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HomeMy WebLinkAboutMONTAVA - PHASE E TOWN CENTER - BDR220003 - MONTAVA SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORT 1-1 | Page Preliminary Development Plan (PDP) Final Drainage Report For Montava Subdivision Phase E: Town Center August 15, 2021 submitted to: City of Fort Collins, Colorado 748 Whalers Way August 15, 2021 Mr. Wes Lamarque City of Fort Collins Development Review Engineer 700 Wood Street Fort Collins, CO 80521 Re: Montava Subdivision Phase E: Town Center Final Design Drainage Report Project No. 1230.0005.00 Dear Ms. Lamarque: TST, Inc. Consulting Engineers (TST) is pleased to submit this Preliminary Design Drainage Report for the Montava Subdivision Phase E: Town Center project to the City of Fort Collins (City) for review and approval. The purpose of this drainage report is to evaluate the drainage conditions of the above-referenced proposed Montava Subdivision Phase E: Town Center project site. The Fort Collins Stormwater Criteria Manual (referred to as FCSCM). Please review the attached report and provide any questions or comments at your earliest convenience. We appreciate the opportunity to be of continued service to the city and look forward to receiving your comments and moving forward on this important project. Sincerely, TST, INC. CONSULTING ENGINEERS Bryston Anthony M. Gartner, E.I. Jonathan F. Sweet, P.E. BAMG JFS I hereby attest that this report for the preliminary drainage design for the Montava Subdivision Phase E: Town Center was prepared by me or under my direct supervision, in accordance with the provisions of the Fort Collins Stormwater Criteria Manual. I understand that the City of Fort Collins does not and will not assume liability for drainage facilities designed by others ______________________________ Jonathan F. Sweet Registered Professional Engineer State of Colorado No. 40341 748 Whalers Way Suite 200 Fort Collins, CO 80525 970.226.0557 main 970.226.0204 fax ideas@tstinc.com www.tstinc.com Table of Contents Preliminary Design Drainage Report Montava Subdivision Phase E: Town Center Page i 1.0 - GENERAL LOCATION AND DESCRIPTION ......................................................... 1 1.1 Project Location and Description ................................................................... 1 1.2 Description of Property ................................................................................... 2 2.0 - DRAINAGE BASINS AND SUB-BASINS .............................................................. 4 2.1 Major Basin Description .................................................................................. 4 2.2 Existing Conditions ......................................................................................... 4 2.3 Proposed Conditions ...................................................................................... 4 3.0 - DRAINAGE DESIGN CRITERIA ............................................................................ 8 3.1 Hydrological and Hydraulic Criteria ............................................................... 8 4.0 - CONCLUSIONS .................................................................................................... 10 5.0 - REFERENCES ...................................................................................................... 12 6.0 - APPENDICES ....................................................................................................... 13 List of Figures 1.1 Vicinity Map ..................................................................................................................... 2 Montava Subdivision Phase E: Town Center Preliminary Drainage Report Page 1 1.0 - General Location and Description The purpose of this Final Drainage Report is to present the drainage design for the Montava Subdivision Phase E: Town Center (Hereinafter referred to as the “Montava Subdivision Phase E”) project site to the City of Fort Collins (hereinafter referred to as the “City”) for review and approval. The design objectives for this drainage report are to present:  Hydrologic analysis of the proposed improvements and surrounding off-site areas to determine the location and magnitude of the site’s storm runoff.  Hydrologic data used to design storm runoff collection and conveyance facilities.  Hydraulic analysis of proposed on-site and existing downstream storm infrastructure to ensure sufficient conveyance of stormwater runoff to the existing and proposed detention areas.  Detention analysis and design of the existing and proposed stormwater detention areas.  Best Management Practices (BMPs) used to prevent erosion and sedimentation before, during, and after construction of the stormwater infrastructure.  Overall storm drainage plan that meets previously approved drainage plans and the FCSCM. The drainage system was designed using the Fort Collins Stormwater Criteria Manual (collectively referred as FCSCM). 1.1 Project Location and Description The Montava Subdivision Phase E project site is located in Section 32, Township 8 North, Range 68 West of the 6th Principal Meridian, within the City of Fort Collins, Larimer County, Colorado. The proposed site is bounded on the north by farmland and Future Montava Subdivision phases, on the east by farmland, N. Giddings Road, and Future Montava Subdivision phases, on the south by Mountain Vista Drive and farmland, on the west by the Number 8 Outlet Ditch and Montava Subdivision Phase G and Future Montava Subdivision phases. A vicinity map illustrating the project location is provided in Figure 1.1. Montava Subdivision Phase E: Town Center Preliminary Drainage Report Page 2 Figure 1.1: Vicinity Map 1.2 Description of Property The Montava Subdivision Phase E project site contains approximately 48 acres and consisting of the Multi-Family, Mixed-Use, and Open Space. The Montava Subdivision Phase E Phase E: Town Center is currently zoned as Low Density Mixed-Use Neighborhood District Zone (LMN). According to Flood Insurance Rate Map (FIRM) #08069C0982 eff. 12/19/2006 prepared by the Federal Emergency Management Agency (FEMA), the Montava Subdivision Phase E is located in unshaded Zone X, which is not designated as a special flood hazard zone. Copies of the FEMA maps that apply to the Montava Subdivision Phase E are included in Appendix B. The types of soils found on the Montava Subdivision Phase E site consist of:  Caruso Clay Loam (22) - 0 to 1 percent slope.  Fort Collins Loam (35) – 0 to 3 percent slopes.  Kim loam (54) – 3 to 5 percent slopes. Montava Subdivision Phase E: Town Center Preliminary Drainage Report Page 3  Satanta loam (94) – 0 to 1 percent slopes.  Satanta Variant clay loam (98) – 0 to 3 percent slopes.  Stoneham loam (101) – 1 to 3 percent slopes.  Stoneham loam (102) – 3 to 5 percent slopes.  Stoneham Loam (103) – 5 to 9 percent slopes. The characteristics of the soil found on the project site include:  Moderate infiltration rate when thoroughly wet.  Moderately fine texture to moderately coarse texture.  Moderate rate of water transmission.  Majority of the site has a wind erodibility rating of 6 (8 being the least susceptible) These soils consist of the following hydrologic soil groups as defined in the United States Department of Agriculture (USDA), Web Soil Survey:  Group B – 15.90%.  Group C – 22.10%.  Group D – 62.00%. The USDA web soil survey report is included in Appendix C. The following reports were utilized in the drainage analysis and design of Montava Subdivision Phase E.  Montava Master Drainage Study Fort Collins, Colorado, prepared by Martin/Martin, Inc., dated January 23, 2019. Hydrologic and hydraulic information was referenced from this report to analyze off-site areas and conveyance links downstream from the Montava Subdivision Phase E and site. Montava Subdivision Phase E: Town Center Preliminary Drainage Report Page 4 2.0 - Drainage Basins and Sub-Basins 2.1 Major Basin Description According to the FCSCM, Montava Subdivision Phase E is located within the Upper Cooper Slough Basin. According to the basin master planning states that the Number 8 Ditch is in need of improvements which will be implemented for the reach that is through the site and Phase G. All Number 8 Ditch improvements will be handled and designed by others in Phase G and Montava Master Drainage Plan. The Upper Cooper Slough Basin stormwater generally flows from north to south which is ultimately being captured by the Larimer and Weld Canal. According to the Montava Master Drainage Study, Montava Subdivision Phase E is primarily located in Basin F, Basin G1, and Basin G2. 2.2 Existing Conditions The Montava Subdivision Phase E is located in an undeveloped lot west of the Anheuser Busch property. The current land is being used for agricultural purposes and undeveloped land. The land currently consists of native grasses, bare ground, and crops. Runoff from the undeveloped site has two flow paths, split by a ridge, and both ends up in the Larimer and Weld Canal that is located south of the site. The majority of Montava Phase E, northeast of the ridge, sheet flows southeast into an inadvertent detention area which will overtop Mountain Vista Drive, and eventually into the Larimer and Weld Canal. The other flow path, southwest of the ridge, sheet flows southwest into the Number 8 Outlet Ditch and eventually into the Larimer and Weld Canal. The Number 8 Outlet Ditch is located to the west of the site and conveys offsite flows and improvements to the ditch will be completed by others. The existing site does not have any existing ponds or drainage facilities. The site has an inadvertent detention area near Giddings Road and Mountain Vista Drive. All water is generated on the existing site sheet flows and ends up in one of the major waterways that are located close to the site. There are two major drainage ways that are being utilized for Montava Subdivision Phase E. One is the Larimer and Weld Canal, which is the waterway that all the water from the proposed site ends up. The second is the Number 8 Ditch, which is being realigned in a pipe that is directed around the proposed Timberline Road. This Number 8 Ditch improvement is being designed by others with Montava Phase G Plans. 2.3 Proposed Conditions The proposed Montava Subdivision Phase E development generally maintains existing drainage patterns. To conform to the Master Drainage Plan for the area the proposed site will be broken into three basins that have been outlined in the Montava Master Drainage Plan. The portion of Montava Subdivision Phase E: Town Center Preliminary Drainage Report Page 5 Montava Subdivision Phase E located in Basin F will generally flow southeast into a pond designed by others with the Master Drainage Study. The portion of Montava Subdivision Phase E located with Basin G1 will generally flow southeast and into an interim pond proposed by others with the Master Drainage Study. The portion of Montava Subdivision Phase E located in Basin G2 will generally flow southwest into a pond proposed by others with the Master Drainage Study and outfall directly into the Number 8 Ditch. The following basins were delineated for the Montava Subdivision Phase E site plan, using the Montava Master Drainage Basins: P Basin F is a portion of Basin F from the Montava Master Drainage Plan. P Basin F is made up of proposed streets, single family development, and future commercial development. This basin is approximately 16.90 acres with an approximate composite imperviousness of roughly 60.4%. P Basin F is an overall basin that is broken up into subbasins that all end up in the proposed Pond F, designed by others. The majority of the basin is directed south and east through various storm infrastructure and into a raingarden that is located off the north corner of Pond F. After that water has been treated in the Rain Garden, it will discharge into the water quality and detention Pond F. The other portion of the basin is directed east into a drainage swale that is captured and spills directly into the water quality and detention Pond F, designed by others. P Basin G1 is a portion of Basin G1 from the Montava Master Drainage Plan. P Basin G1 is made up of proposed streets, single family development, and future commercial development. This basin is approximately 15.76 acres with an approximate composite imperviousness of roughly 53.7%. P Basin G1 is an overall basin that is broken up into subbasins that all end up in the proposed Interim Pond 427, designed by others. The majority of the basin is directed toward various low points across the basin and into the storm line that directs it to the interim Pond 427, designed by others. Some portions of the basin are treated for water quality, before entering the storm line, by pervious pavers or depressed landscape medians. P Basin G2 is a portion of Basin G1 from the Montava Master Drainage Plan. P Basin G2 is made up of proposed streets and future commercial development. This basin is approximately 5.95 acres with an approximate composite imperviousness of roughly 42.2%. P Basin G2 is an overall basin that is broken up into subbasins that all end up in the proposed water quality Pond G2, designed by others. The majority of the basin is directed south and west through various storm infrastructure and into raingardens located at the end of the proposed storm lines. After that water has been treated in the Rain Garden, it will discharge into the water quality and detention Pond G2, ultimately spilling into the piped section of the Number 8 Ditch. Pond F Basin is a portion of Basin F from the Montava Master Drainage Plan. Pond F Basin is made up of proposed Pond F (designed by others), future recreation center, and future sports fields. This basin is approximately 8.26 acres with an approximate composite imperviousness of roughly 23.9 The entirety of the basin sheetflows directly into the pond or into a Rain Garden that ultimately ends up in Pond F. Montava Subdivision Phase E: Town Center Preliminary Drainage Report Page 6 Off-Site Basins Basin D from Montava Master Drainage Plan is made up of existing irrigation and detention pond, future school, future park, future mixed-use lots, and future streets. This basin is approximately 41.83 acres with an approximate composite imperviousness of roughly 60%. Generally, runoff will be directed south to the existing irrigation and detention pond. Future development will have to implement some sort of LID before the runoff will be captured by the pond. This basin was not analyzed for runoff or conformance to the LID section of the FCSCM. The only information used from this basin is the outfall of the pond, which is the only offsite contributing flow for the whole site. The flow that is coming into Phase E is 8.6cfs under Timberline Road and into a drainage swale that ends up in Pond F. 2.4 Low Impact Development (LID) Per City of Fort Collins criteria, Low Impact Development (LID) features are proposed to treat 75% of the newly developed area within Phase E. Timberline Right-of-Way Adjacent to Phase E is discharging to the proposed LID systems and was included in the overall treatment percentage. Two LID systems are being proposed for Phase E, Bioretention (Rain Gardens). The location of these systems is described in Section 2.3 showing the percentage of newly developed area treated by these systems is included in the Appendix. The proposed LID systems, water quality, and detention facilities will be located in tracts owned and maintained by the Montava Metropolitan District. 2.5 MDCIA “Four Step Process” Step 1 – Employee Runoff Reduction Practices Montava Phase E is providing LID treatment for 75% of the site, excluding the future commercial, through various Bioretention (Rain Gardens). The LID systems have been placed throughout the site to minimize directly connected impervious areas. Step 2 – Implement BMPs That Provide a WQCV with Slow Release The remaining 25% if the site not being treated by the LID described is being treated through traditional water quality control volume extended drainage basins designed to release the water quality event within a minimum if 40 hours. Step 3 – Stabilize Streams Phase E will be spilling into an improved Number 8 Ditch, improved by other designing Phase G. Piping of the Number 8 is the preferred solution to minimize public interaction with the existing facilities, as well as reducing the downstream sediment load that was seen with an Montava Subdivision Phase E: Town Center Preliminary Drainage Report Page 7 open irrigation channel. Phase E will also be spilling into a couple of Ponds, designed by others, that are designed to reduce the sediment load to the downstream properties. Phase E only spills into the improved downstream infrastructure that was designed to lessen or solve the problems that have been outlined in the 2017 Selected Plan improvement recommendations. Step 4 – Implement Site Specific and Other Source Control BMPs 1. The following practices suggested by City of Fort Collins Criteria will be implemented throughout the design and construction process: 2. Being a single-family development, trash receptacles will be dispersed throughout the neighborhood and likely be enclosed containers that minimize concentrated and polluted runoff from entering the storm sewer system or receiving drainageways prior to being treated. 3. Phase E of Montava Subdivision does not include a dog park, but any future dog parks shall be located in areas away from detention basins and educational opportunities to reinforce pick-up practices for dog owners shall be employed. 4. Phase E of Montava Subdivision does not include any community gardens, but future community gardens shall be located in areas that are outside of the detention basins to prevent chemical and sediment loading. 5. Construction Best Management Practices (BMPs) will be employed to located material storage away from drainage facilities. 2.6 Variance Requests No drainage variances are being requested at this time. Montava Subdivision Phase E: Town Center Preliminary Drainage Report Page 8 3.0 - Drainage Design Criteria The drainage design presented in this report has been developed in accordance with the guidelines established by the FCSCM dated December 2018. Storm system infrastructure including pipes, culverts, inlets, and drainage swales were sized to convey the 100-year storm event. In areas of concern, storm system infrastructure was sized to handle the 100-year and any additional bypass flow from upstream infrastructure. 3.1 Hydrological and Hydraulic Criteria Design Rainfall & Runoff Calculation Method The hydrology of the project site for developed conditions was evaluated based on the 2-, 10- and 100-year storm frequencies as dictated within the FCSCM manual. The Rational Method was used to determine peak runoff rates for each developed basin. Peak storm runoff values were used to size on-site drainage facilities including storm culverts, sewers, inlets and channels for the initial or major design storms as specified in the FCSCM criteria and standards. Within the criteria and standards, the initial design storm was established as the 2-year minor storm event and the 100-year storm as the major event. Inlet Design All inlets within the project area have been designed to collect and convey the 2-year developed runoff. In areas where flooding is a concern, inlets were upsized to convey much of the 100- year developed runoff. As stated in FCSCM, Inlet Functions, Types and Appropriate Applications, the standard inlets for use on City of Loveland streets are: Inlet Type Permitted Use Curb Opening Inlet Type R All street types with 6 inches of vertical curb Type C Inlet All Alleys with reverse crown and Montava Drive/ Big Timber Drive Storm Sewer and Culvert Design As stated in the FCSCM, the Manning’s roughness coefficient (n) for all storm sewer pipe capacity calculations shall be 0.013 regardless of pipe material. The storm sewers and culverts in the project area were designed in accordance with the criteria and standards of the FCSCM using a minimum pipe diameter of 15 inches. Where applicable, storm sewers have been sized to convey the 100-year developed runoff to the existing detention ponds. Peak runoff for storm sewer design was calculated using the Rational Method per the Montava Subdivision Phase E: Town Center Preliminary Drainage Report Page 9 FCSCM. All storm sewers were sized using the Urban Drainage program, UD-Sewer 2009 Version 1.4.0. All culverts were sized using the Federal Highway Administration (FHA) Program, HY-8 Version 7.30. Riprap Design Riprap was designed at the outlet of all storm sewers to dissipate energy and prevent erosion in the 100-year storm per the FCSCM criteria and standards. Street Capacity The criteria and standards set forth in the FCSCM were used to check street capacity for both the minor (2-year) and major (100-year) storm events. The FCSCM requires that stormwater overtopping curbs should not occur during the minor storms and the flow spread must meet the following guidelines for each street designation:  Local – flow may spread to crown of road.  Collector - flow spread must leave a minimum of 6 feet (6’) wide clear travel lane on each side of the centerline.  Arterial (with median) – flow spread must leave a minimum of 12 feet (12’) wide travel lane in both directions of travel. Additionally, the following allowable street flow depths were used for the drainage design:  Local – Minor Storm (0.50-ft), Major Storm (0.67-ft)  Collector - Minor Storm (0.50-ft), Major Storm (0.67-ft)  Minor Arterial - Minor Storm (0.50-ft), Major Storm (0.67-ft) Swale Design As defined in Chapter 9 of the Fort Collins Stormwater Criteria Manual, open channels are utilized to preserve, enhance, and restore stream corridors, used in the design of constructed channels and swales by use of natural concepts. Per the FCSCM criteria and standards, all open channels must be designed to carry the major (100-year) storm runoff. The swales were sized to either contain the 100-year developed peak runoff plus 1 foot of freeboard or 133 percent of the 100-year developed peak runoff. Drainage swales were designed to be grass-lined, triangular channels with 4:1 side-slopes. Erosion potential in the swales was analyzed to determine if additional protective measures are needed within the project area. Based on Froude number calculations. Montava Subdivision Phase E: Town Center Preliminary Drainage Report Page 10 Detention Discharge and Storage Calculation All stormwater detention ponds are being designed by others. Montava Phase E Drains to three separate water quality control volume extended detention basins. Pond F is located Pond F Basin and captures the runoff from P Basin F and Pond F Basin. This pond discharges into a drainage swale that is southeast of the proposed site, this outfall ultimately ends up in the interim pond 427. Interim Pond 427 is located southeast of the proposed site, near the intersection of Mountain Vista and Giddings and captures the runoff from P Basin G1. This pond discharges under Mountain Vista Drive and follows the existing drainage infrastructure and ultimately ends up in the Larimer and Weld Canal. The remaining area of the proposed site, P Basin G2, is captured by a water quality pond that is located in the southwest corner of P Basin G2. This pond discharges directly into the improved pipe section of the number 8 ditch and ultimately into the Larimer and Weld Ditch. Erosion and Sediment Control Montava Phase E has been designed to be in compliance with the City of Fort Collins Erosion Control Criteria and all Erosion Control Materials will be provided with the Final Drainage Report. Erosion and sedimentation occurring on-site during construction will be controlled by use of temporary Best Management Practices (BMPs – i.e., silt fence, gravel inlet filters, vehicle tracking control pads, and straw wattle barriers). A separate Stormwater Management Plan has been provided with the PDR Submittal. Montava Subdivision Phase E: Town Center Preliminary Drainage Report Page 11 4.0 - Conclusions This preliminary drainage report has been prepared in accordance with the City of Fort Collins Stormwater Criteria Manual for a Project Development Plan (PDP) submittal. The PDP plans have also been prepared to be in compliance with the city’s current drainage criteria. The Montava Subdivision Phase E has been designed to safely and effectively capture, convey, and attenuate stormwater runoff in accordance with the FCSCM, Fort Collins Stormwater Criteria Manual, and Montava Master Drainage Study. The analysis indicates that the proposed development has been designed in a way that is consistent with existing drainage patterns of both FCSCM and Montava Master Drainage Study. 75% of newly developed areas will be connected to a LID system, which will treat storms before the traditional water quality and detention ponds. The traditional water quality and detention ponds will treat the remaining 25% of the site. The proposed drainage infrastructure will attenuate the flow prior to entering the downstream properties/ infrastructure. Additionally, areas of future development adjacent to the project area will have to been analyzed to ensure that adequate facilities will accommodate future development. Montava Subdivision Phase E: Town Center Preliminary Drainage Report Page 12 5.0 - References 1. Fort Collins Stormwater Criteria Manual, as adopted by the city of Fort Collins, as referenced in Section 26-500 of the Code of the City of Fort Collins, December 2018. 2. City of Fort Collins Cooper Slough Alternatives Analysis Update, prepared by Fort Collins Department of Utilities, prepared by ICON Engineering Inc., October 2017 3. Montava Planned Unit Development Master Drainage Study, by Martin/Martin Inc., dated January 23, 2019 Montava Subdivision Phase E: Town Center Preliminary Drainage Report Page 13 6.0 - Appendices The following appendices are attached to and made part of this final drainage design report: APPENDIX A HYDROLOGIC ANALYSIS APPENDIX B LOW IMPACT DEVELOPMENT (LID) CALCULATIONS APPENDIX C FEMA FLOOD INSURANCE RATE MAP APPENDIX D USDA HYDROLOGIC SOIL GROUP MAP APPENDIX E DRAIANGE PLANS Appendix A HYDOLOGIC ANALYSIS MONTAVA SUBDIVISION PHASE E Preliminary Drainage Report Composite C C2 C2 C10 C100 Medium Density 0.50 0.65 50 Streets: Paved 0.26 0.95 90 Lawn, Clayey, >7% Slope 0.05 0.35 2 Medium Density 0.09 0.65 50 Streets: Paved 0.12 0.95 90 Lawn, Sandy, >7% Slope 0.00 0.20 2 Medium Density 0.35 0.65 50 Streets: Paved 0.10 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.07 0.65 50 Streets: Paved 0.06 0.95 90 Lawn, Sandy, >7% Slope 0 0.20 2 Medium Density 0.39 0.65 50 Streets: Paved 0.09 0.95 90 Lawn, Sandy, >7% Slope 0.00 0.20 2 Medium Density 0.17 0.65 50 Streets: Paved 0.04 0.95 90 Lawn, Sandy, >7% Slope 0.04 0.20 2 Medium Density 0.27 0.65 50 Streets: Paved 0.14 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.79 0.65 50 Streets: Paved 0.19 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.36 0.65 50 Streets: Paved 0.15 0.95 90 Lawn, Clayey, >7% Slope 0.30 0.35 2 Medium Density 0.49 0.65 50 Streets: Paved 0.14 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.10 0.65 50 Streets: Paved 0.10 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.36 0.65 50 Streets: Paved 0.25 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.31 0.65 50 Streets: Paved 0.20 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.74 0.65 50 Streets: Paved 0.00 0.95 90 Lawn, Clayey, >7% Slope 1.06 0.35 2 Medium Density 0.27 0.65 50 Streets: Paved 0.96 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.00 0.65 50 Streets: Paved 0.65 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.00 0.65 50 Streets: Paved 0.44 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.00 0.65 50 Streets: Paved 0.58 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.00 0.65 50 Streets: Paved 0.80 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.00 0.65 50 Streets: Paved 0.41 0.95 90 Lawn, Clayey, >7% Slope 0.25 0.35 2 Medium Density 0.35 0.65 50 Streets: Paved 1.06 0.95 90 Lawn, Clayey, >7% Slope 0.75 0.35 2 Medium Density 0.20 0.65 50 Streets: Paved 0.12 0.95 90 Lawn, Clayey, >7% Slope 0.03 0.35 2 Medium Density 0.24 0.65 50 Streets: Paved 0.19 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.55 0.65 50 Streets: Paved 0.15 0.95 90 Lawn, Clayey, >7% Slope 0.07 0.35 2 Medium Density 0.33 0.65 50 Streets: Paved 0.22 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Total F Basins 16.90 Avg. % Imp. 60.4%Avg. 100-yr C100 =0.89 1.00 21.7% 0.47 1.00 F-17 0.44 90.0% 0.95 0.95 1.00 F-16 0.65 0.47 0.88 0.95 0.95 0.47 F-9 0.81 39.6% 0.59 0.59 0.74 F-8 0.98 57.8% 0.71 0.71 F-10 0.63 58.9% 0.72 0.72 90.0% 0.95 0.95 0.59 F-11 0.20 70.0% 0.80 F-15 1.23 81.2% 0.88 F-18 0.58 90.0% F-14 1.80 0.82 0.82 F-4 0.13 F-3 0.45 58.9% 0.72 0.72 Onsite Basin Composite Runoff Coefficients Basin/ Sub- Basin Area (ac) Attribute 59.9% Attribute Area (ac) Composite Runoff CoefficientsRunoff Coefficient, C Percent ImperviousImpervious 0.73 0.73 0.91 0.63 0.80 0.88 0.95 0.95 0.95 F-1 0.81 F-7 0.41 63.7% 0.75 0.75 F-6 0.25 48.7% 0.79 0.79 0.63 68.5% F-2 0.21 72.9% 0.75 0.71 0.59 0.72 0.80 0.77 1.00 0.73 0.82 0.72 0.79 0.71 0.63 0.78 F-13 0.51 F-12 0.61 0.77 0.94 1.00 0.97 65.7% 0.77 0.77 0.96 66.4% 0.77 0.77 0.90 0.89 1.00 0.90 0.99 F-5 0.48 57.5% 0.71 0.71 0.88 F-21 2.16 53.0% 0.69 0.69 0.69 0.87 F-19 0.80 90.0% 0.95 0.95 0.95 1.00 F-20 0.66 56.7% 0.72 0.72 0.72 0.90 F-22 0.35 59.6% 0.73 0.73 0.73 0.91 F-23 0.43 72.3% 0.82 0.82 0.82 1.00 F-24 0.77 53.4% 0.68 0.68 0.68 0.85 F-25 0.55 66.0% 0.77 0.77 0.77 0.96 Appendix A MONTAVA SUBDIVISION PHASE E Preliminary Drainage Report Medium Density 0.73 0.65 50 Streets: Paved 0.98 0.95 90 Lawn, Clayey, >7% Slope 0.74 0.35 2 Medium Density 0.31 0.65 50 Streets: Paved 0.39 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.07 0.65 50 Streets: Paved 1.06 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.22 0.65 50 Streets: Paved 0.26 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.36 0.65 50 Streets: Paved 0.66 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.26 0.65 50 Streets: Paved 0.31 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.10 0.65 50 Streets: Paved 0.37 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.12 0.65 50 Streets: Paved 0.06 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.21 0.65 50 Streets: Paved 0.00 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.17 0.65 50 Streets: Paved 0.36 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.14 0.65 50 Streets: Paved 0.04 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.26 0.65 50 Streets: Paved 0.61 0.95 90 Lawn, Clayey, >7% Slope 0.04 0.35 2 Medium Density 0.30 0.65 50 Streets: Paved 0.18 0.95 90 Lawn, Clayey, >7% Slope 0.06 0.35 2 Medium Density 0.11 0.65 50 Streets: Paved 0.04 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.02 0.65 50 Streets: Paved 0.03 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.03 0.65 50 Streets: Paved 0.04 0.95 90 Lawn, Clayey, >7% Slope 0.00 0.35 2 Medium Density 0.12 0.65 50 Streets: Paved 0.62 0.95 90 Streets: Permeable Pavers 0.45 0.30 40 Lawn, Clayey, >7% Slope 0.65 0.35 2 Medium Density 0.00 0.65 50 Streets: Paved 0.20 0.95 90 Streets: Permeable Pavers 0.44 0.30 40 Medium Density 0.00 0.65 50 Streets: Paved 0.00 0.95 90 Open Lands, Transition 3.64 0.20 20 Total F Basins 15.76 Avg. % Imp. 53.7%Avg. 100-yr C100 =0.73 1.00 G1-14 0.15 60.7% 0.73 0.73 0.73 0.91 0.18 0.91 0.54 0.85 G1-2 G1-3 G1-4 G1-5 G1-6 1.00 0.75 0.94 G1-15 0.05 74.0% 0.83 G1-13 0.81 1.00 81.5% 0.89 0.89 0.89 G1-8 G1-9 0.57 0.47 0.18 0.21 1.00 1.00 1.00 1.00 87.5% 0.93 0.93 0.93 71.7% 0.81 0.81 0.81 75.9% 0.84 0.84 G1-10 G1-11 G1-12 0.53 71.8% 0.81 0.81 0.70 1.13 0.48 1.02 0.82 0.82 0.82 0.72 0.72 51.5% 0.68 0.68 0.68 G1-7 0.84 G1-1 2.45 0.83 0.83 72.3% 63.3% 0.75 0.75 50.0% 0.65 0.65 58.0% 0.65 0.81 77.2% 0.85 0.85 0.85 1.00 0.72 0.72 0.72 0.90 74.7% 0.84 0.84 0.84 1.00 G1-16 0.07 72.9% 0.82 0.82 0.82 1.00 0.72 0.90 58.9% G1-17 1.84 44.1% 0.49 0.49 0.49 0.61 G1-18 0.64 55.6% 0.50 0.50 0.50 0.63 G1-19 3.64 20.0% 0.20 0.20 0.20 0.25 Appendix A MONTAVA SUBDIVISION PHASE E Preliminary Drainage Report Medium Density 0.00 0.65 50 Streets: Paved 0.08 0.95 90 Streets: Permeable Pavers 0.16 0.30 40 Medium Density 0.00 0.65 50 Streets: Paved 0.07 0.95 90 Streets: Permeable Pavers 0.12 0.30 40 Medium Density 1.21 0.65 50 Streets: Paved 0.00 0.95 90 Streets: Permeable Pavers 1.68 0.30 40 Medium Density 0.00 0.65 50 Streets: Paved 0.13 0.95 90 Streets: Permeable Pavers 0.26 0.30 40 Medium Density 0.00 0.65 50 Streets: Paved 0.31 0.95 90 Streets: Permeable Pavers 0.28 0.30 40 Medium Density 0.00 0.65 50 Streets: Paved 0.00 0.95 90 Open Lands, Transition 1.45 0.20 20 Total F Basins 5.75 Avg. % Imp. 42.2%Avg. 100-yr C100 =0.52 Medium Density 1.08 0.65 50 Streets: Paved 0.00 0.95 90 Open Lands, Transition 7.18 0.20 20 Total F Basins 8.26 Avg. % Imp. 23.9%Avg. 100-yr C100 =0.32 66.3% 0.64 0.64 0.64 0.80 G2-3 2.89 44.2% 0.45 0.45 0.45 0.56 G2-4 0.39 56.7% 0.52 0.52 G2-1 0.24 56.7% 0.52 0.52 G2-5 0.59 0.52 0.52 G2-2 0.19 58.4% 0.54 0.54 0.54 POND F 8.26 23.9% 0.26 0.26 0.26 0.32 G2-6 1.45 20.0% 0.20 0.20 0.20 0.25 0.65 0.65 0.67 Appendix A MONTAVA SUBDIVISION PHASE E Preliminary Drainage Report Overland Flow Average Channelized Channel Channel Channelized Length, D Overland Slope Tov Tov Tov Flow Length Slope Velocity Time (Tt) (ft) (%) 2-year 10-year 100-year (ft) (%) (ft/s) (min) 2-year 10-year 100-year F-1 0.73 0.73 0.91 87 0.5 8 8 4 60 0.5 1.5 0.7 9 9 5 F-2 0.82 0.82 1.00 40 0.5 4 4 1 71 0.5 1.5 0.8 5 5 5 F-3 0.72 0.72 0.90 72 0.5 8 8 4 108 0.5 1.5 1.2 9 9 5 F-4 0.79 0.79 0.99 42 0.5 5 5 2 53 0.5 1.5 0.6 6 6 5 F-5 0.71 0.71 0.88 100 0.5 9 9 5 85 0.5 1.5 0.9 10 10 6 F-6 0.63 0.63 0.78 62 0.5 9 9 6 55 0.5 1.5 0.6 10 10 7 F-7 0.75 0.75 0.94 65 0.5 7 7 3 95 0.5 1.5 1.1 8 8 5 F-8 0.71 0.71 0.89 100 0.5 9 9 5 230 0.5 1.5 2.6 12 12 8 F-9 0.59 0.59 0.74 68 0.5 10 10 7 205 0.5 1.5 2.3 12 12 9 F-10 0.72 0.72 0.90 41 0.5 6 6 3 50 0.5 1.5 0.6 7 7 5 F-11 0.80 0.80 1.00 48 0.5 5 5 2 48 0.5 1.5 0.5 6 6 5 F-12 0.77 0.77 0.97 50 0.5 5 5 2 202 0.5 1.5 2.2 7 7 5 F-13 0.77 0.77 0.96 80 0.5 7 7 3 165 0.5 1.5 1.8 9 9 5 F-14 0.47 0.47 0.59 85 0.5 14 14 11 750 0.5 1.5 8.3 22 22 19 F-15 0.88 0.88 1.00 25 0.5 3 3 1 1077 0.5 1.5 12.0 15 15 13 F-16 0.95 0.95 1.00 20 0.5 2 2 1 507 0.5 1.5 5.6 8 8 7 F-17 0.95 0.95 1.00 10 0.5 1 1 1 450 0.5 1.5 5.0 6 6 6 F-18 0.95 0.95 1.00 62 0.5 3 3 2 465 0.5 1.5 5.2 8 8 7 F-19 0.95 0.95 1.00 63 0.5 3 3 2 280 0.5 1.5 3.1 6 6 5 F-20 0.72 0.72 0.90 64 0.5 7 7 4 287 0.5 1.5 3.2 10 10 7 F-21 0.69 0.69 0.87 53 0.5 7 7 4 406 0.5 1.5 4.5 12 12 9 F-22 0.73 0.73 0.91 105 0.5 9 9 5 20 0.5 1.5 0.2 9 9 5 F-23 0.82 0.82 1.00 84 0.5 6 6 2 75 0.5 1.5 0.8 7 7 5 F-24 0.68 0.68 0.85 54 0.5 7 7 4 55 0.5 1.5 0.6 8 8 5 F-25 0.77 0.77 0.96 45 0.5 5 5 2 167 0.5 1.5 1.9 7 7 5 G1-1 0.68 0.68 0.85 65 0.5 8 8 5 782 0.5 1.5 8.7 17 17 14 G1-2 0.82 0.82 1.00 73 0.5 6 6 2 170 0.5 1.5 1.9 8 8 5 G1-3 0.93 0.93 1.00 48 0.5 3 3 2 190 0.5 1.5 2.1 5 5 5 G1-4 0.81 0.81 1.00 53 0.5 5 5 2 316 0.5 1.5 3.5 9 9 6 G1-5 0.84 0.84 1.00 50 0.5 4 4 2 470 0.5 1.5 5.2 9 9 7 G1-6 0.81 0.81 1.00 80 0.5 6 6 2 260 0.5 1.5 2.9 9 9 5 G1-7 0.89 0.89 1.00 42 0.5 3 3 2 101 0.5 1.5 1.1 5 5 5 G1-8 0.75 0.75 0.94 45 0.5 6 6 3 22 0.5 1.5 0.2 6 6 5 G1-9 0.65 0.65 0.81 43 0.5 7 7 4 72 0.5 1.5 0.8 8 8 5 G1-10 0.85 0.85 1.00 83 0.5 5 5 2 260 0.5 1.5 2.9 8 8 5 G1-11 0.72 0.72 0.90 120 0.5 10 10 5 524 0.5 1.5 5.8 16 16 11 G1-12 0.84 0.84 1.00 60 0.5 5 5 2 353 0.5 1.5 3.9 9 9 6 G1-13 0.72 0.72 0.90 120 0.5 10 10 5 1011 0.5 1.5 11.2 21 21 16 G1-14 0.73 0.73 0.91 38 0.5 5 5 3 412 0.5 1.5 4.6 10 10 8 G1-15 0.83 0.83 1.00 38 0.5 4 4 1 412 0.5 1.5 4.6 9 9 6 G1-16 0.82 0.82 1.00 28 0.5 3 3 1 412 0.5 1.5 4.6 8 8 6 G1-17 0.49 0.49 0.61 50 0.5 10 10 8 412 0.5 1.5 4.6 15 15 13 G1-18 0.50 0.50 0.63 28 0.5 7 7 6 412 0.5 1.5 4.6 12 12 11 G1-19 0.20 0.20 0.25 246 0.5 33 33 31 412 0.5 1.5 4.6 38 38 36 G2-1 0.52 0.52 0.65 20 0.5 6 6 5 160 0.5 1.5 1.8 8 8 7 G2-2 0.54 0.54 0.67 20 0.5 6 6 4 375 0.5 1.5 4.2 10 10 8 G2-3 0.45 0.45 0.56 60 0.5 12 12 10 358 0.5 1.5 4.0 16 16 14 G2-4 0.52 0.52 0.65 18 0.5 6 6 5 359 0.5 1.5 4.0 10 10 9 G2-5 0.64 0.64 0.80 35 0.5 6 6 4 192 0.5 1.5 2.1 8 8 6 G2-6 0.20 0.20 0.25 350 0.5 40 40 37 192 0.5 1.5 2.1 42 42 39 POND F 0.26 0.26 0.32 350 0.5 37 37 34 192 0.5 1.5 2.1 39 39 36 Basin Time of Concentration Frequency Adj. Runoff Coefficients (C*Cf) C2 C10 C100 Overland Travel Time Time of Concentration Tc = Tov + Tt (min)Basin Appendix A MONTAVA SUBDIVISION PHASE E Preliminary Drainage Report 2 - year 10 - year 100 - year 2 - year 10 - year 100 - year 2 - Year 10 - Year 100 - Year 2 - Year 10 - Year 100 - Year F-1 0.81 0.73 0.73 0.91 9 9 5 2.30 3.93 9.95 1.36 2.32 7.33 F-2 0.21 0.82 0.82 1.00 5 5 5 2.85 4.87 9.95 0.49 0.84 2.09 F-3 0.45 0.72 0.72 0.90 9 9 5 2.30 3.93 9.95 0.74 1.27 4.01 F-4 0.13 0.79 0.79 0.99 6 6 5 2.67 4.56 9.95 0.27 0.47 1.27 F-5 0.48 0.71 0.71 0.88 10 10 6 2.21 3.78 9.31 0.75 1.28 3.95 F-6 0.25 0.63 0.63 0.78 10 10 7 2.21 3.78 8.80 0.35 0.59 1.72 F-7 0.41 0.75 0.75 0.94 8 8 5 2.40 4.10 9.95 0.74 1.26 3.84 F-8 0.98 0.71 0.71 0.89 12 12 8 2.05 3.50 8.38 1.42 2.43 7.27 F-9 0.81 0.59 0.59 0.74 12 12 9 2.05 3.50 8.03 0.99 1.69 4.83 F-10 0.63 0.72 0.72 0.90 7 7 5 2.52 4.31 9.95 1.14 1.95 5.62 F-11 0.20 0.80 0.80 1.00 6 6 5 2.67 4.56 9.95 0.43 0.73 1.99 F-12 0.61 0.77 0.77 0.97 7 7 5 2.52 4.31 9.95 1.19 2.03 5.86 F-13 0.51 0.77 0.77 0.96 9 9 5 2.30 3.93 9.95 0.90 1.54 4.87 F-14 1.80 0.47 0.47 0.59 22 22 19 1.53 2.61 5.75 1.30 2.22 6.12 F-15 1.23 0.88 0.88 1.00 15 15 13 1.87 3.19 6.92 2.03 3.47 8.51 F-16 0.65 0.95 0.95 1.00 8 8 7 2.40 4.10 8.80 1.48 2.53 5.72 F-17 0.44 0.95 0.95 1.00 6 6 6 2.67 4.56 9.31 1.12 1.91 4.10 F-18 0.58 0.95 0.95 1.00 8 8 7 2.40 4.10 8.80 1.32 2.26 5.10 F-19 0.80 0.95 0.95 1.00 6 6 5 2.67 4.56 9.95 2.03 3.47 7.96 F-20 0.66 0.72 0.72 0.90 10 10 7 2.21 3.78 8.80 1.05 1.80 5.25 F-21 2.16 0.69 0.69 0.87 12 12 9 2.05 3.50 8.03 3.07 5.24 15.03 F-22 0.35 0.73 0.73 0.91 9 9 5 2.30 3.93 9.95 0.59 1.00 3.17 F-23 0.43 0.82 0.82 1.00 7 7 5 2.52 4.31 9.95 0.89 1.51 4.28 F-24 0.77 0.68 0.68 0.85 8 8 5 2.40 4.10 9.95 1.26 2.15 6.52 F-25 0.55 0.77 0.77 0.96 7 7 5 2.52 4.31 9.95 1.07 1.83 5.27 G1-1 2.45 0.68 0.68 0.85 17 17 14 1.75 2.99 6.71 2.9 5.0 14.0 G1-2 0.70 0.82 0.82 1.00 8 8 5 2.40 4.10 9.95 1.4 2.3 7.0 G1-3 1.13 0.93 0.93 1.00 5 5 5 2.85 4.87 9.95 3.0 5.1 11.2 G1-4 0.48 0.81 0.81 1.00 9 9 6 2.30 3.93 9.31 0.9 1.5 4.5 G1-5 1.02 0.84 0.84 1.00 9 9 7 2.30 3.93 8.80 2.0 3.4 9.0 G1-6 0.57 0.81 0.81 1.00 9 9 5 2.30 3.93 9.95 1.1 1.8 5.7 G1-7 0.47 0.89 0.89 1.00 5 5 5 2.85 4.87 9.95 1.2 2.0 4.7 G1-8 0.18 0.75 0.75 0.94 6 6 5 2.67 4.56 9.95 0.4 0.6 1.7 G1-9 0.21 0.65 0.65 0.81 8 8 5 2.40 4.10 9.95 0.3 0.6 1.7 G1-10 0.53 0.85 0.85 1.00 8 8 5 2.40 4.10 9.95 1.1 1.9 5.3 G1-11 0.18 0.72 0.72 0.90 16 16 11 1.81 3.08 7.42 0.2 0.4 1.2 G1-12 0.91 0.84 0.84 1.00 9 9 6 2.30 3.93 9.31 1.8 3.0 8.5 G1-13 0.54 0.72 0.72 0.90 21 21 16 1.56 2.67 6.30 0.6 1.0 3.0 G1-14 0.15 0.73 0.73 0.91 10 10 8 2.21 3.78 8.38 0.2 0.4 1.1 G1-15 0.05 0.83 0.83 1.00 9 9 6 2.30 3.93 9.31 0.1 0.2 0.5 G1-16 0.07 0.82 0.82 1.00 8 8 6 2.40 4.10 9.31 0.1 0.2 0.7 G1-17 1.84 0.49 0.49 0.61 15 15 13 1.87 3.19 6.92 1.7 2.9 7.7 G1-18 0.64 0.50 0.50 0.63 12 12 11 2.05 3.50 7.42 0.7 1.1 3.0 G1-19 3.64 0.20 0.20 0.25 38 38 36 1.11 1.89 4.01 0.8 1.4 3.6 G2-1 0.24 0.52 0.52 0.65 8 8 7 2.40 4.10 8.80 0.3 0.5 1.4 G2-2 0.19 0.54 0.54 0.67 10 10 8 2.21 3.78 8.38 0.2 0.4 1.1 G2-3 2.89 0.45 0.45 0.56 16 16 14 1.81 3.08 6.71 2.3 4.0 10.8 G2-4 0.39 0.52 0.52 0.65 10 10 9 2.21 3.78 8.03 0.4 0.8 2.0 G2-5 0.59 0.64 0.64 0.80 8 8 6 2.40 4.10 9.31 0.9 1.6 4.4 G2-6 1.45 0.20 0.20 0.25 42 42 39 1.04 1.77 3.80 0.3 0.5 1.4 POND F 8.26 0.26 0.26 0.32 39 39 36 1.09 1.86 4.01 2.3 4.0 10.7 Basin Peak Discharge Rainfall Intensity (in/hr) Peak Discharge (cfs)Basin Basin Area (ac) Frequency Adj. Runoff Coefficients P BASIN F P BASIN G1 P BASIN G2 POND F Time of Concentration, Tc (min) Appendix A Appendix B LOW IMPACT DEVELOPMENT (LID) CALCULATIONS MONTAVA SUBDIVISION PHASE E Preliminary Drainage Report Basin/ Sub-Basin Total Area (acres) Impervious Area (acres) % Impervious TO BE LID TREATED PERCENT OF TOTAL SITE AREA TO BE TREATED F-1 0.81 0.49 59.88%YES 1.79% 0.81 F-2 0.21 0.15 72.86%NO 0.46% N/A F-3 0.45 0.27 58.89%NO 1.00% N/A F-4 0.13 0.09 68.46%NO 0.29% N/A F-5 0.48 0.28 57.50%YES 1.06% 0.48 F-6 0.25 0.12 48.72%YES 0.55% 0.25 F-7 0.41 0.26 63.66%NO 0.91% N/A F-8 0.98 0.57 57.76%YES 2.17% 0.98 F-9 0.81 0.32 39.63%YES 1.79% 0.81 F-10 0.63 0.37 58.89%NO 1.39% N/A F-11 0.20 0.14 70.00%YES 0.44% 0.20 F-12 0.61 0.41 66.39%NO 1.35% N/A F-13 0.51 0.34 65.69%YES 1.13% 0.51 F-14 1.80 0.39 21.73%NO 3.98% N/A F-15 1.23 1.00 81.22%YES 2.72% 1.23 F-16 0.65 0.59 90.00%NO 1.44% N/A F-17 0.44 0.40 90.00%YES 0.97% 0.44 F-18 0.58 0.52 90.00%NO 1.28% N/A F-19 0.80 0.72 90.00%NO 1.77% N/A F-20 0.66 0.37 56.67%NO 1.46% N/A F-21 2.16 1.14 52.96%NO 4.78% N/A F-22 0.35 0.21 59.60%YES 0.77% 0.35 F-23 0.43 0.31 72.33%YES 0.95% 0.43 F-24 0.77 0.41 53.43%YES 1.70% 0.77 F-25 0.55 0.36 66.00%YES 1.22% 0.55 Total= 16.90 10.21 60.44% 37.37% 7.81 G1-1 2.45 1.26 51.50%NO 5.42% N/A G1-2 0.70 0.51 72.29%NO 1.55% N/A G1-3 1.13 0.99 87.52%NO 2.50% N/A G1-4 0.48 0.34 71.67%NO 1.06% N/A G1-5 1.02 0.77 75.88%NO 2.26% N/A G1-6 0.57 0.41 71.75%NO 1.26% N/A G1-7 0.47 0.38 81.49%YES 1.04% 0.47 G1-8 0.18 0.11 63.33%NO 0.40% N/A G1-9 0.21 0.11 50.00%NO 0.46% N/A G1-10 0.53 0.41 77.17%NO 1.17% N/A G1-11 0.18 0.11 58.89%NO 0.40% N/A G1-12 0.91 0.68 74.70%YES 2.01% 0.91 G1-13 0.54 0.31 58.00%YES 1.19% 0.54 G1-14 0.15 0.09 60.67%NO 0.33% N/A G1-15 0.05 0.04 74.00%NO 0.11% N/A G1-16 0.07 0.05 72.86%NO 0.15% N/A G1-17 1.84 0.81 44.08%NO 4.07% N/A G1-18 0.64 0.36 55.63%NO 1.42% N/A G1-19 3.64 0.73 20.00%NO 8.05% N/A Total= 15.76 8.47 53.73% 34.85% 1.92 G2-1 0.24 0.14 56.67%YES 0.53% 0.24 G2-2 0.19 0.11 58.42%YES 0.42% 0.19 G2-3 2.89 1.28 44.19%YES 6.39% 2.89 G2-4 0.39 0.22 56.67%YES 0.86% 0.39 G2-5 0.59 0.39 66.27%YES 1.30% 0.59 G2-6 1.45 0.29 20.00%YES 3.21% 1.45 Total= 4.30 2.43 42.19% 12.72% 5.75 POND F 8.26 1.98 23.92% YES (1/4 OF BASIN) 4.57% 2.07 Total= 8.26 1.98 23.92% 4.57% 2.07 17.31 *Percent impervious values based on UDFCD Vol 1., Chapter 6, Table 6-3 Low Impact Development (LID) Per agreements with the City and adjacent property owner, all LID for the H23 project will be handeled offsite on the adjacent H25 developement. Total Impervious Area to be Treated Using LID Techniques (acres) = P BASIN F P BASIN G1 P BASIN G2 P BASIN G2 Appendix C FEMA FLOOD INSURANCE RATE MAP 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 10/12/2021 at 3:48 PM 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°1'53"W 40°36'53"N 105°1'16"W 40°36'25"N Basemap: USGS National Map: Orthoimagery: Data refreshed October, 2020 Appendix D USDA HYDROLOGIC SOIL GROUP MAP 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 March 25, 2022 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.) 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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......................................................................14 5—Aquepts, loamy......................................................................................14 22—Caruso clay loam, 0 to 1 percent slope...............................................15 35—Fort Collins loam, 0 to 3 percent slopes..............................................16 53—Kim loam, 1 to 3 percent slopes..........................................................17 54—Kim loam, 3 to 5 percent slopes..........................................................19 94—Satanta loam, 0 to 1 percent slopes....................................................20 95—Satanta loam, 1 to 3 percent slopes....................................................21 98—Satanta Variant clay loam, 0 to 3 percent slopes.................................23 101—Stoneham loam, 1 to 3 percent slopes..............................................24 102—Stoneham loam, 3 to 5 percent slopes..............................................25 103—Stoneham loam, 5 to 9 percent slopes..............................................27 References............................................................................................................29 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 449550044956004495700449580044959004496000449610044962004496300449550044956004495700449580044959004496000449610044962004496300497200 497300 497400 497500 497600 497700 497800 497900 498000 498100 498200 498300 498400 498500 498600 497200 497300 497400 497500 497600 497700 497800 497900 498000 498100 498200 498300 498400 498500 498600 40° 37' 5'' N 105° 2' 1'' W40° 37' 5'' N105° 0' 56'' W40° 36' 34'' N 105° 2' 1'' W40° 36' 34'' N 105° 0' 56'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 300 600 1200 1800 Feet 0 100 200 400 600 Meters Map Scale: 1:6,950 if printed on A landscape (11" x 8.5") 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 16, Sep 2, 2021 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jul 19, 2018—Aug 10, 2018 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 5 Aquepts, loamy 4.8 2.9% 22 Caruso clay loam, 0 to 1 percent slope 25.4 15.2% 35 Fort Collins loam, 0 to 3 percent slopes 48.9 29.3% 53 Kim loam, 1 to 3 percent slopes 0.0 0.0% 54 Kim loam, 3 to 5 percent slopes 0.3 0.2% 94 Satanta loam, 0 to 1 percent slopes 2.3 1.4% 95 Satanta loam, 1 to 3 percent slopes 0.0 0.0% 98 Satanta Variant clay loam, 0 to 3 percent slopes 57.6 34.6% 101 Stoneham loam, 1 to 3 percent slopes 15.6 9.4% 102 Stoneham loam, 3 to 5 percent slopes 5.3 3.2% 103 Stoneham loam, 5 to 9 percent slopes 6.5 3.9% Totals for Area of Interest 166.6 100.0% 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 Custom Soil Resource Report 11 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. 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. Custom Soil Resource Report 12 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 13 Larimer County Area, Colorado 5—Aquepts, loamy Map Unit Setting National map unit symbol: jpws Elevation: 4,500 to 6,700 feet Mean annual precipitation: 12 to 18 inches Mean annual air temperature: 39 to 50 degrees F Frost-free period: 80 to 140 days Farmland classification: Not prime farmland Map Unit Composition Aquepts and similar soils:80 percent Minor components:20 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Aquepts Setting Landform:Stream terraces, depressions, draws Landform position (three-dimensional):Base slope, tread, dip Down-slope shape:Linear Across-slope shape:Linear Parent material:Loamy alluvium Typical profile H1 - 0 to 60 inches: variable Properties and qualities Slope:0 to 3 percent Depth to restrictive feature:More than 80 inches Drainage class:Very poorly drained Runoff class: Negligible Capacity of the most limiting layer to transmit water (Ksat):Moderately high to very high (0.60 to 99.90 in/hr) Depth to water table:About 6 to 18 inches Frequency of flooding:NoneRare Frequency of ponding:None Interpretive groups Land capability classification (irrigated): 5w Land capability classification (nonirrigated): 3w Hydrologic Soil Group: A/D Ecological site: R067BY073CO - Riparian Hydric soil rating: Yes Minor Components Nunn Percent of map unit:5 percent Ecological site:R067BZ902CO - Loamy Plains Hydric soil rating: No Stoneham Percent of map unit:5 percent Custom Soil Resource Report 14 Ecological site:R067BZ902CO - Loamy Plains Hydric soil rating: No Kim Percent of map unit:5 percent Ecological site:R067BZ902CO - Loamy Plains Hydric soil rating: No Fort collins Percent of map unit:5 percent Ecological site:R067BZ008CO - Loamy Slopes Hydric soil rating: No 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 Custom Soil Resource Report 15 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 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:Interfluves, stream terraces 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 Custom Soil Resource Report 16 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 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):Side slope, interfluve Down-slope shape:Linear Across-slope shape:Linear Ecological site:R067BY024CO - Sandy Plains Hydric soil rating: No 53—Kim loam, 1 to 3 percent slopes Map Unit Setting National map unit symbol: jpwx Elevation: 4,800 to 5,600 feet Custom Soil Resource Report 17 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 Kim and similar soils:90 percent Minor components:10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Kim Setting Landform:Fans Landform position (three-dimensional):Base slope Down-slope shape:Linear Across-slope shape:Linear Parent material:Mixed alluvium Typical profile H1 - 0 to 7 inches: loam H2 - 7 to 60 inches: clay loam Properties and qualities Slope:1 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 (0.60 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 slightly saline (0.0 to 4.0 mmhos/cm) Available water supply, 0 to 60 inches: High (about 9.6 inches) Interpretive groups Land capability classification (irrigated): 2e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: B Ecological site: R067BZ902CO - Loamy Plains Hydric soil rating: No Minor Components Fort collins Percent of map unit:6 percent Ecological site:R067BZ008CO - Loamy Slopes Hydric soil rating: No Stoneham Percent of map unit:3 percent Ecological site:R067BZ902CO - Loamy Plains Hydric soil rating: No Aquic haplustolls Percent of map unit:1 percent Custom Soil Resource Report 18 Landform:Swales Hydric soil rating: Yes 54—Kim loam, 3 to 5 percent slopes Map Unit Setting National map unit symbol: jpwy 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: Farmland of statewide importance Map Unit Composition Kim and similar soils:90 percent Minor components:10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Kim Setting Landform:Fans Landform position (three-dimensional):Base slope Down-slope shape:Linear Across-slope shape:Linear Parent material:Mixed alluvium Typical profile H1 - 0 to 7 inches: loam H2 - 7 to 60 inches: clay loam Properties and qualities Slope:3 to 5 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 slightly saline (0.0 to 4.0 mmhos/cm) Available water supply, 0 to 60 inches: High (about 9.6 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: B Ecological site: R067BZ902CO - Loamy Plains Hydric soil rating: No Custom Soil Resource Report 19 Minor Components Thedalund Percent of map unit:4 percent Ecological site:R067BZ902CO - Loamy Plains Hydric soil rating: No Stoneham Percent of map unit:3 percent Ecological site:R067BZ902CO - Loamy Plains Hydric soil rating: No Fort collins Percent of map unit:2 percent Ecological site:R067BZ008CO - Loamy Slopes Hydric soil rating: No Aquic haplustolls Percent of map unit:1 percent Landform:Swales Hydric soil rating: Yes 94—Satanta loam, 0 to 1 percent slopes Map Unit Setting National map unit symbol: 2wz89 Elevation: 3,670 to 5,410 feet Mean annual precipitation: 10 to 23 inches Mean annual air temperature: 45 to 52 degrees F Frost-free period: 105 to 160 days Farmland classification: Prime farmland if irrigated Map Unit Composition Satanta and similar soils:90 percent Minor components:10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Satanta Setting Landform:Alluvial fans Landform position (two-dimensional):Backslope Landform position (three-dimensional):Head slope Down-slope shape:Linear Across-slope shape:Linear Parent material:Alluvium Typical profile Ap - 0 to 10 inches: loam Bt - 10 to 17 inches: clay loam C - 17 to 79 inches: loam Custom Soil Resource Report 20 Properties and qualities Slope:0 to 1 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Runoff class: Negligible Capacity of the most limiting layer to transmit water (Ksat):Moderately high (0.20 to 0.60 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None 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: Very high (about 12.3 inches) Interpretive groups Land capability classification (irrigated): 1 Land capability classification (nonirrigated): 2e Hydrologic Soil Group: C Ecological site: R072XY111KS - Sandy Plains Hydric soil rating: No Minor Components Nunn Percent of map unit:5 percent Landform:Terraces Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Ecological site:R072XY108KS - Loamy Lowland Hydric soil rating: No Fort collins Percent of map unit:5 percent Landform:Alluvial fans Landform position (two-dimensional):Backslope Landform position (three-dimensional):Head slope Down-slope shape:Linear Across-slope shape:Linear Ecological site:R072XY111KS - Sandy Plains Hydric soil rating: No 95—Satanta loam, 1 to 3 percent slopes Map Unit Setting National map unit symbol: 2w5f3 Elevation: 3,670 to 5,410 feet Mean annual precipitation: 14 to 23 inches Mean annual air temperature: 46 to 54 degrees F Frost-free period: 130 to 163 days Custom Soil Resource Report 21 Farmland classification: Prime farmland if irrigated Map Unit Composition Satanta and similar soils:90 percent Minor components:10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Satanta Setting Landform:Paleoterraces Landform position (two-dimensional):Backslope Landform position (three-dimensional):Head slope Down-slope shape:Linear Across-slope shape:Linear Parent material:Eolian sands Typical profile Ap - 0 to 9 inches: loam Bt - 9 to 18 inches: clay loam C - 18 to 79 inches: loam Properties and qualities Slope:1 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 (0.20 to 0.60 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None 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: Very high (about 12.2 inches) Interpretive groups Land capability classification (irrigated): 2e Land capability classification (nonirrigated): 3e Hydrologic Soil Group: C Ecological site: R067BY024CO - Sandy Plains Hydric soil rating: No Minor Components Nunn Percent of map unit:5 percent Landform:Terraces Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Ecological site:R067BY002CO - Loamy Plains Hydric soil rating: No Fort collins Percent of map unit:5 percent Landform:Alluvial fans Custom Soil Resource Report 22 Landform position (two-dimensional):Backslope Landform position (three-dimensional):Head slope Down-slope shape:Linear Across-slope shape:Linear Ecological site:R067BY024CO - Sandy Plains Hydric soil rating: No 98—Satanta Variant clay loam, 0 to 3 percent slopes Map Unit Setting National map unit symbol: jpyh 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 Satanta variant and similar soils:90 percent Minor components:10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Satanta Variant Setting Landform:Terraces Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Parent material:Alluvium Typical profile H1 - 0 to 9 inches: clay loam H2 - 9 to 22 inches: clay loam H3 - 22 to 60 inches: loam Properties and qualities Slope:0 to 3 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:15 percent Gypsum, maximum content:10 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 8.7 inches) Custom Soil Resource Report 23 Interpretive groups Land capability classification (irrigated): 2e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: D Ecological site: R067BY036CO - Overflow Hydric soil rating: No Minor Components Nunn Percent of map unit:5 percent Ecological site:R067BZ902CO - Loamy Plains Hydric soil rating: No Caruso Percent of map unit:3 percent Ecological site:R067BY036CO - Overflow Hydric soil rating: No Loveland Percent of map unit:2 percent Ecological site:R067BY036CO - Overflow Hydric soil rating: No 101—Stoneham loam, 1 to 3 percent slopes Map Unit Setting National map unit symbol: jptt 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 Stoneham and similar soils:90 percent Minor components:10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Stoneham Setting Landform:Terraces, benches Landform position (three-dimensional):Base slope, tread Down-slope shape:Linear Across-slope shape:Linear Parent material:Mixed alluvium and/or eolian deposits Typical profile H1 - 0 to 4 inches: loam H2 - 4 to 10 inches: sandy clay loam Custom Soil Resource Report 24 H3 - 10 to 60 inches: clay loam Properties and qualities Slope:1 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 (0.60 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) Available water supply, 0 to 60 inches: High (about 9.6 inches) Interpretive groups Land capability classification (irrigated): 2e Land capability classification (nonirrigated): 3e Hydrologic Soil Group: B Ecological site: R067BZ902CO - Loamy Plains Hydric soil rating: No Minor Components Kim Percent of map unit:5 percent Ecological site:R067BZ902CO - Loamy Plains Hydric soil rating: No Fort collins Percent of map unit:5 percent Ecological site:R067BZ902CO - Loamy Plains Hydric soil rating: No 102—Stoneham loam, 3 to 5 percent slopes Map Unit Setting National map unit symbol: 2x0j1 Elevation: 3,500 to 6,500 feet Mean annual precipitation: 12 to 18 inches Mean annual air temperature: 46 to 54 degrees F Frost-free period: 115 to 155 days Farmland classification: Prime farmland if irrigated Map Unit Composition Stoneham and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Custom Soil Resource Report 25 Description of Stoneham Setting Landform:Interfluves, low hills Landform position (two-dimensional):Summit Landform position (three-dimensional):Interfluve Down-slope shape:Linear Across-slope shape:Linear Parent material:Mixed alluvial and/or eolian tertiary aged pedisediment Typical profile Ap - 0 to 4 inches: loam Bt - 4 to 9 inches: clay loam Btk - 9 to 13 inches: clay loam Bk1 - 13 to 18 inches: loam Bk2 - 18 to 34 inches: loam C - 34 to 80 inches: loam Properties and qualities Slope:3 to 5 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 Maximum salinity:Nonsaline to very slightly saline (0.1 to 2.0 mmhos/cm) Sodium adsorption ratio, maximum:0.5 Available water supply, 0 to 60 inches: High (about 9.1 inches) Interpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 4c Hydrologic Soil Group: C Ecological site: R067BY002CO - Loamy Plains Hydric soil rating: No Minor Components Satanta Percent of map unit:5 percent Landform:Interfluves Landform position (two-dimensional):Summit Landform position (three-dimensional):Interfluve Down-slope shape:Linear Across-slope shape:Linear Ecological site:R067BY002CO - Loamy Plains Hydric soil rating: No Weld Percent of map unit:5 percent Landform:Interfluves Landform position (two-dimensional):Summit Custom Soil Resource Report 26 Landform position (three-dimensional):Interfluve Down-slope shape:Linear Across-slope shape:Linear Ecological site:R067BY002CO - Loamy Plains Hydric soil rating: No Kimst Percent of map unit:5 percent Landform:Low hills, interfluves Landform position (two-dimensional):Backslope, shoulder Landform position (three-dimensional):Side slope Down-slope shape:Convex Across-slope shape:Convex Ecological site:R067BY002CO - Loamy Plains Hydric soil rating: No 103—Stoneham loam, 5 to 9 percent slopes Map Unit Setting National map unit symbol: jptw 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: Farmland of local importance Map Unit Composition Stoneham and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Stoneham Setting Landform:Terraces, benches Landform position (three-dimensional):Side slope, tread Down-slope shape:Linear Across-slope shape:Linear Parent material:Mixed alluvium and/or eolian deposits Typical profile H1 - 0 to 3 inches: loam H2 - 3 to 9 inches: clay loam H3 - 9 to 60 inches: clay loam Properties and qualities Slope:5 to 9 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Runoff class: Medium Custom Soil Resource Report 27 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) Available water supply, 0 to 60 inches: High (about 9.6 inches) Interpretive groups Land capability classification (irrigated): 6e Land capability classification (nonirrigated): 6e Hydrologic Soil Group: B Ecological site: R067BZ902CO - Loamy Plains Hydric soil rating: No Minor Components Kim Percent of map unit:8 percent Ecological site:R067BZ902CO - Loamy Plains Hydric soil rating: No Larimer Percent of map unit:5 percent Ecological site:R067BZ902CO - Loamy Plains Hydric soil rating: No Fort collins Percent of map unit:2 percent Ecological site:R067BZ902CO - Loamy Plains Hydric soil rating: No Custom Soil Resource Report 28 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 29 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 30 Appendix E DRAINAGE PLANS 842438426POND EPOND A1424430436435OVERFLOW42924274.17477363535297303022925426426_OVER757228POND BPOND D26.1POND F426MAPLE HILLSUBDIVISIONSTORYBOOKSUBDIVISIONSODFARMANHEUSERBUSCHWATERGLENSUBDIVISIONTRAIL HEADSUBDIVISIONL&W CANALNO. 8 DITCHL&W CANALN. GIDDINGS RD.C&S RAILROADI-25RICHARDS LAKE RD. (CR 52)MOUNTAIN VISTA DR. (CR 50)9079099042131.18334357298294317307258418311689143731427.1822427POND C43483424POND A42512499 WEST COLFAX AVENUE, LAKEWOOD, COLORADO 80215303.431.6100 MARTINMARTIN.COMMONTAVAMASTER DRAINAGE PLANDEVELOPED ROUTING SCHEMATICD1 12499 WEST COLFAX AVENUE, LAKEWOOD, COLORADO 80215303.431.6100 MARTINMARTIN.COMMONTAVAMASTER DRAINAGE PLANDEVELOPED ROUTING SCHEMATICD2DIVERSION SUMMARYSWMMELEMENTQ100 INFLOW(CFS)Q100 DIVERTED(CFS)Q100REMAINING(CFS)833.1 408 279125842 1000 617384OUTFALL SUMMARYSWMMELEMENTQ100 (CFS)904 138907 385909 729POND SUMMARYSWMM ELEMENTQ100 IN (CFS) Q100 OUT (CFS) VOLUME (AC-FT)425 883 819 47426 1322 760 307429 1000 390 13.6430 231 295.5435 468 41530436 1562 1548 25438 732 0 88426 OVERFLOW 167 138 59POND A 1807 1042 123POND A1 76122.8POND A2 78 3.5 3.0POND B 627.22.3POND C 1077.14.6POND D1728.6 9.0POND E17491 3.2POND F 166 6.4 11.4BASIN SUMMARYBASIN IDAREA (AC)% IMPQ2 (CFS) Q100 (CFS)A112.1801170A213.3 801278B 16.6 50 10 62C1 27.6 50 17 107C2 82.0 50 38 246D 47.3 60 26 172E 83.9 25 25 159F 46.9 60 25 166G1 80.4 80 36 249G2 10.0 80 9 59H 45.6 10 10 53I1 58.2 10 8 49I2 34.8 2 2 11J1 20.5 50 9 58J2 22.2 50 18 101J344.550 25 158K122.8 601173K260.0 6027180L 110.5 60 55 361M 42.02214N 86.6 80 61 400O 60.8 10 12 65P 30.2 2 2 12OS-1 45.0 20 11 7124 33.74544 28029 268.8 29 192 100030 33.5 49 44 23137 34.6 232214838 290.7 542469200 33.6 5 5 46DESIGN POINT SUMMARYSWMM ELEMENTQ100 (CFS)16 152138531 35531.1 33831.2 277427 319427.1 6427.29431 1312434 7437 333439 1043442 53725 513729415730 28822 249829 513831224833 138834 1781841 396891 418CONVEYANCE ELEMENT SUMMARYSWMMELEMENTQ100 (CFS)21 38524725 51226 23926.1 626.2 927 1780284529 41330 2731 35331.1 33831.2 27631.3 27134 104335 46872 22473 13974 12574.1 39675 39177 1000229 513231 1310237 310242 493426 760426_OVERFLOW167CULVERT SIZE BY DESIGN POINTSWMMELEMENTBARRELS-SIZEQ100 (CFS)HEADWATER DEPTH(FT)21 2-8x4 3854.4312-7x4355 4.631.1 2-8x4 338 4.131.2 4-48"D2774.1427 2-6x4 319 4.7427.1 1-18"D 6 1.6427.2 1-18"D 9 2.64311-15x10 & 1-5x121312 7.6434 1-18"D 7 1.9437 3-6x3 333 4.2822 3-48"D 249 4.6831 3-48"D2244.3833 2-48"D 138 4.18344-10X51781 7.38412-5X5396 6.29041-60"D138 13.0