLE OVERLAP INTERLOCK WITH ACCESS TO SIOES OF MAT � STRAP CONNECTORS � 20' OR AS REQUIRED TO ACCOMMODATE ANTICIPATED 7RAFFIC {WIDTH CAN BE LESS IF CONST. VEHICLES ARE PHYSICALLY CONFINEO ON BOTH SIDES) VTC-3. VEHICLE TRACKING CONTROL WJ CONSTRUCTION MAT OR TURF REINFORCEMENT MAT (TRM�, November 2010 Urban Drainage and Flood Control District VTGS Urban Starm Draiilage Criteria Manual Volume 3 SM-4 Vehicle Tracking Control (VTC) SrA81LIZE0 CONSTRUCTION ENrRANCE/EXIT INSTALLATION NOTES 1. SEE PLAN VIEW FOR -LOCATION OF CONSTRUCTIQN ENTRANCE(S)/EXIT(S). -TYPE OF CONSTRUCTION ENTRANCE(S)/EXITS(S) (WITN/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 DISTURBING ACTIVITIES. 5. A NON-WOVEN GEOTEXTILE FABRIC SHALL BE PLACED UNDER THE STABILI2ED CONSTRUCTION EN7RANCE/EXIT PRIOR TO THE PLACEMENT OF ROCK. 6. UNLESS OTHERWISE SPECIFIED BY LOCAL JURISDIC710N, ROCK SHALL CONSIST OF DOT SECT. #703, AASHTO fj3 COARSE AGGREGATE OR fi" (MINUS) ROCK. srAewzEo coNsrRucnor, 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 ERaSION, AN� 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 CONSI5TENT DEPTH. 5. SEOIMENT tRACKED ONTO PAVED ROADS IS TO BE REMOVE� THROUGHOUT THE DAY AND AT THE END OF THE DAY BY SHOVELING aR SWEEPING. SEDIMENT MAY NOT BE WASHED OaWN STORM SEWER DRAINS. NOTE; MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCO STANDARD DETAILS, CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD 8E USED WHEN DIFFERENCES ARE NOTED. (DETAILS ADAPiEO FRaM CITY OF BROOMFIELO. COLORADO, NOT AVAILABLE IN AUiOCAD) 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 ._ _ � ,.�� i , roads during construction activities. I�~� �" Appropriate Uses Use on high traffic construction roads to minimize dust and erosion. � � _ �.: � � �; -,�, ,::: �� �. �- 1 ��- 1 , � � �f - ,.� ---� `�. - ���'�--- , _,;� ,� s : e ^ X .t�_� � .- �.:. -:n !�.t,-- .,+r: :.e �. • ��..•, �ti : h 4 �.i.�-,� :�� 'µk _. - . Stabilized construction roadways are used instead of rough-cut street controls on roadways with frequent construction �; traffic. - Design and Installation j ; `, � ' ,. �: � ...� '? ~ `;:�= -' � ' �+r : r � �� *� �. ti ;":,� ': , ` � ,�:.,.:,. .. Photograph SCR-1. Stabilized construction roadway. Stabilized construcrion 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 far final road construction. Maintenance and Removal Apply additional gravel as necessary to ensure roadway integrity. Inspect drainage ditches along the roadway far 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 Noveinber 2010 Urban Drainage and Flood Control District SCR-1 Urban Starm Draiilage Criteria Manual Volume 3 Stabilized Staging Area (SSA) SM-6 Description A stabilized staging area is a clearly designated area where construcrion 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 construction site, more tha11 oi�e staging area may be necessary. Appropriate Uses ;..�. <�. ��.,: , . �.: ��,._ rer�� :^,._...;,ti,^ : -�, � Most construction sites will require a . _.. � .,..�...,. :..__�.: ..,... , , ti....,:-.-._._. Stagtilg ai'ea, Wh1C�1 ShOu�C� be Cleai'ly Photograph SSA-1. Example of a staging area with a gravel surface to deSlgilate(i lfl SWIVIP diaWll�gs. Tile �dy0ut 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 constniction activities beginning on the site. Major components of a stabilized staging area include: ■ Appropriate space to contain starage and provide for loading/unloading operations, as well as parking if necessary. ■ A stabilized surface, either paved ar covered, with 3-incl� diameter aggregate or larger. ■ Perimeter controls such as silt fence, sediment control logs, or other measures. ■ Construction fencing to prevent unauthorized access ro construction materials. ■ Provisions far Good Housekeeping practices related to materials storage aild 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 accammodate 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 far 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, mini�niae the area of disturbance to the extent practical. F'unctions Erosion Control Yes Sediment Control Moderate Site/Material Yes Noveinber 2010 Urban Drainage and Flood Control District SSA-1 Urban Starm Draiilage 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 othe�-wise. ■ Consider use of a bermed contained area for materials and equipment that do not require a stabiliaed 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 stabiliaed staging area when materials staging in roadways is requu-ed. Maintenance and Removal Maintenance ofi 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 soine cases, this will require disposal of coiltaininated soil froin equipment leaks in ai1 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 Y � SF/CF SF/CF � , � �ONSITE c � CON�TRUCTION � " vEHI��.E ' {sARKING (iF � I = NE,EDED) , CONSTRUCTION \ �- SITE ACCESS \ ` � ' , - , o � „ n � � . cn , " 1 I . „ IUATERIAL • STABILIZED � STDRAGE • CONSTRUCTION ENTRANCE (SEE DETAILS vTC-1 TO VTC-3) CONSTRUCTION TRAILERS SSA 3" MIN. THICKNESS GRANULAR MATERIAL AR EA . � � < � � N <<�.j: � - � .� .�_� SF/CF SF/CF ��— SILT FENCE OR CONSTRUCTION FENCING AS NEEDED EXISTING ROADWAY SSA-1. STABILIZED STAGING AREA STABILIZEO STAGING AREA INSTALLATION NOTES 1. SEE PLAN VIEW FOR —LOCATION aF STAGING AREA(S). —CONTRACTOR MAY A�JUST 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 OPERATIQNS ON THE SITE. 4. THE STABILIZEO STAGING AREA SHALL CONSIST OF A MINIMUM 3" THICK GR,4NULAR MATERIAL. 5. UNLESS OTHERWISE SPECIFIED 8Y LOCAL JURISOICTION, ROCK SHALL CONSIST OF OOT SECT. #703, AASHTO �j3 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 ERaSION, 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 6ECaMES EXPOSEO. November 2010 Urban Drainage and Flood Control District SSA-3 Urban Starm Draiilage 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, ANO UNLOAOING/LOAOING OPER,4TIONS. 6. THE STA8ILIZED STAGING AREA SHALL 6E REMOVED AT THE END OF CONSTRlJC710N THE GRANULAR MATERIAL SHALL BE REMOVED OR, IF APPROVED BY THE LOCAL JURISDICTION, uSEO ON SITE, AND THE AREA COvEREO wITH TOPSOIL, SEEDEO AND MUI.CHED OR OTHERWISE STABILIZED IN A MANNER APPROVED BY LOCAL JURISDICTION. NOTE: MANY MUNICIPALITIES PROHIBIT THE USE OF RECYCLED CaNCRETE AS GRANULAR MATERIAL FOR STABILIZED STAGING AREAS DUE TQ 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 OETAIL SHOULD BE USED WHEN OIFFERENCES ARE NOTED. (DETniLS AOAPTEO FROM OOUGVS COUNiY, COLORnDO, NOT AVau�BLE IN AUTOCnD) 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 Use this practice at construction sites where vehicles may track sediment offsite onto paved roadways. Design and Installation Street sweeping or vacuuming should be conducted when there is noticeable � �� , �1 � ��''� ' i� • - ' � r,� �. �_ � _; � ,-, -�� Photograph SS-1. A sh-eet sweeper removes sediment and potential pollutants along the curb line at a construction site. Photo courtesy of 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 construcrion entrances, vehicle tracking controls and tire wash facilities can help reduce the necessary frequency of street sweeping and vacuum�ng. On smaller construction sites, street sweeping can be conducted manually using a sl�ovel 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 protecrion that may have been displaced during street sweeping. ■ Inspect area to be swept for materials that may be hazardous prior to begimling sweeping operations. Street Sweeping/ Vacuuming Functions Erosion Control No Sediment Control Yes Site/Materia] Management Yes Noveinber 2010 Urban Drainage and Flood Control District SS-1 Urban Starm Draiilage Criteria Manual Volume 3 Temporary Diversion Channel (TDC) SM-8 Description A temporary diversion channel diverts water from a stream to allow for construction activities to take place underneath or in the stream. Diversion channels are often required during the construction of detention ponds, dams, in-stream grade control structures, utility installation and other activities that require working in waterways. Appropriate Uses Temporary diversion channels vary with the size of the waterway that is , •r-_� betng d]v0I'ted. FoC lacge Stre�t7ls, a to enable installation of a grade control structure (left side). Photo temporary diversion may consist of courtesy of W WE. 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 far construction of dams and detenCion basins, a temporary diversion channel may divert the entire waterway, as illustrated in Figure TDG1. For very shart 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 tl�e 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 ]ived, 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 a��d 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 temparary diversion. Design and Installation Temporary Diversion Channel siaing procedures typically include the following steps: Using the tributary area, A(in acres), determine the design peak flow rate according to Figure TDG2. Note: For long duration projects, or where the consequences of diversion failure warrant, a larger design t1ow may be necessary. Tem orar Diversion Channel Functions Erosion Control Yes Sediment Contro] No Site/Material Management No ■ Determine depth of flow, 1-foot maximum for flows less than 20 cfs and 3 feet maximum for t1ows less than 100 cfs. (Flows in excess of 100 cfs should be designed in accordance with the Major Dr-ain�age chapter in Volume 1). August 2011 Urban Drainage and Flood Control District TDG1 Urban Starm Draiilage Criteria Manual Volume 3 Photograph TDC-l. Use of a temporary diversion channel (right side) SM-8 Temporary Diversion Channel (TDC) ■ Determine channel slope based on existing and proposed site conditions. ■ Perfarm initial channel sizing calculations using Manning's Equation. Determine maximum permissible velocities based on lining material. ■ Determii�e the channel geometry and check the capacity Lising Manning's Equation and the "n" value given in Table TDC-1. The steepest side slope allowable far 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 TDG2 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 TDG2 were taken during the high flood potential period of April through September. The valLies from Figure TDC-2 represent approximately the 95T� 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 TDG2 was developed using data from small watersheds, it is not appropriate to extrapolate fram this figure far larger, more complex watersheds. For larger waterways (e.g., South Platte River, Sand Creek, Bear Creek, etc.), including ones controlled by t7ood control reservoirs (e.g. Chatfield Dam, Cherry Creek Dain, 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 contractar to assess their risk of having the temparary 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 far the design flow with the channel shear stress less than ihe 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 far lining materials. Design procedures for temporary channels are described in detail in the Hydraulic Engineering Circular No. IS 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 Stream Bank FLOW 1 PI.ACE RIPRAP AT TRANSITION FLOW BARRIERlDIVERSION (RIPRAP, SANDBAGS, JERSEY BARRIERS OR SHEET PILING) ORIGINAL STREAM BED FLOW BARRIER Former Location of Stream Bank �� �o� � PLACE RIPRAP Al TRANSITION Figure TDC-l. Typical Temporary Diversion Channel August 2011 Urban Drainage and Flood Control District TDC-3 Urban Starm Draiilage Criteria Manual Volume 3 SM-8 Temporary Diversion Channel (TDC) 1000 900 800 700 Vi 600 U � 500 � 0 � 400 300 200 100 Imp. = 60% ♦ Imp. = 40% "- ' "u' ..� ' � • 43.� • 46.5 /o 0 Imp. = 30% . _���_� � � — � ♦ 55.4 /o � � �33.3% �mp. = 2�% � � v • : .1 °o i 0. % � .� � ' � � 1�3.0% ♦ o . � � ` 10.,%� 15. % i �, . o � � �26.8% � 4�3 % 0 2 4 6 8 10 TRIBUTARY AREA (SQUARE MILES) 12 Figure TDG2. 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 TDGL 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 Ofttol.Oft 1.Oftto3.Oft 3.OfttoS.Oft Plastic Membrane O.011 OA10 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 manufact�irer's Manning's n when available. See the Major- Drainage chapter of Volume 1 for riprap gradatio». Erosion protecrion should extend a miilimum of 0.5 feet above the design water depth. Maintenance and Removal Because temporary diversion channels are one of the most critical BMPs for wark in waterways, they must be inspected and maintained frequently to remain in effective operating condition. Flow b�rriers should be inspected at the start and end oti 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 arinorii�g if erosioil 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 bacicfilled and stabilized. Points of tie-in to the natural channel should be protected with riprap sized in accordance with the Major Drainage chapter in Volwne l. August 2011 Urban Drainage and Flood Control District TDGS Urban Starm Draiilage Criteria Manual Volume 3 SM-8 Temporary Diversion Channel (TDC) 30 MIL MIN PLASTIC — SILT FENCE, TYP (SEE SF DE7AIL D C FOR INSTALlATION REQUIREMENTS) 7 / W (VARIES D (vARIES) BW NO ANCHOR TRENCH AT STAKING PERIMETER OF BLANKET AND AT OVERLAPPING JOINTS WITH ADJACENT R�LLS OF BLANKET, SIMILAR TO ECB/TRM, BUT NO STAKING L/ �L�I r----'1 � \ INTERMEDIATE ANCHOR TRENCH AT ` � ONE—HALF ROLL—LENGTH SIMILAR � rRANSVERSE ANCHOR TRENCHES EC8/TRM DETAIL, 8UT NO AT PERIMETER OF BLANKET AND STAKING AT OVERLAPPING JOINTS WITH AOJACENT ROLLS OF BLANKET, SIMILAR TO ECB, BUT NO STAKING DC-1. PLASTIC LINED DIVERSION CHANNEL STAKES (SEE �ESIGN DETAIL EC-1fl) EROSION CONTROL BLANKET {ECB) OR TURF REINFORCED MAT (TRM) (SEE ECB/TRM) \ INTERMEDIATE ANCHOR TRENCH AT ONE—HALF ROLL—LENGTH (SEE ECB/TRM) SILT FENCE, TYP (SEE SF DETAIL FOR INSTALLATION REQUIREMENTS) W(5'-0" MIN.) I ANCHOR TRENCH AT PERIMETER Of BLANKET AND AT OVERLAPPING �(10" MIN.) JOINTS WITH ANY BW ADJACENT ROLLS OF (VARIES) BLANKET. (SEE DETAIL �"� ECB/TRM) � ' � TRANSVERSE ANCHOR TRENCHES AT PERIMETER OF BLANKET AND AT OVERLAPPING JOINTS WITH ANY ADJACENT ROLLS OF BLANKET. {SEE EC8/TRM) DC-2. GEOTEXTILE OR MAT LINED DIVERSION CHANNEL THICKNESS=2 x D5o W (5'-0" MIN.) r D (lQ" MIN) + BW \ (VARIES) \ �`� - _ f - - SILT FENCE, TYP (SEE SF FOR INSTALLATION REQUIREMENTS) 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 DIVERSIQN 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 NPE OF CHANNEL. —OEPTH, 0, WIDTH, W, AND BOTTOM WIDTH, 8W. —FaR RIPRAP LINED CHANNEL, SIZE OF RIPRAP, D50, SHALL BE SHOWN ON PLANS. 2. SEE DRAINAGE PLANS FOR DETAILS OF PERMANENT CONVEYANCE FACILITIES. 3. OIVERSION CHANNELS INDICATED ON THE SWMP PLAN SHALL 8E INSTALLED PRIQR 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 ECB, FOR PLASTIC LINEO CHANNELS, INSTALLATION OF ANCHOR TRENCHES SHALL CONFORM TO THE REQUIREMENTS OF OETAIL 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. DNERSION CHANNELS ARE TO REMAIN IN PLACE UNTIL WORK IN THE DOWNGRADIENT AREA OR NATURAL CHANNEL 15 NO LONGER REQUIREO. 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 MULCHEO OR OTHERWISE STABILIZED IN A MANNER APPROVED BY LaCAL JURISDICTIaN. (DETAILS AOAPiE� fR4M OOUGIAS COUNTY, COLORA00) 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 Starm Draiilage Criteria Manual Volume 3 Dewatering Operations (DW) SM-9 Description The BMPs selected for construcrion dewatering vary depending on site- specific fieatures such as soils, topograpl�y, anticipated discharge quantities, and discharge locarion. Dewatering typically involves pumpin� 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 sequence. Appropriate Uses DewaCering operations are used wheil an area of the construction site needs to be dewatered as the result of a large storm event, groundwater, or existing poilding conditions. This can occur during deep excavation, utility trenching, and wetland or pond excavation. Design and Installation - _;��. 0 i� � K-• ,`� =� Dewatering techniques will vary ' �;s ; ��;` 4"� _� "�;;; " . :�- ,,,.�,�r�-��*•��, . depending on site conditions. However. , s� `� "� '� .` _ � ` ' x' `— �'� � all dewatering discharges must be treated ��� `"" - to remove sediment before discharging �!�� from the construction site. Discharging -� ��� � -+,w,� � � �� � � �, water inio a sediment trap or basin is an ��� � aCCeptab�e tt'eat171011t OptlOtl. Wat01' iTlay Pliotograph DW-2. Dewatering bags used f'or 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 ar the ability to passively treat the discharge to remove sedimeilt, 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. F7occulants 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 to vegetated areas through a perforated discharge hose (i.e., the "sprinkler method") or dispersal from a water truck for dust control. S�FI`r{ � ` ' ie't �403 ' � � rdnt�'+� 0:d 1^jl��j}+ 1ti , -c4�p � �'�� d�'��'Vb's�4ti�♦ �`i i � .�. 1p��P1?�� �+r ��a� �',..fp�� `�q� �'e°eh�y qe.�y�R� ��� '1 ; ��,t ��s°� y�b,., �� 9�ka"-°'�01�27*!*ia�'b ..�cxar>�.�.:� __ .....�5. �� � � e:,^ e �M1`04�, _ . y . �d�:�A�7M1! �, 4-��A � � av � , ��i►-��if' . �.��,`� �F `���f � : y � . •„' ~ ~ . . ����'^f�• �� - --� _ ��,� Photograph DW-1. A relatively small dewatering operation using straw bales and a dewatering bag. Dewaterin O erations Functions Erosion Control Moderate Sediment Control Yes Site/Material Mana ement Yes Noveinber 2010 Urban Drainage and Flood Control District DW-1 Urban Starm Draiilage 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 usin� a velocity dissipation device or dewatering filter bag. Design Details are provided for these rypes of dewatering situations: DW-1. Dewatering for Pond Already Filled with Water DW-2 Dewatering Sump far 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, iiispect the basin far sediment accumulation. Remove sediinent prior to the basin or trap reaching half full. Inspect treatment facilities prior to any dewaterin� activity. If using a sediment� control practice such as a sediment trap or basin, complete all inaintenance requirements as described in the fact sheets prior to dewatering. Properly dispose ofi used dewatering bags, as well as sediment removed from the dewatering BMPs. Depending on the size of the dewatering operation, it inay 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 PUMP SUCTION LINE OR SUBMERSIBLE PUMP CENTERED IN BUCKET 12�� MIN. eE�ow eucKEr BUCKET FILLED WITH AASHTO �3 GRAVEL (C�OT SECT. 703, #3) DW-1 . DEWATERING POND ALREADY FILLED WITH WATER PUMP SUCTION LINE OR SUBMERSIBLE PUMP 12" MIN. AROUND ON ALL SIDES OF BUCKET DW LID WITH HOLE CUT FOR SUCTION LINE PLASTIC 5—GALLON BUCKET WITH MANY 3/8" HOLES DRILLED IN SIDES LOWEST SUBGRADE ELEVATION TO BE DEWATERED LID WITH HOLE CUr 2' MIN. FOR SUCTION LINE '=-.; PLASTIC 5—GALLON BUCKET WITH �`"`'�-- MANY 3/8" HOLES DRILLED IN SIDES - - - AND BOTTOM - j� AASHTO �3 GRAVEL (coor sEcr. �os, �3) DW-2. DEWATERING SUMP FOR SUBMERSED PUMP DEWATERING PUMP DISCHARGE �INE STAKES TO SECURE END OF DISCHARGE LINE 4' (MIN.) S�UARE RIPRAP PAD TO DISSIPATE THE ENERGY OF THE FLOW EXITING THE DISCHARGE LINE 4� MIN. SETTLING POND � 2 SURFACE AREA, "A" MIN. 1 SF PER 1 GPM A 1 , RIPRAP D50=fi" ,c � 12„ 2� MIN. 2 X 050 MIN. {12" MIN) STABILIZE FLOW PATH TO OUTFALL OR RECENING WATERS 2' MIN. 12 �� 12" � MIN. MIN. ' `,� ,Y a a''y.'`,� � -z- .,. w. � : � � ,,,'.�- � RIPRAP 050=6" DW-3. SUMP DISCHARGE SETTLING BASIN SETTLING BASIN SECTION A Noveinber 2010 Urban Drainage and Flood Control District Urban Starm Draiilage Criteria Manual Volume 3 DW-3 SM-9 Dewatering Operations (DW) ,� � r _ � =•� � , � ���,�� � �,y� i i } ili _ f r+C � 1, t �,� ; ' i' I i * �, t l VEGETATION `�'r�\� ` -��� �� � � � \ _,� �-, r„i ; _�� �„ _� ti� �.ir� �_,_ , SEDIMENT CaNTROL LOG ,"a' :; � '��� (SEE SCL-1 DETAIL) r �'�� -d � ` i ` � �' , n�,. j ; �,. � ��1'��� i�z . � ROCK WILL BE INS7ALLE0, ��L'� '' D AS NECESSARY, Ta r, �,V r: =`� ' �� --+ ` PREVENT EROSION � � � ��=�> �', ��i'i � �� DISCHARGE PIPE . ,�r L,�, , � i ' f �` �;�Y '' �i �� � 7p �� : _ ; ( �_ . , � I 1�,�.. 1 '^l. +{ J t7 r �'" � I �F ' i �L " rf� _ � � , _ =' `� D �4.r� • tl � ' i r � fi '.� , . . � �y � r_t ,�; / '1 , :� _ \ �' Y. �,� l Y ' ,1 :��i.:�aJ.T . �JI�/�/;�. . :� ir �,, . � `,�A` • ��1 � z �� . ; � I, ', �� _ �`? ,�-R+-r, ', ' � �%�. r>, "S 'i ' �I .:�G} , I��i\� `;• i' - � � ��) ' i .� A : ��i=y i . . - �r� ,R �g �` \ , h� ,� � � v�^ i,* �i y L•`�w���3 ��I�.\'i"il,'� �1���.� � ��� � - � � ;� . �. �%. � �� - ` . � - � _, 1 � �' � ; : ��, , , c �� • —� �- ii ��< ..:x ,..��. �e �.:. -4'.. i FILTER BAG ON STRAW BALES OR ROCK PAD DW-4. DEWATERING FILTER BAG DEWATERING INSTALLATION NOTES 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 OEWATERING SYSTEMS OF SUFFICIENT SIZE AND CAPACITY TO PERMIT EXCAVAT10N 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 OISCHARGE POINT ANO THE OISCHARGE 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 (AN� ALWAYS WITHIN 24 HOURS) FO�LOWING A STORM rr,a,r ca,usEs suRF,acE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPEC710NS AND CORRECTIVE MEASURES SHOULD BE D�CUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPIACEMENT SHOULD BE INITIATEO 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 N� L�NGER NEEDED FOR DEWATERING OPERATIONS. ANY DISTURBED AREA SHALL BE COVERE� WITH TOPSOIL, SEEDED AND MULCHED aR aTHERWISE STABILIZED IN A MANNER APPROVEO 8Y THE LOCAL JURISDICTION. NOTE: MANY JURISDICTIONS HAVE BMP OETAILS THAT VARY FROM UOFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. (DETAILS ADAPiEO FROM DOUGLAS COUNTY. COLORADO, NOT AVAILABLE IN AUTOCAD) Noveinber 2010 Urban Drainage and Flood Control District DW-5 Urban Starm Draiilage Criteria Manual Volume 3 Temporary Stream Crossing (TSC) SM-10 Description 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 metl�ods. Due to the expense associated wiih a temporary bridge, these are used primarily on long- term projects. Appropriate Uses �r. � . ; : � -- �, �.�.: - , �� � . �:� , �, y,.. _ , fe� -- �'t �, _''�'��;� � . r, - �,'�'�J�-4�� T . . � ?� .� u � � t�: �.��_.:� , + � - ,: _'��'3`'.- � , "� � Y+ti.'� � ` �� "� �! 1 �+�s: � . � � ; k � �,,t � ;,,� t, �i+ ,;�,�1 � � A � . � ���,� �r ._ -< - ��., .� ._ �= '�;' r, � " , C pr�� .� '!5� i1' '�.�e`, ,� � � i �'. �N► � . .� � - s '� ���� y -- " .p� . p� i��,� 1 n�� ` Y_ � ��` '� ��� • , . f , r' f :-; �' � � _ � � •`�'�) rI� _�` J . +, ._ �� ���'t, a``�,f� � � :� �. +� ��, , w�;- �.. �,,,,,� ' � µ .� ,�'if ' ' _ . � ;�- '� � 4 ..� ..n ."�'fr'< ,a6'.'+J�tdJt•�� .. -'.���_ , �r'.L�_'- . . _ .,;ii;t h.�i:�_, - - Photograph TSC-1. A temporary strea�n crossing using culverts. Photo courtesy of Tom Gore. Construction vehicles shall be kept out of waterways to the maximum extent practicable. Use a temparary 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. Anny Corps of Engineers (USACE) should be contacied concerning the requirements for obtainii�g a 404 permit. In addition, a permit from the U.S. Fish a»d Wildlife Service (USFWS) may be needed if endangered species are ofi concern in the work area. Typically, the USF'WS 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 fior these rypes of stream crossings: TSG1. Culvert Crossing TSG2. Fard Crossing TSC-3. Flume Crossing Tem orar Stream Crossin Functions Erosion Control Yes Sediment Control Yes Site/Material Management No November 2010 Urban Drainage and Flood Control District TSC-1 Urban Starm Draiilage 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 Cl�annel Diversion Fact Sheet to determine the 2-year peak flow rate. Culvert sizing must account for the headwater a11d tailwatei• connols to properly size the culvert. For addirional discussion on design of box culverts and pipes, see the Major• Dr•ainage 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-ii�ch thick layer of Type VL (Dso = 6 inches) ar Type L(D5� = 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 alten�atives. 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 degradarion 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 sedi�nent as needed to mai�ltain the fu»ctionaliry of the crossing. Remove the temporary crossing when it is no longer needed far 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. TSG2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Temporary Stream Crossing (TSC) SM-10 LENGTH L TSC CREST LENGTH z � CL A �5 f 1 �..;, , �� M, r t � ��, AVOID BANK EXCAVATION EXISTING � `.� y 'r ,� , , , , _ _ � - IF POSSIBLE GRADE _..�_ ;t� %=t DEPTH D -� CULVERT {AS SPECIFIED) HEIGHT H J CULVERT DIAMETER CD CULVERT CROSSING SECTION 1Y1" (MINUS) CRUSHED ROCK 12" MIN. COVER � FLOW f :�_:=� i��;� GEOTEXTILE FABRIC FOR MATERIAL SEPARATION S MIN � >2 �11 [�141�:iL�'L�'�9,Xy1�1�1�; GE�TEXTILE OR MAT SECTION A TSC-1. CULVERT CROSSING D50-12" TYP. RIPRAP November 2010 Urban Drainage and Flood Control District TSC-3 Urban Starm Draiilage Criteria Manual Volume 3 SM-10 Temporary Stream Crossing (TSC) ��� �a.�Hr:■• LENGTH CL � EXISTING CHANNEL GRADE AVOID BANK EXCAVATION IF POSSIBLE i�7:��i�I:Z�I►'�►�I�il�`1�.��i�7� 8' MIN I � EXISTING CHANNEL GRADE >2 � FLOW 1 ---�- D50-6" RIPRAP VdIDS FILLED L 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 EXCAVATED UTILITY FLO�h EMBANKMENT, STREAM BANK TSC STREAM sraBiuzEo EMBANKMENT, TYP. FLUME PIPE STREAM FLOW � I STREAM BOTTOM PROPOSED UTILITY � � EXCAVATED UTILITY TRENCH SECTION A TSC-3. FLUME CROSSING November 2010 Urban Drainage and Flood Control District TSGS Urban Starm Draiilage Criteria Manual Volume 3 FLUME CROSSING PLAN SM-10 Temporary Stream Crossing (TSC) TEMPORARY STREAM CROSSING INSTALLATION NOTES 1. SEE PLAN VIEW FOR: -LOCA710NS OF TEMPORARY STREAM CROSSINGS. -STREAM CROSSING TYPE (FORD, CULVERT, OR FLUME). -FaR FORD CROSSING: LENGTH (L), CREST LENGTH (C�), AND DEPTH (D). -FOR CULVERT CROSSING: LENGTH (L), CREST LENGTH (CL), CROSSING HEIGHT (H), DEPTH (D), CULVERT DIAMETER (CO), AND NUMBER, TYPE AND CLASS OR GAUGE OF CULVERTS. 2. TEMPORARY STREAM CROSSING DIMENSIONS, D50, ANO 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 FL000 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 CONOITION. 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 ERaSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT 08SERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AN� CORRECTNE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. REMOVE SEOIMENT 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 ANO SHALL 8E REMOVED PRIOR TO THE END OF CONSTRUCTION. 6. WHEN STREAM CROSSINGS ARE REMOVED, THE OISTURBED AREA SHALL BE COVERED WITH TOPSOiL, SEEDED a,rvD Mu�CHED aND COVEREO wiTH GEOTExTi�E OR OTHERWiSE STABiLIZED IN A MANNER APPROVED BY THE LOCAL JURISDICTION. NOTE: MANY JURISDICTIONS HAVE BMP OETAILS THAT VARY FROM UDFCD STANOAR� OETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH OETAIL SHOULD 8E USED WHEN DIFFERENCES ARE NOiED. (�ETA1L ADAPTED FROM OOUGLAS 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 Descr iption Temparary batch plant management includes implemenring multiple BMPs such as perimeter controls, concrete wasl�out area, stabilized construcrion access, good housekeeping, and other 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 0 .,, , '.i � i�'�+ •'?^ � .���. ��.�; �� - _ _ --=� '",�,�,--�. . _ 7�.� � _ batCh plant in the SWMP. Photograph TBP-1. Effective stormwater management at temporary Uatch plants requires implementation of multiple BMPs. Photo Additional permitting may be required for courtesy of California sco�mwater BMP Handbook. the operation of batch plants depending on their duration and location. Design and Installation The following lists temporary management st�ategies 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 periineter control should be installed around the temporary batch plant. ■ b�stall run-on controls where fieasible. ■ 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 contaimnent ineasures, materials storage, and waste starage practices. ■ A stabilized construction entrance or vehicle tracking control pad should be installed at the plant entrance, in accardance with the Vehicle Tracking Control BMP. Maintenance and Removal Inspect the batch p]ant for proper functioning of the BMPs, with attenrion to material and waste storage areas, integrity of perimeter BMPs, and an effective stabiliaed construction entrance. Temporary Batch Plants Functions Erosion Control No Sediment Control No Site/Materia] Mana ement Yes November 2010 Urban Drainage and Flood Control District TBP-1 Urban Starm Draiilage 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 ar 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 entering storm drainage systems �nd natural drainageways. Appropriate Uses Use runoff management practices during all paving and grinding operations such as surfacing, resurfacing, and saw cutting. Design and Installation � � �' � � d�- � � ,,, . y �::. _ �Y... ���` . . , ,. Photograph PGO-1. Paving o�erations on a Colorado highway. Photo courtesy of CDOT. There are a variery 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 far stored equipinent. ■ 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. filstead, loose material should be swept or vacuumed following paving and grinding operations. ■ Store materials away froin 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 far 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. Paving and Grinding Operations Functions Erosion Control No Sediment Control No Site/Material Mana ement Yes Promptly respond to spills in accordai�ce with the spill prevention and control plan. Noveinber 2010 Urban Drainage and Flood Control District PGO-1 Urban Starm Draiilage Criteria Manual Volume 3 . -,.. � �' �� Grass Buffer Description Grass buffers are densely vegetated strips of grass designed to accept sheet flow from upgradient development. Properly designed grass buffers play a key role in LID, enabling infiltration and slowing runoff. Grass buffers provide filtration (straining) of sediment. Buffers differ from swales in that they are designed to accommodate overland sheet flow rather than concentrated or channelized flow. Site Selection � ... � T-1 yY��� � } 5.. � l � �"4 � , E r ,� �'•y:t - .?�a �� •�� � e � - ;�� �` r � ` �+ ~�i Y ��.� �� � ���' y . � . . 'r�' a �j ��3 K} � _ h�' ' �'N �� Y`��5���� 1'1S�r -� _ __ r�l;R. . �:,�tl ,, ��`. � -�� � _ —�'�� !.. . Grass buffers can be incorporated inro a �-- ' ���� Wide 1'ange Of development SetttngS. Photograph GB-1. A flush curb allows roadway runoff ro sheet flow RUnOff Can be d1YeCtly aCCepted fI'Om a through the grass buffer. Flows are then further treated by the grass parking lot, I'OadWay, or the roof ofi a swale. Photo com-tesy of Muller Engineering. skructure, 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 sometiines serve multiple functions such as recreatioii. Grass Buffer Functions LID/Volume Red. Yes WQCV Capture No WQCV+FIood Conh-o] No Fact Sheet Includes EURV Guidance No Typical Effectiveness for Targeted Pollutants3 Sediment/Solids Good Nutrients Moderate Total Metals Good Bacteria Poor Other Considerations Life-cycle Costs Low 3 Based primarily on data from the International Stoi�rnwater BMP Database (www.bmpdatabase. org). Hydrologic Soil Groups A and B provide the best infiltration capacity for grass buffers. For Type C and D soils, buffers still serve to provide filtration (straining) although infiltration rates are lower. Designing for Maintenance Recommended ongoin� maintenance practices for all BMPs are provided in Chapter 6 of this manual. During design the following should be considered to ensure ease of maintenance over the long-term: Where appropriate (where vehicle safety would not be impacted), install the top of the buffer 1 to 3 inches below the adjacent pavement so that growth of vegetation and accumulation of sediment at the edge of the strip does not prevent runoff from entering the buffer. Alterilatively, a sloped edge can be used adjacent to vehicular traffic areas. ■ Amend soils to encourage deep roots and reduce irrigation requirements, as well as promote infiltration. November 2010 Urban Drainage and Flood Control District GB-1 Urban Storin Drainage Criteria Manual Voluine 3 T-1 ■ Design and adjust the irrigation system (temporary or permanent) to provide water in amounts appropriate for the selected vegetation. Irrigation needs will change from month to month and year to year. Grass Buffer Benefits ■ Filters (strains) sediment and trash. ■ Protect the grass buffer from vehicular traffic when using ■ Reduces directly coilnected 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). Design Procedure and Criteria The following steps outline the grass buffer design procedure and criteria. Figllre GB-1 is a schematic of the faciliry and its components: 1. Design Discharge: Use the hydrologic procedures described in t�he Rr�noff chapter of Volume 1 to determine ihe 2-year peak flow rate (Q�) of the area draining to the grass bufifer. 2. Minimum Width: The width (4T�, norinal to flow of the buffer, is typically Che same as the contributing basin (see Figure GB-1). An exception to this is where flows become concentrated. Concentrated flows require a level spreader to distribute flows evenly across the width of the buffer. Tl�e minimum width should be: Q2 w 0.05 Where: W = width of buffer (ft) Qz = 2-year peak runoff (cfs) Equation GB-1 3. Length: The recommended length (L), the distance along the sheet flow direction, should be a minimum of 14 feet. This value is based on the findings of Barrett et al. 2004 in Stormwater Pollutant Removal in Roadside Vegetated ■ Can easily be incorporated into a treatment train approach. ■ Provides green space available for multiple uses including recreation and snow storage. ■ Straightforward maintenance requirements when the buffer is protected from vehicular traffic. Limitations ■ Frequently damaged by vehicles when adjacent to roadways and unprotected. ■ A thick vegetative cover is needed for grass buffers to be effective. ■ Nutrient removal in grass buffers is typically low. ■ High loadii�gs of coarse solids, trash, and debris require pretreatment. ■ Space for grass buffers may not be available in ultra urban areas (lot-line-to-lot-line). Strips ancl is appropriate for buffers with greater than 80°�0 vegetative cover and slopes up to 10°Io. The study found that pollutant removal continues throughout a length of 14 feet. Beyond this length, a point of diminishing retui7ls ii1 pollutant reduction was found. It is iir�portant to i�ote that shorter lengths or slightly steeper slopes will also provide some level of removal where site coi�straints 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 4. Buffer Slope: The design slope of a grass buffer in the direction of flow should not exceed ] 0%. Generally, a minimum slope of 2% or mare in turf is adequate to facilitate positive drainage. For slopes less than 2%0, consider including an underdrain system to mitigate nuisance drainage. Flow Characteristics (sheet or concentrated): Concentrated flows can occur when the width of the watershed differs from that of the grass buffer. Additionally, when the product of the watershed flow length and the interface slope (the slope of the watershed normal to flow at the grass buffer) exceeds approximately one, flows inay become concentrated. Use the following equations to determine flow characteristics: Sheet Flow: FL(SI) < 1 Concentrated Flow: FL(SI) > 1 Where: FL = watershed flow length (ft) SI = interface slope (normal to flow) (ft/ft) Equation GB-2 Equation GB-3 6. Flow Distribution: Flows delivered to a grass buffer must be sheet flows. Slotted ar 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 GB-2. It could be an exfiltration irench filled with gravel, which allows water to infiltrate prior to discharging over a level concrete ar rock curb. There are many ways to design and construct a level spreader. They can also be used in series when thc length of the buffer allows flows to re- concentrate. See Figure GB-2 foi• various level spreader sections. , � �'c, � __ _ —�• '�+�rs - w�'- ^'�''�1 t � —' 1 _�—.—�..�..�: ,:,� .� � _ �. , •.'. �;,,Iq.��r, , ! . � i . n , � ��: i r ' j_ i, � � �� X ���;�,�yI{�.��,'�����'�;� ,�4�� �1�� . '� i �������� 4}� `1I''�1,1 ,j'�, ��:��: y` 11 ' `�y ; 4 : �''� �� ����.�''.�� # ��1,� I�����E�� id �r Photograph GB-2. This level spreader can-ies concentrated tlows into a slotted pipe encased in concrete to distribute tlows eve�nly to the grass buffer shown left in the pl�oto. Pl�oto courtesy of Bill Wenk. T-1 Use of Grass Buffers Sheet flow of stormwater through a grassed area provides some benefit in pollutant removal and volume reduction even when Che 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, this treatment concept is still encouraged. November 2010 Urban Drainage and Flood Control District GB-3 Urban Storin Drainage Criteria Manual Voluine 3 T-1 Photos GB-3 and CB-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 leve] spreader completely. 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, it is essential that soil conditions be properly prepared prior to 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 ol•der 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.) Vegetation: This is the most critical ��� , �.- . .� . � ti ,.. t . �`' � 1� F�. .� . �� Grass Buffer •�� � � �� �- ; ��, Iy� a l� ,� . j .��" ��:,Jj� F F.�I��s.'.. �. r.� � � ,��� � ) �� , - �� . ' ,:. . -, �� � '� r � =��:;�;,;' ,..,"- 7 'f� .,,� T' �'. '- � �' , "`� — , � ; M������' .1� '�^�.�t��s�� 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°/0 (BaiYett et a1.2004). GB-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Photograph GB-3. This level spreader includes the added benePit of a sedimenCation basin prior tio even dist�ribution o9' concemrated �Plows fi-om the roadway into the grass buffer. Photo courtesy of Bill Wenk. Photograph GB-4. Maintenance access is provided via the ramp located at the end of the basin. Phofo courtesy of Bill Wenk. 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 requireinents. See the Revegetation chapter in Volume 2 of this manual with regard to seed mix selection, planting and ground preparaCion. Depeilding on soils and anticipated flows, consider erosioi� control measures until vegetation has been established. 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 rype ofi 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, narive grasses require the same irrigatioi� requirements as bluegrass. After the grass is established, irrigation requirements fior 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 infiltrarion capacity and contributing to nuisance baseflows. Conversely, under watering may result in delays in establishment of tlle vegetation in the short term and unhealthy vegetation that provides less filtering ai�d increased susceptibiliry to erosion and rilling over the long term. 10. Outflow Collection: Provide a ineans far 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 faciliry 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 wark crossing the buffer has been coinpleted. ■ 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 healChy, although less lush, with much less irrigation than is typically applied. November 2010 Urban Drainage and Flood Control District GB-5 Urban Storin Drainage Criteria Manual Voluine 3 T-1 �-�: �u:�� � . . � �t v' � � "''r . � ., � � l � -� C� I i. �' �4 'y}� �'• '�� � � ; , �= � a�., u�ti 4 V� �� L�,� _ �`` ` �:� � � r �- �� '�,'r . , � ���� � � � � � � ; ,j' . .;i��, . `, 1 � = . �` �J c `yY'' ty�.�,r:� �,Y, �i � . ,�� �:� t , . , �� �, � I ,d .' ,Y �, . ��: �� , H �i 9 � w � ' o � � W ` Z � 3 Grass Buffer � ' 3 �t� r��,��y�. ��� ?�= ,'�� ; .; � �'' � � � ,� �-�� (�-�� � ' WAi�RSNEO I�LoW I%`1 � � '� 1�,� � k.. � , i� �;r< ���'•� ��> 1= � ,t? �-r � � ���� t -- PLAN :. I'TO 3' LIP WNERE�, SUITABI.E \ � ;y '�� <:h'ti�ir�'°�-;• ,; �1 �` '' �o°� ►�nx. �' �� L M�N ) � �� 1 r � l � _ ,�.. • 14 � �A�AEND�O SOILS� \� ��€1��� \�.1 tatt :'- ���' , \ \ \\�\r,. r.. \\ � C� (PHA(i�1A� , .� �. �, ,, ��, ��„�, ,,., , ., �l_ _� = � � _�� .�� ; —; _. �; ca J^ LEV�L SPREADE.R PROFILE Figure GB-1. Typical Grass Buffer Graphic by Adia Davis. Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Grass Buffer CORRUGATED SLOTfED DRAIN PIPE GRASS BUFFER ✓ � 11�` � AGGREGATE BASE COURSE SECTION � LEVEL SPREADER FOR PIPE FLOWS PIPE AND HEADWALL BEYOND - GRASS BUFFER SLOT7E0 CURB DRAIN PAN WITH CURBS SECTION n LEVEL SPREADER FOR PIPE FLOWS - GRASS BUFFER � r - UNDERDRAIN, SEE SECTION 5 �OR PROVIOE SMA�L OPENING IN WALL) SECTION � L.EVEL SPREADER FOR SURFACE FLOWS `' GRASS BUFFER , :, r- ,: ; ..'..;, ;. .. 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 FILTER � 4,. MATERIAL PER TABLE SLOTTED PIPE PER TABLE GS-3� GS-2' 1. SEE BMP FACT SHEEf T-2, GRASS SWALE SECTION � UNDERDRAIN `' Figure GB-2. Typical Level Spreader Details T-1 November 2010 Urban Drainage and Flood Control District GB-7 Urban Storin Drainage Criteria Manual Voluine 3 Grass Swale 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 tlow in a slow and shallow manner, thereby facilitating sedimentation aild filterii�g (straining) while limiting erosion. Berms ar check dams may be incorporated into grass swales to reduce velocities and encourage settling and infiltration. When using ber�ns, an underdrain system should be provided. Grass swales are an integral part of the Low Impact Development (LID) concept and may be used as an alternative to a curb and gutter system. Site Selection �-1a►� � ', E � �� x1 �;� i I �� ' ' �� �Y �'�' �� �`,'- i fi � � '¢ ��, , � � i� r � �' . � �� - � � " '�� d' .. �� n;� � r, ..�1 .�' ; 4 � �L �•' �,.�� �._ } g ��: a �, � . i�.:!�.V�4 � '-� _ F�-w _ .:�-w ` :, . �yr1�R+dlYswe�:n, . �i: `=, � ' - -- � �r4 -. �3�; ti_ • � - _. � Photobraph GS-1. This grass swale provides h�eahnent of roadway runoff in a residential area. Photo courtesy of Bill Ruzzo. Grass swales are well suited for sites with low to moderate slopes. Drop structures or other features designed to provide the same function as a drop structures (e.g., a driveway with a stabilized grade differential at the downstream end) can be integrated into the design to enable use of this BMP at a broader range of site coi�ditioils. Grass swales provide conveyance so they can also be used to replace curb and gutter systems making them well suited for roadway projecis. Designing for Maintenance Recommended ongoing maintenance practices fior all BMPs are provided in Chapter 6 of this manual. During design, the following should be considered to ensure ease of ir►aintenance over the long-term: ■ Consider the use as�d function of other site features so that the swale fits into the landscape in a natural way. This cai� encourage upkeep of the area, which is particularly important in residential areas where a loss of aesthetics and/or function can lead to homeowners filling in and/or piping reaches of this BMP. Grass Swale Functions LID/Volume Red. Yes WQCV Ca ture No WQCV+FIood Control No Fact Sheet Includes EURV Guidance No Typical Ef%ctiveness %r Targeted Pollutants3 Sediment/Solicls Good Nutrients Moderate Total Meta(s Good Bacteria Poor Other Considerations Life-cycle Costs Low � Based piiinarily on data from the International StoiTnwater BMP Database (www.bmpdatabase.org). November 2010 Urban Drainage and Flood Control District GS-1 Urban Storm Drainage Criteria Manual Voluine 3 1 ��1 ■ Provide access to the swale for mowing equipment and design sideslopes flat enough far the safe operation of equipinent. ■ Design and adjust the irrigation system (temporary or permanent) to provide appropriate water far the selected vegetation. ■ An underdrain systein wi]] reduce excessively wet areas, which can cause ruttii�g and damage to the vegetation during mowing operations. ■ When using an underdrain, do not put a filter sock on the pipe. This is unnecessary and can cause the slots ar perforations in the pipe to clog. Design Procedure and Criteria The following steps outline the design procedure and criteria for stormwater treatment in a grass swale. Figure CS-I shows trapezoida] and triangular swale configurations. Grass Swale Benefits ■ Removal of sediment and associated constituents through filtering (straining) ■ Reduces length of storm sewer systems in the upper partions of a watershed ■ Provides a less expensive and mare attractive conveyance element ■ Reduces directly connected impervious area and can help reduce runoff volumes. Limitations ■ Requires more area than traditional storm sewers. 1. 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°Io. ihe Run�off Chapter in Volume 1. ■ Erosion problems may occur if not 2. Hydraulic Residence Time: Increased hydraulic designed and constructed resideilce tiine 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 tiine. 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 ar 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 exceedin� 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 �-1a►� 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 mare natural look is desirable. Tlus 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-tenn (for establishment) and ]ong-term maintenance requirements, given that some varieties have higher maintenance requirements than others. Follow criteria in the Revegetation Chapter of Volume 2, with regard to seed mix selection, planting, and ground preparation. Native grasses provide a more natural aesthetic and require less water once established. 6. Design Velocity: Maximum flow velocity in the swale should not exceed one foot per second. Use the Soil Coilservation 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 froin sod, curve "D" (low retardance) should be used. When starting vegetation from seed, use t�he 'B" curve (very low vegetal retardance). 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 reducrioil even when the geometry ofi 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. ' Al[hough Kentucky bluegrass has relatively high irrigation requirements to maintain a lush, green aesthetic, it also wiYhsfands drought conditions by going doimant. Over-irrigation ol 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 Voluine 3 1 ��1 Grass Swale 8. Underdrain: An underdrain is necessary for swales with longitudinal slopes less than 2.0°Io. The underdrain can drain directly into an inlet box at tl�e 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 reyuired, this layer is not required. The aggregate layer should consist of an 8-inch thick layer of CDOT Class C filter material meetii�g the gradarion in Table GS-2. Use of CDOT Class C Filter material with a slotted pipe that ineets 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 contiilues to provide an acceptable alterilative 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 S uare Mesl� Sieves 19.0 mm (3/4") 100 4.75 inm (No. 4) 60 — 100 300 m(No. 50) 10 — 30 150 µm (No. 100) 0— 10 75 um (No. 200) 0- 3 Table GS-3. Dimensions for Slotted Pipe Slot Maximum Slot Slot O en Area� Pipe Diameter , , p 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 leilgth 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 �-1a►� Soil preparation: Poor soi] 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 sui�ace elevation. This will improve infiltration and reduce pondi�7g. 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, srockpiled, aild then replaced just priar to seeding ar 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 far vegetation to thrive, as well as to enable infiltration of runoff. ] 0. 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 susceptibiliry 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 practices that enable the BMP to function as designed. Construction considerations include: ■ Perform fine grading, soil amendment, and seeding only after upgradient surfaces have been stabilized and utility wark crossing the swale has been coinpleted. ■ Avoid compaction of soils to preserve infiltration capacities. ■ Provide irrigation appropriate to the grass type. ■ Weed the area during the establislunent of vegetation by hand or mowing. Mechanical weed control is preferred over chemical weed killer. ■ Protect the swale fro�n other coilstruction activities. �ARKING ON SWALE -��� -- _ .�_ Photograph CS-2. This community used signage to mitigate coiropaction of soils post- construction. Photo courtesy of Nancy Sryles. ■ 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 Voluine 3 1 ��1 RESIDUAL CAPACITY FOR �;� LARCER FLOODS 2-YR WSE 6" MI YR)<1.0 FPS r:; -,� i . 4�� (MIN) SANDY LOAM ' � 1'" MIN 12" MIN BOTTOM WIDTH (W) ��� � � ` � ✓,;�;�RESIDUAL CAPACITY FOR I"> LARGER FLOODS ��! X ' J 12' MIN. 2-YR WSE �«-� 6" MIN �[� r'�'xt._ T I I 4' MIN. SANDY LOAM Q t" MIN. D (2oYR) 1.0 FPS ���N TRIANGULAR SWALE SECTION NTS GRADE CONTROL STRUCTURE BEYOND • GRADE CONTROL STRUCTURE BEYONO O UNDERDRAIN AND SANDY LOAM RECOMMENDED FOR LONGITUDINAL SLOPES < 2.OX. 4" SLOTTED PIPE MEEfING TABLE GS-3 WfTH CDOT CLASS C FILTER MATERIAL ALL AROUND OR PERFORATED HDPE PIPE WITH AASHTO �67 ALL AROUND CONTAINED WITHIN GEOTEXTILE FABRIC. ASTM D4751-A05 US STD. SIEVE (�50 TO �70, ASTM D4533 MIN. TRAPEZOIDAL TEAR STRENGTH 100 X 60 LBS, MINIMUM COE SPECIFIED OPEN AREA QF 445. CONCRETE COLLAR i i ENERGY GRADE CONTROL EXTEND GRADE CONTRO� DISSIPATION __ STRUCTURE � STRUCTURES INTO THE •.,�;., i - BANK A MIN. 0.5' i�, ,� � ABOVE THE 2-YR WSE �"`^��. _. . . . _ .. :r'G � ,..,,�v... , , , . . I I PROVIDE DOUBLE CLEANOUTS L� 1�: �.. WITH WATER TIGHT CAPS �150' � O.C. USE 90' SWEEP OR (Z) 45' BENDS (OFFSET FROM SWALE UNDER�RAIN CENTERUNE TO AVOID IMPEOING 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.udfcd.or�. This section provides a completed design form from this workbook as an example. �� 4 MIN. Grass Swale �1 4 MIN. GS-6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 NORTHERNENGINEERING.COM � 970.221.4158 SWMP: SNOW RIDGEAPARTMENTS FORT COLLINS � GREELEY APPENDIX / � NORTHERNENGINEERING.COM � 970.221.4158 FORT COLLINS � GREELEY �� SWMP: SNOW RIDGEAPARTMENTS APPENDIX NORTHERNENGINEERING.COM � 970.221.4158 SWMP: SNOW RIDGEAPARTMENTS FORT COLLINS � 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) 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) 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) 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) 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) 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) 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) 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) 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) 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 NORTHERNENGINEERING.COM � 970.221.4158 SWMP: SNOW RIDGEAPARTMENTS FORT COLLINS � GREELEY APPENDIX NORTHERNENGINEERING.COM � 970.221.4158 SWMP: SNOW RIDGEAPARTMENTS FORT COLLINS � GREELEY APPENDIX