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HomeMy WebLinkAboutTHE LANDING AT LEMAY MULTIFAMILY AND MIXED-USE - FDP230020 - SUBMITTAL DOCUMENTS - ROUND 3 - DRAINAGE REPORT FINAL DRAINAGE REPORT THE LANDING AT LEMAY FORT COLLINS, CO January 10, 2024 Owner: Thompson Thrift Residential Planner: Ripley Design, Inc. 970.224.5828 Design Engineer: Avant Civil Group 970.286.7995 AVANTCIVILGROUP.COM FORT COLLINS, CO 80525 ii January 10, 2024 City of Fort Collins Stormwater Utility 700 Wood Street Fort Collins, CO 80521 RE: FINAL DRAINAGE REPORT FOR THE LANDING AT LEMAY Dear Staff: Avant Civil Group is pleased to submit this Final Drainage Report for The Landing at Lemay for your review. This report accompanies the FDP 02 submittal for the project. This report has been prepared in accordance with the Fort Collins Stormwater Criteria Manual (FCSCM) and serves to document the stormwater impacts associated with the proposed Landing at Lemay project. We understand that review by the City of Fort Collins is to ensure general compliance with FCSCM drainage criteria. If you should have any questions as you review this report, please feel free to contact us. Sincerely, AVANT CIVIL GROUP Austin Snow, PE Project Engineer iii Engineer Certification: “I hereby attest that this report for the Final drainage design of The Landing at Lemay was prepared by me, or under my direct supervision, in accordance with the provisions of the FCSCM. I understand that the City of Fort Collins does not and shall not assume liability for drainage facilities designed by others.” Austin Snow, PE State of Colorado License No. 53340 01/10/2024 iv Table of Contents General Location and Description .................................................................................................................................................................. 1 Location................................................................................................................................................................................................................ 1 Description of Property .................................................................................................................................................................................. 1 Existing Conditions ...................................................................................................................................................................................... 2 Drainage Basins ..................................................................................................................................................................................................... 2 Major Basin Description ................................................................................................................................................................................. 2 Sub-Basin Description .................................................................................................................................................................................... 2 Drainage Design Criteria .................................................................................................................................................................................... 3 Optional Provisions.......................................................................................................................................................................................... 3 Stormwater Management Strategy ........................................................................................................................................................... 3 Development Criteria Reference and Constraints ............................................................................................................................... 3 Hydrologic Design Criteria ........................................................................................................................................................................... 4 Hydraulic Design Criteria............................................................................................................................................................................... 4 Conformance with Water Quality Treatment Criteria ........................................................................................................................ 4 Conformance with Low Impact Development (LID) Requirements .............................................................................................. 4 Sizing of LID and WQ Facilities ................................................................................................................................................................... 4 Rain Gardens ................................................................................................................................................................................................. 4 Stormtech Chambers .................................................................................................................................................................................. 5 Water Quality ................................................................................................................................................................................................ 5 Drainage Facility Design ................................................................................................................................................................................ 5 General Proposed Concept(s) ................................................................................................................................................................. 5 Sub-Basin Descriptions .............................................................................................................................................................................. 6 Detention Details .............................................................................................................................................................................................. 7 Conclusions ............................................................................................................................................................................................................. 8 v Compliance With Standards ......................................................................................................................................................................... 8 Drainage Concepts .......................................................................................................................................................................................... 8 References................................................................................................................................................................................................................ 9 APPENDIX A – HYDROLOGIC CALCULATIONS ................................................................................................................................................. A APPENDIX B – HYDRAULIC CALCULATIONS .................................................................................................................................................... B APPENDIX C – LID AND WATER QUALITY ...................................................................................................................................................... C APPENDIX D – USDA SOILS REPORT .............................................................................................................................................................. D APPENDIX E – FEMA FIRMETTE ........................................................................................................................................................................ E APPENDIX F – DRAINAGE EXHIBIT .................................................................................................................................................................... F 1 General Location and Description Location The Landing at Lemay project site is located in a tract of land located in the Northwest Quarter of Section 7, Township 7 North, Range 68 West of the 6th Principal Meridian, City of Fort Collins, County of Larimer, State of Colorado. Figure 1 - Site Location The project site (see Figure 1) is bordered to the north by open space and E Vine Drive, to the east by Cordova Road and industrial buildings, to the south by The Cottages of Fort Collins, and to the west by South Lemay Avenue. There is existing storm drainage infrastructure that was constructed with the Cottage of Fort Collins. Description of Property The Landing at Lemay is comprised of 28.19 acres. The site is currently comprised of undeveloped open space. The project site resides in the City of Fort Collins Dry Creek Master Drainage Basin. The detention requirements and release rates of the subject area were considered in the design of the detention ponds for 2 The Landing at Lemay and have been factored into the LID requirements, which are described in further detail throughout this report. The proposed development will consist of ten (10) multi-family residential buildings containing 336 units with on-site and street parking, and a clubhouse. The proposed land use is multi-family, which is a permitted land use for this area. Exis ng Condi ons The existing on-site runoff generally drains from the Northwest to the Southeast across flat grades (e.g., 0.50% - 2.00%) towards the intersection of Duff Drive and Cordova Road. According to the United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) Soil Survey website: (http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx), the site consists primarily of Caruso Clay Loam (Hydrologic Soil Group D). Groundwater was found to be present approximately 7-10 feet below existing ground elevations. Proposed site development will maintain a minimum of 2 feet between existing groundwater levels and proposed ground levels. The highest amount of cut on the site occurs where the proposed detention ponds will be placed. Table 1 - Groundwater Elevations vs. Proposed Elevations Pond 1 Pond 2 Existing Ground Elevation 4940.80 4941.15 Groundwater Elevation 4932.80 4932.15 Proposed Elevation 4936.40 4935.00 Floodplain The entirety of the site is located in a FEMA moderate-risk floodplain zone. There are no special floodplain considerations required regarding finished floor elevations of building footprints. A floodplain use permit will be required prior to construction for any work in the floodplain. Drainage Basins Major Basin Description The project area of The Landing at Lemay is located within the City of Fort Collins Dry Creek Drainage Basin. Detention requirements for this basin are to detain the difference between the 100-yr developed inflow rate and the historic 2-year release rate. However, outflow from this property is limited by release rates determined for the Dry Creek Basin which are 0.2 cfs/acre. Sub-Basin Description The outfall for the project site is at the south end of the project site to existing storm infrastructure in Duff 3 Drive. The existing subject site can be defined with 13 distinct drainage basins (see DR1 in the provided map pocket). The existing site runoff generally drains from Northwest to Southeast towards proposed Cordova Road. The project area receives offsite runoff from the northeast. This is accounted for in the drainage design for this project site. Drainage Design Criteria Optional Provisions There are no optional provisions outside of the FCSCM proposed with Landing at Lemay. Stormwater Management Strategy The overall stormwater management strategy employed with The Landing at Lemay utilizes the “Four Step Process” to minimize adverse impacts of urbanization on receiving waters. The following is a description of how the proposed development has incorporated each step. Step 1 – Employ Runoff Reduction Practices. The first consideration taken in trying to reduce the stormwater impacts of this development is the site selection itself. By choosing an already developed site with public storm sewer currently in place, the burden is significantly less than developing a vacant parcel absent of any infrastructure. The Landing at Lemay aims to reduce runoff peaks, volumes and pollutant loads from frequently occurring storm events (i.e., water quality (i.e., 80th percentile) and 2-year storm events) by implementing Low Impact Development (LID) strategies. Wherever practical, runoff will be routed across landscaped areas or through a rain garden or water quality pond. These LID practices reduce the overall amount of impervious area, while at the same time Minimizing Directly Connected Impervious Areas (MDCIA). The combined LID/MDCIA techniques will be implemented, where practical, throughout the development, thereby slowing runoff and increasing opportunities for infiltration. Step 2 – Implement BMPs that Provide a Water Quality Capture Volume (WQCV) with Slow Release. The efforts taken in Step 1 will help to minimize excess runoff from frequently occurring storm events; however, urban development of this intensity will still have stormwater runoff leaving the site. The primary water quality treatment will occur between several rain gardens between major parking areas of the property and the existing detention ponds installed for Impala Redevelopment. Step 3 – Stabilize Drainageways. While not directly applicable to this site, the project will pay one-time stormwater development fees as well as ongoing monthly stormwater utility fees, both of which help achieve citywide drainageway stability. Step 4 – Implement Site Specific and Other Source Control BMPs. This step typically applies to industrial and commercial developments. Development Criteria Reference and Constraints The subject property is not part of an overall development plan. The project area is constrained to the west 4 by N Lemay Avenue, to the north by undeveloped open space, to the east by industrial buildings, and to south by The Cottages of Fort Collins. Hydrologic Design Criteria The City of Fort Collins Rainfall Intensity-Duration-Frequency Curves, as depicted in Figure 3.4-1 of the FCSCM, serve as the source for all hydrologic computations associated with The Landing at Lemay project. Tabulated data contained in Table 3.4-1 has been utilized for Rational Method runoff calculations. The Rational Method has been used to estimate peak developed stormwater runoff from drainage basins within the developed site for the 2-year, 10-year, and 100-year design storms. Peak runoff discharges determined using this methodology will be used to check the street capacities, inlets, swales, and storm drain lines at final design. Two separate design storms have been utilized to address distinct drainage scenarios. The first event analyzed is the “Minor,” or “Initial” Storm, which has a 2-year recurrence interval. The second event considered is the “Major Storm,” which has a 100-year recurrence interval. Hydraulic Design Criteria The drainage facilities proposed with The Landing at Lemay project are designed in accordance with criteria outlined in the FCSCM. As stated above, the subject property is located within a FEMA moderate-risk floodplain, but is not located within a City regulated floodplain. There are no formal modifications outside of the FCSCM proposed with Landing at Lemay. Conformance with Water Quality Treatment Criteria City Code requires that 100% of runoff from new or modified areas in a project site shall receive some sort of water quality treatment, of which a majority of the site is receiving. Each proposed drainage basin features or drains to an LID facility to treat runoff for water quality. All onsite basins will receive water quality treatment either via a rain garden or detention pond. There are also two offsite basins that flow directly onsite that will be treated for water quality. Both proposed detention ponds will be equipped with outlet structures and appropriately sized water quality structures to treat runoff from basins that flow directly into the ponds. Conformance with Low Impact Development (LID) Requirements The project site will conform with the requirement to treat a minimum of 75% of new or modified impervious area using a LID technique. The proposed project site will treat approximately 88% of modified area with LID. Five rain gardens and a bank of Stormtech chambers are responsible for treating a majority of the impervious area on the site. Sizing of LID and WQ Facilities Rain Gardens The rain gardens were sized by first determining the required water quality capture volume (WQCV) for 5 Sub-Basins A-D and M. Once the WQCV was identified, the rain garden area was sized for its respective WQCV. The rain gardens will be constructed with a biomedia filter and underdrain. An overflow inlet and spillway will be provided to provide safe conveyance of storms greater than the WQCV. Stormtech Chambers Stormtech chambers were used where rain gardens were not feasible due to available space – Sub-Basin E in this instance. The chambers were sized by first determining the required WQCV for the basin. Once the WQCV was identified, the chamber area was sized for its respective WQCV. The chambers will be constructed with stone beds/backfill and underdrain. Overflows will spill directly into the downstream detention pond. Table 2 - LID Summary LID Summary per LID Structure LID ID Area Weighted % Impervious Subbasin ID Treatment Type Volume per UD- BMP (ft3) Impervious Area (ft2) Sq. Ft. Acres Rain Garden A 98,840 2.27 62% A Rain Garden 1,653 61,281 Rain Garden B 66,289 1.52 78% B Rain Garden 1,361 51,705 Rain Garden C 172,098 3.95 48% C Rain Garden 2,305 84,832 Rain Garden D 68,833 1.58 66% D Rain Garden 1,183 45,430 Chambers E 171,002 3.93 61% E Chambers 2,714 104,311 Rain Garden M 107,554 2.47 79% M Rain Garden 2,310 82,743 Total 684,469 15.71 431,080 Water Quality WQCV was calculated for the site using UDFCD equations – Pond 1 does not treat for water quality; Pond 2 provides the remaining water quality treatment for the site after accounting for water quality volumes in LID facilities. Drainage Facility Design General Proposed Concept(s) The main objective of The Landing at Lemay drainage design is to maintain existing drainage patterns, while not adversely impacting adjacent properties. All storm drains on the site (which will be a private utility) have been designed to convey 100-yr flows except for Storm 3, which runs NW-SE through the middle of the site. Due to a general lack of cover/slope through the site, Storm 3 has been designed to 6 convey the 10-year flows from the contributing area; additional flows above the 10-year storm will be conveyed via surface drainage southeast through the site and directly into Pond 2. Sub-Basin Descrip ons Drainage for the project site has been analyzed using 16 drainage sub-basins, designated as sub-basins A-N and OS1. Sub-basins A-N are on-site basins. OS1 is an off-site basins whose flows are collected in Detention Pond 2. Sub-Basin A Sub-Basin A is composed of multi-family residential rooftops, paved roadways, and a clubhouse and pool. Flows from this basin travel via overland flow and curb and gutter flow to Rain Garden A where they are treated for water quality. Sub-Basin B Sub-Basin B contains multi-family residential rooftops, garages, paved roadways, and a dog park. These flows travel via overland flow and curb and gutter flow to Rain Garden B where they are treated for water quality. From here, flows are routed to Detention Pond 1. Sub-Basin C Sub-Basin C is composed of multi-family residential rooftops, paved roadways and parking lots, Rain Garden C and Detention Pond 2. Runoff travels via overland flow and curb and gutter to Rain Garden C, which treats these flows for water quality. Runoff will then be routed to Detention Pond 2 and then will be released via proposed outlet structure to existing storm drain offsite. Sub-Basin D Sub-Basin D consists of multi-family residential rooftops, paved roadways, parking, open space, and Rain Garden D. Runoff travels via overland flow, curb and gutter, and storm pipe to Rain Garden D where it is treated for water quality. Rain Garden D then releases to Detention Pond 2. Overflows from Sub-Basin D are conveyed via surface drainage to Sub-Basin C and Pond 2. Sub-Basin E Sub-Basin E contains multi-family residential rooftops, garages, paved roadways and parking, Rain Garden E, and Detention Pond 1. Flows from this basin travel via overland flow, curb and gutter northeast towards a curb cut that conveys flows to Rain Garden E. After being treated for water quality, these flows continue into Detention Pond 1 which outfalls into Detention Pond 2 (ponds in series), then to existing storm drain infrastructure offsite. Sub-Basin F-K Sub-Basins F-K are composed of a paved roadway on the southeast side of the proposed multifamily development. Sub-basins F and G are not treated for water quality via a rain garden, but are directed into Detention Pond 2, where they will be treated for water quality before they are released offsite. Sub-basins H and I are captured and routed to Rain Garden C for water quality treatment before continuing to Detention Pond 2. Sub-basins J and K are captured and routed 7 directly to Detention Pond 1 where they will be treated for water quality before they are routed offsite. Sub-Basin L Sub-Basin L contains multi-family residential rooftops and open space. Flows from this basin travel via overland flow into area inlets, where they are conveyed to Detention Pond 2 via storm drains. Sub-Basin M Sub-Basin M contains multi-family residential, garages, paved roadways and parking, and Rain Garden M. Flows from this basin travel via overland flow and curb and gutter to the center of the site where a curb cut conveys flows to Rain Garden E. After being treated for water quality, these flows continue into Detention Pond 2 which outfalls to existing storm drain infrastructure offsite. Overflows from Sub-Basin M are conveyed via surface drainage to Sub-Basin D. Sub-Basin N Sub-Basin N contains open space and walkways. Flows from this basin travel via overland flow and a swale/concrete pan south towards an inlet that conveys flows via storm drain to Detention Pond 2. Sub-Basin OS1 Sub-Basin OS1 is composed of open space to the northwest of the proposed project site. The natural landscape of this basin directs flow onto the project site and for this reason, they will be routed through the site in a proposed swale with concrete pan. These flows are then captured in a storm pipe and directed to Detention Pond 2. Detention Details There are 2 proposed detention ponds on the project site that will detain up to the 100-year storm event and release at or below the allowed historic release for the Dry Creek Basin. See Table 2 for detention summary. Table 3 - Detention Summary POND SUMMARY TABLE Pond ID Tributary Area (Ac)1 Weighted % Imperviousness (%) Extended Detention WQCV (Cu. Ft.)2 100-Yr. Detention Vol. (Ac-Ft) 100-Yr. Detention WSEL(Ft) Peak Release (cfs)3 Pond 1 6.29 67 Provided in Pond 2 1.52 4942.40 1.20 Pond 2 12.91 59 6,231 2.94 4941.60 2.40 Notes: 1. Tributary area shown does not include off-site basin(s) 2. WQCV calculated minus RG/Chamber volume; will be provded in Pond 2 3. Overall site release rate of 3.6 cfs divided between Ponds 1 and 2 8 Detention Ponds 1 and 2 will be constructed in series; Pond 1 will capture flows from sub-basins B, E, J, and K. Pond 2 will capture flows from sub-basins A, C, D, F, G, H, I, L, M, N, and OS1. The site has a previously established allowed release rate of 3.6 cfs based on the master drainage basin; Pond 1 will release at 1.2 cfs, and Pond 2 will release at 2.4 cfs. Both Pond 1 and Pond 2 utilize outlet structures to achieve the desired release rate; the outfall pipe into existing storm infrastructure for Pond 2 features a 2nd inlet/spill point downstream of the outlet structure which has been set at the 100-year WSEL of Pond 1 (which is higher in elevation than the 100-year WSEL of Pond 2) and will act as the overflow point for Pond 1. That inlet has been sized to intercept the combined release rate for Ponds 1 and 2 (3.6 cfs). LID treatment is being provided within rain gardens and underground chambers. These treat approximately 84% of the modified site impervious runoff, which is more than the required 75% LID treatment. Please see the LID exhibit and calculations in Appendix C. All required water quality volume (after accounting for LID) will be provided in Pond 2. The detention allowable release rate is based on the allowed release rate from the Dry Creek Basin, which is 0.2 cfs/acre. Stormwater facility Standard Operations Procedures (SOP) will be provided by the City of Fort Collins in the Development Agreement. Conclusions Compliance With Standards The drainage design proposed with The Landing at Lemay complies with the City of Fort Collins Master Drainage Plan for the Canal Importation Basin. The drainage plan and stormwater management measures proposed with The Landing at Lemay project are compliant with all applicable State and Federal regulations governing stormwater discharge. Drainage Concepts The drainage plan and stormwater management measures proposed with The Landing at Lemay project are compliant with all applicable regulations governing stormwater discharge. The Landing at Lemay will not impact the Master Drainage Plan recommendations for the Fort Collins Dry Creek Major Drainage Basin. 9 References 1. Fort Collins Stormwater Criteria Manual, City of Fort Collins, Colorado, as adopted by Ordinance No. 159, 2018, and referenced in Section 26-500 of the City of Fort Collins Municipal Code. 2. Soils Resource Report for Larimer County Area, Colorado, Natural Resources Conservation Service, United States Department of Agriculture. 3. Urban Storm Drainage Criteria Manual, Volumes 1-3, Urban Drainage and Flood Control District, Wright- McLaughlin Engineers, Denver, Colorado, Revised April 2008. A APPENDIX A – HYDROLOGIC CALCULATIONS B APPENDIX B – HYDRAULIC CALCULATIONS C APPENDIX C – LID AND WATER QUALITY iv Table of Contents General Location and Description .................................................................................................................................................................. 1 Location................................................................................................................................................................................................................ 1 Description of Property .................................................................................................................................................................................. 1 Existing Conditions ...................................................................................................................................................................................... 2 Drainage Basins ..................................................................................................................................................................................................... 2 Major Basin Description ................................................................................................................................................................................. 2 Sub-Basin Description .................................................................................................................................................................................... 2 Drainage Design Criteria .................................................................................................................................................................................... 3 Optional Provisions.......................................................................................................................................................................................... 3 Stormwater Management Strategy ........................................................................................................................................................... 3 Development Criteria Reference and Constraints ............................................................................................................................... 3 Hydrologic Design Criteria ........................................................................................................................................................................... 4 Hydraulic Design Criteria............................................................................................................................................................................... 4 Conformance with Water Quality Treatment Criteria ........................................................................................................................ 4 Conformance with Low Impact Development (LID) Requirements .............................................................................................. 4 Sizing of LID and WQ Facilities ................................................................................................................................................................... 4 Rain Gardens ................................................................................................................................................................................................. 4 Stormtech Chambers .................................................................................................................................................................................. 5 Water Quality ................................................................................................................................................................................................ 5 Drainage Facility Design ................................................................................................................................................................................ 5 General Proposed Concept(s) ................................................................................................................................................................. 5 Sub-Basin Descriptions .............................................................................................................................................................................. 6 Detention Details .............................................................................................................................................................................................. 7 Conclusions ............................................................................................................................................................................................................. 8 v Compliance With Standards ......................................................................................................................................................................... 8 Drainage Concepts .......................................................................................................................................................................................... 8 References................................................................................................................................................................................................................ 9 APPENDIX A – HYDROLOGIC CALCULATIONS ................................................................................................................................................. A APPENDIX B – HYDRAULIC CALCULATIONS .................................................................................................................................................... B APPENDIX C – LID AND WATER QUALITY ...................................................................................................................................................... C APPENDIX D – USDA SOILS REPORT .............................................................................................................................................................. D APPENDIX E – FEMA FIRMETTE ........................................................................................................................................................................ E APPENDIX F – DRAINAGE EXHIBIT .................................................................................................................................................................... F 1 General Location and Description Location The Landing at Lemay project site is located in a tract of land located in the Northwest Quarter of Section 7, Township 7 North, Range 68 West of the 6th Principal Meridian, City of Fort Collins, County of Larimer, State of Colorado. Figure 1 - Site Location The project site (see Figure 1) is bordered to the north by open space and E Vine Drive, to the east by Cordova Road and industrial buildings, to the south by The Cottages of Fort Collins, and to the west by South Lemay Avenue. There is existing storm drainage infrastructure that was constructed with the Cottage of Fort Collins. Description of Property The Landing at Lemay is comprised of 28.19 acres. The site is currently comprised of undeveloped open space. The project site resides in the City of Fort Collins Dry Creek Master Drainage Basin. The detention requirements and release rates of the subject area were considered in the design of the detention ponds for 2 The Landing at Lemay and have been factored into the LID requirements, which are described in further detail throughout this report. The proposed development will consist of ten (10) multi-family residential buildings containing 336 units with on-site and street parking, and a clubhouse. The proposed land use is multi-family, which is a permitted land use for this area. Exis ng Condi ons The existing on-site runoff generally drains from the Northwest to the Southeast across flat grades (e.g., 0.50% - 2.00%) towards the intersection of Duff Drive and Cordova Road. According to the United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) Soil Survey website: (http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx), the site consists primarily of Caruso Clay Loam (Hydrologic Soil Group D). Groundwater was found to be present approximately 7-10 feet below existing ground elevations. Proposed site development will maintain a minimum of 2 feet between existing groundwater levels and proposed ground levels. The highest amount of cut on the site occurs where the proposed detention ponds will be placed. Table 1 - Groundwater Elevations vs. Proposed Elevations Pond 1 Pond 2 Existing Ground Elevation 4940.80 4941.15 Groundwater Elevation 4932.80 4932.15 Proposed Elevation 4936.40 4935.00 Floodplain The entirety of the site is located in a FEMA moderate-risk floodplain zone. There are no special floodplain considerations required regarding finished floor elevations of building footprints. A floodplain use permit will be required prior to construction for any work in the floodplain. Drainage Basins Major Basin Description The project area of The Landing at Lemay is located within the City of Fort Collins Dry Creek Drainage Basin. Detention requirements for this basin are to detain the difference between the 100-yr developed inflow rate and the historic 2-year release rate. However, outflow from this property is limited by release rates determined for the Dry Creek Basin which are 0.2 cfs/acre. Sub-Basin Description The outfall for the project site is at the south end of the project site to existing storm infrastructure in Duff 3 Drive. The existing subject site can be defined with 13 distinct drainage basins (see DR1 in the provided map pocket). The existing site runoff generally drains from Northwest to Southeast towards proposed Cordova Road. The project area receives offsite runoff from the northeast. This is accounted for in the drainage design for this project site. Drainage Design Criteria Optional Provisions There are no optional provisions outside of the FCSCM proposed with Landing at Lemay. Stormwater Management Strategy The overall stormwater management strategy employed with The Landing at Lemay utilizes the “Four Step Process” to minimize adverse impacts of urbanization on receiving waters. The following is a description of how the proposed development has incorporated each step. Step 1 – Employ Runoff Reduction Practices. The first consideration taken in trying to reduce the stormwater impacts of this development is the site selection itself. By choosing an already developed site with public storm sewer currently in place, the burden is significantly less than developing a vacant parcel absent of any infrastructure. The Landing at Lemay aims to reduce runoff peaks, volumes and pollutant loads from frequently occurring storm events (i.e., water quality (i.e., 80th percentile) and 2-year storm events) by implementing Low Impact Development (LID) strategies. Wherever practical, runoff will be routed across landscaped areas or through a rain garden or water quality pond. These LID practices reduce the overall amount of impervious area, while at the same time Minimizing Directly Connected Impervious Areas (MDCIA). The combined LID/MDCIA techniques will be implemented, where practical, throughout the development, thereby slowing runoff and increasing opportunities for infiltration. Step 2 – Implement BMPs that Provide a Water Quality Capture Volume (WQCV) with Slow Release. The efforts taken in Step 1 will help to minimize excess runoff from frequently occurring storm events; however, urban development of this intensity will still have stormwater runoff leaving the site. The primary water quality treatment will occur between several rain gardens between major parking areas of the property and the existing detention ponds installed for Impala Redevelopment. Step 3 – Stabilize Drainageways. While not directly applicable to this site, the project will pay one-time stormwater development fees as well as ongoing monthly stormwater utility fees, both of which help achieve citywide drainageway stability. Step 4 – Implement Site Specific and Other Source Control BMPs. This step typically applies to industrial and commercial developments. Development Criteria Reference and Constraints The subject property is not part of an overall development plan. The project area is constrained to the west 4 by N Lemay Avenue, to the north by undeveloped open space, to the east by industrial buildings, and to south by The Cottages of Fort Collins. Hydrologic Design Criteria The City of Fort Collins Rainfall Intensity-Duration-Frequency Curves, as depicted in Figure 3.4-1 of the FCSCM, serve as the source for all hydrologic computations associated with The Landing at Lemay project. Tabulated data contained in Table 3.4-1 has been utilized for Rational Method runoff calculations. The Rational Method has been used to estimate peak developed stormwater runoff from drainage basins within the developed site for the 2-year, 10-year, and 100-year design storms. Peak runoff discharges determined using this methodology will be used to check the street capacities, inlets, swales, and storm drain lines at final design. Two separate design storms have been utilized to address distinct drainage scenarios. The first event analyzed is the “Minor,” or “Initial” Storm, which has a 2-year recurrence interval. The second event considered is the “Major Storm,” which has a 100-year recurrence interval. Hydraulic Design Criteria The drainage facilities proposed with The Landing at Lemay project are designed in accordance with criteria outlined in the FCSCM. As stated above, the subject property is located within a FEMA moderate-risk floodplain, but is not located within a City regulated floodplain. There are no formal modifications outside of the FCSCM proposed with Landing at Lemay. Conformance with Water Quality Treatment Criteria City Code requires that 100% of runoff from new or modified areas in a project site shall receive some sort of water quality treatment, of which a majority of the site is receiving. Each proposed drainage basin features or drains to an LID facility to treat runoff for water quality. All onsite basins will receive water quality treatment either via a rain garden or detention pond. There are also two offsite basins that flow directly onsite that will be treated for water quality. Both proposed detention ponds will be equipped with outlet structures and appropriately sized water quality structures to treat runoff from basins that flow directly into the ponds. Conformance with Low Impact Development (LID) Requirements The project site will conform with the requirement to treat a minimum of 75% of new or modified impervious area using a LID technique. The proposed project site will treat approximately 88% of modified area with LID. Five rain gardens and a bank of Stormtech chambers are responsible for treating a majority of the impervious area on the site. Sizing of LID and WQ Facilities Rain Gardens The rain gardens were sized by first determining the required water quality capture volume (WQCV) for 5 Sub-Basins A-D and M. Once the WQCV was identified, the rain garden area was sized for its respective WQCV. The rain gardens will be constructed with a biomedia filter and underdrain. An overflow inlet and spillway will be provided to provide safe conveyance of storms greater than the WQCV. Stormtech Chambers Stormtech chambers were used where rain gardens were not feasible due to available space – Sub-Basin E in this instance. The chambers were sized by first determining the required WQCV for the basin. Once the WQCV was identified, the chamber area was sized for its respective WQCV. The chambers will be constructed with stone beds/backfill and underdrain. Overflows will spill directly into the downstream detention pond. Table 2 - LID Summary LID Summary per LID Structure LID ID Area Weighted % Impervious Subbasin ID Treatment Type Volume per UD- BMP (ft3) Impervious Area (ft2) Sq. Ft. Acres Rain Garden A 98,840 2.27 62% A Rain Garden 1,653 61,281 Rain Garden B 66,289 1.52 78% B Rain Garden 1,361 51,705 Rain Garden C 172,098 3.95 48% C Rain Garden 2,305 84,832 Rain Garden D 68,833 1.58 66% D Rain Garden 1,183 45,430 Chambers E 171,002 3.93 61% E Chambers 2,714 104,311 Rain Garden M 107,554 2.47 79% M Rain Garden 2,310 82,743 Total 684,469 15.71 431,080 Water Quality WQCV was calculated for the site using UDFCD equations – Pond 1 does not treat for water quality; Pond 2 provides the remaining water quality treatment for the site after accounting for water quality volumes in LID facilities. Drainage Facility Design General Proposed Concept(s) The main objective of The Landing at Lemay drainage design is to maintain existing drainage patterns, while not adversely impacting adjacent properties. All storm drains on the site (which will be a private utility) have been designed to convey 100-yr flows except for Storm 3, which runs NW-SE through the middle of the site. Due to a general lack of cover/slope through the site, Storm 3 has been designed to 6 convey the 10-year flows from the contributing area; additional flows above the 10-year storm will be conveyed via surface drainage southeast through the site and directly into Pond 2. Sub-Basin Descrip ons Drainage for the project site has been analyzed using 16 drainage sub-basins, designated as sub-basins A-N and OS1. Sub-basins A-N are on-site basins. OS1 is an off-site basins whose flows are collected in Detention Pond 2. Sub-Basin A Sub-Basin A is composed of multi-family residential rooftops, paved roadways, and a clubhouse and pool. Flows from this basin travel via overland flow and curb and gutter flow to Rain Garden A where they are treated for water quality. Sub-Basin B Sub-Basin B contains multi-family residential rooftops, garages, paved roadways, and a dog park. These flows travel via overland flow and curb and gutter flow to Rain Garden B where they are treated for water quality. From here, flows are routed to Detention Pond 1. Sub-Basin C Sub-Basin C is composed of multi-family residential rooftops, paved roadways and parking lots, Rain Garden C and Detention Pond 2. Runoff travels via overland flow and curb and gutter to Rain Garden C, which treats these flows for water quality. Runoff will then be routed to Detention Pond 2 and then will be released via proposed outlet structure to existing storm drain offsite. Sub-Basin D Sub-Basin D consists of multi-family residential rooftops, paved roadways, parking, open space, and Rain Garden D. Runoff travels via overland flow, curb and gutter, and storm pipe to Rain Garden D where it is treated for water quality. Rain Garden D then releases to Detention Pond 2. Overflows from Sub-Basin D are conveyed via surface drainage to Sub-Basin C and Pond 2. Sub-Basin E Sub-Basin E contains multi-family residential rooftops, garages, paved roadways and parking, Rain Garden E, and Detention Pond 1. Flows from this basin travel via overland flow, curb and gutter northeast towards a curb cut that conveys flows to Rain Garden E. After being treated for water quality, these flows continue into Detention Pond 1 which outfalls into Detention Pond 2 (ponds in series), then to existing storm drain infrastructure offsite. Sub-Basin F-K Sub-Basins F-K are composed of a paved roadway on the southeast side of the proposed multifamily development. Sub-basins F and G are not treated for water quality via a rain garden, but are directed into Detention Pond 2, where they will be treated for water quality before they are released offsite. Sub-basins H and I are captured and routed to Rain Garden C for water quality treatment before continuing to Detention Pond 2. Sub-basins J and K are captured and routed 7 directly to Detention Pond 1 where they will be treated for water quality before they are routed offsite. Sub-Basin L Sub-Basin L contains multi-family residential rooftops and open space. Flows from this basin travel via overland flow into area inlets, where they are conveyed to Detention Pond 2 via storm drains. Sub-Basin M Sub-Basin M contains multi-family residential, garages, paved roadways and parking, and Rain Garden M. Flows from this basin travel via overland flow and curb and gutter to the center of the site where a curb cut conveys flows to Rain Garden E. After being treated for water quality, these flows continue into Detention Pond 2 which outfalls to existing storm drain infrastructure offsite. Overflows from Sub-Basin M are conveyed via surface drainage to Sub-Basin D. Sub-Basin N Sub-Basin N contains open space and walkways. Flows from this basin travel via overland flow and a swale/concrete pan south towards an inlet that conveys flows via storm drain to Detention Pond 2. Sub-Basin OS1 Sub-Basin OS1 is composed of open space to the northwest of the proposed project site. The natural landscape of this basin directs flow onto the project site and for this reason, they will be routed through the site in a proposed swale with concrete pan. These flows are then captured in a storm pipe and directed to Detention Pond 2. Detention Details There are 2 proposed detention ponds on the project site that will detain up to the 100-year storm event and release at or below the allowed historic release for the Dry Creek Basin. See Table 2 for detention summary. Table 3 - Detention Summary POND SUMMARY TABLE Pond ID Tributary Area (Ac)1 Weighted % Imperviousness (%) Extended Detention WQCV (Cu. Ft.)2 100-Yr. Detention Vol. (Ac-Ft) 100-Yr. Detention WSEL(Ft) Peak Release (cfs)3 Pond 1 6.29 67 Provided in Pond 2 1.52 4942.40 1.20 Pond 2 12.91 59 6,231 2.94 4941.60 2.40 Notes: 1. Tributary area shown does not include off-site basin(s) 2. WQCV calculated minus RG/Chamber volume; will be provded in Pond 2 3. Overall site release rate of 3.6 cfs divided between Ponds 1 and 2 8 Detention Ponds 1 and 2 will be constructed in series; Pond 1 will capture flows from sub-basins B, E, J, and K. Pond 2 will capture flows from sub-basins A, C, D, F, G, H, I, L, M, N, and OS1. The site has a previously established allowed release rate of 3.6 cfs based on the master drainage basin; Pond 1 will release at 1.2 cfs, and Pond 2 will release at 2.4 cfs. Both Pond 1 and Pond 2 utilize outlet structures to achieve the desired release rate; the outfall pipe into existing storm infrastructure for Pond 2 features a 2nd inlet/spill point downstream of the outlet structure which has been set at the 100-year WSEL of Pond 1 (which is higher in elevation than the 100-year WSEL of Pond 2) and will act as the overflow point for Pond 1. That inlet has been sized to intercept the combined release rate for Ponds 1 and 2 (3.6 cfs). LID treatment is being provided within rain gardens and underground chambers. These treat approximately 84% of the modified site impervious runoff, which is more than the required 75% LID treatment. Please see the LID exhibit and calculations in Appendix C. All required water quality volume (after accounting for LID) will be provided in Pond 2. The detention allowable release rate is based on the allowed release rate from the Dry Creek Basin, which is 0.2 cfs/acre. Stormwater facility Standard Operations Procedures (SOP) will be provided by the City of Fort Collins in the Development Agreement. Conclusions Compliance With Standards The drainage design proposed with The Landing at Lemay complies with the City of Fort Collins Master Drainage Plan for the Canal Importation Basin. The drainage plan and stormwater management measures proposed with The Landing at Lemay project are compliant with all applicable State and Federal regulations governing stormwater discharge. Drainage Concepts The drainage plan and stormwater management measures proposed with The Landing at Lemay project are compliant with all applicable regulations governing stormwater discharge. The Landing at Lemay will not impact the Master Drainage Plan recommendations for the Fort Collins Dry Creek Major Drainage Basin. 9 References 1. Fort Collins Stormwater Criteria Manual, City of Fort Collins, Colorado, as adopted by Ordinance No. 159, 2018, and referenced in Section 26-500 of the City of Fort Collins Municipal Code. 2. Soils Resource Report for Larimer County Area, Colorado, Natural Resources Conservation Service, United States Department of Agriculture. 3. Urban Storm Drainage Criteria Manual, Volumes 1-3, Urban Drainage and Flood Control District, Wright- McLaughlin Engineers, Denver, Colorado, Revised April 2008. A APPENDIX A – HYDROLOGIC CALCULATIONS CHARACTER OF SURFACE1: Percentage Impervious 2-yr Runoff Coefficient 100-yr Runoff Coefficient Developed Asphalt .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………100% 0.95 1.00 Concrete .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………100% 0.95 1.00 Rooftop .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………90% 0.95 1.00 Gravel .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………40% 0.50 0.63 Pavers .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………40% 0.50 0.63 Landscape or Pervious Surface Playgrounds .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………25% 0.35 0.44 Lawns Clayey Soil .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………2% 0.25 0.31 Lawns Sandy Soil .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………2%0.15 0.19 Notes: Basin ID Basin Area (ac) Area of Asphalt (ac) Area of Concrete (ac) Area of Rooftop (ac) Area of Gravel (ac) Area of Pavers (ac) Area of Playgrounds (ac) Area of Lawns (ac) Composite % Imperv. 2-year Composite Runoff Coefficient 100-year Composite Runoff Coefficient A 2.269 0.780 0.181 0.485 0.00 0.00 0.00 0.823 62% 0.70 0.88 B 1.522 0.771 0.09 0.359 0.00 0.00 0.00 0.300 78% 0.81 1.00 C 3.951 1.040 0.21 0.662 0.00 0.00 0.00 2.040 48% 0.59 0.74 D 1.580 0.409 0.17 0.504 0.00 0.00 0.00 0.499 66% 0.73 0.91 E 3.926 1.431 0.34 0.644 0.00 0.00 0.00 1.507 61% 0.68 0.85 F 0.120 0.088 0.00 0.000 0.00 0.00 0.00 0.032 74% 0.76 0.95 G 0.151 0.083 0.02 0.000 0.00 0.00 0.00 0.053 66% 0.70 0.88 H 0.314 0.268 0.00 0.000 0.00 0.00 0.00 0.047 85% 0.85 1.00 I 0.449 0.329 0.00 0.000 0.00 0.00 0.00 0.120 74% 0.76 0.95 J 0.349 0.222 0.04 0.000 0.00 0.00 0.00 0.085 76% 0.78 0.98 K 0.494 0.359 0.00 0.000 0.00 0.00 0.00 0.135 73% 0.76 0.95 L 0.637 0.000 0.06 0.332 0.00 0.00 0.00 0.244 57% 0.68 0.85 M 2.469 1.061 0.27 0.682 0.00 0.00 0.00 0.458 79% 0.82 1.00 N 0.967 0.029 0.08 0.000 0.861 13% 0.33 0.41 OS1 0.906 0.000 0.00 0.000 0.00 0.00 0.00 0.906 2% 0.25 0.31 Detention Pond 1 (B, E, J, K) 6.291 2.782 0.478 1.003 0.000 0.000 0.000 2.028 67% 0.72 0.90 Detention Pond 2 (A, C, D, F, G, H, I, L, M, N)12.908 4.086 0.980 2.665 0.000 0.000 0.000 5.177 59% 0.67 0.83 DEVELOPED BASIN % IMPERVIOUSNESS AND RUNOFF COEFFICIENT CALCULATIONS 2) Runoff Coefficients are taken from the Fort Collins Stormwater Criteria Manual, Chapter 3. Table 3.2-1 and 3.2-2 1) Percentage impervious taken from the Fort Collins Stormwater Criteria Manual, Chapter 5, Table 4.1-2 and Table 4.1-3 Combined Basins Rational Method Equation: Rainfall Intensity: a 2.27 5.0 0.88 2.85 4.87 9.95 4.53 7.74 19.75 b 1.52 5.7 1.00 2.76 4.72 9.63 3.40 5.81 14.65 c 3.95 5.2 0.74 2.85 4.87 9.95 6.64 11.35 28.99 d 1.58 5.0 0.91 2.85 4.87 9.95 3.29 5.62 14.35 e 3.93 5.0 0.85 2.85 4.87 9.95 7.61 13.00 33.20 f 0.12 5.0 0.95 2.85 4.87 9.95 0.26 0.44 1.13 g 0.15 5.0 0.88 2.85 4.87 9.95 0.30 0.52 1.32 h 0.31 5.0 1.00 2.85 4.87 9.95 0.76 1.30 3.13 i 0.45 5.0 0.95 2.85 4.87 9.95 0.97 1.66 4.24 j 0.35 5.0 0.98 2.85 4.87 9.95 0.78 1.33 3.39 k 0.49 5.0 0.95 2.85 4.87 9.95 1.07 1.83 4.67 l 0.64 5.0 0.85 2.85 4.87 9.95 1.24 2.11 5.39 m 2.47 5.0 1.00 2.85 4.87 9.95 5.77 9.86 24.57 n 0.97 10.0 0.41 2.21 3.78 7.72 0.71 1.21 3.08 DEVELOPED RUNOFF COMPUTATIONS Design Point Area, A (acres) Flow, Q2 (cfs) Flow, Q100 (cfs) C100 IDF Table for Rational Method - Table 3.4-1 FCSCM Intensity, i10 (in/hr) Flow, Q10 (cfs) Tc100 (min) Intensity, i2 (in/hr) Intensity, i100 (in/hr) ()()()AiCCQf= Overland Flow, Time of Concentration: Channelized Flow, Time of Concentration: UPDATE Total Time of Concentration : T c is the lesser of the values of Tc calculated using T c = T i + T t C2 Length, L (ft) Ti2 Length, L (ft) Roughness Coefficient Velocity, V (ft/s) Tt (min) Tc (Eq. 3.3-5) Tc2 = Ti +Tt Tc100 = Ti +Tt Tc2 Tc100 a 0.70 25 2.8 402 0.015 2.53 2.7 12.4 5.4 4.2 5.4 5.0 b 0.81 192 9.2 351 0.015 2.34 2.5 13.0 11.7 5.7 11.7 5.7 c 0.59 26 3.9 286 0.015 1.98 2.4 11.7 6.3 5.2 6.3 5.2 d 0.73 25 2.7 75 0.015 3.46 0.4 10.6 3.1 1.7 5.0 5.0 e 0.68 64 4.3 149 0.015 3.74 0.7 11.2 4.9 3.2 5.0 5.0 f 0.76 25 2.4 107 0.015 1.97 0.9 10.7 3.3 2.0 5.0 5.0 g 0.70 26 2.8 77 0.038 0.72 1.8 10.6 4.6 3.4 5.0 5.0 h 0.85 26 1.9 196 0.015 2.07 1.6 11.2 3.5 2.4 5.0 5.0 i 0.76 26 2.4 203 0.015 1.81 1.9 11.3 4.2 2.9 5.0 5.0 j 0.78 26 2.3 198 0.015 1.87 1.8 11.2 4.0 2.6 5.0 5.0 k 0.76 26 2.4 201 0.015 1.83 1.8 11.3 4.3 2.9 5.0 5.0 l 0.68 26 2.8 0.015 N/A N/A 10.1 2.8 1.7 5.0 5.0 m 0.82 25 2.3 474 0.015 4.88 1.6 12.8 3.9 3.0 5.0 5.0 n 0.33 38 7.1 824 0.015 3.70 3.7 14.8 10.8 10.0 10.8 10.0 DEVELOPED DIRECT TIME OF CONCENTRATION Channelized Flow Design Point Overland Flow Time of Concentration Frequency Adjustment Factor: (Equation 3.3-2 (Equation 5-5 FCSCM) (Equation 5-4 FCSCM) (Equation 3.3-5 Table 3.2- 3 FCSCM Notes: 1) Add 4900 to all elevations. 2) Per Fort Collins Stormwater Manual, minimum Tc = 5 min. 3) Assume a water depth of 6" and a typical curb and gutter per Larimer County Urban Street Standard Detail 701 for curb and gutter channelized flow. Assume a water depth of 1', fixed side slopes, and a triangular swale section for grass channelized flow. Assume a water depth of 1', 4:1 side slopes, and a 2' wide valley pan for channelized flow in a valley pan. B APPENDIX B – HYDRAULIC CALCULATIONS Project: 1791-003 By: ARS Date: 9/27/23 Pond ID Tributary Area (Ac)1 Weighted % Imperviousness (%) Extended Detention WQCV (Cu. Ft.)2 100-Yr. Detention Vol. (Ac-Ft) 100-Yr. Detention WSEL(Ft) Peak Release (cfs)3 Pond 1 6.29 67 Provided in Pond 2 1.52 4942.40 1.20 Pond 2 12.91 59 6,231 2.94 4941.60 2.40 Notes: 1. Tributary area shown does not include off-site basin(s) 2. WQCV calculated minus RG/Chamber volume; will be provded in Pond 2 3. Overall site release rate of 3.6 cfs divided between Ponds 1 and 2 POND SUMMARY TABLE POND 1 Project: Basin ID: Depth Increment = 0.20 ft Watershed Information Top of Micropool -- 0.00 -- -- -- 3 0.000 Selected BMP Type =EDB -- 0.20 -- -- -- 155 0.004 16 0.000 Watershed Area = 6.29 acres -- 0.40 -- -- -- 618 0.014 93 0.002 Watershed Length = 1,168 ft -- 0.60 -- -- -- 1,170 0.027 272 0.006 Watershed Length to Centroid = 550 ft -- 0.80 -- -- -- 1,976 0.045 586 0.013 Watershed Slope = 0.009 ft/ft -- 1.00 -- -- -- 3,029 0.070 1,087 0.025 Watershed Imperviousness = 67.00% percent -- 1.20 -- -- --4,273 0.098 1,817 0.042 Percentage Hydrologic Soil Group A = 0.0% percent -- 1.40 -- -- -- 5,892 0.135 2,834 0.065 Percentage Hydrologic Soil Group B = 0.0% percent -- 1.60 -- -- -- 7,788 0.179 4,202 0.096 Percentage Hydrologic Soil Groups C/D = 100.0% percent -- 1.80 -- -- -- 9,376 0.215 5,918 0.136 Target WQCV Drain Time = 40.0 hours -- 2.00 -- -- -- 10,558 0.242 7,911 0.182 Location for 1-hr Rainfall Depths = User Input -- 2.20 -- -- -- 11,585 0.266 10,126 0.232 -- 2.40 -- -- -- 12,385 0.284 12,523 0.287 -- 2.60 -- -- -- 13,087 0.300 15,070 0.346 Optional User Overrides -- 2.80 -- -- -- 13,800 0.317 17,759 0.408 Water Quality Capture Volume (WQCV) = 0.137 acre-feet acre-feet -- 3.00 -- -- -- 14,524 0.333 20,591 0.473 Excess Urban Runoff Volume (EURV) = 0.408 acre-feet acre-feet -- 3.20 -- -- -- 15,262 0.350 23,570 0.541 2-yr Runoff Volume (P1 = 0.82 in.) = 0.267 acre-feet 0.82 inches -- 3.40 -- -- -- 16,013 0.368 26,697 0.613 5-yr Runoff Volume (P1 = 1.14 in.) = 0.410 acre-feet 1.14 inches -- 3.60 -- -- -- 16,759 0.385 29,974 0.688 10-yr Runoff Volume (P1 = 1.4 in.) = 0.543 acre-feet 1.40 inches -- 3.80 -- -- -- 17,483 0.401 33,399 0.767 25-yr Runoff Volume (P1 = 1.81 in.) = 0.778 acre-feet 1.81 inches -- 4.00 -- -- -- 18,197 0.418 36,967 0.849 50-yr Runoff Volume (P1 = 2.27 in.) = 1.031 acre-feet 2.27 inches -- 4.20 -- -- -- 18,910 0.434 40,677 0.934 100-yr Runoff Volume (P1 = 2.86 in.) = 1.370 acre-feet 2.86 inches -- 4.40 -- -- -- 19,627 0.451 44,531 1.022 500-yr Runoff Volume (P1 = 4.39 in.) = 2.237 acre-feet 4.39 inches -- 4.60 -- -- -- 20,328 0.467 48,526 1.114 Approximate 2-yr Detention Volume = 0.252 acre-feet --4.80 -- -- -- 21,007 0.482 52,660 1.209 Approximate 5-yr Detention Volume = 0.391 acre-feet --5.00 -- -- -- 21,693 0.498 56,930 1.307 Approximate 10-yr Detention Volume = 0.471 acre-feet -- 5.20 -- -- -- 22,386 0.514 61,338 1.408 Approximate 25-yr Detention Volume = 0.568 acre-feet 100 YR WSEL -- 5.40 -- -- -- 28,932 0.664 66,470 1.526 Approximate 50-yr Detention Volume = 0.651 acre-feet -- -- -- -- Approximate 100-yr Detention Volume = 0.797 acre-feet -- -- -- -- -- -- -- -- Define Zones and Basin Geometry -- -- -- -- Zone 1 Volume (User Defined) = 1.520 acre-feet -- -- -- -- Select Zone 2 Storage Volume (Optional) = acre-feet -- -- -- -- Select Zone 3 Storage Volume (Optional) = acre-feet -- -- -- -- Total Detention Basin Volume = 1.520 acre-feet -- -- -- -- Initial Surcharge Volume (ISV) = user ft 3 -- -- -- -- Initial Surcharge Depth (ISD) = user ft -- -- -- -- Total Available Detention Depth (Htotal) =user ft -- -- -- -- Depth of Trickle Channel (HTC) =user ft -- -- -- -- Slope of Trickle Channel (STC) =user ft/ft -- -- -- -- Slopes of Main Basin Sides (Smain) =user H:V -- -- -- -- Basin Length-to-Width Ratio (RL/W) =user -- -- -- -- -- -- -- -- Initial Surcharge Area (AISV) =user ft 2 -- -- -- -- Surcharge Volume Length (LISV) =user ft -- -- -- -- Surcharge Volume Width (WISV) =user ft -- -- -- -- Depth of Basin Floor (HFLOOR) =user ft -- -- -- -- Length of Basin Floor (LFLOOR) =user ft -- -- -- -- Width of Basin Floor (WFLOOR) =user ft -- -- -- -- Area of Basin Floor (AFLOOR) =user ft 2 -- -- -- -- Volume of Basin Floor (VFLOOR) =user ft 3 -- -- -- -- Depth of Main Basin (HMAIN) =user ft -- -- -- -- Length of Main Basin (LMAIN) =user ft -- -- -- -- Width of Main Basin (WMAIN) =user ft -- -- -- -- Area of Main Basin (AMAIN) =user ft 2 -- -- -- -- Volume of Main Basin (VMAIN) =user ft 3 -- -- -- -- Calculated Total Basin Volume (Vtotal) =user acre-feet -- -- -- -- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- DETENTION BASIN STAGE-STORAGE TABLE BUILDER Optional Override Area (ft 2) Length (ft) Optional Override Stage (ft) Stage (ft) Stage - Storage Description Area (ft 2) Width (ft) Landing at Lemay Pond 1 MHFD-Detention, Version 4.06 (July 2022) Volume (ft 3) Volume (ac-ft) Area (acre) After providing required inputs above including 1-hour rainfall depths, click 'Run CUHP' to generate runoff hydrographs using the embedded Colorado Urban Hydrograph Procedure. Example Zone Configuration (Retention Pond) MHFD-Detention_v4-06 - Pond 1, Basin 9/26/2023, 1:36 PM 1 User Defined Stage-Area Booleans for Message 1 Equal Stage-Area Inputs Watershed L:W 1 CountA Watershed Lc:L Watershed Slope 0 Calc_S_TC Booleans for CUHP 1 CUHP Inputs Complete H_FLOOR 1 CUHP Results Calculated L_FLOOR_OTHER 0.00 ISV 0.00 ISV 0.00 Floor 0.00 Floor 5.40 Zone 1 (User) 5.40 Zone 1 (User) 0.00 Zone 2 0.00 Zone 2 0.00 Zone 3 0.00 Zone 3 DETENTION BASIN STAGE-STORAGE TABLE BUILDER MHFD-Detention, Version 4.06 (July 2022) 0.000 0.385 0.770 1.155 1.540 0.000 0.170 0.340 0.510 0.680 0.00 1.50 3.00 4.50 6.00 Vo l u m e ( a c - f t ) Ar e a ( a c r e s ) Stage (ft.) Area (acres)Volume (ac-ft) 0 7300 14600 21900 29200 0 5 10 15 20 0.00 1.50 3.00 4.50 6.00 Ar e a ( s q . f t . ) Le n g t h , W i d t h ( f t . ) Stage (ft) Length (ft)Width (ft)Area (sq.ft.) MHFD-Detention_v4-06 - Pond 1, Basin 9/26/2023, 1:36 PM Project: Basin ID: Estimated Estimated Stage (ft) Volume (ac-ft) Outlet Type Zone 1 (User) 5.40 1.520 Weir&Pipe (Circular) Zone 2 Zone 3 Total (all zones) 1.520 User Input: Orifice at Underdrain Outlet (typically used to drain WQCV in a Filtration BMP)Calculated Parameters for Underdrain Underdrain Orifice Invert Depth = N/A ft (distance below the filtration media surface) Underdrain Orifice Area = N/A ft2 Underdrain Orifice Diameter = N/A inches Underdrain Orifice Centroid = N/A feet User Input: Orifice Plate with one or more orifices or Elliptical Slot Weir (typically used to drain WQCV and/or EURV in a sedimentation BMP)Calculated Parameters for Plate Centroid of Lowest Orifice = N/A ft (relative to basin bottom at Stage = 0 ft) WQ Orifice Area per Row = N/A ft2 Depth at top of Zone using Orifice Plate = N/A ft (relative to basin bottom at Stage = 0 ft) Elliptical Half-Width = N/A feet Orifice Plate: Orifice Vertical Spacing = N/A inches Elliptical Slot Centroid = N/A feet Orifice Plate: Orifice Area per Row = N/A sq. inches Elliptical Slot Area = N/A ft2 User Input: Stage and Total Area of Each Orifice Row (numbered from lowest to highest) Row 1 (optional) Row 2 (optional) Row 3 (optional) Row 4 (optional) Row 5 (optional) Row 6 (optional) Row 7 (optional) Row 8 (optional) Stage of Orifice Centroid (ft) N/A N/A N/A N/A N/A N/A N/A N/A Orifice Area (sq. inches) N/A N/A N/A N/A N/A N/A N/A N/A Row 9 (optional) Row 10 (optional) Row 11 (optional) Row 12 (optional) Row 13 (optional) Row 14 (optional) Row 15 (optional) Row 16 (optional) Stage of Orifice Centroid (ft) N/A N/A N/A N/A N/A N/A N/A N/A Orifice Area (sq. inches) N/A N/A N/A N/A N/A N/A N/A N/A User Input: Vertical Orifice (Circular or Rectangular)Calculated Parameters for Vertical Orifice Not Selected Not Selected Not Selected Not Selected Invert of Vertical Orifice = 0.00 ft (relative to basin bottom at Stage = 0 ft) Vertical Orifice Area = 0.05 ft2 Depth at top of Zone using Vertical Orifice = 1.00 ft (relative to basin bottom at Stage = 0 ft) Vertical Orifice Centroid = 0.13 feet Vertical Orifice Diameter = 3.00 inches User Input: Overflow Weir (Dropbox with Flat or Sloped Grate and Outlet Pipe OR Rectangular/Trapezoidal Weir and No Outlet Pipe) Calculated Parameters for Overflow Weir grate Zone 1 Weir Not Selected Zone 1 Weir Not Selected Overflow Weir Front Edge Height, Ho = 1.00 ft (relative to basin bottom at Stage = 0 ft)Height of Grate Upper Edge, Ht =2.00 feet Overflow Weir Front Edge Length = 4.00 feet Overflow Weir Slope Length = 4.12 feet Overflow Weir Grate Slope = 4.00 H:V Grate Open Area / 100-yr Orifice Area = 241.05 Horiz. Length of Weir Sides = 4.00 feet Overflow Grate Open Area w/o Debris = 13.05 ft2 Overflow Grate Type = Close Mesh Grate Overflow Grate Open Area w/ Debris = 6.52 ft2 Debris Clogging % = 50% % User Input: Outlet Pipe w/ Flow Restriction Plate (Circular Orifice, Restrictor Plate, or Rectangular Orifice)Calculated Parameters for Outlet Pipe w/ Flow Restriction Plate Zone 1 Circular Not Selected Zone 1 Circular Not Selected Depth to Invert of Outlet Pipe = 18.00 ft (distance below basin bottom at Stage = 0 ft)Outlet Orifice Area = 0.05 ft2 Circular Orifice Diameter = 3.15 inches Outlet Orifice Centroid = 0.13 feet Half-Central Angle of Restrictor Plate on Pipe = N/A N/A radians User Input: Emergency Spillway (Rectangular or Trapezoidal)Calculated Parameters for Spillway Spillway Invert Stage= 5.40 ft (relative to basin bottom at Stage = 0 ft) Spillway Design Flow Depth= 0.47 feet Spillway Crest Length = 15.00 feet Stage at Top of Freeboard = 6.47 feet Spillway End Slopes = 5.00 H:V Basin Area at Top of Freeboard = 0.66 acres Freeboard above Max Water Surface = 0.60 feet Basin Volume at Top of Freeboard = 1.53 acre-ft Max Ponding Depth of Target Storage Volume =5.40 feet Discharge at Top of Freeboard = 1.26 cfs Routed Hydrograph Results Design Storm Return Period =WQCV EURV 2 Year 5 Year 10 Year 25 Year 50 Year 100 Year 500 Year One-Hour Rainfall Depth (in) =N/A N/A 0.82 1.14 1.40 1.81 2.27 2.86 4.39 CUHP Runoff Volume (acre-ft) =0.137 0.408 0.267 0.410 0.543 0.778 1.031 1.370 2.237 Inflow Hydrograph Volume (acre-ft) =N/A N/A 0.267 0.410 0.543 0.778 1.031 1.370 2.237 CUHP Predevelopment Peak Q (cfs) =N/A N/A 0.0 0.5 1.2 3.1 4.7 7.0 12.5 OPTIONAL Override Predevelopment Peak Q (cfs) =N/A N/A 1.2 Predevelopment Unit Peak Flow, q (cfs/acre) =N/A N/A 0.01 0.08 0.19 0.49 0.74 0.19 1.98 Peak Inflow Q (cfs) =N/A N/A 3.0 4.7 6.2 9.5 12.5 16.6 26.7 Peak Outflow Q (cfs) =1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.3 Ratio Peak Outflow to Predevelopment Q =N/A N/A N/A 2.4 1.0 0.4 0.3 1.0 0.1 Structure Controlling Flow =Outlet Plate 1 Outlet Plate 1 Outlet Plate 1 Outlet Plate 1 Outlet Plate 1 Outlet Plate 1 Outlet Plate 1 Outlet Plate 1 N/A Max Velocity through Grate 1 (fps) =0.07 0.06 0.07 0.1 0.1 0.1 0.1 0.1 0.1 Max Velocity through Grate 2 (fps) =N/A N/A N/A N/A N/A N/A N/A N/A N/A Time to Drain 97% of Inflow Volume (hours) =3 5 4 6 7 9 11 14 22 Time to Drain 99% of Inflow Volume (hours) =3 6 5 6 7 10 12 15 23 Maximum Ponding Depth (ft) =1.81 2.81 1.68 2.19 2.61 3.31 3.93 4.68 5.40 Area at Maximum Ponding Depth (acres) =0.22 0.32 0.19 0.26 0.30 0.36 0.41 0.47 0.66 Maximum Volume Stored (acre-ft) =0.138 0.411 0.111 0.230 0.346 0.577 0.820 1.152 1.526 DETENTION BASIN OUTLET STRUCTURE DESIGN MHFD-Detention, Version 4.06 (July 2022) Landing at Lemay Pond 1 The user can override the default CUHP hydrographs and runoff volumes by entering new values in the Inflow Hydrographs table (Columns W through AF). Example Zone Configuration (Retention Pond) MHFD-Detention_v4-06 - Pond 1, Outlet Structure 9/26/2023, 1:49 PM COUNTA for Basin Tab = 1 Ao Dia WQ Plate Type Vert Orifice 1Vert Orifice 2 Count_Underdrain = 0 0.11(diameter = 3/8 inch)1 2 1 Count_WQPlate = 0 0.14(diameter = 7/16 inch) Count_VertOrifice1 = 1 0.18(diameter = 1/2 inch)Outlet Plate 1 Outlet Plate 2 Drain Time Message Boolean Count_VertOrifice2 = 0 0.24(diameter = 9/16 inch)2 1 5yr, <72hr 0 Count_Weir1 = 1 0.29(diameter = 5/8 inch)>5yr, <120hr 0 Count_Weir2 = 0 0.36(diameter = 11/16 inch)Max Depth Row Count_OutletPipe1 = 1 0.42(diameter = 3/4 inch)WQCV 182 Count_OutletPipe2 = 0 0.50(diameter = 13/16 inch)2 Year 169 COUNTA_2 (Standard FSD Setup)= 0 0.58(diameter = 7/8 inch)EURV 282 Hidden Parameters & Calculations 0.67(diameter = 15/16 inch)5 Year 220 MaxPondDepth_Error? FALSE 0.76 (diameter = 1 inch)10 Year 262 Spillway Depth Cd_Broad-Crested Weir 3.00 0.86(diameter = 1-1/16 inches)25 Year 332 0.47 WQ Plate Flow at 100yr depth = 0.00 0.97(diameter = 1-1/8 inches)50 Year 394 CLOG #1= 50% 1.08(diameter = 1-3/16 inches)100 Year 469 1 Z1_Boolean n*Cdw #1 = 0.44 1.20(diameter = 1-1/4 inches)500 Year 541 1 Z2_Boolean n*Cdo #1 = 1.83 1.32(diameter = 1-5/16 inches)Zone3_Pulldown Message 1 Z3_Boolean Overflow Weir #1 Angle = 0.245 1.45(diameter = 1-3/8 inches)1 Opening Message CLOG #2= 100% 1.59(diameter = 1-7/16 inches)Draintime Running n*Cdw #2 = 0.00 1.73(diameter = 1-1/2 inches)Outlet Boolean Outlet Rank Total (1 to 4) n*Cdo #2 = 0.00 1.88(diameter = 1-9/16 inches)Vertical Orifice 1 1 1 2 Overflow Weir #2 Angle = 0.000 2.03(diameter = 1-5/8 inches)Vertical Orifice 2 0 0 Boolean Underdrain Q at 100yr depth = 0.00 2.20(diameter = 1-11/16 inches)Overflow Weir 1 1 2 0 Max Depth VertOrifice1 Q at 100yr depth = 0.50 2.36(diameter = 1-3/4 inches)Overflow Weir 2 0 0 0 500yr Depth VertOrifice2 Q at 100yr depth = 0.00 2.54(diameter = 1-13/16 inches)Outlet Pipe 1 1 2 1 Freeboard 2.72(diameter = 1-7/8 inches)Outlet Pipe 2 0 0 1 Spillway Count_User_Hydrographs 0 2.90(diameter = 1-15/16 inches)0 Spillway Length CountA_3 (EURV & 100yr) = 1 3.09(diameter = 2 inches)FALSE Time Interval CountA_4 (100yr Only) = 1 3.29(use rectangular openings)Button Visibility Boolean COUNTA_5 (FSD Weir Only)= 0 0 WQCV Underdrain COUNTA_6 (EURV Weir Only)= 1 0 WQCV Plate 0 EURV-WQCV Plate Outlet1_Pulldown_Boolean 0 EURV-WQCV VertOriice Outlet2_Pulldown_Boolean 0 Outlet 90% Qpeak Outlet3_Pulldown_Boolean 1 Outlet Undetained 0 Weir Only 90% Qpeak 0 Five Year Ratio Plate 0 Five Year Ratio VertOrifice EURV_draintime_user Spillway Options Offset Overlapping S-A-V-D Chart Axis Default X-axis Left Y-Axis Right Y-Axis minimum bound 0.00 0 0 maximum bound 8.00 70,000 10 S-A-V-D Chart Axis Override X-axis Left Y-Axis Right Y-Axis minimum bound maximum bound DETENTION BASIN OUTLET STRUCTURE DESIGN MHFD-Detention, Version 4.06 (July 2022) 0 5 10 15 20 25 30 0.1 1 10 FL O W [ c f s ] TIME [hr] 500YR IN 500YR OUT 100YR IN 100YR OUT 50YR IN 50YR OUT 25YR IN 25YR OUT 10YR IN 10YR OUT 5YR IN 5YR OUT 2YR IN 2YR OUT EURV IN EURV OUT WQCV IN WQCV OUT 0 1 2 3 4 5 6 0.1 1 10 100 PO N D I N G D E P T H [ f t ] DRAIN TIME [hr] 500YR 100YR 50YR 25YR 10YR 5YR 2YR EURV WQCV 0 1 2 3 4 5 6 7 8 9 10 0 10,000 20,000 30,000 40,000 50,000 60,000 70,000 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 OU T F L O W [ c f s ] AR E A [ f t ^ 2 ] , V O L U M E [ f t ^ 3 ] PONDING DEPTH [ft] User Area [ft^2] Interpolated Area [ft^2] Summary Area [ft^2] Volume [ft^3] Summary Volume [ft^3] Outflow [cfs] Summary Outflow [cfs] MHFD-Detention_v4-06 - Pond 1, Outlet Structure 9/26/2023, 1:49 PM POND 2 Project: Basin ID: Depth Increment = 0.20 ft Watershed Information Top of Micropool -- 0.00 -- -- -- 166 0.004 Selected BMP Type =EDB -- 0.20 -- -- -- 1,131 0.026 130 0.003 Watershed Area = 12.91 acres -- 0.40 -- -- -- 2,747 0.063 517 0.012 Watershed Length = 1,321 ft -- 0.60 -- -- -- 4,868 0.112 1,279 0.029 Watershed Length to Centroid = 601 ft -- 0.80 -- -- -- 7,520 0.173 2,518 0.058 Watershed Slope = 0.010 ft/ft -- 1.00 -- -- -- 9,804 0.225 4,250 0.098 Watershed Imperviousness = 59.00% percent WQCV -- 1.20 -- -- -- 11,736 0.269 6,404 0.147 Percentage Hydrologic Soil Group A = 0.0% percent -- 1.40 -- -- -- 13,454 0.309 8,923 0.205 Percentage Hydrologic Soil Group B = 0.0% percent -- 1.60 -- -- -- 15,019 0.345 11,770 0.270 Percentage Hydrologic Soil Groups C/D = 100.0% percent -- 1.80 -- -- -- 16,448 0.378 14,917 0.342 Target WQCV Drain Time = 40.0 hours -- 2.00 -- -- -- 17,526 0.402 18,314 0.420 Location for 1-hr Rainfall Depths = User Input -- 2.20 -- -- -- 18,178 0.417 21,885 0.502 -- 2.40 -- -- -- 18,818 0.432 25,584 0.587 -- 2.60 -- -- -- 19,461 0.447 29,412 0.675 Optional User Overrides -- 2.80 -- -- -- 20,109 0.462 33,369 0.766 Water Quality Capture Volume (WQCV) =0.143 acre-feet 0.143 acre-feet -- 3.00 -- -- -- 20,762 0.477 37,456 0.860 Excess Urban Runoff Volume (EURV) = 0.730 acre-feet acre-feet -- 3.20 -- -- -- 21,421 0.492 41,675 0.957 2-yr Runoff Volume (P1 = 0.82 in.) = 0.477 acre-feet 0.82 inches -- 3.40 -- -- -- 22,087 0.507 46,026 1.057 5-yr Runoff Volume (P1 = 1.14 in.) = 0.751 acre-feet 1.14 inches -- 3.60 -- -- -- 22,758 0.522 50,510 1.160 10-yr Runoff Volume (P1 = 1.4 in.) = 1.014 acre-feet 1.40 inches -- 3.80 -- -- -- 23,435 0.538 55,129 1.266 25-yr Runoff Volume (P1 = 1.81 in.) = 1.499 acre-feet 1.81 inches -- 4.00 -- -- -- 24,118 0.554 59,885 1.375 50-yr Runoff Volume (P1 = 2.27 in.) = 2.013 acre-feet 2.27 inches -- 4.20 -- -- -- 24,806 0.569 64,777 1.487 100-yr Runoff Volume (P1 = 2.86 in.) = 2.713 acre-feet 2.86 inches -- 4.40 -- -- -- 25,501 0.585 69,808 1.603 500-yr Runoff Volume (P1 = 4.39 in.) = 4.492 acre-feet 4.39 inches -- 4.60 -- -- -- 26,201 0.601 74,978 1.721 Approximate 2-yr Detention Volume = 0.448 acre-feet --4.80 -- -- -- 26,907 0.618 80,289 1.843 Approximate 5-yr Detention Volume = 0.712 acre-feet --5.00 -- -- -- 27,619 0.634 85,741 1.968 Approximate 10-yr Detention Volume = 0.856 acre-feet -- 5.20 -- -- -- 28,337 0.651 91,337 2.097 Approximate 25-yr Detention Volume = 1.038 acre-feet -- 5.40 -- -- -- 29,061 0.667 97,077 2.229 Approximate 50-yr Detention Volume = 1.193 acre-feet -- 5.60 -- -- -- 29,761 0.683 102,959 2.364 Approximate 100-yr Detention Volume = 1.489 acre-feet -- 5.80 -- -- -- 30,526 0.701 108,988 2.502 -- 6.00 -- -- -- 31,267 0.718 115,167 2.644 Define Zones and Basin Geometry -- 6.20 -- -- -- 32,015 0.735 121,495 2.789 Zone 1 Volume (WQCV) = 0.143 acre-feet -- 6.40 -- -- -- 35,875 0.824 128,284 2.945 Zone 2 Volume (User Defined - Zone 1) = 2.900 acre-feet 100 YR WSEL -- 6.60 -- -- -- 36,931 0.848 135,565 3.112 Select Zone 3 Storage Volume (Optional) = acre-feet -- 6.80 -- -- -- 38,155 0.876 143,073 3.285 Total Detention Basin Volume = 3.043 acre-feet -- 7.00 -- -- -- 39,961 0.917 150,885 3.464 Initial Surcharge Volume (ISV) = user ft 3 -- 7.20 -- -- -- 42,325 0.972 159,114 3.653 Initial Surcharge Depth (ISD) = user ft -- 7.40 -- -- -- 44,849 1.030 167,831 3.853 Total Available Detention Depth (Htotal) = user ft -- 7.60 -- -- -- 47,790 1.097 177,095 4.066 Depth of Trickle Channel (HTC) = user ft -- 7.80 -- -- -- 52,168 1.198 187,091 4.295 Slope of Trickle Channel (STC) = user ft/ft -- 8.00 -- -- -- 52,978 1.216 197,605 4.536 Slopes of Main Basin Sides (Smain) = user H:V -- 8.10 -- -- -- 54,078 1.241 202,958 4.659 Basin Length-to-Width Ratio (RL/W) = user -- -- -- -- -- -- -- -- Initial Surcharge Area (AISV) =user ft 2 -- -- -- -- Surcharge Volume Length (LISV) =user ft -- -- -- -- Surcharge Volume Width (WISV) =user ft -- -- -- -- Depth of Basin Floor (HFLOOR) =user ft -- -- -- -- Length of Basin Floor (LFLOOR) =user ft -- -- -- -- Width of Basin Floor (WFLOOR) =user ft -- -- -- -- Area of Basin Floor (AFLOOR) =user ft 2 -- -- -- -- Volume of Basin Floor (VFLOOR) =user ft 3 -- -- -- -- Depth of Main Basin (HMAIN) =user ft -- -- -- -- Length of Main Basin (LMAIN) =user ft -- -- -- -- Width of Main Basin (WMAIN) =user ft -- -- -- -- Area of Main Basin (AMAIN) =user ft 2 -- -- -- -- Volume of Main Basin (VMAIN) =user ft 3 -- -- -- -- Calculated Total Basin Volume (Vtotal) =user acre-feet -- -- -- -- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- DETENTION BASIN STAGE-STORAGE TABLE BUILDER Optional Override Area (ft 2) Length (ft) Optional Override Stage (ft) Stage (ft) Stage - Storage Description Area (ft 2) Width (ft) Landing at Lemay Pond 2 MHFD-Detention, Version 4.06 (July 2022) Volume (ft 3) Volume (ac-ft) Area (acre) After providing required inputs above including 1-hour rainfall depths, click 'Run CUHP' to generate runoff hydrographs using the embedded Colorado Urban Hydrograph Procedure. ExampleZone Configuration (Retention Pond) MHFD-Detention_v4-06 - Pond 2, Basin 9/26/2023, 1:33 PM 1 User Defined Stage-Area Booleans for Message 1 Equal Stage-Area Inputs Watershed L:W 1 CountA Watershed Lc:L Watershed Slope 0 Calc_S_TC Booleans for CUHP 1 CUHP Inputs Complete H_FLOOR 1 CUHP Results Calculated L_FLOOR_OTHER 0.00 ISV 0.00 ISV 0.00 Floor 0.00 Floor 1.19 Zone 1 (WQCV) 1.19 Zone 1 (WQCV) 6.52 Zone 2 (User) 6.52 Zone 2 (User) 0.00 Zone 3 0.00 Zone 3 DETENTION BASIN STAGE-STORAGE TABLE BUILDER MHFD-Detention, Version 4.06 (July 2022) 0.000 1.165 2.330 3.495 4.660 0.000 0.315 0.630 0.945 1.260 0.00 2.50 5.00 7.50 10.00 Vo l u m e ( a c - f t ) Ar e a ( a c r e s ) Stage (ft.) Area (acres)Volume (ac-ft) 0 13600 27200 40800 54400 0 5 10 15 20 0.00 2.50 5.00 7.50 10.00 Ar e a ( s q . f t . ) Le n g t h , W i d t h ( f t . ) Stage (ft) Length (ft)Width (ft)Area (sq.ft.) MHFD-Detention_v4-06 - Pond 2, Basin 9/26/2023, 1:33 PM Project: Basin ID: Estimated Estimated Stage (ft) Volume (ac-ft) Outlet Type Zone 1 (WQCV) 1.19 0.143 Orifice Plate Zone 2 (User) 6.52 2.900 Weir&Pipe (Circular) Zone 3 Total (all zones) 3.043 User Input: Orifice at Underdrain Outlet (typically used to drain WQCV in a Filtration BMP)Calculated Parameters for Underdrain Underdrain Orifice Invert Depth = N/A ft (distance below the filtration media surface) Underdrain Orifice Area = N/A ft2 Underdrain Orifice Diameter = N/A inches Underdrain Orifice Centroid = N/A feet User Input: Orifice Plate with one or more orifices or Elliptical Slot Weir (typically used to drain WQCV and/or EURV in a sedimentation BMP)Calculated Parameters for Plate Centroid of Lowest Orifice = 0.00 ft (relative to basin bottom at Stage = 0 ft) WQ Orifice Area per Row =6.111E-03 ft2 Depth at top of Zone using Orifice Plate = 1.19 ft (relative to basin bottom at Stage = 0 ft) Elliptical Half-Width = N/A feet Orifice Plate: Orifice Vertical Spacing = 4.76 inches Elliptical Slot Centroid = N/A feet Orifice Plate: Orifice Area per Row = 0.88 sq. inches (diameter = 1-1/16 inches) Elliptical Slot Area = N/A ft2 User Input: Stage and Total Area of Each Orifice Row (numbered from lowest to highest) Row 1 (required) Row 2 (optional) Row 3 (optional) Row 4 (optional) Row 5 (optional) Row 6 (optional) Row 7 (optional) Row 8 (optional) Stage of Orifice Centroid (ft) 0.00 0.40 0.80 Orifice Area (sq. inches) 0.88 0.88 0.88 Row 9 (optional) Row 10 (optional) Row 11 (optional) Row 12 (optional) Row 13 (optional) Row 14 (optional) Row 15 (optional) Row 16 (optional) Stage of Orifice Centroid (ft) Orifice Area (sq. inches) User Input: Vertical Orifice (Circular or Rectangular)Calculated Parameters for Vertical Orifice Not Selected Not Selected Not Selected Not Selected Invert of Vertical Orifice = ft (relative to basin bottom at Stage = 0 ft) Vertical Orifice Area =ft2 Depth at top of Zone using Vertical Orifice = ft (relative to basin bottom at Stage = 0 ft) Vertical Orifice Centroid = feet Vertical Orifice Diameter = inches User Input: Overflow Weir (Dropbox with Flat or Sloped Grate and Outlet Pipe OR Rectangular/Trapezoidal Weir and No Outlet Pipe) Calculated Parameters for Overflow Weir grate Zone 2 Weir Not Selected Zone 2 Weir Not Selected Overflow Weir Front Edge Height, Ho = 1.19 ft (relative to basin bottom at Stage = 0 ft)Height of Grate Upper Edge, Ht =2.19 feet Overflow Weir Front Edge Length = 4.00 feet Overflow Weir Slope Length = 4.12 feet Overflow Weir Grate Slope = 4.00 H:V Grate Open Area / 100-yr Orifice Area = 59.32 Horiz. Length of Weir Sides = 4.00 feet Overflow Grate Open Area w/o Debris = 13.05 ft2 Overflow Grate Type = Close Mesh Grate Overflow Grate Open Area w/ Debris = 6.52 ft2 Debris Clogging % = 50% % User Input: Outlet Pipe w/ Flow Restriction Plate (Circular Orifice, Restrictor Plate, or Rectangular Orifice)Calculated Parameters for Outlet Pipe w/ Flow Restriction Plate Zone 2 Circular Not Selected Zone 2 Circular Not Selected Depth to Invert of Outlet Pipe = 0.00 ft (distance below basin bottom at Stage = 0 ft)Outlet Orifice Area = 0.22 ft2 Circular Orifice Diameter = 6.35 inches Outlet Orifice Centroid = 0.26 feet Half-Central Angle of Restrictor Plate on Pipe = N/A N/A radians User Input: Emergency Spillway (Rectangular or Trapezoidal)Calculated Parameters for Spillway Spillway Invert Stage= 8.10 ft (relative to basin bottom at Stage = 0 ft) Spillway Design Flow Depth= 0.43 feet Spillway Crest Length = 25.00 feet Stage at Top of Freeboard = 9.23 feet Spillway End Slopes = 50.00 H:V Basin Area at Top of Freeboard = 1.24 acres Freeboard above Max Water Surface = 0.70 feet Basin Volume at Top of Freeboard = 4.66 acre-ft Max Ponding Depth of Target Storage Volume =7.58 feet Discharge at Top of Freeboard = 2.96 cfs Routed Hydrograph Results Design Storm Return Period =WQCV EURV 2 Year 5 Year 10 Year 25 Year 50 Year 100 Year 500 Year One-Hour Rainfall Depth (in) =N/A N/A 0.82 1.14 1.40 1.81 2.27 2.86 4.39 CUHP Runoff Volume (acre-ft) =0.143 0.730 0.477 0.751 1.014 1.499 2.013 2.713 4.492 Inflow Hydrograph Volume (acre-ft) =N/A N/A 0.477 0.751 1.014 1.499 2.013 2.713 4.492 CUHP Predevelopment Peak Q (cfs) =N/A N/A 0.1 1.3 3.1 7.7 11.7 17.4 30.9 OPTIONAL Override Predevelopment Peak Q (cfs) =N/A N/A 2.4 Predevelopment Unit Peak Flow, q (cfs/acre) =N/A N/A 0.01 0.10 0.24 0.60 0.90 0.19 2.40 Peak Inflow Q (cfs) =N/A N/A 6.2 9.9 13.4 20.6 27.7 37.3 60.7 Peak Outflow Q (cfs) =0.1 1.7 1.3 1.5 1.7 2.0 2.2 2.4 2.9 Ratio Peak Outflow to Predevelopment Q =N/A N/A N/A 1.2 0.5 0.3 0.2 1.0 0.1 Structure Controlling Flow =Overflow Weir 1 Outlet Plate 1 Outlet Plate 1 Outlet Plate 1 Outlet Plate 1 Outlet Plate 1 Outlet Plate 1 Outlet Plate 1 Outlet Plate 1 Max Velocity through Grate 1 (fps) =N/A 0.12 0.09 0.1 0.1 0.1 0.2 0.2 0.2 Max Velocity through Grate 2 (fps) =N/A N/A N/A N/A N/A N/A N/A N/A N/A Time to Drain 97% of Inflow Volume (hours) =37 36 38 36 35 34 32 31 29 Time to Drain 99% of Inflow Volume (hours) =40 43 44 44 44 44 45 46 48 Maximum Ponding Depth (ft) =1.19 2.73 1.74 2.30 2.81 3.72 4.56 5.59 7.58 Area at Maximum Ponding Depth (acres) =0.27 0.46 0.37 0.42 0.46 0.53 0.60 0.68 1.09 Maximum Volume Stored (acre-ft) =0.144 0.734 0.320 0.540 0.766 1.223 1.691 2.350 4.033 DETENTION BASIN OUTLET STRUCTURE DESIGN MHFD-Detention, Version 4.06 (July 2022) Landing at Lemay Pond 2 The user can override the default CUHP hydrographs and runoff volumes by entering new values in the Inflow Hydrographs table (Columns W through AF). Example Zone Configuration (Retention Pond) MHFD-Detention_v4-06 - Pond 2, Outlet Structure 9/26/2023, 1:44 PM COUNTA for Basin Tab = 1 Ao Dia WQ Plate Type Vert Orifice 1Vert Orifice 2 Count_Underdrain = 0 0.11(diameter = 3/8 inch)2 1 1 Count_WQPlate = 1 0.14(diameter = 7/16 inch) Count_VertOrifice1 = 0 0.18(diameter = 1/2 inch)Outlet Plate 1 Outlet Plate 2 Drain Time Message Boolean Count_VertOrifice2 = 0 0.24(diameter = 9/16 inch)2 1 5yr, <72hr 0 Count_Weir1 = 1 0.29(diameter = 5/8 inch)>5yr, <120hr 0 Count_Weir2 = 0 0.36(diameter = 11/16 inch)Max Depth Row Count_OutletPipe1 = 1 0.42(diameter = 3/4 inch)WQCV 120 Count_OutletPipe2 = 0 0.50(diameter = 13/16 inch)2 Year 175 COUNTA_2 (Standard FSD Setup)= 1 0.58(diameter = 7/8 inch)EURV 274 Hidden Parameters & Calculations 0.67(diameter = 15/16 inch)5 Year 231 MaxPondDepth_Error? FALSE 0.76 (diameter = 1 inch)10 Year 282 Spillway Depth Cd_Broad-Crested Weir 3.00 0.86(diameter = 1-1/16 inches)25 Year 373 0.43 WQ Plate Flow at 100yr depth = 0.20 0.97(diameter = 1-1/8 inches)50 Year 457 CLOG #1= 50% 1.08(diameter = 1-3/16 inches)100 Year 560 1 Z1_Boolean n*Cdw #1 = 0.44 1.20(diameter = 1-1/4 inches)500 Year 759 1 Z2_Boolean n*Cdo #1 = 1.83 1.32(diameter = 1-5/16 inches)Zone3_Pulldown Message 1 Z3_Boolean Overflow Weir #1 Angle = 0.245 1.45(diameter = 1-3/8 inches)1 Opening Message CLOG #2= 100% 1.59(diameter = 1-7/16 inches)Draintime Running n*Cdw #2 = 0.00 1.73(diameter = 1-1/2 inches)Outlet Boolean Outlet Rank Total (1 to 4) n*Cdo #2 = 0.00 1.88(diameter = 1-9/16 inches)Vertical Orifice 1 0 0 1 Overflow Weir #2 Angle = 0.000 2.03(diameter = 1-5/8 inches)Vertical Orifice 2 0 0 Boolean Underdrain Q at 100yr depth = 0.00 2.20(diameter = 1-11/16 inches)Overflow Weir 1 1 1 0 Max Depth VertOrifice1 Q at 100yr depth = 0.00 2.36(diameter = 1-3/4 inches)Overflow Weir 2 0 0 0 500yr Depth VertOrifice2 Q at 100yr depth = 0.00 2.54(diameter = 1-13/16 inches)Outlet Pipe 1 1 1 1 Freeboard 2.72(diameter = 1-7/8 inches)Outlet Pipe 2 0 0 1 Spillway Count_User_Hydrographs 0 2.90(diameter = 1-15/16 inches)0 Spillway Length CountA_3 (EURV & 100yr) = 1 3.09(diameter = 2 inches)FALSE Time Interval CountA_4 (100yr Only) = 1 3.29(use rectangular openings)Button Visibility Boolean COUNTA_5 (FSD Weir Only)= 0 0 WQCV Underdrain COUNTA_6 (EURV Weir Only)= 1 1 WQCV Plate 0 EURV-WQCV Plate Outlet1_Pulldown_Boolean 0 EURV-WQCV VertOriice Outlet2_Pulldown_Boolean 0 Outlet 90% Qpeak Outlet3_Pulldown_Boolean 1 Outlet Undetained 0 Weir Only 90% Qpeak 0 Five Year Ratio Plate 0 Five Year Ratio VertOrifice EURV_draintime_user Spillway Options Offset Overlapping S-A-V-D Chart Axis Default X-axis Left Y-Axis Right Y-Axis minimum bound 0.00 0 0 maximum bound 10.00 210,000 10 S-A-V-D Chart Axis Override X-axis Left Y-Axis Right Y-Axis minimum bound maximum bound DETENTION BASIN OUTLET STRUCTURE DESIGN MHFD-Detention, Version 4.06 (July 2022) 0 10 20 30 40 50 60 70 0.1 1 10 FL O W [ c f s ] TIME [hr] 500YR IN 500YR OUT 100YR IN 100YR OUT 50YR IN 50YR OUT 25YR IN 25YR OUT 10YR IN 10YR OUT 5YR IN 5YR OUT 2YR IN 2YR OUT EURV IN EURV OUT WQCV IN WQCV OUT 0 1 2 3 4 5 6 7 8 0.1 1 10 100 PO N D I N G D E P T H [ f t ] DRAIN TIME [hr] 500YR 100YR 50YR 25YR 10YR 5YR 2YR EURV WQCV 0 1 2 3 4 5 6 7 8 9 10 0 50,000 100,000 150,000 200,000 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 OU T F L O W [ c f s ] AR E A [ f t ^ 2 ] , V O L U M E [ f t ^ 3 ] PONDING DEPTH [ft] User Area [ft^2] Interpolated Area [ft^2] Summary Area [ft^2] Volume [ft^3] Summary Volume [ft^3] Outflow [cfs] Summary Outflow [cfs] MHFD-Detention_v4-06 - Pond 2, Outlet Structure 9/26/2023, 1:44 PM STORM SEWERS RG RG RG Pond 1 Pond 2 Cordova Inlets Pond 2 Storm 3 - Pond 2 Outfall Pipe Pond 2 RG SWALE INFLOW AREA INLETS POND 1 AREA INLETS AREA INLETS RG Culvert Crossing: Storm 7 Culvert Summary Table - Storm 7 Discharge Names Total Discharge (cfs) Culvert Discharge (cfs) Headwater Elevation (ft) Inlet Control Depth(ft) Outlet Control Depth(ft) Flow Type Normal Depth (ft) Critical Depth (ft) Outlet Depth (ft) Tailwater Depth (ft) Outlet Velocity (ft/s) Tailwater Velocity (ft/s) Q2 0.71 0.71 4943.61 0.47 0.20 1-S2n 0.32 0.33 0.32 0.14 2.88 1.92 Q100 3.08 3.08 4944.33 1.07 1.19 2- M2c 0.71 0.71 0.71 0.32 4.31 2.98 Crossing Summary Table Headwater Elevation (ft) Discharge Names Total Discharge (cfs) Storm 7 Discharge (cfs) Roadway Discharge (cfs) Iterations 4943.61 Q2 0.71 0.71 0.00 1 4944.33 Q100 3.08 3.08 0.00 1 4946.10 Overtopping 8.09 8.09 0.00 Overtopping TYPE-R INLET BASIN E STORMTECH CHAMBERS FOR LID POND 1 INLETS INLET SUMMARY Inlet Design Point Contributing Basin Inlet Type Inlet Size Q2 Flow Q100 Flow Intercepted Q100 Flow Not Intercepted Notes 1-1 c Pond 1 & 2 Type-C 3' x 3' 3.6 3.6 -- Pond 1+2 Release Rate 1-2 c Basin C / Pond 2 Pond 2 Outlet Structure See Detail 2.4 2.4 -- Pond 2 Release Rate 2-1 f Basin F Type-R 5' 0.26 1.13 -- 2-2 g Basin G Type-R 5' 0.3 1.32 -- 3-1 c Basin C Type-C 3' x 3' 6.64 28.99 -- 10-year flow (11.35 cfs) is captured by inlet; 100-yr flow passes over directly into Pond 2 3-2.1 h Basin H Type-R 5' 0.76 3.13 -- 3-2.2 i Basin I Type-R 5' 0.97 4.24 -- 3-3.1 e Basin E / Pond 1 Pond 1 Outlet Structure See Detail 1.2 1.2 -- Pond 1 Release Rate 3-4 d Basin D Type-C 3' x 3' 3.29 14.35 -- Basin D Q10 (5.62 cfs) is captured by inlet/pipe; remaining Q100 flow overtops and sheet flows to Pond 2. 3-5 m Basin M Type-C 3' x 3' 5.77 24.57 -- Basin M Q10 (9.86 cfs) is captured by inlet/pipe; remaining Q100 flow overtops and sheet flows to Pond 2. 4-1 j Basin J Type-R 5' 0.78 3.39 -- 4-2 k Basin K Type-R 5' 1.07 4.67 -- 5-2.1 a Basin A Type-C 3' x 3' 4.53 19.75 -- 6-8 b Basin B Type-C 3' x 3' 3.4 14.65 -- 8-4 e Basin E Type-R 5' 7.61 33.2 20.9 Basin E total Q100 is 33.2 cfs; Interception limited to 9.3 cfs inlet/chambers capacity; remaining 23.9 cfs overtops walk directly into Pond 1 Area Inlets around Building 1 Area Inlet 8" Dome N/A 0.94 -- Area Inlets around Building 3 Area Inlet 8" Dome N/A 0.94 -- Area Inlets around Building 4 Area Inlet 8" Dome N/A 0.94 -- Area Inlets around Building 5 Area Inlet 8" Dome N/A 0.94 -- Area Inlets around Building 8 Area Inlet 8" Dome N/A 0.94 -- Area Inlets around Building 9 Area Inlet 8" Dome N/A 0.94 -- Area Inlets around Clubhouse Area Inlet 8" Dome N/A 0.94 -- n/a 8" Dome Capacity @ 1' of depth. Area inlet + pipe capacities are for drainage only; total flows are assigned at design points for primary pipe sizing. n/a Inlet Name: 1-1 Project: 2-Year Design Flow (cfs) 3.60 Location: 100-Year Design Flow (cfs) 3.60 Calc. By: Type of Grate: 9.00 Length of Grate (ft): 3.0 4,941.52 Width of Grate (ft): 3.0 0.50 Depth Above Inlet (ft)Elevation (ft) Shallow Weir Flow (cfs) Orifice Flow (cfs) Actual Flow (cfs)Notes 0.00 4,941.52 0.00 0.00 0.00 0.20 4,941.72 1.61 10.82 1.61 0.40 4,941.92 4.55 15.30 4.55 Pond 1+2 Release Rate interpolated at 0.34' 0.60 4,942.12 8.37 18.73 8.37 0.80 4,942.32 12.88 21.63 12.88 1.00 4,942.52 18.00 24.18 18.00 1.20 4,942.72 23.66 26.49 23.66 1.40 4,942.92 29.82 28.61 29.82 1.60 4,943.12 36.43 30.59 36.43 1.80 4,943.32 43.47 32.45 32.45 2.00 4,943.52 50.91 34.20 34.20 Depth vs. Flow Fabricated 1791-003 Landing A. Snow Reduction Factor: AREA INLET PERFORMANCE CURVE Governing Equations If H > 1.792 (A/P), then the grate operates like an orifice; otherwise it operates like a weir. Input Parameters Rim Elevation (ft): Open Area of Grate (ft2): 0.00 10.00 20.00 30.00 40.00 50.00 60.00 0.00 0.50 1.00 1.50 2.00 2.50 Di s c h a r g e ( c f s ) Stage (ft) Stage - Discharge Curves Series1 Series2 At low flow dephs, the inlet will act like a weir governed by the following equation: * where P = 2(L + W) * where H corresponds to the depth of water above the flowline At higher flow depths, the inlet will act like an orifice governed by the following equation: * where A equals the open area of the inlet grate * where H corresponds to the depth of water above the centroid of the cross-sectional area (A). = 3.0 . = 0.67 (2 ) . Inlet Name: 3-1 Project: 2-Year Design Flow (cfs) 6.64 Location: 10-Year Design Flow (cfs) 11.35 Calc. By: Type of Grate: 9.00 Length of Grate (ft): 3.0 4,940.90 Width of Grate (ft): 3.0 0.50 Depth Above Inlet (ft)Elevation (ft) Shallow Weir Flow (cfs) Orifice Flow (cfs) Actual Flow (cfs)Notes 0.00 4,940.90 0.00 0.00 0.00 0.10 4,941.00 0.57 7.65 0.57 0.20 4,941.10 1.61 10.82 1.61 0.30 4,941.20 2.96 13.25 2.96 0.40 4,941.30 4.55 15.30 4.55 0.50 4,941.40 6.36 17.10 6.36 0.60 4,941.50 8.37 18.73 8.37 0.70 4,941.60 10.54 20.23 10.54 0.80 4,941.70 12.88 21.63 12.88 10-yr flow 11.35 cfs 0.90 4,941.80 15.37 22.94 15.37 1.00 4,941.90 18.00 24.18 18.00 1.10 4,942.00 20.77 25.36 20.77 1.20 4,942.10 23.66 26.49 23.66 1.25 4,942.15 25.16 27.04 25.16 Depth vs. Flow Fabricated 1791-003 Landing A. Snow Reduction Factor: AREA INLET PERFORMANCE CURVE Governing Equations If H > 1.792 (A/P), then the grate operates like an orifice; otherwise it operates like a weir. Input Parameters Rim Elevation (ft): Open Area of Grate (ft 2): 0.00 5.00 10.00 15.00 20.00 25.00 30.00 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 Di s c h a r g e ( c f s ) Stage (ft) Stage - Discharge Curves Series1 Series2 Atlow flow dephs, the inlet will act like a weir governed by the following equation: * where P = 2(L + W) * where H corresponds to the depth of water above the flowline At higher flow depths, the inlet will act like an orifice governed by the following equation: * where A equals the open area of the inlet grate * where H corresponds to the depth of water above the centroid of the cross-sectional area (A). = 3.0 . = 0.67 (2 ) . Inlet Name:3-4 Project: 2-Year Design Flow (cfs)3.29 Location: 100-Year Design Flow (cfs)14.35 Calc. By: Type of Grate: 9.00 Length of Grate (ft):3.0 4,942.10 Width of Grate (ft):3.0 0.50 Depth Above Inlet (ft)Elevation (ft) Shallow Weir Flow (cfs) Orifice Flow (cfs) Actual Flow (cfs)Notes 0.00 4,942.10 0.00 0.00 0.00 0.10 4,942.20 0.57 7.65 0.57 0.20 4,942.30 1.61 10.82 1.61 0.30 4,942.40 2.96 13.25 2.96 0.40 4,942.50 4.55 15.30 4.55 0.50 4,942.60 6.36 17.10 6.36 0.60 4,942.70 8.37 18.73 8.37 0.70 4,942.80 10.54 20.23 10.54 0.80 4,942.90 12.88 21.63 12.88 0.90 4,943.00 15.37 22.94 15.37 100-yr flow interpolated at 0.86' 1.00 4,943.10 18.00 24.18 18.00 AREA INLET PERFORMANCE CURVE Governing Equations If H > 1.792 (A/P), then the grate operates like an orifice; otherwise it operates like a weir. Input Parameters Rim Elevation (ft): Open Area of Grate (ft 2): Depth vs. Flow Fabricated 1791-003 Landing A. Snow Reduction Factor: 0.00 5.00 10.00 15.00 20.00 25.00 30.00 0.00 0.20 0.40 0.60 0.80 1.00 1.20 Di s c h a r g e ( c f s ) Stage (ft) Stage - Discharge Curves Series1 Series2 Atlow flow dephs, the inlet will act like a weir governed by the following equation: * where P = 2(L + W) * where H corresponds to the depth of water above the flowline At higher flow depths, the inlet will act like an orifice governed by the following equation: * where A equals the open area of the inlet grate * where H corresponds to the depth of water above the centroid of the cross-sectional area (A). = 3.0 . = 0.67 (2 ) . Inlet Name:3-5 Project: 2-Year Design Flow (cfs)6.08 Location: 100-Year Design Flow (cfs)26.54 Calc. By: Type of Grate: 9.00 Length of Grate (ft):3.0 4,943.75 Width of Grate (ft):3.0 0.50 Depth Above Inlet (ft)Elevation (ft) Shallow Weir Flow (cfs) Orifice Flow (cfs) Actual Flow (cfs)Notes 0.00 4,943.75 0.00 0.00 0.00 0.20 4,943.95 1.61 10.82 1.61 0.40 4,944.15 4.55 15.30 4.55 0.60 4,944.35 8.37 18.73 8.37 0.80 4,944.55 12.88 21.63 12.88 1.00 4,944.75 18.00 24.18 18.00 1.20 4,944.95 23.66 26.49 23.66 1.40 4,945.15 29.82 28.61 29.82 100-yr flow interpolated at 1.29' 1.60 4,945.35 36.43 30.59 36.43 1.80 4,945.55 43.47 32.45 32.45 2.00 4,945.75 50.91 34.20 34.20 AREA INLET PERFORMANCE CURVE Governing Equations If H > 1.792 (A/P), then the grate operates like an orifice; otherwise it operates like a weir. Input Parameters Rim Elevation (ft): Open Area of Grate (ft 2): Depth vs. Flow Fabricated 1791-003 Landing A. Snow Reduction Factor: 0.00 10.00 20.00 30.00 40.00 50.00 60.00 0.00 0.50 1.00 1.50 2.00 2.50 Di s c h a r g e ( c f s ) Stage (ft) Stage - Discharge Curves Series1 Series2 Atlow flow dephs, the inlet will act like a weir governed by the following equation: * where P = 2(L + W) * where H corresponds to the depth of water above the flowline At higher flow depths, the inlet will act like an orifice governed by the following equation: * where A equals the open area of the inlet grate * where H corresponds to the depth of water above the centroid of the cross-sectional area (A). = 3.0 . = 0.67 (2 ) . Inlet Name:5-2.1 Project: 2-Year Design Flow (cfs)4.53 Location: 100-Year Design Flow (cfs)19.75 Calc. By: Type of Grate: 9.00 Length of Grate (ft):3.0 4,944.50 Width of Grate (ft):3.0 0.50 Depth Above Inlet (ft)Elevation (ft) Shallow Weir Flow (cfs) Orifice Flow (cfs) Actual Flow (cfs)Notes 0.00 4,944.50 0.00 0.00 0.00 0.20 4,944.70 1.61 10.82 1.61 0.40 4,944.90 4.55 15.30 4.55 0.60 4,945.10 8.37 18.73 8.37 0.80 4,945.30 12.88 21.63 12.88 1.00 4,945.50 18.00 24.18 18.00 1.20 4,945.70 23.66 26.49 23.66 100-yr flow interpolated at 1.06' 1.40 4,945.90 29.82 28.61 29.82 1.60 4,946.10 36.43 30.59 36.43 1.80 4,946.30 43.47 32.45 32.45 2.00 4,946.50 50.91 34.20 34.20 Depth vs. Flow Fabricated 1791-003 Landing A. Snow Reduction Factor: AREA INLET PERFORMANCE CURVE Governing Equations If H > 1.792 (A/P), then the grate operates like an orifice; otherwise it operates like a weir. Input Parameters Rim Elevation (ft): Open Area of Grate (ft2): 0.00 10.00 20.00 30.00 40.00 50.00 60.00 0.00 0.50 1.00 1.50 2.00 2.50 Di s c h a r g e ( c f s ) Stage (ft) Stage - Discharge Curves Series1 Series2 At low flow dephs, the inlet will act like a weir governed by the following equation: * where P = 2(L + W) * where H corresponds to the depth of water above the flowline At higher flow depths, the inlet will act like an orifice governed by the following equation: * where A equals the open area of the inlet grate * where H corresponds to the depth of water above the centroid of the cross-sectional area (A). = 3.0 . = 0.67 (2 ) . Inlet Name:6-8 Project: 2-Year Design Flow (cfs)3.40 Location: 100-Year Design Flow (cfs)14.65 Calc. By: Type of Grate: 9.00 Length of Grate (ft):3.0 4,944.50 Width of Grate (ft):3.0 0.50 Depth Above Inlet (ft)Elevation (ft) Shallow Weir Flow (cfs) Orifice Flow (cfs) Actual Flow (cfs)Notes 0.00 4,944.50 0.00 0.00 0.00 0.20 4,944.70 1.61 10.82 1.61 0.40 4,944.90 4.55 15.30 4.55 0.60 4,945.10 8.37 18.73 8.37 0.80 4,945.30 12.88 21.63 12.88 1.00 4,945.50 18.00 24.18 18.00 100-yr flow interpolated at 0.87' 1.20 4,945.70 23.66 26.49 23.66 1.40 4,945.90 29.82 28.61 29.82 1.60 4,946.10 36.43 30.59 36.43 1.80 4,946.30 43.47 32.45 32.45 2.00 4,946.50 50.91 34.20 34.20 AREA INLET PERFORMANCE CURVE Governing Equations If H > 1.792 (A/P), then the grate operates like an orifice; otherwise it operates like a weir. Input Parameters Rim Elevation (ft): Open Area of Grate (ft2): Depth vs. Flow Fabricated 1791-003 Landing A. Snow Reduction Factor: 0.00 10.00 20.00 30.00 40.00 50.00 60.00 0.00 0.50 1.00 1.50 2.00 2.50 Di s c h a r g e ( c f s ) Stage (ft) Stage - Discharge Curves Series1 Series2 At low flow dephs, the inlet will act like a weir governed by the following equation: * where P = 2(L + W) * where H corresponds to the depth of water above the flowline At higher flow depths, the inlet will act like an orifice governed by the following equation: * where A equals the open area of the inlet grate * where H corresponds to the depth of water above the centroid of the cross-sectional area (A). = 3.0 . = 0.67 (2 ) . Project: Inlet ID: Gutter Geometry: Maximum Allowable Width for Spread Behind Curb TBACK =15.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.012 Height of Curb at Gutter Flow Line HCURB =6.00 inches Distance from Curb Face to Street Crown TCROWN =23.0 ft Gutter Width W =2.00 ft Street Transverse Slope SX =0.022 ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft Street Longitudinal Slope - Enter 0 for sump condition SO =0.000 ft/ft Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016 Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm TMAX =23.0 23.0 ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 6.0 inches Check boxes are not applicable in SUMP conditions MINOR STORM Allowable Capacity is not applicable to Sump Condition Minor Storm Major Storm MAJOR STORM Allowable Capacity is not applicable to Sump Condition Qallow =SUMP SUMP cfs MHFD-Inlet, Version 5.02 (August 2022) ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) Landing at Lemay Inlet 2-1 1 Design Information (Input)MINOR MAJOR Type of Inlet Type = Local Depression (additional to continuous gutter depression 'a' from above)alocal =3.00 3.00 inches Number of Unit Inlets (Grate or Curb Opening)No =1 1 Water Depth at Flowline (outside of local depression)Ponding Depth =6.0 6.0 inches Grate Information MINOR MAJOR Length of a Unit Grate Lo (G) =N/A N/A feet Width of a Unit Grate Wo =N/A N/A feet Open Area Ratio for a Grate (typical values 0.15-0.90)Aratio =N/A N/A Clogging Factor for a Single Grate (typical value 0.50 - 0.70)Cf (G) =N/A N/A Grate Weir Coefficient (typical value 2.15 - 3.60)Cw (G) =N/A N/A Grate Orifice Coefficient (typical value 0.60 - 0.80)Co (G) =N/A N/A Curb Opening Information MINOR MAJOR Length of a Unit Curb Opening Lo (C) =5.00 5.00 feet Height of Vertical Curb Opening in Inches Hvert =6.00 6.00 inches Height of Curb Orifice Throat in Inches Hthroat =6.00 6.00 inches Angle of Throat (see USDCM Figure ST-5)Theta =63.40 63.40 degrees Side Width for Depression Pan (typically the gutter width of 2 feet)Wp =2.00 2.00 feet Clogging Factor for a Single Curb Opening (typical value 0.10)Cf (C) =0.10 0.10 Curb Opening Weir Coefficient (typical value 2.3-3.7)Cw (C) =3.60 3.60 Curb Opening Orifice Coefficient (typical value 0.60 - 0.70)Co (C) =0.67 0.67 Low Head Performance Reduction (Calculated)MINOR MAJOR Depth for Grate Midwidth dGrate =N/A N/A ft Depth for Curb Opening Weir Equation dCurb =0.33 0.33 ft Grated Inlet Performance Reduction Factor for Long Inlets RFGrate =N/A N/A Curb Opening Performance Reduction Factor for Long Inlets RFCurb =1.00 1.00 Combination Inlet Performance Reduction Factor for Long Inlets RFCombination =N/A N/A MINOR MAJOR Total Inlet Interception Capacity (assumes clogged condition)Qa =5.4 5.4 cfs Inlet Capacity IS GOOD for Minor and Major Storms (>Q Peak)Q PEAK REQUIRED =0.3 1.1 cfs CDOT Type R Curb Opening INLET IN A SUMP OR SAG LOCATION MHFD-Inlet, Version 5.02 (August 2022) H-VertH-Curb W Lo (C) Lo (G) Wo WP CDOT Type R Curb Opening Override Depths 1 Project: Inlet ID: Gutter Geometry: Maximum Allowable Width for Spread Behind Curb TBACK =15.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.012 Height of Curb at Gutter Flow Line HCURB =6.00 inches Distance from Curb Face to Street Crown TCROWN =23.0 ft Gutter Width W =2.00 ft Street Transverse Slope SX =0.022 ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft Street Longitudinal Slope - Enter 0 for sump condition SO =0.000 ft/ft Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016 Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm TMAX =23.0 23.0 ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 6.0 inches Check boxes are not applicable in SUMP conditions MINOR STORM Allowable Capacity is not applicable to Sump Condition Minor Storm Major Storm MAJOR STORM Allowable Capacity is not applicable to Sump Condition Qallow =SUMP SUMP cfs MHFD-Inlet, Version 5.02 (August 2022) ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) Landing at Lemay Inlet 2-2 1 Design Information (Input)MINOR MAJOR Type of Inlet Type = Local Depression (additional to continuous gutter depression 'a' from above)alocal =3.00 3.00 inches Number of Unit Inlets (Grate or Curb Opening)No =1 1 Water Depth at Flowline (outside of local depression)Ponding Depth =6.0 6.0 inches Grate Information MINOR MAJOR Length of a Unit Grate Lo (G) =N/A N/A feet Width of a Unit Grate Wo =N/A N/A feet Open Area Ratio for a Grate (typical values 0.15-0.90)Aratio =N/A N/A Clogging Factor for a Single Grate (typical value 0.50 - 0.70)Cf (G) =N/A N/A Grate Weir Coefficient (typical value 2.15 - 3.60)Cw (G) =N/A N/A Grate Orifice Coefficient (typical value 0.60 - 0.80)Co (G) =N/A N/A Curb Opening Information MINOR MAJOR Length of a Unit Curb Opening Lo (C) =5.00 5.00 feet Height of Vertical Curb Opening in Inches Hvert =6.00 6.00 inches Height of Curb Orifice Throat in Inches Hthroat =6.00 6.00 inches Angle of Throat (see USDCM Figure ST-5)Theta =63.40 63.40 degrees Side Width for Depression Pan (typically the gutter width of 2 feet)Wp =2.00 2.00 feet Clogging Factor for a Single Curb Opening (typical value 0.10)Cf (C) =0.10 0.10 Curb Opening Weir Coefficient (typical value 2.3-3.7)Cw (C) =3.60 3.60 Curb Opening Orifice Coefficient (typical value 0.60 - 0.70)Co (C) =0.67 0.67 Low Head Performance Reduction (Calculated)MINOR MAJOR Depth for Grate Midwidth dGrate =N/A N/A ft Depth for Curb Opening Weir Equation dCurb =0.33 0.33 ft Grated Inlet Performance Reduction Factor for Long Inlets RFGrate =N/A N/A Curb Opening Performance Reduction Factor for Long Inlets RFCurb =1.00 1.00 Combination Inlet Performance Reduction Factor for Long Inlets RFCombination =N/A N/A MINOR MAJOR Total Inlet Interception Capacity (assumes clogged condition)Qa =5.4 5.4 cfs Inlet Capacity IS GOOD for Minor and Major Storms (>Q Peak)Q PEAK REQUIRED =0.3 1.3 cfs CDOT Type R Curb Opening INLET IN A SUMP OR SAG LOCATION MHFD-Inlet, Version 5.02 (August 2022) H-VertH-Curb W Lo (C) Lo (G) Wo WP CDOT Type R Curb Opening Override Depths 1 Project: Inlet ID: Gutter Geometry: Maximum Allowable Width for Spread Behind Curb TBACK =15.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.012 Height of Curb at Gutter Flow Line HCURB =6.00 inches Distance from Curb Face to Street Crown TCROWN =23.0 ft Gutter Width W =2.00 ft Street Transverse Slope SX =0.022 ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft Street Longitudinal Slope - Enter 0 for sump condition SO =0.000 ft/ft Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016 Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm TMAX =23.0 23.0 ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 6.0 inches Check boxes are not applicable in SUMP conditions MINOR STORM Allowable Capacity is not applicable to Sump Condition Minor Storm Major Storm MAJOR STORM Allowable Capacity is not applicable to Sump Condition Qallow =SUMP SUMP cfs MHFD-Inlet, Version 5.02 (August 2022) ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) Landing at Lemay Inlet 3-2.1 1 Design Information (Input)MINOR MAJOR Type of Inlet Type = Local Depression (additional to continuous gutter depression 'a' from above)alocal =3.00 3.00 inches Number of Unit Inlets (Grate or Curb Opening)No =1 1 Water Depth at Flowline (outside of local depression)Ponding Depth =6.0 6.0 inches Grate Information MINOR MAJOR Length of a Unit Grate Lo (G) =N/A N/A feet Width of a Unit Grate Wo =N/A N/A feet Open Area Ratio for a Grate (typical values 0.15-0.90)Aratio =N/A N/A Clogging Factor for a Single Grate (typical value 0.50 - 0.70)Cf (G) =N/A N/A Grate Weir Coefficient (typical value 2.15 - 3.60)Cw (G) =N/A N/A Grate Orifice Coefficient (typical value 0.60 - 0.80)Co (G) =N/A N/A Curb Opening Information MINOR MAJOR Length of a Unit Curb Opening Lo (C) =5.00 5.00 feet Height of Vertical Curb Opening in Inches Hvert =6.00 6.00 inches Height of Curb Orifice Throat in Inches Hthroat =6.00 6.00 inches Angle of Throat (see USDCM Figure ST-5)Theta =63.40 63.40 degrees Side Width for Depression Pan (typically the gutter width of 2 feet)Wp =2.00 2.00 feet Clogging Factor for a Single Curb Opening (typical value 0.10)Cf (C) =0.10 0.10 Curb Opening Weir Coefficient (typical value 2.3-3.7)Cw (C) =3.60 3.60 Curb Opening Orifice Coefficient (typical value 0.60 - 0.70)Co (C) =0.67 0.67 Low Head Performance Reduction (Calculated)MINOR MAJOR Depth for Grate Midwidth dGrate =N/A N/A ft Depth for Curb Opening Weir Equation dCurb =0.33 0.33 ft Grated Inlet Performance Reduction Factor for Long Inlets RFGrate =N/A N/A Curb Opening Performance Reduction Factor for Long Inlets RFCurb =1.00 1.00 Combination Inlet Performance Reduction Factor for Long Inlets RFCombination =N/A N/A MINOR MAJOR Total Inlet Interception Capacity (assumes clogged condition)Qa =5.4 5.4 cfs Inlet Capacity IS GOOD for Minor and Major Storms (>Q Peak)Q PEAK REQUIRED =0.8 3.1 cfs CDOT Type R Curb Opening INLET IN A SUMP OR SAG LOCATION MHFD-Inlet, Version 5.02 (August 2022) H-VertH-Curb W Lo (C) Lo (G) Wo WP CDOT Type R Curb Opening Override Depths 1 Project: Inlet ID: Gutter Geometry: Maximum Allowable Width for Spread Behind Curb TBACK =15.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.012 Height of Curb at Gutter Flow Line HCURB =6.00 inches Distance from Curb Face to Street Crown TCROWN =23.0 ft Gutter Width W =2.00 ft Street Transverse Slope SX =0.022 ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft Street Longitudinal Slope - Enter 0 for sump condition SO =0.000 ft/ft Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016 Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm TMAX =23.0 23.0 ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 6.0 inches Check boxes are not applicable in SUMP conditions MINOR STORM Allowable Capacity is not applicable to Sump Condition Minor Storm Major Storm MAJOR STORM Allowable Capacity is not applicable to Sump Condition Qallow =SUMP SUMP cfs MHFD-Inlet, Version 5.02 (August 2022) ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) Landing at Lemay Inlet 3-2.2 1 Design Information (Input)MINOR MAJOR Type of Inlet Type = Local Depression (additional to continuous gutter depression 'a' from above)alocal =3.00 3.00 inches Number of Unit Inlets (Grate or Curb Opening)No =1 1 Water Depth at Flowline (outside of local depression)Ponding Depth =6.0 6.0 inches Grate Information MINOR MAJOR Length of a Unit Grate Lo (G) =N/A N/A feet Width of a Unit Grate Wo =N/A N/A feet Open Area Ratio for a Grate (typical values 0.15-0.90)Aratio =N/A N/A Clogging Factor for a Single Grate (typical value 0.50 - 0.70)Cf (G) =N/A N/A Grate Weir Coefficient (typical value 2.15 - 3.60)Cw (G) =N/A N/A Grate Orifice Coefficient (typical value 0.60 - 0.80)Co (G) =N/A N/A Curb Opening Information MINOR MAJOR Length of a Unit Curb Opening Lo (C) =5.00 5.00 feet Height of Vertical Curb Opening in Inches Hvert =6.00 6.00 inches Height of Curb Orifice Throat in Inches Hthroat =6.00 6.00 inches Angle of Throat (see USDCM Figure ST-5)Theta =63.40 63.40 degrees Side Width for Depression Pan (typically the gutter width of 2 feet)Wp =2.00 2.00 feet Clogging Factor for a Single Curb Opening (typical value 0.10)Cf (C) =0.10 0.10 Curb Opening Weir Coefficient (typical value 2.3-3.7)Cw (C) =3.60 3.60 Curb Opening Orifice Coefficient (typical value 0.60 - 0.70)Co (C) =0.67 0.67 Low Head Performance Reduction (Calculated)MINOR MAJOR Depth for Grate Midwidth dGrate =N/A N/A ft Depth for Curb Opening Weir Equation dCurb =0.33 0.33 ft Grated Inlet Performance Reduction Factor for Long Inlets RFGrate =N/A N/A Curb Opening Performance Reduction Factor for Long Inlets RFCurb =1.00 1.00 Combination Inlet Performance Reduction Factor for Long Inlets RFCombination =N/A N/A MINOR MAJOR Total Inlet Interception Capacity (assumes clogged condition)Qa =5.4 5.4 cfs Inlet Capacity IS GOOD for Minor and Major Storms (>Q Peak)Q PEAK REQUIRED =1.0 4.2 cfs CDOT Type R Curb Opening INLET IN A SUMP OR SAG LOCATION MHFD-Inlet, Version 5.02 (August 2022) H-VertH-Curb W Lo (C) Lo (G) Wo WP CDOT Type R Curb Opening Override Depths 1 Project: Inlet ID: Gutter Geometry: Maximum Allowable Width for Spread Behind Curb TBACK =15.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.012 Height of Curb at Gutter Flow Line HCURB =6.00 inches Distance from Curb Face to Street Crown TCROWN =23.0 ft Gutter Width W =2.00 ft Street Transverse Slope SX =0.022 ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft Street Longitudinal Slope - Enter 0 for sump condition SO =0.000 ft/ft Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016 Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm TMAX =23.0 23.0 ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 6.0 inches Check boxes are not applicable in SUMP conditions MINOR STORM Allowable Capacity is not applicable to Sump Condition Minor Storm Major Storm MAJOR STORM Allowable Capacity is not applicable to Sump Condition Qallow =SUMP SUMP cfs MHFD-Inlet, Version 5.02 (August 2022) ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) Landing at Lemay Inlet 4-1 1 Design Information (Input)MINOR MAJOR Type of Inlet Type = Local Depression (additional to continuous gutter depression 'a' from above)alocal =3.00 3.00 inches Number of Unit Inlets (Grate or Curb Opening)No =1 1 Water Depth at Flowline (outside of local depression)Ponding Depth =6.0 6.0 inches Grate Information MINOR MAJOR Length of a Unit Grate Lo (G) =N/A N/A feet Width of a Unit Grate Wo =N/A N/A feet Open Area Ratio for a Grate (typical values 0.15-0.90)Aratio =N/A N/A Clogging Factor for a Single Grate (typical value 0.50 - 0.70)Cf (G) =N/A N/A Grate Weir Coefficient (typical value 2.15 - 3.60)Cw (G) =N/A N/A Grate Orifice Coefficient (typical value 0.60 - 0.80)Co (G) =N/A N/A Curb Opening Information MINOR MAJOR Length of a Unit Curb Opening Lo (C) =5.00 5.00 feet Height of Vertical Curb Opening in Inches Hvert =6.00 6.00 inches Height of Curb Orifice Throat in Inches Hthroat =6.00 6.00 inches Angle of Throat (see USDCM Figure ST-5)Theta =63.40 63.40 degrees Side Width for Depression Pan (typically the gutter width of 2 feet)Wp =2.00 2.00 feet Clogging Factor for a Single Curb Opening (typical value 0.10)Cf (C) =0.10 0.10 Curb Opening Weir Coefficient (typical value 2.3-3.7)Cw (C) =3.60 3.60 Curb Opening Orifice Coefficient (typical value 0.60 - 0.70)Co (C) =0.67 0.67 Low Head Performance Reduction (Calculated)MINOR MAJOR Depth for Grate Midwidth dGrate =N/A N/A ft Depth for Curb Opening Weir Equation dCurb =0.33 0.33 ft Grated Inlet Performance Reduction Factor for Long Inlets RFGrate =N/A N/A Curb Opening Performance Reduction Factor for Long Inlets RFCurb =1.00 1.00 Combination Inlet Performance Reduction Factor for Long Inlets RFCombination =N/A N/A MINOR MAJOR Total Inlet Interception Capacity (assumes clogged condition)Qa =5.4 5.4 cfs Inlet Capacity IS GOOD for Minor and Major Storms (>Q Peak)Q PEAK REQUIRED =0.8 3.4 cfs CDOT Type R Curb Opening INLET IN A SUMP OR SAG LOCATION MHFD-Inlet, Version 5.02 (August 2022) H-VertH-Curb W Lo (C) Lo (G) Wo WP CDOT Type R Curb Opening Override Depths 1 Project: Inlet ID: Gutter Geometry: Maximum Allowable Width for Spread Behind Curb TBACK =15.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.012 Height of Curb at Gutter Flow Line HCURB =6.00 inches Distance from Curb Face to Street Crown TCROWN =23.0 ft Gutter Width W =2.00 ft Street Transverse Slope SX =0.022 ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft Street Longitudinal Slope - Enter 0 for sump condition SO =0.000 ft/ft Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016 Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm TMAX =23.0 23.0 ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 6.0 inches Check boxes are not applicable in SUMP conditions MINOR STORM Allowable Capacity is not applicable to Sump Condition Minor Storm Major Storm MAJOR STORM Allowable Capacity is not applicable to Sump Condition Qallow =SUMP SUMP cfs MHFD-Inlet, Version 5.02 (August 2022) ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) Landing at Lemay Inlet 4-2 1 Design Information (Input)MINOR MAJOR Type of Inlet Type = Local Depression (additional to continuous gutter depression 'a' from above)alocal =3.00 3.00 inches Number of Unit Inlets (Grate or Curb Opening)No =1 1 Water Depth at Flowline (outside of local depression)Ponding Depth =6.0 6.0 inches Grate Information MINOR MAJOR Length of a Unit Grate Lo (G) =N/A N/A feet Width of a Unit Grate Wo =N/A N/A feet Open Area Ratio for a Grate (typical values 0.15-0.90)Aratio =N/A N/A Clogging Factor for a Single Grate (typical value 0.50 - 0.70)Cf (G) =N/A N/A Grate Weir Coefficient (typical value 2.15 - 3.60)Cw (G) =N/A N/A Grate Orifice Coefficient (typical value 0.60 - 0.80)Co (G) =N/A N/A Curb Opening Information MINOR MAJOR Length of a Unit Curb Opening Lo (C) =5.00 5.00 feet Height of Vertical Curb Opening in Inches Hvert =6.00 6.00 inches Height of Curb Orifice Throat in Inches Hthroat =6.00 6.00 inches Angle of Throat (see USDCM Figure ST-5)Theta =63.40 63.40 degrees Side Width for Depression Pan (typically the gutter width of 2 feet)Wp =2.00 2.00 feet Clogging Factor for a Single Curb Opening (typical value 0.10)Cf (C) =0.10 0.10 Curb Opening Weir Coefficient (typical value 2.3-3.7)Cw (C) =3.60 3.60 Curb Opening Orifice Coefficient (typical value 0.60 - 0.70)Co (C) =0.67 0.67 Low Head Performance Reduction (Calculated)MINOR MAJOR Depth for Grate Midwidth dGrate =N/A N/A ft Depth for Curb Opening Weir Equation dCurb =0.33 0.33 ft Grated Inlet Performance Reduction Factor for Long Inlets RFGrate =N/A N/A Curb Opening Performance Reduction Factor for Long Inlets RFCurb =1.00 1.00 Combination Inlet Performance Reduction Factor for Long Inlets RFCombination =N/A N/A MINOR MAJOR Total Inlet Interception Capacity (assumes clogged condition)Qa =5.4 5.4 cfs Inlet Capacity IS GOOD for Minor and Major Storms (>Q Peak)Q PEAK REQUIRED =1.1 4.7 cfs CDOT Type R Curb Opening INLET IN A SUMP OR SAG LOCATION MHFD-Inlet, Version 5.02 (August 2022) H-VertH-Curb W Lo (C) Lo (G) Wo WP CDOT Type R Curb Opening Override Depths 1 Project: Inlet ID: Gutter Geometry: Maximum Allowable Width for Spread Behind Curb TBACK =25.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.060 ft/ft Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.012 Height of Curb at Gutter Flow Line HCURB =6.00 inches Distance from Curb Face to Street Crown TCROWN =41.0 ft Gutter Width W =2.00 ft Street Transverse Slope SX =0.020 ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft Street Longitudinal Slope - Enter 0 for sump condition SO =0.000 ft/ft Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016 Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm TMAX =41.0 41.0 ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 8.0 inches Check boxes are not applicable in SUMP conditions MINOR STORM Allowable Capacity is not applicable to Sump Condition Minor Storm Major Storm MAJOR STORM Allowable Capacity is not applicable to Sump Condition Qallow =SUMP SUMP cfs MHFD-Inlet, Version 5.02 (August 2022) ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) Landing at Lemay Inlet 8-4 1 Design Information (Input)MINOR MAJOR Type of Inlet Type = Local Depression (additional to continuous gutter depression 'a' from above)alocal =3.00 3.00 inches Number of Unit Inlets (Grate or Curb Opening)No =1 1 Water Depth at Flowline (outside of local depression)Ponding Depth =6.0 8.0 inches Grate Information MINOR MAJOR Length of a Unit Grate Lo (G) =N/A N/A feet Width of a Unit Grate Wo =N/A N/A feet Open Area Ratio for a Grate (typical values 0.15-0.90)Aratio =N/A N/A Clogging Factor for a Single Grate (typical value 0.50 - 0.70)Cf (G) =N/A N/A Grate Weir Coefficient (typical value 2.15 - 3.60)Cw (G) =N/A N/A Grate Orifice Coefficient (typical value 0.60 - 0.80)Co (G) =N/A N/A Curb Opening Information MINOR MAJOR Length of a Unit Curb Opening Lo (C) =5.00 5.00 feet Height of Vertical Curb Opening in Inches Hvert =6.00 6.00 inches Height of Curb Orifice Throat in Inches Hthroat =6.00 6.00 inches Angle of Throat (see USDCM Figure ST-5)Theta =63.40 63.40 degrees Side Width for Depression Pan (typically the gutter width of 2 feet)Wp =2.00 2.00 feet Clogging Factor for a Single Curb Opening (typical value 0.10)Cf (C) =0.10 0.10 Curb Opening Weir Coefficient (typical value 2.3-3.7)Cw (C) =3.60 3.60 Curb Opening Orifice Coefficient (typical value 0.60 - 0.70)Co (C) =0.67 0.67 Low Head Performance Reduction (Calculated)MINOR MAJOR Depth for Grate Midwidth dGrate =N/A N/A ft Depth for Curb Opening Weir Equation dCurb =0.33 0.50 ft Grated Inlet Performance Reduction Factor for Long Inlets RFGrate =N/A N/A Curb Opening Performance Reduction Factor for Long Inlets RFCurb =1.00 1.00 Combination Inlet Performance Reduction Factor for Long Inlets RFCombination =N/A N/A MINOR MAJOR Total Inlet Interception Capacity (assumes clogged condition)Qa =5.4 9.3 cfs WARNING: Inlet Capacity < Q Peak for Minor and Major Storms Q PEAK REQUIRED =7.6 33.2 cfs INLET IN A SUMP OR SAG LOCATION MHFD-Inlet, Version 5.02 (August 2022) CDOT Type R Curb Opening H-VertH-Curb W Lo (C) Lo (G) Wo WP CDOT Type R Curb Opening Override Depths 1 SWALES Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Tuesday, Sep 26 2023 West Swale/Trickle Channel Trapezoidal Bottom Width (ft) = 2.00 Side Slopes (z:1) = 3.00, 10.00 Total Depth (ft) = 2.00 Invert Elev (ft) = 4943.00 Slope (%) = 0.50 N-Value = 0.013 Calculations Compute by: Known Q Known Q (cfs) = 3.08 Highlighted Depth (ft) = 0.30 Q (cfs) = 3.080 Area (sqft) = 1.19 Velocity (ft/s) = 2.60 Wetted Perim (ft) = 5.96 Crit Depth, Yc (ft) = 0.31 Top Width (ft) = 5.90 EGL (ft) = 0.41 0 5 10 15 20 25 30 35 40 Elev (ft) Depth (ft)Section 4942.50 -0.50 4943.00 0.00 4943.50 0.50 4944.00 1.00 4944.50 1.50 4945.00 2.00 4945.50 2.50 4946.00 3.00 Reach (ft) SCOURSTOP SUMMARY Project: Project Location: Calculations By: Date: Forebay/ Rain Garden Basin WQCV (ft 3) Forebay Design Volume (ft3)Forebay Depth Forebay Length Forebay Width Forebay Area Basin Q100 (cfs)Release (cfs) Pipe Size as calculated/shown in LID Summary Table 1% of WQCV (ft) (ft) (ft) (ft2)see hydrology tables 2% of Q100 (in) A 1798 17.98 1 4.5 4 18 19.75 0.40 2.5 B 1361 13.61 1 3.5 4 14 14.65 0.29 2 C 2305 23.05 1 6 4 24 27.47 0.55 3 D 1183 11.83 1 6 2 12 14.35 0.29 2 M 2310 23.1 1 6 4 24 26.54 0.53 3 Forebay Calculations Landing at Lemay Fort Collins, CO A. Snow 11.10.23 SCOURSTOP CALCULATIONS Storm Line Diameter (in.) Flow Velocity (cfs) Mat Length (ft) Mat Width (ft) Quantity of Mats 2 15 2.71 8 8 4 4 15 6.95 8 8 4 5 24 8.02 8 8 4 SCOURSTOP PROTECTION CALCULATIONS ScourStop® DESIGN GUIDE Circular Culvert Outlet Protection scourstop.com PERFORMANCE AESTHETICS NPDES-COMPLIANT COST-EFFECTIVE the green solution to riprap ® ScourStop transition mats protect against erosion and scour at culvert outlets with a vegetated solution in areas traditionally protected with rock or other hard armor. ScourStop is part of a system that includes semi-rigid transition mats installed over sod or turf reinforcement mats. Each 4’ x 4’ x 1/2” mat is made of high-density polyethylene and secured tightly to the ground with anchors. why use the SCOURSTOP SYSTEM? - If velocity is greater than 16 fps, contact manufacturer for design assistance. - ScourStop mats have been shown to at least double the effectiveness of turf reinforcement mats. - ScourStop fully vegetated channel (2:1 slope): velocity = 31 fps, shear stress = 16 psf. PIPE DIAMETER VELOCITY < 10 FT/SEC 10 < VELOCITY < 16 FT/SEC TRANSITION MAT W x L QUANTITY OF MATS TRANSITION MAT W x L QUANTITY OF MATS 12”4’ x 4’1 4’ x 8’2 24”8’ x 8’4 8’ x 12’6 36”8’ x 12’6 12’ x 20’15 48”12’ x 16’12 12’ x 24’18 60”12’ x 20’15 16’ x 32’32 72”16’ x 24’24 20’ x 36’45 Circular Culvert Outlet Protection These are minimum recommendations. More ScourStop protection may be needed depending upon site and soil conditions, per project engineer. 1. ScourStop mats must be installed over a soil cover: sod, seeded turf reinforcement mat (TRM), geotextile, or a combination thereof. 2. For steep slopes (>10%) or higher velocities (>10 ft/sec), sod is the recommended soil cover. 3. Follow manufacturer’s ScourStop Installation Guidelines to ensure proper installation. 4. Install ScourStop mats at maximum 1-2” below flowline of culvert or culvert apron. (No waterfall impacts onto ScourStop mats.) 5. Performance of protected area assumes stable downstream conditions. Transition mat apron protects culvert outlet. *Width of protection: Bottom width of channel and up both side slopes to a depth at least half the culvert diameter. Protect bare/disturbed downstream soils from erosion with appropriate soil cover. Use normal-depth calculator to compute for downstream protection. Install anchors per ScourStop Installation Guidelines. Minimum depth 24” in compacted, cohesive soil. Minimum depth 30” in loose, sandy, or wet soil. Extra anchors as needed to secure mat tightly over soil cover. Abut transition mats to end of culvert or culvert apron. Adjacent mats abut together laterally and longitudinally. Minimum 8 anchors per mat. Extra anchors as needed for loose or wet soils. Extra anchors as needed for uneven soil surface. ScourStop® Installation Recommendations A A MAX. 1"-2" DROP FROM CULVERT FLOWLINE ONTO SCOURSTOP MATSCULVERT FLOWLINE PROFILE VIEW A LEADER in the GEOSYNTHETIC and EROSION CONTROL industries Learn more about our products at: HanesGeo.com | 888.239.4539 the green solution to riprap ©2014 Leggett & Platt, Incorporated | 16959_1114 AA C APPENDIX C – LID AND WATER QUALITY Project Number:Project: Project Location: Calculations By:Date: Sq. Ft. Acres A 98,840 2.27 62%Rain Garden A 1,798 2,039 61,281 B 66,289 1.52 78%Rain Garden B 1,361 1,507 51,705 C 172,098 3.95 48%Rain Garden C 2,305 2,369 84,832 D 68,833 1.58 66%Rain Garden D 1,183 1,401 45,430 E 171,002 3.93 61%Chambers E 2,714 2,771 104,311 F 5,206 0.12 74%n/a 0 0 3,852 G 6,594 0.15 66%n/a 0 0 4,352 H 13,692 0.31 85%n/a 0 0 11,638 I 19,551 0.45 74%n/a 0 0 14,468 J 15,206 0.35 76%n/a 0 0 11,557 K 21,523 0.49 73%n/a 0 0 15,712 L 27,767 0.64 57%n/a 0 0 15,827 M 107,554 2.47 79%Rain Garden M 2,310 2,377 82,743 N 42,143 0.97 13%n/a 0 0 5,479 Total 836,298 16.93 12,464 513,187 Sq. Ft.Acres Rain Garden A 98,840 2.27 62%A Rain Garden 1,798 61,281 Rain Garden B 66,289 1.52 78%B Rain Garden 1,361 51,705 Rain Garden C 172,098 3.95 48%C Rain Garden 2,209 82,607 Rain Garden D 68,833 1.58 66%D Rain Garden 1,183 45,430 Chambers E 171,002 3.93 61%E Chambers 2,714 104,311 Rain Garden M 119,169 2.74 74%M Rain Garden 2,338 88,185 Total 696,231 15.98 433,519 836,298 ft2 513,187 ft2 82,885 ft2 384890.0775 ft3 430,302 ft2 83.8% LID Summary AreaBasin ID Percent Impervious LID ID Landing at Lemay 11/15/2023 1791-003 Fort Collins, Colorado ARS Total Impervious Area Treated (ft2) Required Volume (ft3) LID Summary per Basin Provided Volume (ft3) Area Weighted % Impervious Impervious Area (ft2) LID Summary per LID Structure LID Site Summary - New Impervious Area Subbasin ID Treatment TypeLID ID Volume per UD-BMP (ft3) Total Treated Area Percent Impervious Treated by LID 75% Required Minimum Area to be Treated Total Area of Current Development Total Impervious Area Total Impervious Area without LID Treatment: F, G, H, I, J, K, L, N NO R T H L E M A Y A V E N U E DUFF DRIVE CO R D O V A R O A D LINK LANE DETENTION POND 2 RAIN GARDEN A RAIN GARDEN D RAIN GARDEN C DETENTION POND 1 RAIN GARDEN B RAIN GARDEN M KEYMAP NOT TO SCALE OF SCALE: PROJECT NO. PR O J E C T M A N A G E R : NO . RE V I S I O N S BY : DA T E : SU B M I T T A L D A T E : SHEET: HORIZ: VERT: CAUTION The engineer preparing these plans will not be responsible for, or liable for, unauthorized changes to or uses of these plans. All changes must be approved by the Professional Engineer of these plans. 09 / 2 7 / 2 3 TH E L A N D I N G A T L E M A Y 64 1791-003 D. W e b e r 13 3 7 R I V E R S I D E A V E . # 2 FO R T C O L L I N S , C O 8 0 5 2 4 AV A N T C I V I L G R O U P . C O M 97 0 . 2 8 6 . 7 9 9 5 NORTH ( IN FEET ) 1 inch = ft. Feet05050 50 100 150 LI D E X H I B I T LID 1" = 50' N/A LID SUMMARY TABLE TOTAL NEW (IMPROVED) IMPERVIOUS AREA, (SF)544,896 TARGET TREATMENT AREA (75%) (SF)408,672 TOTAL AREA TREATED BY LID (SF) (GREEN HATCH)461268 PERCENTAGE OF TOTAL 84.7% TOTAL AREA NOT TREATED BY LID (SF) (RED HATCH)83,628 PERCENTAGE OF TOTAL 15.35% Sheet 1 of 2 Designer: Company: Date: Project: Location: 1. Basin Storage Volume A) Effective Imperviousness of Tributary Area, Ia Ia =62.0 % (100% if all paved and roofed areas upstream of rain garden) B) Tributary Area's Imperviousness Ratio (i = Ia/100)i =0.620 C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.19 watershed inches (WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i) D) Contributing Watershed Area (including rain garden area) Area = 110,951 sq ft E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =1,798 cu ft Vol = (WQCV / 12) * Area F) For Watersheds Outside of the Denver Region, Depth of d6 = in Average Runoff Producing Storm G) For Watersheds Outside of the Denver Region, VWQCV OTHER =cu ft Water Quality Capture Volume (WQCV) Design Volume H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER =cu ft (Only if a different WQCV Design Volume is desired) 2. Basin Geometry A) WQCV Depth (12-inch maximum)DWQCV =12 in B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 4.00 ft / ft (Use "0" if rain garden has vertical walls) C) Mimimum Flat Surface Area AMin =1376 sq ft D) Actual Flat Surface Area AActual =1376 sq ft E) Area at Design Depth (Top Surface Area)ATop =2702 sq ft F) Rain Garden Total Volume VT=2,039 cu ft (VT= ((ATop + AActual) / 2) * Depth) 3. Growing Media 4. Underdrain System A) Are underdrains provided?1 B) Underdrain system orifice diameter for 12 hour drain time i) Distance From Lowest Elevation of the Storage y =50.0 ft Volume to the Center of the Orifice ii) Volume to Drain in 12 Hours Vol12 =1,798 cu ft iii) Orifice Diameter, 3/8" Minimum DO =1/2 in Design Procedure Form: Rain Garden (RG) AS Avant Civil Group July 18, 2023 Landing at Lemay Rain Garden A UD-BMP (Version 3.07, March 2018) Choose One Choose One 18" Rain Garden Growing Media Other (Explain): YES NO UD-BMP_v3.07_Rain Garden A, RG 7/18/2023, 2:30 PM Sheet 1 of 2 Designer: Company: Date: Project: Location: 1. Basin Storage Volume A) Effective Imperviousness of Tributary Area, Ia Ia =60.0 % (100% if all paved and roofed areas upstream of rain garden) B) Tributary Area's Imperviousness Ratio (i = Ia/100)i =0.600 C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.19 watershed inches (WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i) D) Contributing Watershed Area (including rain garden area) Area = 86,471 sq ft E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =1,361 cu ft Vol = (WQCV / 12) * Area F) For Watersheds Outside of the Denver Region, Depth of d6 = in Average Runoff Producing Storm G) For Watersheds Outside of the Denver Region, VWQCV OTHER =cu ft Water Quality Capture Volume (WQCV) Design Volume H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER =cu ft (Only if a different WQCV Design Volume is desired) 2. Basin Geometry A) WQCV Depth (12-inch maximum)DWQCV =12 in B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 4.00 ft / ft (Use "0" if rain garden has vertical walls) C) Mimimum Flat Surface Area AMin =1038 sq ft D) Actual Flat Surface Area AActual =1060 sq ft E) Area at Design Depth (Top Surface Area)ATop =1954 sq ft F) Rain Garden Total Volume VT=1,507 cu ft (VT= ((ATop + AActual) / 2) * Depth) 3. Growing Media 4. Underdrain System A) Are underdrains provided?1 B) Underdrain system orifice diameter for 12 hour drain time i) Distance From Lowest Elevation of the Storage y =50.0 ft Volume to the Center of the Orifice ii) Volume to Drain in 12 Hours Vol12 =1,361 cu ft iii) Orifice Diameter, 3/8" Minimum DO =7/16 in Design Procedure Form: Rain Garden (RG) AS Avant Civil Group May 16, 2023 Landing at Lemay Rain Garden B UD-BMP (Version 3.07, March 2018) Choose One Choose One 18" Rain Garden Growing Media Other (Explain): YES NO UD-BMP_v3.07_Rain Garden B, RG 5/16/2023, 3:13 PM Sheet 1 of 2 Designer: Company: Date: Project: Location: 1. Basin Storage Volume A) Effective Imperviousness of Tributary Area, Ia Ia =48.0 % (100% if all paved and roofed areas upstream of rain garden) B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 0.480 C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.16 watershed inches (WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i) D) Contributing Watershed Area (including rain garden area) Area = 172,098 sq ft E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =2,305 cu ft Vol = (WQCV / 12) * Area F) For Watersheds Outside of the Denver Region, Depth of d6 = in Average Runoff Producing Storm G) For Watersheds Outside of the Denver Region, VWQCV OTHER =cu ft Water Quality Capture Volume (WQCV) Design Volume H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER =cu ft (Only if a different WQCV Design Volume is desired) 2. Basin Geometry A) WQCV Depth (12-inch maximum)DWQCV =12 in B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 4.00 ft / ft (Use "0" if rain garden has vertical walls) C) Mimimum Flat Surface Area AMin =1652 sq ft D) Actual Flat Surface Area AActual =1988 sq ft E) Area at Design Depth (Top Surface Area)ATop =2750 sq ft F) Rain Garden Total Volume VT=2,369 cu ft (VT= ((ATop + AActual) / 2) * Depth) 3. Growing Media 4. Underdrain System A) Are underdrains provided?1 B) Underdrain system orifice diameter for 12 hour drain time i) Distance From Lowest Elevation of the Storage y =50.0 ft Volume to the Center of the Orifice ii) Volume to Drain in 12 Hours Vol12 =2,305 cu ft iii) Orifice Diameter, 3/8" Minimum DO =9/16 in Design Procedure Form: Rain Garden (RG) AS Avant Civil Group November 14, 2023 Landing at Lemay Rain Garden C UD-BMP (Version 3.07, March 2018) Choose One Choose One 18" Rain Garden Growing Media Other (Explain): YES NO UD-BMP_v3.07_Rain Garden C, RG 11/14/2023, 3:38 PM Sheet 1 of 2 Designer: Company: Date: Project: Location: 1. Basin Storage Volume A) Effective Imperviousness of Tributary Area, Ia Ia =66.0 % (100% if all paved and roofed areas upstream of rain garden) B) Tributary Area's Imperviousness Ratio (i = Ia/100)i =0.660 C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.21 watershed inches (WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i) D) Contributing Watershed Area (including rain garden area) Area = 68,789 sq ft E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =1,183 cu ft Vol = (WQCV / 12) * Area F) For Watersheds Outside of the Denver Region, Depth of d6 = in Average Runoff Producing Storm G) For Watersheds Outside of the Denver Region, VWQCV OTHER =cu ft Water Quality Capture Volume (WQCV) Design Volume H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER =cu ft (Only if a different WQCV Design Volume is desired) 2. Basin Geometry A) WQCV Depth (12-inch maximum)DWQCV =12 in B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 4.00 ft / ft (Use "0" if rain garden has vertical walls) C) Mimimum Flat Surface Area AMin =908 sq ft D) Actual Flat Surface Area AActual =1171 sq ft E) Area at Design Depth (Top Surface Area)ATop =1725 sq ft F) Rain Garden Total Volume VT=1,448 cu ft (VT= ((ATop + AActual) / 2) * Depth) 3. Growing Media 4. Underdrain System A) Are underdrains provided?1 B) Underdrain system orifice diameter for 12 hour drain time i) Distance From Lowest Elevation of the Storage y =50.0 ft Volume to the Center of the Orifice ii) Volume to Drain in 12 Hours Vol12 =1,183 cu ft iii) Orifice Diameter, 3/8" Minimum DO =7/16 in Design Procedure Form: Rain Garden (RG) AS Avant Civil Group May 16, 2023 Landing at Lemay Rain Garden D UD-BMP (Version 3.07, March 2018) Choose One Choose One 18" Rain Garden Growing Media Other (Explain): YES NO UD-BMP_v3.07_Rain Garden D, RG 5/16/2023, 3:14 PM Sheet 1 of 2 Designer: Company: Date: Project: Location: 1. Basin Storage Volume A) Effective Imperviousness of Tributary Area, Ia Ia =79.0 % (100% if all paved and roofed areas upstream of rain garden) B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 0.790 C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.26 watershed inches (WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i) D) Contributing Watershed Area (including rain garden area) Area = 107,554 sq ft E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =2,310 cu ft Vol = (WQCV / 12) * Area F) For Watersheds Outside of the Denver Region, Depth of d6 = in Average Runoff Producing Storm G) For Watersheds Outside of the Denver Region, VWQCV OTHER =cu ft Water Quality Capture Volume (WQCV) Design Volume H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER =cu ft (Only if a different WQCV Design Volume is desired) 2. Basin Geometry A) WQCV Depth (12-inch maximum)DWQCV =12 in B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 0.00 ft / ft (Use "0" if rain garden has vertical walls) C) Mimimum Flat Surface Area AMin =1699 sq ft D) Actual Flat Surface Area AActual =2377 sq ft E) Area at Design Depth (Top Surface Area)ATop =2377 sq ft F) Rain Garden Total Volume VT=2,377 cu ft (VT= ((ATop + AActual) / 2) * Depth) 3. Growing Media 4. Underdrain System A) Are underdrains provided?1 B) Underdrain system orifice diameter for 12 hour drain time i) Distance From Lowest Elevation of the Storage y =50.0 ft Volume to the Center of the Orifice ii) Volume to Drain in 12 Hours Vol12 =2,310 cu ft iii) Orifice Diameter, 3/8" Minimum DO =9/16 in Design Procedure Form: Rain Garden (RG) AS Avant Civil Group November 14, 2023 Landing at Lemay Rain Garden M UD-BMP (Version 3.07, March 2018) Choose One Choose One 18" Rain Garden Growing Media Other (Explain): YES NO UD-BMP_v3.07_Rain Garden M, RG 11/14/2023, 3:34 PM Project Title Date: Project Number Calcs By: City Basins 0.8 WQCV = Watershed inches of Runoff (inches)61% a = Runoff Volume Reduction (constant) i = Total imperviousness Ratio (i = Iwq/100)0.192 in A =3.93 ac V = 0.0627 ac-ft V = Water Quality Design Volume (ac-ft) WQCV = Water Quality Capture Volume (inches) A = Watershed Area (acres) The landing at Lemay September 27, 2023 1791-003 ARS Fort Collins Stormtech Chambers E 2731 cu. ft. Drain Time a = i = WQCV = Figure EDB-2 - Water Quality Capture Volume (WQCV), 80th Percentile Runoff Event 0.231 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0 0. 1 0. 2 0. 3 0. 4 0. 5 0. 6 0. 7 0. 8 0. 9 1 WQ C V ( w a t e r s h e d i n c h e s ) Total Imperviousness Ratio (i = Iwq/100) Water Quality Capture Volume 6 hr 12 hr 24 hr 40 hr ()iii78.019.10.91aWQCV 23 +-= ()iii78.019.10.91aWQCV 23 +-= AV* 12 WQCV   = 12 hr Vault ID Total Required WQ Volume (cf) Flow, WQ (cfs) Chamber Type Chamber Release Ratea (cfs) Chamber Volumeb (cf) Installed Chamber w/ Aggregatec (cf) Mimimum No. of Chambersd Total Release Ratee (cfs) Required Storage Volume by FAA Method (cf) Provided Number of Chambers Provided Release Rate (cfs) Storage Provided within the Chambersg (cf) Total Installed System Volumeh (cf) Basin E 2731 1.97 SC-740 0.024 45.90 74.90 37 0.87 3566 37 0.87 1698 2771 a. Release rate per chamber, limited by flow through geotextile with accumulated sediment. b. Volume within chamber only, not accounting for void spaces in surrounding aggregate. c. Volume includes chamber and void spaces (40%) in surrounding aggregate, per chamber unit. d. Number of chambers required to provide full WQCV within total installed system, including aggregate. e. Release rate per chamber times number of chambers. f. Number of chambers required to provide required FAA storage volume stored within the chamber only (no aggregate storage). g. Volume provided in chambers only (no aggregate storage). This number must meet or exceed the required FAA storage volume. h. System volume includes total number of chambers, plus surrounding aggregate. This number must meet or exceed the required WQCV. Chamber Configuration Summary Advanced Drainage Systems, Inc. FOR STORMTECH INSTALLATION INSTRUCTIONS VISIT OUR APP SiteAssist IMPORTANT - NOTES FOR THE BIDDING AND INSTALLATION OF THE SC-740 SYSTEM 1.STORMTECH SC-740 CHAMBERS SHALL NOT BE INSTALLED UNTIL THE MANUFACTURER'S REPRESENTATIVE HAS COMPLETED A PRE-CONSTRUCTION MEETING WITH THE INSTALLERS. 2.STORMTECH SC-740 CHAMBERS SHALL BE INSTALLED IN ACCORDANCE WITH THE "STORMTECH SC-310/SC-740/DC-780 CONSTRUCTION GUIDE". 3.CHAMBERS ARE NOT TO BE BACKFILLED WITH A DOZER OR AN EXCAVATOR SITUATED OVER THE CHAMBERS. STORMTECH RECOMMENDS 3 BACKFILL METHODS: ·STONESHOOTER LOCATED OFF THE CHAMBER BED. ·BACKFILL AS ROWS ARE BUILT USING AN EXCAVATOR ON THE FOUNDATION STONE OR SUBGRADE. ·BACKFILL FROM OUTSIDE THE EXCAVATION USING A LONG BOOM HOE OR EXCAVATOR. 4.THE FOUNDATION STONE SHALL BE LEVELED AND COMPACTED PRIOR TO PLACING CHAMBERS. 5.JOINTS BETWEEN CHAMBERS SHALL BE PROPERLY SEATED PRIOR TO PLACING STONE. 6.MAINTAIN MINIMUM - 6" (150 mm) SPACING BETWEEN THE CHAMBER ROWS. 7.EMBEDMENT STONE SURROUNDING CHAMBERS MUST BE A CLEAN, CRUSHED, ANGULAR STONE 3/4-2" (20-50 mm). 8.THE CONTRACTOR MUST REPORT ANY DISCREPANCIES WITH CHAMBER FOUNDATION MATERIALS BEARING CAPACITIES TO THE SITE DESIGN ENGINEER. 9.ADS RECOMMENDS THE USE OF "FLEXSTORM CATCH IT" INSERTS DURING CONSTRUCTION FOR ALL INLETS TO PROTECT THE SUBSURFACE STORMWATER MANAGEMENT SYSTEM FROM CONSTRUCTION SITE RUNOFF. NOTES FOR CONSTRUCTION EQUIPMENT 1.STORMTECH SC-740 CHAMBERS SHALL BE INSTALLED IN ACCORDANCE WITH THE "STORMTECH SC-310/SC-740/DC-780 CONSTRUCTION GUIDE". 2.THE USE OF CONSTRUCTION EQUIPMENT OVER SC-740 CHAMBERS IS LIMITED: ·NO EQUIPMENT IS ALLOWED ON BARE CHAMBERS. ·NO RUBBER TIRED LOADERS, DUMP TRUCKS, OR EXCAVATORS ARE ALLOWED UNTIL PROPER FILL DEPTHS ARE REACHED IN ACCORDANCE WITH THE "STORMTECH SC-310/SC-740/DC-780 CONSTRUCTION GUIDE". ·WEIGHT LIMITS FOR CONSTRUCTION EQUIPMENT CAN BE FOUND IN THE "STORMTECH SC-310/SC-740/DC-780 CONSTRUCTION GUIDE". 3.FULL 36" (900 mm) OF STABILIZED COVER MATERIALS OVER THE CHAMBERS IS REQUIRED FOR DUMP TRUCK TRAVEL OR DUMPING. USE OF A DOZER TO PUSH EMBEDMENT STONE BETWEEN THE ROWS OF CHAMBERS MAY CAUSE DAMAGE TO THE CHAMBERS AND IS NOT AN ACCEPTABLE BACKFILL METHOD. ANY CHAMBERS DAMAGED BY THE "DUMP AND PUSH" METHOD ARE NOT COVERED UNDER THE STORMTECH STANDARD WARRANTY. CONTACT STORMTECH AT 1-888-892-2694 WITH ANY QUESTIONS ON INSTALLATION REQUIREMENTS OR WEIGHT LIMITS FOR CONSTRUCTION EQUIPMENT. SC-740 STORMTECH CHAMBER SPECIFICATIONS 1.CHAMBERS SHALL BE STORMTECH SC-740. 2.CHAMBERS SHALL BE ARCH-SHAPED AND SHALL BE MANUFACTURED FROM VIRGIN, IMPACT-MODIFIED POLYPROPYLENE COPOLYMERS. 3.CHAMBERS SHALL MEET THE REQUIREMENTS OF ASTM F2418, "STANDARD SPECIFICATION FOR POLYPROPYLENE (PP) CORRUGATED WALL STORMWATER COLLECTION CHAMBERS". 4.CHAMBER ROWS SHALL PROVIDE CONTINUOUS, UNOBSTRUCTED INTERNAL SPACE WITH NO INTERNAL SUPPORTS THAT WOULD IMPEDE FLOW OR LIMIT ACCESS FOR INSPECTION. 5.THE STRUCTURAL DESIGN OF THE CHAMBERS, THE STRUCTURAL BACKFILL, AND THE INSTALLATION REQUIREMENTS SHALL ENSURE THAT THE LOAD FACTORS SPECIFIED IN THE AASHTO LRFD BRIDGE DESIGN SPECIFICATIONS, SECTION 12.12, ARE MET FOR: 1) LONG-DURATION DEAD LOADS AND 2) SHORT-DURATION LIVE LOADS, BASED ON THE AASHTO DESIGN TRUCK WITH CONSIDERATION FOR IMPACT AND MULTIPLE VEHICLE PRESENCES. 6.CHAMBERS SHALL BE DESIGNED, TESTED AND ALLOWABLE LOAD CONFIGURATIONS DETERMINED IN ACCORDANCE WITH ASTM F2787, "STANDARD PRACTICE FOR STRUCTURAL DESIGN OF THERMOPLASTIC CORRUGATED WALL STORMWATER COLLECTION CHAMBERS". LOAD CONFIGURATIONS SHALL INCLUDE: 1) INSTANTANEOUS (<1 MIN) AASHTO DESIGN TRUCK LIVE LOAD ON MINIMUM COVER 2) MAXIMUM PERMANENT (75-YR) COVER LOAD AND 3) ALLOWABLE COVER WITH PARKED (1-WEEK) AASHTO DESIGN TRUCK. 7.REQUIREMENTS FOR HANDLING AND INSTALLATION: ·TO MAINTAIN THE WIDTH OF CHAMBERS DURING SHIPPING AND HANDLING, CHAMBERS SHALL HAVE INTEGRAL, INTERLOCKING STACKING LUGS. ·TO ENSURE A SECURE JOINT DURING INSTALLATION AND BACKFILL, THE HEIGHT OF THE CHAMBER JOINT SHALL NOT BE LESS THAN 2”. ·TO ENSURE THE INTEGRITY OF THE ARCH SHAPE DURING INSTALLATION, a) THE ARCH STIFFNESS CONSTANT SHALL BE GREATER THAN OR EQUAL TO 550 LBS/FT/%. THE ASC IS DEFINED IN SECTION 6.2.8 OF ASTM F2418. AND b) TO RESIST CHAMBER DEFORMATION DURING INSTALLATION AT ELEVATED TEMPERATURES (ABOVE 73° F / 23° C), CHAMBERS SHALL BE PRODUCED FROM REFLECTIVE GOLD OR YELLOW COLORS. 8.ONLY CHAMBERS THAT ARE APPROVED BY THE SITE DESIGN ENGINEER WILL BE ALLOWED. UPON REQUEST BY THE SITE DESIGN ENGINEER OR OWNER, THE CHAMBER MANUFACTURER SHALL SUBMIT A STRUCTURAL EVALUATION FOR APPROVAL BEFORE DELIVERING CHAMBERS TO THE PROJECT SITE AS FOLLOWS: ·THE STRUCTURAL EVALUATION SHALL BE SEALED BY A REGISTERED PROFESSIONAL ENGINEER. ·THE STRUCTURAL EVALUATION SHALL DEMONSTRATE THAT THE SAFETY FACTORS ARE GREATER THAN OR EQUAL TO 1.95 FOR DEAD LOAD AND 1.75 FOR LIVE LOAD, THE MINIMUM REQUIRED BY ASTM F2787 AND BY SECTIONS 3 AND 12.12 OF THE AASHTO LRFD BRIDGE DESIGN SPECIFICATIONS FOR THERMOPLASTIC PIPE. ·THE TEST DERIVED CREEP MODULUS AS SPECIFIED IN ASTM F2418 SHALL BE USED FOR PERMANENT DEAD LOAD DESIGN EXCEPT THAT IT SHALL BE THE 75-YEAR MODULUS USED FOR DESIGN. 9.CHAMBERS AND END CAPS SHALL BE PRODUCED AT AN ISO 9001 CERTIFIED MANUFACTURING FACILITY. ©2023 ADS, INC. PROJECT INFORMATION ADS SALES REP PROJECT NO. ENGINEERED PRODUCT MANAGER THE LANDING AT LEMAY FORT COLLINS, CO, USA MARK KAELBERER 720-256-8225 MARK.KAELBERER@ADS-PIPE.COM S377242 JEROME MAGSINO 303-349-7555 JEROME.MAGSINO@ADSPIPE.COM St o r m T e c h 88 8 - 8 9 2 - 2 6 9 4 | WW W . S T O R M T E C H . C O M ® Ch a m b e r S y s t e m 46 4 0 T R U E M A N B L V D HI L L I A R D , O H 4 3 0 2 6 1- 8 0 0 - 7 3 3 - 7 4 7 3 DA T E : 1 1 / 1 5 / 2 0 2 3 DR A W N : E M PR O J E C T # : S 3 7 7 2 4 2 CH E C K E D : R C TH I S D R A W I N G H A S B E E N P R E P A R E D B A S E D O N I N F O R M A T I O N P R O V I D E D T O A D S U N D E R T H E D I R E C T I O N O F T H E S I T E D E S I G N E N G I N E E R O R O T H E R P R O J E C T R E P R E S E N T A T I V E . T H E S I T E D E S I G N E N G I N E E R S H A L L R E V I E W T H I S D R A W I N G P R I O R T O C O N S T R U C T I O N . I T I S T H E U L T I M A T E RE S P O N S I B I L I T Y O F T H E S I T E D E S I G N E N G I N E E R T O E N S U R E T H A T T H E P R O D U C T ( S ) D E P I C T E D A N D A L L A S S O C I A T E D D E T A I L S M E E T A L L A P P L I C A B L E L A W S , R E G U L A T I O N S , A N D P R O J E C T R E Q U I R E M E N T S . DA T E DR W CH K DE S C R I P T I O N TH E L A N D I N G A T L E M A Y FO R T C O L L I N S , C O , U S A SHEET OF2 5 NOTES •MANIFOLD SIZE TO BE DETERMINED BY SITE DESIGN ENGINEER. SEE TECH NOTE #6.32 FOR MANIFOLD SIZING GUIDANCE. •DUE TO THE ADAPTATION OF THIS CHAMBER SYSTEM TO SPECIFIC SITE AND DESIGN CONSTRAINTS, IT MAY BE NECESSARY TO CUT AND COUPLE ADDITIONAL PIPE TO STANDARD MANIFOLD COMPONENTS IN THE FIELD. •THE SITE DESIGN ENGINEER MUST REVIEW ELEVATIONS AND IF NECESSARY ADJUST GRADING TO ENSURE THE CHAMBER COVER REQUIREMENTS ARE MET. •THIS CHAMBER SYSTEM WAS DESIGNED WITHOUT SITE-SPECIFIC INFORMATION ON SOIL CONDITIONS OR BEARING CAPACITY. THE SITE DESIGN ENGINEER IS RESPONSIBLE FOR DETERMINING THE SUITABILITY OF THE SOIL AND PROVIDING THE BEARING CAPACITY OF THE INSITU SOILS. THE BASE STONE DEPTH MAY BE INCREASED OR DECREASED ONCE THIS INFORMATION IS PROVIDED. ·THE STORMTECH SYSTEM DEPICTED DOES NOT PROVIDE THE ABILITY TO BE MAINTAINED. NOT MAINTAINING THE SYSTEM MAY LEAD TO ACCUMULATION OF SEDIMENT AND DECREASE IN STORAGE VOLUME OVER TIME DEPENDENT ON UPSTREAM WATER QUALITY DEVICES. ·THE STORMTECH SYSTEM DEPICTED DOES NOT CONTAIN PROPER WATER QUALITY MEASURES. ABSENCE OF WATER QUALITY MEASURES CAN RESULT IN UNTREATED STORMWATER. ADS RECOMMENDS THE USE OF ISOLATOR ROW PLUS AND AN UPSTREAM HIGH FLOW BYPASS ON ALL STORMTECH SYSTEMS TO PROPERLY DIRECT THE FIRST FLUSH. ·NOT FOR CONSTRUCTION: THIS LAYOUT IS FOR DIMENSIONAL PURPOSES ONLY TO PROVE CONCEPT & THE REQUIRED STORAGE VOLUME CAN BE ACHIEVED ON SITE. CONCEPTUAL ELEVATIONS: MAXIMUM ALLOWABLE GRADE (TOP OF PAVEMENT/UNPAVED): MINIMUM ALLOWABLE GRADE (UNPAVED WITH TRAFFIC): MINIMUM ALLOWABLE GRADE (UNPAVED NO TRAFFIC): MINIMUM ALLOWABLE GRADE (TOP OF RIGID CONCRETE PAVEMENT): MINIMUM ALLOWABLE GRADE (BASE OF FLEXIBLE PAVEMENT): TOP OF STONE: TOP OF SC-740 CHAMBER: 24" BOTTOM MANIFOLD INVERT: 24" ISOLATOR ROW PLUS INVERT: BOTTOM OF SC-740 CHAMBER: BOTTOM OF STONE:4938.36 PROPOSED LAYOUT 32 STORMTECH SC-740 CHAMBERS 8 STORMTECH SC-740 END CAPS 6 STONE ABOVE (in) 6 STONE BELOW (in) 40 STONE VOID 1326 SYSTEM AREA (SF) 170 SYSTEM PERIMETER (ft) *INVERT ABOVE BASE OF CHAMBER MAX FLOWINVERT*DESCRIPTIONITEM ON LAYOUTPART TYPE 0.10"24" BOTTOM PREFABRICATED EZ END CAP, PART#: SC740ECEZ / TYP OF ALL 24" BOTTOM CONNECTIONS AND ISOLATOR PLUS ROWSAPREFABRICATED EZ END CAP INSTALL FLAMP ON 24" ACCESS PIPE / PART#: SC74024RAMP (TYP 2 PLACES)BFLAMP 0.10"24" x 24" BOTTOM MANIFOLD, ADS N-12CMANIFOLD E (DESIGN BY ENGINEER / PROVIDED BY OTHERS) F CONCRETE STRUCTURE (DESIGN BY ENGINEER / PROVIDED BY OTHERS) G OUTLET STRUCTURE 4" SEE DETAIL (TYP 4 PLACES)INSPECTION PORT ISOLATOR ROW PLUS (SEE DETAIL/TYP 4 PLACES) PLACE MINIMUM 12.50' OF ADSPLUS125 WOVEN GEOTEXTILE OVER BEDDING STONE AND UNDERNEATH CHAMBER FEET FOR SCOUR PROTECTION AT ALL CHAMBER INLET ROWS BED LIMITS 0 5 10 20 . 5 0 ' 18 . 5 0 ' C B F A E D UNDERDRAIN INVERT:4938.36 4938.86 4938.87 4938.87 4941.36 4941.86 4942.86 4942.86 4942.86 4943.36 4949.36 D G UNDERDRAIN 6" ADS N-12 DUAL WALL PERFORATED HDPE UNDERDRAIN 64.67' 56.93' WEIR, ELEV. 4941.37' UNDERDRAIN OUTFALLS DIRECTLY TO POND St o r m T e c h 88 8 - 8 9 2 - 2 6 9 4 | WW W . S T O R M T E C H . C O M ® Ch a m b e r S y s t e m ACCEPTABLE FILL MATERIALS: STORMTECH SC-740 CHAMBER SYSTEMS PLEASE NOTE: 1.THE LISTED AASHTO DESIGNATIONS ARE FOR GRADATIONS ONLY. THE STONE MUST ALSO BE CLEAN, CRUSHED, ANGULAR. FOR EXAMPLE, A SPECIFICATION FOR #4 STONE WOULD STATE: "CLEAN, CRUSHED, ANGULAR NO. 4 (AASHTO M43) STONE". 2.STORMTECH COMPACTION REQUIREMENTS ARE MET FOR 'A' LOCATION MATERIALS WHEN PLACED AND COMPACTED IN 6" (150 mm) (MAX) LIFTS USING TWO FULL COVERAGES WITH A VIBRATORY COMPACTOR. 3.WHERE INFILTRATION SURFACES MAY BE COMPROMISED BY COMPACTION, FOR STANDARD DESIGN LOAD CONDITIONS, A FLAT SURFACE MAY BE ACHIEVED BY RAKING OR DRAGGING WITHOUT COMPACTION EQUIPMENT. FOR SPECIAL LOAD DESIGNS, CONTACT STORMTECH FOR COMPACTION REQUIREMENTS. 4.ONCE LAYER 'C' IS PLACED, ANY SOIL/MATERIAL CAN BE PLACED IN LAYER 'D' UP TO THE FINISHED GRADE. MOST PAVEMENT SUBBASE SOILS CAN BE USED TO REPLACE THE MATERIAL REQUIREMENTS OF LAYER 'C' OR 'D' AT THE SITE DESIGN ENGINEER'S DISCRETION. NOTES: 1.CHAMBERS SHALL MEET THE REQUIREMENTS OF ASTM F2418, "STANDARD SPECIFICATION FOR POLYPROPYLENE (PP) CORRUGATED WALL STORMWATER COLLECTION CHAMBERS". 2.SC-740 CHAMBERS SHALL BE DESIGNED IN ACCORDANCE WITH ASTM F2787 "STANDARD PRACTICE FOR STRUCTURAL DESIGN OF THERMOPLASTIC CORRUGATED WALL STORMWATER COLLECTION CHAMBERS". 3.THE SITE DESIGN ENGINEER IS RESPONSIBLE FOR ASSESSING THE BEARING RESISTANCE (ALLOWABLE BEARING CAPACITY) OF THE SUBGRADE SOILS AND THE DEPTH OF FOUNDATION STONE WITH CONSIDERATION FOR THE RANGE OF EXPECTED SOIL MOISTURE CONDITIONS. 4.PERIMETER STONE MUST BE EXTENDED HORIZONTALLY TO THE EXCAVATION WALL FOR BOTH VERTICAL AND SLOPED EXCAVATION WALLS. 5.REQUIREMENTS FOR HANDLING AND INSTALLATION: ·TO MAINTAIN THE WIDTH OF CHAMBERS DURING SHIPPING AND HANDLING, CHAMBERS SHALL HAVE INTEGRAL, INTERLOCKING STACKING LUGS. ·TO ENSURE A SECURE JOINT DURING INSTALLATION AND BACKFILL, THE HEIGHT OF THE CHAMBER JOINT SHALL NOT BE LESS THAN 2”. ·TO ENSURE THE INTEGRITY OF THE ARCH SHAPE DURING INSTALLATION, a) THE ARCH STIFFNESS CONSTANT SHALL BE GREATER THAN OR EQUAL TO 550 LBS/FT/%. THE ASC IS DEFINED IN SECTION 6.2.8 OF ASTM F2418. AND b) TO RESIST CHAMBER DEFORMATION DURING INSTALLATION AT ELEVATED TEMPERATURES (ABOVE 73° F / 23° C), CHAMBERS SHALL BE PRODUCED FROM REFLECTIVE GOLD OR YELLOW COLORS. MATERIAL LOCATION DESCRIPTION AASHTO MATERIAL CLASSIFICATIONS COMPACTION / DENSITY REQUIREMENT D FINAL FILL: FILL MATERIAL FOR LAYER 'D' STARTS FROM THE TOP OF THE 'C' LAYER TO THE BOTTOM OF FLEXIBLE PAVEMENT OR UNPAVED FINISHED GRADE ABOVE. NOTE THAT PAVEMENT SUBBASE MAY BE PART OF THE 'D' LAYER. ANY SOIL/ROCK MATERIALS, NATIVE SOILS, OR PER ENGINEER'S PLANS. CHECK PLANS FOR PAVEMENT SUBGRADE REQUIREMENTS.N/A PREPARE PER SITE DESIGN ENGINEER'S PLANS. PAVED INSTALLATIONS MAY HAVE STRINGENT MATERIAL AND PREPARATION REQUIREMENTS. C INITIAL FILL: FILL MATERIAL FOR LAYER 'C' STARTS FROM THE TOP OF THE EMBEDMENT STONE ('B' LAYER) TO 18" (450 mm) ABOVE THE TOP OF THE CHAMBER. NOTE THAT PAVEMENT SUBBASE MAY BE A PART OF THE 'C' LAYER. GRANULAR WELL-GRADED SOIL/AGGREGATE MIXTURES, <35% FINES OR PROCESSED AGGREGATE. MOST PAVEMENT SUBBASE MATERIALS CAN BE USED IN LIEU OF THIS LAYER. AASHTO M145¹ A-1, A-2-4, A-3 OR AASHTO M43¹ 3, 357, 4, 467, 5, 56, 57, 6, 67, 68, 7, 78, 8, 89, 9, 10 BEGIN COMPACTIONS AFTER 12" (300 mm) OF MATERIAL OVER THE CHAMBERS IS REACHED. COMPACT ADDITIONAL LAYERS IN 6" (150 mm) MAX LIFTS TO A MIN. 95% PROCTOR DENSITY FOR WELL GRADED MATERIAL AND 95% RELATIVE DENSITY FOR PROCESSED AGGREGATE MATERIALS. ROLLER GROSS VEHICLE WEIGHT NOT TO EXCEED 12,000 lbs (53 kN). DYNAMIC FORCE NOT TO EXCEED 20,000 lbs (89 kN). B EMBEDMENT STONE: FILL SURROUNDING THE CHAMBERS FROM THE FOUNDATION STONE ('A' LAYER) TO THE 'C' LAYER ABOVE.CLEAN, CRUSHED, ANGULAR STONE AASHTO M43¹ 3, 357, 4, 467, 5, 56, 57 NO COMPACTION REQUIRED. A FOUNDATION STONE: FILL BELOW CHAMBERS FROM THE SUBGRADE UP TO THE FOOT (BOTTOM) OF THE CHAMBER.CLEAN, CRUSHED, ANGULAR STONE AASHTO M43¹ 3, 357, 4, 467, 5, 56, 57 PLATE COMPACT OR ROLL TO ACHIEVE A FLAT SURFACE.2,3 18" (450 mm) MIN* 8' (2.4 m) MAX 6" (150 mm) MIN D C B A 12" (300 mm) MIN 12" (300 mm) TYP51" (1295 mm)6" (150 mm) MIN 30" (760 mm) DEPTH OF STONE TO BE DETERMINED BY SITE DESIGN ENGINEER 6" (150 mm) MIN *TO BOTTOM OF FLEXIBLE PAVEMENT. FOR UNPAVED INSTALLATIONS WHERE RUTTING FROM VEHICLES MAY OCCUR, INCREASE COVER TO 24" (600 mm). PAVEMENT LAYER (DESIGNED BY SITE DESIGN ENGINEER) SC-740 END CAP EXCAVATION WALL (CAN BE SLOPED OR VERTICAL) PERIMETER STONE (SEE NOTE 4) SUBGRADE SOILS (SEE NOTE 3) ADS GEOSYNTHETICS 601T NON-WOVEN GEOTEXTILE ALL AROUND CLEAN, CRUSHED, ANGULAR STONE IN A & B LAYERS 46 4 0 T R U E M A N B L V D HI L L I A R D , O H 4 3 0 2 6 1- 8 0 0 - 7 3 3 - 7 4 7 3 DA T E : 1 1 / 1 5 / 2 0 2 3 DR A W N : E M PR O J E C T # : S 3 7 7 2 4 2 CH E C K E D : R C TH I S D R A W I N G H A S B E E N P R E P A R E D B A S E D O N I N F O R M A T I O N P R O V I D E D T O A D S U N D E R T H E D I R E C T I O N O F T H E S I T E D E S I G N E N G I N E E R O R O T H E R P R O J E C T R E P R E S E N T A T I V E . T H E S I T E D E S I G N E N G I N E E R S H A L L R E V I E W T H I S D R A W I N G P R I O R T O C O N S T R U C T I O N . I T I S T H E U L T I M A T E RE S P O N S I B I L I T Y O F T H E S I T E D E S I G N E N G I N E E R T O E N S U R E T H A T T H E P R O D U C T ( S ) D E P I C T E D A N D A L L A S S O C I A T E D D E T A I L S M E E T A L L A P P L I C A B L E L A W S , R E G U L A T I O N S , A N D P R O J E C T R E Q U I R E M E N T S . DA T E DR W CH K DE S C R I P T I O N TH E L A N D I N G A T L E M A Y FO R T C O L L I N S , C O , U S A SHEET OF3 5 St o r m T e c h 88 8 - 8 9 2 - 2 6 9 4 | WW W . S T O R M T E C H . C O M ® Ch a m b e r S y s t e m INSPECTION & MAINTENANCE STEP 1)INSPECT ISOLATOR ROW PLUS FOR SEDIMENT A.INSPECTION PORTS (IF PRESENT) A.1.REMOVE/OPEN LID ON NYLOPLAST INLINE DRAIN A.2.REMOVE AND CLEAN FLEXSTORM FILTER IF INSTALLED A.3.USING A FLASHLIGHT AND STADIA ROD, MEASURE DEPTH OF SEDIMENT AND RECORD ON MAINTENANCE LOG A.4.LOWER A CAMERA INTO ISOLATOR ROW PLUS FOR VISUAL INSPECTION OF SEDIMENT LEVELS (OPTIONAL) A.5.IF SEDIMENT IS AT, OR ABOVE, 3" (80 mm) PROCEED TO STEP 2. IF NOT, PROCEED TO STEP 3. B.ALL ISOLATOR PLUS ROWS B.1.REMOVE COVER FROM STRUCTURE AT UPSTREAM END OF ISOLATOR ROW PLUS B.2.USING A FLASHLIGHT, INSPECT DOWN THE ISOLATOR ROW PLUS THROUGH OUTLET PIPE i)MIRRORS ON POLES OR CAMERAS MAY BE USED TO AVOID A CONFINED SPACE ENTRY ii)FOLLOW OSHA REGULATIONS FOR CONFINED SPACE ENTRY IF ENTERING MANHOLE B.3.IF SEDIMENT IS AT, OR ABOVE, 3" (80 mm) PROCEED TO STEP 2. IF NOT, PROCEED TO STEP 3. STEP 2)CLEAN OUT ISOLATOR ROW PLUS USING THE JETVAC PROCESS A.A FIXED CULVERT CLEANING NOZZLE WITH REAR FACING SPREAD OF 45" (1.1 m) OR MORE IS PREFERRED B.APPLY MULTIPLE PASSES OF JETVAC UNTIL BACKFLUSH WATER IS CLEAN C.VACUUM STRUCTURE SUMP AS REQUIRED STEP 3)REPLACE ALL COVERS, GRATES, FILTERS, AND LIDS; RECORD OBSERVATIONS AND ACTIONS. STEP 4)INSPECT AND CLEAN BASINS AND MANHOLES UPSTREAM OF THE STORMTECH SYSTEM. NOTES 1.INSPECT EVERY 6 MONTHS DURING THE FIRST YEAR OF OPERATION. ADJUST THE INSPECTION INTERVAL BASED ON PREVIOUS OBSERVATIONS OF SEDIMENT ACCUMULATION AND HIGH WATER ELEVATIONS. 2.CONDUCT JETTING AND VACTORING ANNUALLY OR WHEN INSPECTION SHOWS THAT MAINTENANCE IS NECESSARY. CATCH BASIN OR MANHOLE SC-740 ISOLATOR ROW PLUS DETAIL NTS STORMTECH HIGHLY RECOMMENDS FLEXSTORM INSERTS IN ANY UPSTREAM STRUCTURES WITH OPEN GRATES OPTIONAL INSPECTION PORT SC-740 END CAP ONE LAYER OF ADSPLUS125 WOVEN GEOTEXTILE BETWEEN FOUNDATION STONE AND CHAMBERS 5' (1.5 m) MIN WIDE CONTINUOUS FABRIC WITHOUT SEAMS SUMP DEPTH TBD BY SITE DESIGN ENGINEER (24" [600 mm] MIN RECOMMENDED) INSTALL FLAMP ON 24" (600 mm) ACCESS PIPE PART#: SC74024RAMP 24" (600 mm) HDPE ACCESS PIPE REQUIRED USE EZ END CAP PART #: SC740ECEZ SC-740 CHAMBER NOTE: INSPECTION PORTS MAY BE CONNECTED THROUGH ANY CHAMBER CORRUGATION CREST. STORMTECH CHAMBER CONCRETE COLLAR ASPHALT OVERLAY FOR TRAFFIC APPLICATIONS 12" (300 mm) MIN WIDTH 8" (200 mm) MIN THICKNESS OF ASPHALT OVERLAY AND CONCRETE COLLAR 4" PVC INSPECTION PORT DETAIL (SC SERIES CHAMBER) NTS 8" NYLOPLAST INSPECTION PORT BODY (PART# 2708AG4IPKIT) OR TRAFFIC RATED BOX W/SOLID LOCKING COVER CONCRETE COLLAR / ASPHALT OVERLAY NOT REQUIRED FOR GREENSPACE OR NON-TRAFFIC APPLICATIONS 4" (100 mm) SDR 35 PIPE 4" (100 mm) INSERTA TEE TO BE CENTERED ON CORRUGATION CREST NYLOPLAST 8" LOCKING SOLID COVER AND FRAME 46 4 0 T R U E M A N B L V D HI L L I A R D , O H 4 3 0 2 6 1- 8 0 0 - 7 3 3 - 7 4 7 3 DA T E : 1 1 / 1 5 / 2 0 2 3 DR A W N : E M PR O J E C T # : S 3 7 7 2 4 2 CH E C K E D : R C TH I S D R A W I N G H A S B E E N P R E P A R E D B A S E D O N I N F O R M A T I O N P R O V I D E D T O A D S U N D E R T H E D I R E C T I O N O F T H E S I T E D E S I G N E N G I N E E R O R O T H E R P R O J E C T R E P R E S E N T A T I V E . T H E S I T E D E S I G N E N G I N E E R S H A L L R E V I E W T H I S D R A W I N G P R I O R T O C O N S T R U C T I O N . I T I S T H E U L T I M A T E RE S P O N S I B I L I T Y O F T H E S I T E D E S I G N E N G I N E E R T O E N S U R E T H A T T H E P R O D U C T ( S ) D E P I C T E D A N D A L L A S S O C I A T E D D E T A I L S M E E T A L L A P P L I C A B L E L A W S , R E G U L A T I O N S , A N D P R O J E C T R E Q U I R E M E N T S . DA T E DR W CH K DE S C R I P T I O N TH E L A N D I N G A T L E M A Y FO R T C O L L I N S , C O , U S A SHEET OF4 5 WEIR, ELEV. 4941.37' St o r m T e c h 88 8 - 8 9 2 - 2 6 9 4 | WW W . S T O R M T E C H . C O M ® Ch a m b e r S y s t e m NOMINAL CHAMBER SPECIFICATIONS SIZE (W X H X INSTALLED LENGTH)51.0" X 30.0" X 85.4" (1295 mm X 762 mm X 2169 mm) CHAMBER STORAGE 45.9 CUBIC FEET (1.30 m³) MINIMUM INSTALLED STORAGE*74.9 CUBIC FEET (2.12 m³) WEIGHT 75.0 lbs.(33.6 kg) *ASSUMES 6" (152 mm) STONE ABOVE, BELOW, AND BETWEEN CHAMBERS SC-740 TECHNICAL SPECIFICATION NTS BUILD ROW IN THIS DIRECTION OVERLAP NEXT CHAMBER HERE (OVER SMALL CORRUGATION) START END 90.7" (2304 mm) ACTUAL LENGTH 85.4" (2169 mm) INSTALLED LENGTH A A C B 51.0" (1295 mm) 30.0" (762 mm) 45.9" (1166 mm)12.2" (310 mm) 29.3" (744 mm) PART #STUB A B C SC740EPE06T / SC740EPE06TPC 6" (150 mm)10.9" (277 mm)18.5" (470 mm)--- SC740EPE06B / SC740EPE06BPC ---0.5" (13 mm) SC740EPE08T /SC740EPE08TPC 8" (200 mm)12.2" (310 mm)16.5" (419 mm)--- SC740EPE08B / SC740EPE08BPC ---0.6" (15 mm) SC740EPE10T / SC740EPE10TPC 10" (250 mm)13.4" (340 mm)14.5" (368 mm)--- SC740EPE10B / SC740EPE10BPC ---0.7" (18 mm) SC740EPE12T / SC740EPE12TPC 12" (300 mm)14.7" (373 mm)12.5" (318 mm)--- SC740EPE12B / SC740EPE12BPC ---1.2" (30 mm) SC740EPE15T / SC740EPE15TPC 15" (375 mm)18.4" (467 mm)9.0" (229 mm)--- SC740EPE15B / SC740EPE15BPC ---1.3" (33 mm) SC740EPE18T / SC740EPE18TPC 18" (450 mm)19.7" (500 mm)5.0" (127 mm)--- SC740EPE18B / SC740EPE18BPC ---1.6" (41 mm) SC740ECEZ*24" (600 mm)18.5" (470 mm)---0.1" (3 mm) ALL STUBS, EXCEPT FOR THE SC740ECEZ ARE PLACED AT BOTTOM OF END CAP SUCH THAT THE OUTSIDE DIAMETER OF THE STUB IS FLUSH WITH THE BOTTOM OF THE END CAP. FOR ADDITIONAL INFORMATION CONTACT STORMTECH AT 1-888-892-2694. * FOR THE SC740ECEZ THE 24" (600 mm) STUB LIES BELOW THE BOTTOM OF THE END CAP APPROXIMATELY 1.75" (44 mm). BACKFILL MATERIAL SHOULD BE REMOVED FROM BELOW THE N-12 STUB SO THAT THE FITTING SITS LEVEL. NOTE: ALL DIMENSIONS ARE NOMINAL PRE-FAB STUB AT BOTTOM OF END CAP WITH FLAMP END WITH "BR" PRE-FAB STUBS AT BOTTOM OF END CAP FOR PART NUMBERS ENDING WITH "B" PRE-FAB STUBS AT TOP OF END CAP FOR PART NUMBERS ENDING WITH "T" PRE-CORED END CAPS END WITH "PC" 46 4 0 T R U E M A N B L V D HI L L I A R D , O H 4 3 0 2 6 1- 8 0 0 - 7 3 3 - 7 4 7 3 DA T E : 1 1 / 1 5 / 2 0 2 3 DR A W N : E M PR O J E C T # : S 3 7 7 2 4 2 CH E C K E D : R C TH I S D R A W I N G H A S B E E N P R E P A R E D B A S E D O N I N F O R M A T I O N P R O V I D E D T O A D S U N D E R T H E D I R E C T I O N O F T H E S I T E D E S I G N E N G I N E E R O R O T H E R P R O J E C T R E P R E S E N T A T I V E . T H E S I T E D E S I G N E N G I N E E R S H A L L R E V I E W T H I S D R A W I N G P R I O R T O C O N S T R U C T I O N . I T I S T H E U L T I M A T E RE S P O N S I B I L I T Y O F T H E S I T E D E S I G N E N G I N E E R T O E N S U R E T H A T T H E P R O D U C T ( S ) D E P I C T E D A N D A L L A S S O C I A T E D D E T A I L S M E E T A L L A P P L I C A B L E L A W S , R E G U L A T I O N S , A N D P R O J E C T R E Q U I R E M E N T S . DA T E DR W CH K DE S C R I P T I O N TH E L A N D I N G A T L E M A Y FO R T C O L L I N S , C O , U S A SHEET OF5 5 UNDERDRAIN DETAIL NTS A A B B SECTION A-A SECTION B-B NUMBER AND SIZE OF UNDERDRAINS PER SITE DESIGN ENGINEER 4" (100 mm) TYP FOR SC-310 & SC-160LP SYSTEMS 6" (150 mm) TYP FOR SC-740, DC-780, MC-3500, MC-4500 & MC-7200 SYSTEMS OUTLET MANIFOLD STORMTECH END CAP STORMTECH CHAMBERS STORMTECH CHAMBER STORMTECH END CAP DUAL WALL PERFORATED HDPE UNDERDRAIN ADS GEOSYNTHETICS 601T NON-WOVEN GEOTEXTILE ADS GEOSYNTHETICS 601T NON-WOVEN GEOTEXTILE FOUNDATION STONE BENEATH CHAMBERS FOUNDATION STONE BENEATH CHAMBERS D APPENDIX D – USDA SOILS REPORT United States Department of Agriculture A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Larimer County Area, ColoradoNatural Resources Conservation Service January 31, 2023 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/ portal/nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid=nrcs142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require 2 alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface....................................................................................................................2 How Soil Surveys Are Made..................................................................................5 Soil Map..................................................................................................................8 Soil Map................................................................................................................9 Legend................................................................................................................10 Map Unit Legend................................................................................................11 Map Unit Descriptions.........................................................................................11 Larimer County Area, Colorado......................................................................13 22—Caruso clay loam, 0 to 1 percent slope...............................................13 35—Fort Collins loam, 0 to 3 percent slopes..............................................14 64—Loveland clay loam, 0 to 1 percent slopes...........................................15 76—Nunn clay loam, wet, 1 to 3 percent slopes.........................................16 105—Table Mountain loam, 0 to 1 percent slopes......................................18 Soil Information for All Uses...............................................................................20 Soil Properties and Qualities..............................................................................20 Soil Erosion Factors........................................................................................20 K Factor, Whole Soil....................................................................................20 References............................................................................................................24 4 How Soil Surveys Are Made Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil 5 scientists classified and named the soils in the survey area, they compared the individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil-landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil-landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field-observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and Custom Soil Resource Report 6 identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. Custom Soil Resource Report 7 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 8 9 Custom Soil Resource Report Soil Map 44 9 3 2 0 0 44 9 3 3 0 0 44 9 3 4 0 0 44 9 3 5 0 0 44 9 3 6 0 0 44 9 3 7 0 0 44 9 3 8 0 0 44 9 3 9 0 0 44 9 4 0 0 0 44 9 4 1 0 0 44 9 3 2 0 0 44 9 3 3 0 0 44 9 3 4 0 0 44 9 3 5 0 0 44 9 3 6 0 0 44 9 3 7 0 0 44 9 3 8 0 0 44 9 3 9 0 0 44 9 4 0 0 0 44 9 4 1 0 0 495200 495300 495400 495500 495600 495700 495800 495200 495300 495400 495500 495600 495700 495800 40° 35' 52'' N 10 5 ° 3 ' 2 6 ' ' W 40° 35' 52'' N 10 5 ° 2 ' 5 4 ' ' W 40° 35' 21'' N 10 5 ° 3 ' 2 6 ' ' W 40° 35' 21'' N 10 5 ° 2 ' 5 4 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 200 400 800 1200 Feet 0 50 100 200 300 Meters Map Scale: 1:4,750 if printed on A portrait (8.5" x 11") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Larimer County Area, Colorado Survey Area Data: Version 17, Sep 7, 2022 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jul 2, 2021—Aug 25, 2021 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 10 Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 22 Caruso clay loam, 0 to 1 percent slope 53.1 52.9% 35 Fort Collins loam, 0 to 3 percent slopes 14.4 14.4% 64 Loveland clay loam, 0 to 1 percent slopes 10.2 10.2% 76 Nunn clay loam, wet, 1 to 3 percent slopes 18.6 18.5% 105 Table Mountain loam, 0 to 1 percent slopes 4.0 4.0% Totals for Area of Interest 100.2 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. Custom Soil Resource Report 11 The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha-Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. Custom Soil Resource Report 12 Larimer County Area, Colorado 22—Caruso clay loam, 0 to 1 percent slope Map Unit Setting National map unit symbol: jpvt Elevation: 4,800 to 5,500 feet Mean annual precipitation: 13 to 15 inches Mean annual air temperature: 48 to 50 degrees F Frost-free period: 135 to 150 days Farmland classification: Prime farmland if irrigated Map Unit Composition Caruso and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Caruso Setting Landform:Flood-plain steps, stream terraces Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Parent material:Mixed alluvium Typical profile H1 - 0 to 35 inches: clay loam H2 - 35 to 44 inches: fine sandy loam H3 - 44 to 60 inches: gravelly sand Properties and qualities Slope:0 to 1 percent Depth to restrictive feature:More than 80 inches Drainage class:Somewhat poorly drained Runoff class: High Capacity of the most limiting layer to transmit water (Ksat):Moderately low to moderately high (0.06 to 0.20 in/hr) Depth to water table:About 24 to 48 inches Frequency of flooding:NoneOccasional Frequency of ponding:None Calcium carbonate, maximum content:5 percent Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water supply, 0 to 60 inches: Moderate (about 8.4 inches) Interpretive groups Land capability classification (irrigated): 3w Land capability classification (nonirrigated): 5w Hydrologic Soil Group: D Ecological site: R067BY036CO - Overflow Hydric soil rating: No Minor Components Loveland Percent of map unit:9 percent Custom Soil Resource Report 13 Landform:Terraces Ecological site:R067BY036CO - Overflow Hydric soil rating: Yes Fluvaquents Percent of map unit:6 percent Landform:Terraces Hydric soil rating: Yes 35—Fort Collins loam, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 2tlnc Elevation: 4,020 to 6,730 feet Mean annual precipitation: 14 to 16 inches Mean annual air temperature: 46 to 48 degrees F Frost-free period: 135 to 160 days Farmland classification: Prime farmland if irrigated Map Unit Composition Fort collins and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Fort Collins Setting Landform:Stream terraces, interfluves Landform position (three-dimensional):Interfluve, tread Down-slope shape:Linear Across-slope shape:Linear Parent material:Pleistocene or older alluvium and/or eolian deposits Typical profile Ap - 0 to 4 inches: loam Bt1 - 4 to 9 inches: clay loam Bt2 - 9 to 16 inches: clay loam Bk1 - 16 to 29 inches: loam Bk2 - 29 to 80 inches: loam Properties and qualities Slope:0 to 3 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high (0.20 to 2.00 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Calcium carbonate, maximum content:12 percent Custom Soil Resource Report 14 Maximum salinity:Nonsaline to very slightly saline (0.1 to 2.0 mmhos/cm) Available water supply, 0 to 60 inches: High (about 9.1 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 3e Hydrologic Soil Group: C Ecological site: R067BY002CO - Loamy Plains Hydric soil rating: No Minor Components Nunn Percent of map unit:10 percent Landform:Stream terraces Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Ecological site:R067BY002CO - Loamy Plains Hydric soil rating: No Vona Percent of map unit:5 percent Landform:Interfluves Landform position (three-dimensional):Interfluve, side slope Down-slope shape:Linear Across-slope shape:Linear Ecological site:R067BY024CO - Sandy Plains Hydric soil rating: No 64—Loveland clay loam, 0 to 1 percent slopes Map Unit Setting National map unit symbol: jpx9 Elevation: 4,800 to 5,500 feet Mean annual precipitation: 13 to 15 inches Mean annual air temperature: 48 to 50 degrees F Frost-free period: 135 to 150 days Farmland classification: Prime farmland if irrigated Map Unit Composition Loveland and similar soils:90 percent Minor components:10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Loveland Setting Landform:Flood plains, stream terraces Landform position (three-dimensional):Tread Down-slope shape:Linear Custom Soil Resource Report 15 Across-slope shape:Linear Parent material:Alluvium Typical profile H1 - 0 to 15 inches: clay loam H2 - 15 to 32 inches: loam H3 - 32 to 60 inches: very gravelly sand Properties and qualities Slope:0 to 1 percent Depth to restrictive feature:More than 80 inches Drainage class:Poorly drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat):Moderately high (0.20 to 0.60 in/hr) Depth to water table:About 18 to 36 inches Frequency of flooding:OccasionalNone Frequency of ponding:None Calcium carbonate, maximum content:15 percent Maximum salinity:Very slightly saline to slightly saline (2.0 to 4.0 mmhos/cm) Available water supply, 0 to 60 inches: Moderate (about 7.5 inches) Interpretive groups Land capability classification (irrigated): 3w Land capability classification (nonirrigated): 3w Hydrologic Soil Group: C Ecological site: R067BY036CO - Overflow Hydric soil rating: No Minor Components Aquolls Percent of map unit:5 percent Landform:Swales Hydric soil rating: Yes Poudre Percent of map unit:5 percent Ecological site:R067BY036CO - Overflow Hydric soil rating: No 76—Nunn clay loam, wet, 1 to 3 percent slopes Map Unit Setting National map unit symbol: jpxq Elevation: 4,800 to 5,600 feet Mean annual precipitation: 13 to 15 inches Mean annual air temperature: 48 to 50 degrees F Frost-free period: 135 to 150 days Farmland classification: Prime farmland if irrigated Custom Soil Resource Report 16 Map Unit Composition Nunn, wet, and similar soils:90 percent Minor components:10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Nunn, Wet Setting Landform:Alluvial fans, stream terraces Landform position (three-dimensional):Base slope, tread Down-slope shape:Linear Across-slope shape:Linear Parent material:Alluvium Typical profile H1 - 0 to 10 inches: clay loam H2 - 10 to 47 inches: clay H3 - 47 to 60 inches: gravelly loam Properties and qualities Slope:1 to 3 percent Depth to restrictive feature:More than 80 inches Drainage class:Somewhat poorly drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat):Moderately low to moderately high (0.06 to 0.60 in/hr) Depth to water table:About 24 to 36 inches Frequency of flooding:NoneRare Frequency of ponding:None Calcium carbonate, maximum content:10 percent Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water supply, 0 to 60 inches: High (about 9.9 inches) Interpretive groups Land capability classification (irrigated): 2w Land capability classification (nonirrigated): 3s Hydrologic Soil Group: C Ecological site: R067BY038CO - Wet Meadow Hydric soil rating: No Minor Components Heldt Percent of map unit:6 percent Ecological site:R067BY042CO - Clayey Plains Hydric soil rating: No Dacono Percent of map unit:3 percent Ecological site:R067BY042CO - Clayey Plains Hydric soil rating: No Mollic halaquepts Percent of map unit:1 percent Landform:Swales Hydric soil rating: Yes Custom Soil Resource Report 17 105—Table Mountain loam, 0 to 1 percent slopes Map Unit Setting National map unit symbol: jpty Elevation: 4,800 to 5,600 feet Mean annual precipitation: 13 to 15 inches Mean annual air temperature: 48 to 50 degrees F Frost-free period: 135 to 150 days Farmland classification: Prime farmland if irrigated Map Unit Composition Table mountain and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Table Mountain Setting Landform:Flood plains, stream terraces Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Parent material:Alluvium Typical profile H1 - 0 to 36 inches: loam H2 - 36 to 60 inches: clay loam Properties and qualities Slope:0 to 1 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high (0.60 to 2.00 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Calcium carbonate, maximum content:15 percent Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Sodium adsorption ratio, maximum:5.0 Available water supply, 0 to 60 inches: High (about 9.8 inches) Interpretive groups Land capability classification (irrigated): 1 Land capability classification (nonirrigated): 3c Hydrologic Soil Group: B Ecological site: R049XY036CO - Overflow Hydric soil rating: No Custom Soil Resource Report 18 Minor Components Caruso Percent of map unit:7 percent Hydric soil rating: No Fluvaquentic haplustolls Percent of map unit:4 percent Landform:Terraces Hydric soil rating: Yes Paoli Percent of map unit:4 percent Hydric soil rating: No Custom Soil Resource Report 19 Soil Information for All Uses Soil Properties and Qualities The Soil Properties and Qualities section includes various soil properties and qualities displayed as thematic maps with a summary table for the soil map units in the selected area of interest. A single value or rating for each map unit is generated by aggregating the interpretive ratings of individual map unit components. This aggregation process is defined for each property or quality. Soil Erosion Factors Soil Erosion Factors are soil properties and interpretations used in evaluating the soil for potential erosion. Example soil erosion factors can include K factor for the whole soil or on a rock free basis, T factor, wind erodibility group and wind erodibility index. K Factor, Whole Soil Erosion factor K indicates the susceptibility of a soil to sheet and rill erosion by water. Factor K is one of six factors used in the Universal Soil Loss Equation (USLE) and the Revised Universal Soil Loss Equation (RUSLE) to predict the average annual rate of soil loss by sheet and rill erosion in tons per acre per year. The estimates are based primarily on percentage of silt, sand, and organic matter and on soil structure and saturated hydraulic conductivity (Ksat). Values of K range from 0.02 to 0.69. Other factors being equal, the higher the value, the more susceptible the soil is to sheet and rill erosion by water. "Erosion factor Kw (whole soil)" indicates the erodibility of the whole soil. The estimates are modified by the presence of rock fragments. Factor K does not apply to organic horizons and is not reported for those layers. 20 21 Custom Soil Resource Report Map—K Factor, Whole Soil 44 9 3 2 0 0 44 9 3 3 0 0 44 9 3 4 0 0 44 9 3 5 0 0 44 9 3 6 0 0 44 9 3 7 0 0 44 9 3 8 0 0 44 9 3 9 0 0 44 9 4 0 0 0 44 9 4 1 0 0 44 9 3 2 0 0 44 9 3 3 0 0 44 9 3 4 0 0 44 9 3 5 0 0 44 9 3 6 0 0 44 9 3 7 0 0 44 9 3 8 0 0 44 9 3 9 0 0 44 9 4 0 0 0 44 9 4 1 0 0 495200 495300 495400 495500 495600 495700 495800 495200 495300 495400 495500 495600 495700 495800 40° 35' 52'' N 10 5 ° 3 ' 2 6 ' ' W 40° 35' 52'' N 10 5 ° 2 ' 5 4 ' ' W 40° 35' 21'' N 10 5 ° 3 ' 2 6 ' ' W 40° 35' 21'' N 10 5 ° 2 ' 5 4 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 200 400 800 1200 Feet 0 50 100 200 300 Meters Map Scale: 1:4,750 if printed on A portrait (8.5" x 11") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons .02 .05 .10 .15 .17 .20 .24 .28 .32 .37 .43 .49 .55 .64 Not rated or not available Soil Rating Lines .02 .05 .10 .15 .17 .20 .24 .28 .32 .37 .43 .49 .55 .64 Not rated or not available Soil Rating Points .02 .05 .10 .15 .17 .20 .24 .28 .32 .37 .43 .49 .55 .64 Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Larimer County Area, Colorado Survey Area Data: Version 17, Sep 7, 2022 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jul 2, 2021—Aug 25, 2021 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 22 Table—K Factor, Whole Soil Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 22 Caruso clay loam, 0 to 1 percent slope .32 53.1 52.9% 35 Fort Collins loam, 0 to 3 percent slopes .43 14.4 14.4% 64 Loveland clay loam, 0 to 1 percent slopes .20 10.2 10.2% 76 Nunn clay loam, wet, 1 to 3 percent slopes .24 18.6 18.5% 105 Table Mountain loam, 0 to 1 percent slopes .37 4.0 4.0% Totals for Area of Interest 100.2 100.0% Rating Options—K Factor, Whole Soil Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher Layer Options (Horizon Aggregation Method): Surface Layer (Not applicable) Custom Soil Resource Report 23 References American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs142p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ home/?cid=nrcs142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 24 United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/soils/scientists/?cid=nrcs142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/? cid=nrcs142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf Custom Soil Resource Report 25 E APPENDIX E – FEMA FIRMETTE National Flood Hazard Layer FIRMette 0 500 1,000 1,500 2,000250 Feet Ü SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOOD HAZARD AREAS Without Base Flood Elevation (BFE) Zone A, V, A99 With BFE or DepthZone AE, AO, AH, VE, AR Regulatory Floodway 0.2% Annual Chance Flood Hazard, Areas of 1% annual chance flood with average depth less than one foot or with drainage areas of less than one square mileZone X Future Conditions 1% Annual Chance Flood HazardZone X Area with Reduced Flood Risk due to Levee. See Notes.Zone X Area with Flood Risk due to LeveeZone D NO SCREEN Area of Minimal Flood Hazard Zone X Area of Undetermined Flood HazardZone D Channel, Culvert, or Storm Sewer Levee, Dike, or Floodwall Cross Sections with 1% Annual Chance 17.5 Water Surface Elevation Coastal Transect Coastal Transect Baseline Profile Baseline Hydrographic Feature Base Flood Elevation Line (BFE) Effective LOMRs Limit of Study Jurisdiction Boundary Digital Data Available No Digital Data Available Unmapped This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from the authoritative NFHL web services provided by FEMA. This map was exported on 2/3/2023 at 11:33 AM and does not reflect changes or amendments subsequent to this date and time. The NFHL and effective information may change or become superseded by new data over time. This map image is void if the one or more of the following map elements do not appear: basemap imagery, flood zone labels, legend, scale bar, map creation date, community identifiers, FIRM panel number, and FIRM effective date. Map images for unmapped and unmodernized areas cannot be used for regulatory purposes. Legend OTHER AREAS OF FLOOD HAZARD OTHER AREAS GENERAL STRUCTURES OTHER FEATURES MAP PANELS 8 B 20.2 The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. 1:6,000 105°3'31"W 40°35'47"N 105°2'54"W 40°35'20"N Basemap: USGS National Map: Orthoimagery: Data refreshed October, 2020 F APPENDIX F – D RAINAGE E XHIBIT TEST STA TEST STA V.P. ST F.O. X X XX X X X X X X X X X FD C FD C FD C FDC FD C FD C FDC FDC FD C FD C U D UD UD UD UD UD UDUD UD U D UD UD U D UD UD UD UD UD UD UD UD UD UD UD UD UD UD UD UD UD / / / / / / / / / / / / / / / / NO R T H L E M A Y A V E N U E DUFF DRIVE CO R D O V A R O A D LINK LANE A 2.55 ac B 1.93 ac D 1.58 ac C 3.95 ac E 3.93 ac F 0.12 ac G 0.15 ac H 0.31 ac I 0.45 ac J 0.33 ac K 0.49 ac OS1 .906 ac DETENTION POND 2 RAIN GARDEN A RAIN GARDEN D RAIN GARDEN C DETENTION POND 1 RAIN GARDEN B PROPOSED STORM DRAIN PROPOSED POND OUTFALL PROPOSED 2' CONCRETE PAN PROPOSED STORM DRAIN PROPOSED STORM DRAIN PROPOSED STORM DRAIN PROPOSED 2' CONCRETE PAN PROPOSED 2' CONCRETE PAN PROPOSED 2' CONCRETE PAN PROPOSED STORM DRAIN PROPOSED STORM DRAIN EXISTING STORM DRAIN EXISTING STORM DRAIN PROPOSED 2' CONCRETE PAN C D E B A F G H I J K OS1 POND OUTLET STRUCTURE POND OUTLET STRUCTURE M 2.47 ac L 0.64 ac N 1.01 ac DOG PARK PROPOSED CULVERT L MRAIN GARDEN M N OF SCALE: PROJECT NO. PR O J E C T M A N A G E R : NO . RE V I S I O N S BY : DA T E : SU B M I T T A L D A T E : SHEET: HORIZ: VERT: CAUTION The engineer preparing these plans will not be responsible for, or liable for, unauthorized changes to or uses of these plans. All changes must be approved by the Professional Engineer of these plans. 11 / 1 5 / 2 3 TH E L A N D I N G A T L E M A Y 68 1791-003 D. W e b e r 13 3 7 R I V E R S I D E A V E . # 2 FO R T C O L L I N S , C O 8 0 5 2 4 AV A N T C I V I L G R O U P . C O M 97 0 . 2 8 6 . 7 9 9 5 N O T F O R C O N S T R U C T I O N R E V I E W S E T ( IN FEET ) 1 inch = ft. Feet05050 50 100 150 PROPOSED CONTOUR PROPOSED STORM SEWER PROPOSED SWALE EXISTING CONTOUR PROPOSED CURB & GUTTER PROPERTY BOUNDARY PROPOSED INLET A DESIGN POINT FLOW ARROW DRAINAGE BASIN LABEL DRAINAGE BASIN BOUNDARY PROPOSED SWALE SECTION 11 1.REFER TO THE FINAL DRAINAGE REPORT, DATED NOVEMBER 15, 2023 BY AVANT CIVIL GROUP FOR ADDITIONAL INFORMATION. A FOR DRAINAGE REVIEW ONLY NOT FOR CONSTRUCTION LEGEND NOTES CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU DIG, GRADE, OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES. CALL UTILITY NOTIFICATION CENTER OF COLORADO Know what'sbelow. before you dig.Call R DE V E L O P E D D R A I N A G E E X H I B I T 56 1" = 50' N/A C 701 POND SUMMARY TABLE Pond ID Tributary Area (Ac)1 Weighted % Imperviousness (%) Extended Detention WQCV (Cu. Ft.)2 100-Yr. Detention Vol. (Ac-Ft) 100-Yr. Detention WSEL(Ft) Peak Release (cfs)3 Pond 1 6.291 67 Provided in Pond 2 1.52 4942.40 1.2 Pond 2 12.905 59 6231 2.94 4941.60 2.4 Notes: 1. Tributary area shown does not include off-site basin(s) 2. WQCV calculated minus RG/Chamber volume; will be provded in Pond 2 3. Overall site release rate of 3.6 cfs divided between Ponds 1 and 2