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HomeMy WebLinkAboutTHE FLATS AT HANSEN FARM - FDP230004 - SUBMITTAL DOCUMENTS - ROUND 3 - DRAINAGE REPORT FINAL DRAINAGE REPORT THE FLATS AT HANSEN FARM FORT COLLINS, COLORADO MAY 24, 2023 NORTHERNENGINEERING.COM 970.221.4158 FORT COLLINS GREELEY This Drainage Report is consciously provided as a PDF. Please consider the environment before printing this document in its entirety. When a hard copy is necessary, we recommend double-sided printing. NORTHERNENGINEERING.COM | 970.221.4158 FORT COLLINS | GREELEY FINAL DRAINAGE REPORT: THE FLATS AT HANSEN FARM COVER SHEET May 24, 2023 City of Fort Collins Stormwater Utility 700 Wood Street Fort Collins, CO 80521 RE: FINAL DRAINAGE REPORT FOR THE FLATS AT HANSEN FARM Dear Staff, Northern Engineering is pleased to submit this Final Drainage Report for your review. This report accompanies the Final Development Plan submittal for the proposed The Flats at Hansen Farm. This report has been prepared in accordance with the Fort Collins Stormwater Criteria Manual (FCSCM) and serves to document the stormwater impacts associated with the proposed The Flats at Hansen Farm project. We understand that review by the City of Fort Collins is to assure general compliance with standardized criteria contained in the FCSCM. If you should have any questions as you review this report, please feel free to contact us. Sincerely, NORTHERN ENGINEERING SERVICES, INC. CASSANDRA UNGERMAN, EI Project Engineer Compliance Statement I hereby attest that this report for the Final drainage design for The Flats at Hansen Farm 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. NORTHERNENGINEERING.COM | 970.221.4158 FORT COLLINS | GREELEY FINAL DRAINAGE REPORT: THE FLATS AT HANSEN FARM TABLE OF CONTENTS TABLE OF CONTENTS I. GENERAL LOCATION AND DESCRIPTION ....................................................................................... 4 II. DRAINAGE BASINS AND SUB-BASINS ............................................................................................ 6 III. DRAINAGE DESIGN CRITERIA ....................................................................................................... 6 IV. DRAINAGE FACILITY DESIGN ....................................................................................................... 8 V. CONCLUSIONS......................................................................................................................... 10 VI. REFERENCES ........................................................................................................................... 12 TABLES AND FIGURES Figure 1 - Vicinity Map ................................................................................................................................ 4 Figure 2 - Aerial Photograph ..................................................................................................................... 5 Figure 3 - Existing Floodplains .................................................................................................................. 5 Table 1 - LID Summary ............................................................................................................................... 8 Table 2 - Detention Summary ................................................................................................................. 10 APPENDICES APPENDIX A – HYDROLOGIC COMPUTATIONS APPENDIX B – HYDRAULIC COMPUTATIONS B.1 – Detention Ponds B.2 – Water Quality B.3 – Storm Sewers B.4 – Inlets B.5 – Erosion Control Mat Calculations APPENDIX C – LID EXHIBIT APPENDIX D – USDA SOILS REPORT MAP POCKET DR1 – DRAINAGE EXHIBIT NORTHERNENGINEERING.COM | 970.221.4158 FORT COLLINS | GREELEY FINAL DRAINAGE REPORT: THE FLATS AT HANSEN FARM 4 | 12 I. GENERAL LOCATION AND DESCRIPTION A. LOCATION 1. Vicinity Map Figure 1 - Vicinity Map 2. The Flats at Hansen Farm project site is located in the northeast quarter of Section 7, Township 6 North, Range 69 West of the 6th Principal Meridian, City of Fort Collins, County of Larimer, State of Colorado. 3. The project site (refer to Figure 1) is bordered to the north by Twisted Root Drive and single-family residential; to the east by South Timberline Road; to the south by Zephyr Road and a future park tract, and the west by an existing detention facility. 4. There is existing storm drainage infrastructure as part of the Hansen Farm subdivision supporting these Tracts for development. B. DESCRIPTION OF PROPERTY 1. The Flats at Hansen Farm is comprised 10.4 acres. 2. The site is currently undeveloped tracts that were graded in consideration with the design of the adjacent Hansen Farm subdivision. 3. The project site resides in the City of Fort Collins Fossil Creek Master Drainage Basin. The detention requirements of the subject area were considered in the design of the detention ponds for the Hansen Farm subdivision and have been factored into the LID requirements for The Flats at Hansen Farm, which are described in further detail throughout this report. 4. The existing groundcover consists of short grasses over designed grades and detention ponds installed for the drainage infrastructure of the Hansen Farm subdivision. The existing on-site runoff generally drains from the Northwest to the Southeast across flat grades (e.g., 0.50% - 2.00%) to South Timberline Road. NORTHERNENGINEERING.COM | 970.221.4158 FORT COLLINS | GREELEY FINAL DRAINAGE REPORT: THE FLATS AT HANSEN FARM 5 | 12 5. According to the United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) Soil Survey website: (http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx), the site consists primarily of Nunn clay loam (Hydrologic Soil Group C) and Caruso Clay loam (Hydrological Soil Group D). Figure 2 - Aerial Photograph 6. The Mail Creek Ditch and Williamson Ditch Lateral are significant irrigation channels located to the North and Southwest of the project site respectively, but not directly adjacent to the site. 7. The proposed development will consist of eight (8) multi-family residential buildings containing 255 units with onsite and street parking, a community pool, and amenity areas. 8. The proposed land use is medium density mixed-use. C. FLOODPLAIN 1. No portions of the site are located in a FEMA regulatory floodplain, according to the Hansen Overall Development Plan. Figure 3 - Existing Floodplains NORTHERNENGINEERING.COM | 970.221.4158 FORT COLLINS | GREELEY FINAL DRAINAGE REPORT: THE FLATS AT HANSEN FARM 6 | 12 2. There are no special floodplain considerations required regarding finished floor elevations of building footprints. 3. No floodplain use permit will be required for this project. 4. A 50’ natural habitat buffer along the Mail Creek Ditch and the irrigation lateral to the south exists on the site. All drainage improvements will be located outside this 50’ natural habitat buffer. II. DRAINAGE BASINS AND SUB-BASINS A. Major Basin Description The project area of The Flats at Hansen Farm is located within the City of Fort Collins Fossil Creek Master Drainage Basin. Detention requirements for this basin are to detain the difference between the 100-yr developed inflow rate and the historic 2-year release rate. However, outflow from this property is limited by an existing outfall ditch, located on the southern property line of The Timbers subdivision, to The Timbers. B. Sub-Basin Description 1. The outfall for the project site is South Timberline Road along the East edge, which eventually conveys runoff to Fossil Creek Reservoir, approximately ¼ mile to the south. 2. The existing subject site can be defined with 20 distinct drainage basins (see DR1 in the provided map pocket). 3. The existing site runoff generally drains from Northwest to Southeast onto South Timberline Road. 4. The project area receives no offsite runoff as a deliberate design aspect of the Overall Hansen Development Plan. III. DRAINAGE DESIGN CRITERIA A. OPTIONAL PROVISIONS There are no optional provisions outside of the FCSCM proposed with The Flats at Hansen Farm. B. STORMWATER MANAGEMENT STRATEGY The overall stormwater management strategy employed with The Flats at Hansen Farm utilizes the “Four Step Process” to minimize adverse impacts of urbanization on receiving waters. The following is a description of how the proposed development has incorporated each step. Step 1 – Employ Runoff Reduction Practices. The first consideration taken in trying to reduce the stormwater impacts of this development is the site selection itself. By choosing an already developed site with public storm sewer currently in place, the burden is significantly less than developing a vacant parcel absent of any infrastructure. The Flats at Hansen Farm aims to reduce runoff peaks, volumes and pollutant loads from frequently occurring storm events (i.e., water quality (i.e., 80th percentile) and 2-year storm events) by implementing Low Impact Development (LID) strategies. Wherever practical, runoff will be routed across landscaped areas or through a rain garden or water quality pond. These LID practices reduce the overall amount of impervious area, while at the same time Minimizing Directly Connected Impervious Areas (MDCIA). The combined LID/MDCIA techniques will be implemented, where practical, throughout the development, thereby slowing runoff and increasing opportunities for infiltration. Step 2 – Implement BMPs that Provide a Water Quality Capture Volume (WQCV) with Slow Release. The efforts taken in Step 1 will help to minimize excess runoff from frequently occurring storm events; however, urban development of this intensity will still have stormwater runoff leaving the site. The primary water quality treatment will occur between several rain gardens between major parking areas of the property and the existing detention ponds installed for the Hansen Farm Subdivision. NORTHERNENGINEERING.COM | 970.221.4158 FORT COLLINS | GREELEY FINAL DRAINAGE REPORT: THE FLATS AT HANSEN FARM 7 | 12 Step 3 – Stabilize Drainageways. While not directly applicable to this site, the project will pay one-time stormwater development fees as well as ongoing monthly stormwater utility fees, both of which help achieve citywide drainageway stability. Step 4 – Implement Site Specific and Other Source Control BMPs. This step typically applies to industrial and commercial developments. C. DEVELOPMENT CRITERIA REFERENCE AND CONSTRAINTS 1. The subject property is part of the Hansen Overall Development Plan (ODP). 2. The project area is constrained on all sides by public streets, with the exception of the south edge and the west half of the north edge, which are constrained by existing single-family lots. D. HYDROLOGICAL CRITERIA 1. The City of Fort Collins Rainfall Intensity-Duration-Frequency Curves, as depicted in Figure 3.4-1 of the FCSCM, serve as the source for all hydrologic computations associated with The Flats at Hansen Farm development. Tabulated data contained in Table 3.4-1 has been utilized for Rational Method runoff calculations. 2. The Rational Method has been used to estimate peak developed stormwater runoff from drainage basins within the developed site for the 2-year, 10-year, and 100-year design storms. Peak runoff discharges determined using this methodology have been used to check the street capacities, inlets, swales, and storm drain lines. 3. Two separate design storms have been utilized to address distinct drainage scenarios. The first event analyzed is the “Minor,” or “Initial” Storm, which has a 2-year recurrence interval. The second event considered is the “Major Storm,” which has a 100-year recurrence interval. E. HYDRAULIC CRITERIA 1. The drainage facilities proposed with The Flats at Hansen Farm project are designed in accordance with criteria outlined in the FCSCM. 2. As stated in Section I.C.1, above, the subject property is not located next to a FEMA designated floodplain, nor is it located within any identified floodplain limits. F. FLOODPLAIN REGULATIONS COMPLIANCE As previously mentioned, this project is not adjacent to a FEMA regulated floodplain and as such, it will not be subject to any floodplain regulations. G. MODIFICATIONS OF CRITERIA There are no formal modifications outside of the FCSCM proposed with The Flats at Hansen Farm. H. CONFORMANCE WITH WATER QUALITY TREATMENT CRITERIA City Code requires that 100% of runoff from new impervious surfaces in a project site shall receive some sort of water quality treatment, to which the site is abiding by in its drainage design. There are several small areas that flow directly offsite to existing inlets where they are directed to existing or proposed detention ponds to receive water quality treatment there. The basins that remain onsite will be treated by rain gardens before being directed to detention ponds. I. CONFORMANCE WITH LOW IMPACT DEVELOPMENT (LID) The project site will conform with the requirement to treat a minimum of 75% of the project site using a LID technique. The proposed project site will treat 84.5% of the site with LID, with small portions of the site flowing directly to Detention Ponds 1, 2, & 3. Five rain gardens will be used to capture and treat most of the impervious area on the project site. NORTHERNENGINEERING.COM | 970.221.4158 FORT COLLINS | GREELEY FINAL DRAINAGE REPORT: THE FLATS AT HANSEN FARM 8 | 12 J. SIZING OF LID & WQ FACILITIES Rain Gardens/Underground Chambers 1. The rain gardens were sized by first determining the required water quality capture volume (WQCV) for Sub-basins A, B, C, D, and E for the rain gardens. A 12-hour drain time was used in this calculation. 2. Once the WQCV was identified, each rain garden area was sized for its respective WQCV. The rain gardens will be constructed with a biomedia filter and underdrain. An overflow drain will be provided in each rain garden to pass storms greater than the WQCV. Table 1 - LID Summary LID ID Area (ft2) Weighted % Impervious Volume per UD-BMP (ft3) Vol. w/ 20% increase per FC Manual (ft3) Impervious area (ft2) Rain Garden A 60,121 71% 1,121 1,313 42,686 Rain Garden B 37,002 67% 674 809 24,888 Rain Garden C 77,529 64% 1,294 1,536 49,269 Rain Garden D 45,306 85% 1,094 1,313 38,358 Rain Garden E 118,951 70% 2,181 2,617 83,354 IV. DRAINAGE FACILITY DESIGN A. GENERAL CONCEPT 1. The main objective of The Flats at Hansen Farm drainage design is to maintain existing drainage patterns, while not adversely impacting adjacent properties. 2. All storm drains on the site have been designed to convey 100-yr flows. 3. A list of tables and figures used within this report can be found in the Table of Contents at the front of the document. The tables and figures are located within the sections to which the content best applies. 4. Drainage for the project site has been analyzed using 20 onsite drainage sub-basins, designated as sub-basins A-F and O1-O8. Sub-basins O1-O8 do not go to onsite rain gardens or detention ponds. Sub-basins A, B, C, C1, C2, O1, O7, & O8 make up the west side while sub-basins D, D1, D2, E, E1, E2, F, & O2-O6 make up the east side. The Sub-basins are discussed in further detail below. Sub-Basin A Sub-basin A is comprised of multi-family residential, asphalt drives and parking, and landscaped areas. Rain Garden A is located in Sub-Basin A and serves as the sole method of treating this basin for LID. The flows from this basin travel via overland flow, curb and gutter, and storm pipe to Rain Garden A. From Rain Garden A, flows are discharged into existing Detention Pond 1, proposed with Hansen Farm. Flows greater than the 2-year storm from rain garden A will flow through proposed sidewalk chases that direct flows to existing detention pond 1. NORTHERNENGINEERING.COM | 970.221.4158 FORT COLLINS | GREELEY FINAL DRAINAGE REPORT: THE FLATS AT HANSEN FARM 9 | 12 Sub-Basins B Sub-Basins B is composed of multi-family residential, asphalt drives and parking, and small landscaped areas. Sub-Basin B also contains Rain Garden B, which serves to treat the sub-basin for LID. Flows travel via overland flow, and curb and gutter to Rain Garden B, before being discharged into existing Detention Pond 1. Flows larger than the 2-year storm in Rain Garden B will flow up the grass lined swale to a sidewalk chase that routes flows back onto Burly Tree Drive where they will enter an existing inlet that directs them to existing detention pond 2 on the north east side of the site. Sub-Basins C, C1, & C2 Sub-Basins C, C1, & C2 contain asphalt drives and parking and small portions of multi-family residential as well as the clubhouse, pool, and Rain Garden C. Rain Garden C will treat Sub-Basins C, C1, and C2 for LID. Flows from these sub-basins travel via overland flow, curb and gutter, and storm pipe to Rain Garden C. Rain Garden C then discharges though existing and proposed storm pipes to the east where it ultimately goes to Detention Pond 3. The overflow structure proposed with Rain Garden C is designed to capture the 10-yr design storm. Sub-Basins D, D1, & D2 Sub-Basins D, D1, & D2 are comprised of multi-family residential, asphalt drives and parking, and landscaped areas. Sub-Basin D contains Detention Pond 3 and Rain Garden D. Detention Pond 3 was previously proposed and constructed with Hansen Farm but is being modified to better suit the needs of the proposed site. Rain Garden D will treat the entirety of Sub-Basins D1 and D2 for LID. Sub-Basin D will not be treated for LID. Sub-Basins E, E1, & E2 Sub-Basins E, E1 & E2 are composed of multi-family residential, asphalt drives and parking, and landscaped areas. Sub-Basin E also contains Rain Garden E, which treats sub-basins E, E1, and E2 for LID before flows are discharged to Detention Pond 3. 10-yr flows are captured in the proposed overflow inlet in Rain Garden E. Sub-Basins O1-O8 Sub-Basins O1-O8 are not treated for LID and flow directly offsite. Sub-Basin O1 flows via overland flow to existing Detention Pond 1 on the west side of the proposed project site. Sub-Basins O2 and O7 flow via overland flow onto Burly Tree Drive where runoff is directed south to existing inlets and storm pipe that carry these flows to existing Detention Pond 3. Sub-Basin O3 flows via overland flow to Twisted Root Drive where it is picked up by an existing inlet on the north side of Burly Tree Drive that routes flows to existing Detention Pond 2 on the northeast side of the proposed site. Sub- Basin O4 flows directly onto Zephyr Road where existing inlets and storm take these flows to existing Detention Pond 4. Sub-Basins O5 and O8 travel via overland flow to Burly Tree Drive where runoff flows north via curb and gutter to existing inlets and storm pipe that convey flows to existing Detention Pond 2. Sub-Basin O6 travels via overland flow and curb and gutter to the south side of Burly Tree Drive where it is directed to an existing storm drain and inlet that carry flows to Detention Pond 3. A full-size copy of the Drainage Exhibit can be found in the Map Pocket at the end of this report. B. SPECIFIC DETAILS 1. There are no new detention ponds being proposed with this development. Previously constructed ponds will detain up to the 100-yr storm event and release at or below the calculated release rates. 2. Detention Pond 1 will capture 2.12 acres of the proposed project site, as opposed to the 1.80 acres assumed with the Hansen Farm submittal. However, the percent impervious decreased from the NORTHERNENGINEERING.COM | 970.221.4158 FORT COLLINS | GREELEY FINAL DRAINAGE REPORT: THE FLATS AT HANSEN FARM 10 | 12 assumed 70% to 66% as calculated in the rational calcs for this project site. The volume of this pond increased from 10.01 acre-feet to 10.07 acre-feet which is negligible considering this pond’s capacity is nearly 15 acre-feet. 3. Detention Pond 2 will capture only 0.23 acres from the proposed project site as opposed to the 1.15 acres that were assumed in the Hansen Farm design. The percentage impervious for this portion of site decreased from the assumed 70% to 46%, and the pond’s overall volume decreased from 1.85 acre-feet to 1.64 acre-feet. 4. The portion of the proposed site that will be captured by Detention Pond 3 increased from 7.43 acres to 8.00 acres, while the percent impervious went down from 70% to 60%. The overall pond volume decreased from 2.24 acre-feet, that was assumed with Hansen Farm, to 2.17 acre-feet. Modifications, however, were made to this pond in order to lessen the impact that earthwork had on the rest of the site. A SWMM model was created with the previous Hansen Farm submittal to determine the detention volumes. See Table 2 for detention summary. 5. A setback inlet is used for Inlet 2-2. Setback inlets have been utilized by Northern Engineering for many different projects in Northern Colorado. The setback inlet structure has the advantage of acting as a sump inlet, greatly increasing the hydraulic efficiency of the structure, providing more than twice the capacity of an on-grade inlet. We have utilized a sump depth of 7.3 inches (0.60 feet) to conservatively model the inlet in a shallow sump condition. In many cases, sump inlets will have in excess of 0.75 feet of sump depth; however, to be conservative and allow for some construction tolerance, we have modeled the setback inlets in this shallower sump configuration. The construction detail for the setback inlet shows an elevation differential of 0.36 feet from inlet flowline elevation to downstream curb and gutter tie-in elevation. In a 100-year event, there is also generally at least 0.33 feet (4 inches) to 0.75 feet (9 inches) of 100-year flow depth in the road section. Therefore, in a typical 100-year flood event, there would be 0.69 feet to 1.11 feet of hydraulic head influencing the setback inlet. Again, we have conservatively analyzed the setback inlets with 0.60 feet of head. Table 2 - Detention Summary 6. LID treatment is being provided within Rain Gardens A-E. These treat approximately 77% of the site impervious runoff, which is more than the required 75% LID treatment. Please see the LID exhibit and calculations in Appendix C. 7. Detention allowable release rate is based on computed 2-year historic flow for the overall property as proposed with the Hansen Farm development plan. 8. Stormwater facility Standard Operations Procedures (SOP) will be provided by the City of Fort Collins in the Development Agreement. 9. Design details and construction documentation shall be provided to the City of Fort Collins for review prior to Final Development Plan approval. V. CONCLUSIONS A. COMPLIANCE WITH STANDARDS 1. The drainage design proposed with The Flats at Hansen Farm complies with the City of Fort Collins Master Drainage Plan for the Fossil Creek Basin. 2. The drainage plan and stormwater management measures proposed with The Flats at Hansen NORTHERNENGINEERING.COM | 970.221.4158 FORT COLLINS | GREELEY FINAL DRAINAGE REPORT: THE FLATS AT HANSEN FARM 11 | 12 Farm project are compliant with all applicable State and Federal regulations governing stormwater discharge. B. DRAINAGE CONCEPT 1. The Flats at Hansen Farm will not impact the Master Drainage Plan recommendations for the City of Fort Collins Fossil Creek Major Drainage Basin. 2. The proposed drainage plan for the Flats at Hansen Farm complies with the previously proposed impervious values, pond volumes, and release rates for the site from the Hansen Farm plan dated August 26, 2020. For this reason, it is believed the previous infrastructure constructed with Hansen Farm will continue to be sufficient as this portion of the site is developed. NORTHERNENGINEERING.COM | 970.221.4158 FORT COLLINS | GREELEY FINAL DRAINAGE REPORT: THE FLATS AT HANSEN FARM 12 | 12 VI. REFERENCES 1. Fort Collins Stormwater Criteria Manual, City of Fort Collins, Colorado, as adopted by Ordinance No. 159, 2018, and referenced in Section 26-500 of the City of Fort Collins Municipal Code. 2. Soils Resource Report for Larimer County Area, Colorado, Natural Resources Conservation Service, United States Department of Agriculture. 3. Urban Storm Drainage Criteria Manual, Volumes 1-3, Urban Drainage and Flood Control District, Wright- McLaughlin Engineers, Denver, Colorado, Revised April 2008. 4. Final Drainage and Erosion Control Report for Hansen Farm, Northern Engineering, Fort Collins, Colorado, dated August 26, 2020. NORTHERNENGINEERING.COM | 970.221.4158 FORT COLLINS | GREELEY FINAL DRAINAGE REPORT: THE FLATS AT HANSEN FARM APPENDIX APPENDIX A HYDROLOGIC COMPUTATIONS CHARACTER OF SURFACE1: Percentage Impervious 2-yr Runoff Coefficient 10-yr Runoff Coefficient 100-yr Runoff Coefficient Developed Asphalt .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………100%0.95 0.95 1.00 Concrete .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………90%0.95 0.95 1.00 Rooftop .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………90%0.95 0.95 1.00 Gravel .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………40%0.50 0.50 0.63 Pavers .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………40%0.50 0.50 0.63 Landscape or Pervious Surface Playgrounds .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………25%0.35 0.35 0.44 Lawns Clayey Soil .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………2%0.25 0.25 0.31 Lawns Sandy Soil .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………2%0.15 0.15 0.19 Notes: Basin ID Basin Area (ac) Area of Asphalt/Con crete (ac) Area of Concrete (ac) Area of Rooftop (ac) Area of Gravel (ac) Area of Pavers (ac) Area of Playgrounds (ac) Area of Lawns (ac) Composite % Imperv. 2-year Composite Runoff Coefficient 10-year Composite Runoff Coefficient 100-year Composite Runoff Coefficient H1 1.92 0.00 0.00 0.00 0.00 0.00 0.00 1.92 2% 0.25 0.25 0.31 H2 1.69 0.00 0.00 0.00 0.00 0.00 0.00 1.69 2% 0.25 0.25 0.31 H3 0.15 0.00 0.00 0.00 0.00 0.00 0.00 0.15 2% 0.25 0.25 0.31 H4 0.45 0.00 0.00 0.00 0.00 0.00 0.00 0.45 2% 0.25 0.25 0.31 H5 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.01 2% 0.25 0.25 0.31 H6 3.18 0.00 0.00 0.00 0.00 0.00 0.00 3.18 2% 0.25 0.25 0.31 H7 2.99 0.00 0.00 0.00 0.00 0.00 0.00 2.99 2% 0.25 0.25 0.31 HISTORIC BASIN % IMPERVIOUSNESS AND RUNOFF COEFFICIENT CALCULATIONS 2) Runoff Coefficients are taken from the Fort Collins Stormwater Criteria Manual, Chapter 3. Table 3.2-1 and 3.2-2 1) Percentage impervious taken from the Fort Collins Stormwater Criteria Manual, Chapter 5, Table 4.1-2 and Table 4.1-3 Overland Flow, Time of Concentration: Channelized Flow, Time of Concentration: Total Time of Concentration : T c is the lesser of the values of Tc calculated using T c = T i + T t C2 C100 Length, L (ft) Slope, S (%) Ti2 Ti100 Length, L (ft) Slope, S (%) Roughness Coefficient Assumed Hydraulic Radius Velocity, V (ft/s) Tt (min)Tc (Eq. 3.3-5) Tc2 = Ti +Tt Tc100 = Ti +Tt Tc2 Tc100 h1 H1 0.25 0.31 192 0.75%24.2 22.5 N/A 0.015 0.59 N/A N/A 11.1 24.2 22.5 11.1 11.1 h2 H2 0.25 0.31 179 0.53%26.4 24.4 N/A 0.015 0.59 N/A N/A 11.0 26.4 24.4 11.0 11.0 h3 H3 0.25 0.31 79 1.13%13.6 12.6 N/A 0.015 0.59 N/A N/A 10.4 13.6 12.6 10.4 10.4 h4 H4 0.25 0.31 94 0.46%20.0 18.5 245 0.30%0.015 0.59 3.84 1.1 11.9 21.1 19.6 11.9 11.9 h5 H5 0.25 0.31 13 1.31%5.2 4.9 N/A 0.015 0.59 N/A N/A 10.1 5.2 4.9 5.2 5.0 h6 H6 0.25 0.31 284 12.99%11.4 10.6 135 0.61%0.015 0.59 5.48 0.4 12.3 11.8 11.0 11.8 11.0 h7 H7 0.25 0.31 282 1.84% 21.8 20.2 244 0.47% 0.015 0.59 4.80 0.8 12.9 22.6 21.0 12.9 12.9 HISTORIC DIRECT TIME OF CONCENTRATION Channelized Flow Design Point Basin Overland Flow Time of Concentration Frequency Adjustment Factor: (Equation 3.3-2 FCSCM) (Equation 5-5 FCSCM) (Equation 5-4 FCSCM) (Equation 3.3-5 FCSCM) Table 3.2-3 FCSCM Therefore Tc2=Tc10 Notes: 1) Add 5000 to all elevations. 2) Per Fort Collins Stormwater Manual, minimum Tc = 5 min. 3) Assume a water depth of 6" and a typical curb and gutter per Larimer County Urban Street Standard Detail 701 for curb and gutter channelized flow. Assume a water depth of 1', fixed side slopes, and a triangular swale section for grass channelized flow. Assume a water depth of 1', 4:1 side slopes, and a 2' wide valley pan for channelized flow in a valley pan. Rational Method Equation: Rainfall Intensity: h1 H1 1.92 11.1 11.1 0.25 0.31 2.13 3.63 7.42 1.02 1.74 4.44 h2 H2 1.69 11.0 11.0 0.25 0.31 2.17 3.71 7.57 0.92 1.56 3.99 h3 H3 0.15 10.4 10.4 0.25 0.31 2.21 3.78 7.72 0.08 0.14 0.35 h4 H4 0.45 11.9 11.9 0.25 0.31 2.09 3.57 7.29 0.24 0.40 1.03 h5 H5 0.01 5.2 5.0 0.25 0.31 2.85 4.87 9.95 0.01 0.01 0.03 h6 H6 3.18 11.8 11.0 0.25 0.31 2.09 3.57 7.57 1.66 2.84 7.53 h7 H7 2.99 12.9 12.9 0.25 0.31 2.02 3.45 7.04 1.51 2.58 6.58 Tc100 (min) Intensity, i2 (in/hr) Intensity, i100 (in/hr) HISTORIC RUNOFF COMPUTATIONS Design Point Basin(s)Area, A (acres) Tc2 (min) Flow, Q2 (cfs) Flow, Q100 (cfs) C2 C100 IDF Table for Rational Method - Table 3.4-1 FCSCM Intensity, i10 (in/hr) Flow, Q10 (cfs) ()()()AiCCQf= CHARACTER OF SURFACE1: Percentage Impervious 2-yr Runoff Coefficient 10-yr Runoff Coefficient 100-yr Runoff Coefficient Developed Asphalt .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………100%0.95 0.95 1.00 Concrete .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………100%0.95 0.95 1.00 Rooftop .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………90%0.95 0.95 1.00 Gravel .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………40%0.50 0.50 0.63 Pavers .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………40%0.50 0.50 0.63 Landscape or Pervious Surface Playgrounds .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………25%0.35 0.35 0.44 Lawns Clayey Soil .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………2%0.25 0.25 0.31 Lawns Sandy Soil .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………2%0.15 0.15 0.19 Notes: Basin ID Basin Area (ac) Area of Asphalt/Con crete (ac) Area of Concrete (ac) Area of Rooftop (ac) Area of Gravel (ac) Area of Pavers (ac) Area of Playgrounds (ac) Area of Lawns (ac) Composite % Imperv. 2-year Composite Runoff Coefficient 10-year Composite Runoff Coefficient 100-year Composite Runoff Coefficient A 1.38 0.48 0.07 0.47 0.00 0.00 0.00 0.43 71% 0.78 0.78 0.98 B 0.58 0.22 0.08 0.06 0.00 0.00 0.00 0.21 63% 0.69 0.69 0.86 C 0.70 0.33 0.02 0.17 0.00 0.00 0.00 0.18 72% 0.77 0.77 0.96 C1 1.00 0.28 0.06 0.30 0.00 0.00 0.00 0.71 62% 0.78 0.78 0.98 C2 0.07 0.00 0.00 0.00 0.00 0.00 0.00 0.07 2% 0.25 0.25 0.31 D 1.27 0.00 0.06 0.13 0.00 0.00 0.00 1.08 16% 0.35 0.35 0.44 D1 0.55 0.26 0.02 0.22 0.00 0.00 0.00 0.05 87% 0.88 0.88 1.00 D2 0.49 0.29 0.02 0.10 0.00 0.00 0.00 0.08 82% 0.84 0.84 1.00 E 2.15 0.98 0.15 0.45 0.00 0.00 0.00 0.57 72% 0.77 0.77 0.96 E1 0.23 0.18 0.02 0.00 0.00 0.00 0.00 0.03 86% 0.85 0.85 1.00 E2 0.35 0.00 0.01 0.18 0.00 0.00 0.00 0.17 48% 0.61 0.61 0.76 F 0.13 0.04 0.02 0.00 0.00 0.00 0.00 0.07 45% 0.56 0.56 0.70 O1 0.16 0.00 0.05 0.00 0.00 0.00 0.00 0.11 31% 0.46 0.46 0.58 O2 0.31 0.10 0.01 0.13 0.00 0.00 0.00 0.07 74% 0.79 0.79 0.99 O3 0.06 0.01 0.00 0.00 0.00 0.00 0.00 0.05 21% 0.41 0.41 0.51 O4 0.15 0.01 0.00 0.01 0.00 0.00 0.00 0.14 17% 0.39 0.39 0.49 O5 0.06 0.00 0.00 0.02 0.00 0.00 0.00 0.06 39% 0.63 0.63 0.79 O6 0.42 0.08 0.02 0.17 0.00 0.00 0.00 0.15 61% 0.70 0.70 0.88 O7 0.24 0.00 0.00 0.16 0.00 0.00 0.00 0.08 61% 0.72 0.72 0.90 O8 0.11 0.00 0.00 0.08 0.00 0.00 0.00 0.04 62% 0.73 0.73 0.91 DEVELOPED BASIN % IMPERVIOUSNESS AND RUNOFF COEFFICIENT CALCULATIONS 2) Runoff Coefficients are taken from the Fort Collins Stormwater Criteria Manual, Chapter 3. Table 3.2-1 and 3.2-2 1) Percentage impervious taken from the Fort Collins Stormwater Criteria Manual, Chapter 5, Table 4.1-2 and Table 4.1-3 Overland Flow, Time of Concentration: Channelized Flow, Time of Concentration: Total Time of Concentration : T c is the lesser of the values of Tc calculated using T c = T i + T t C2 C100 Length, L (ft) Slope, S (%) Ti2 Ti100 Length, L (ft) Slope, S (%) Roughness Coefficient Assumed Hydraulic Radius Velocity, V (ft/s) Tt (min)Tc (Eq. 3.3-5) Tc2 = Ti +Tt Tc100 = Ti +Tt Tc2 Tc100 a A 0.78 0.98 78 3.19%3.6 1.4 140 2.29%0.015 0.59 10.56 0.2 11.2 3.8 1.6 5.0 5.0 b B 0.69 0.86 23 1.74%3.1 1.8 234 2.19%0.015 0.59 10.34 0.4 11.4 3.4 2.1 5.0 5.0 c C 0.77 0.96 45 3.58%2.7 1.1 231 1.05%0.015 0.59 7.17 0.5 11.5 3.2 1.7 5.0 5.0 c1 C1 0.78 0.98 28 11.00%1.4 0.6 215 0.60%0.015 0.59 5.39 0.7 11.4 2.1 1.2 5.0 5.0 c2 C2 0.25 0.31 33 1.32%8.3 7.6 N/A 0.015 0.59 N/A N/A 10.2 8.3 7.6 8.3 7.6 d D 0.35 0.44 143 5.06%9.8 8.6 297 0.56%0.015 0.59 5.21 1.0 12.4 10.7 9.6 10.7 9.6 d1 D1 0.88 1.00 46 2.13%2.2 1.0 113 0.78%0.015 0.59 6.17 0.3 10.9 2.5 1.3 5.0 5.0 d2 D2 0.84 1.00 27 1.93%2.0 0.8 219 0.72%0.015 0.59 5.92 0.6 11.4 2.6 1.4 5.0 5.0 e E 0.77 0.96 90 2.98%4.1 1.7 451 1.02%0.015 0.59 7.06 1.1 13.0 5.1 2.8 5.1 5.0 e1 E1 0.85 1.00 55 2.00%2.8 1.1 145 0.59%0.015 0.59 5.35 0.5 11.1 3.2 1.6 5.0 5.0 e2 E2 0.61 0.76 55 2.67%4.9 3.4 292 0.60%0.015 0.59 5.41 0.9 11.9 5.8 4.3 5.8 5.0 f F 0.56 0.70 77 3.96%5.6 4.1 N/A 0.015 0.59 N/A N/A 10.4 5.6 4.1 5.6 5.0 o1 O1 0.46 0.58 15 5.45%2.6 2.1 N/A 0.015 0.59 N/A N/A 10.1 2.6 2.1 5.0 5.0 o2 O2 0.79 0.99 145 1.52%6.1 2.2 21 1.35%0.015 0.59 8.13 0.0 10.9 6.1 2.2 6.1 5.0 o3 O3 0.41 0.51 12 9.25%2.1 1.8 N/A 0.038 0.50 N/A N/A 10.1 2.1 1.8 5.0 5.0 o4 O4 0.39 0.49 35 5.46%4.5 3.8 N/A 0.015 n/a N/A N/A 10.2 4.5 3.8 5.0 5.0 o5 O5 0.63 0.79 48 1.94%4.9 3.2 N/A 1.015 n/a N/A N/A 10.3 4.9 3.2 5.0 5.0 o6 O6 0.70 0.88 50 3.68%3.4 1.9 203 0.40%0.015 0.59 4.44 0.8 11.4 4.2 2.7 5.0 5.0 o7 O7 0.72 0.90 58 2.78%3.8 2.0 N/A 0.015 0.59 N/A N/A 10.3 3.8 2.0 5.0 5.0 o8 O8 0.73 0.91 55 2.65%3.7 1.9 N/A 0.015 0.59 N/A N/A 10.3 3.7 1.9 5.0 5.0 DEVELOPED DIRECT TIME OF CONCENTRATION Channelized Flow Design Point Basin Overland Flow Time of Concentration Frequency Adjustment Factor: (Equation 3.3-2 FCSCM) (Equation 5-5 FCSCM) (Equation 5-4 FCSCM) (Equation 3.3-5 FCSCM) Table 3.2-3 FCSCM Therefore Tc2=Tc10 Notes: 1) Add 5000 to all elevations. 2) Per Fort Collins Stormwater Manual, minimum Tc = 5 min. 3) Assume a water depth of 6" and a typical curb and gutter per Larimer County Urban Street Standard Detail 701 for curb and gutter channelized flow. Assume a water depth of 1', fixed side slopes, and a triangular swale section for grass channelized flow. Assume a water depth of 1', 4:1 side slopes, and a 2' wide valley pan for channelized flow in a valley pan. Rational Method Equation: Rainfall Intensity: a A 1.38 5.0 5.0 0.78 0.98 2.85 4.87 9.95 3.07 5.24 13.39 b B 0.58 5.0 5.0 0.69 0.86 2.85 4.87 9.95 1.14 1.95 4.98 c C 0.70 5.0 5.0 0.77 0.96 2.85 4.87 9.95 1.54 2.64 6.74 c1 C1 1.00 5.0 5.0 0.78 0.98 2.85 4.87 9.95 2.23 3.82 9.75 c2 C2 0.07 8.3 7.6 0.25 0.31 2.40 4.10 8.59 0.04 0.07 0.19 d D 1.27 10.7 9.6 0.35 0.44 2.17 3.71 7.88 0.96 1.64 4.36 d1 D1 0.55 5.0 5.0 0.88 1.00 2.85 4.87 9.95 1.39 2.37 5.51 d2 D2 0.49 5.0 5.0 0.84 1.00 2.85 4.87 9.95 1.16 1.99 4.84 e E 2.15 5.1 5.0 0.77 0.96 2.85 4.87 9.95 4.72 8.06 20.59 e1 E1 0.23 5.0 5.0 0.85 1.00 2.85 4.87 9.95 0.55 0.95 2.27 e2 E2 0.35 5.8 5.0 0.61 0.76 2.76 4.72 9.95 0.59 1.01 2.67 f F 0.13 5.6 5.0 0.56 0.70 2.76 4.72 9.95 0.21 0.35 0.92 o1 O1 0.16 5.0 5.0 0.46 0.58 2.85 4.87 9.95 0.20 0.35 0.89 o2 O2 0.31 6.1 5.0 0.79 0.99 2.67 4.56 9.95 0.65 1.12 3.04 o3 O3 0.06 5.0 5.0 0.41 0.51 2.85 4.87 9.95 0.07 0.12 0.30 o4 O4 0.15 5.0 5.0 0.39 0.49 2.85 4.87 9.95 0.16 0.28 0.71 o5 O5 0.06 5.0 5.0 0.63 0.79 2.85 4.87 9.95 0.10 0.18 0.46 o6 O6 0.42 5.0 5.0 0.70 0.88 2.85 4.87 9.95 0.84 1.44 3.67 o7 O7 0.24 5.0 5.0 0.72 0.90 2.85 4.87 9.95 0.50 0.85 2.18 o8 O8 0.11 5.0 5.0 0.73 0.91 2.85 4.87 9.95 0.24 0.40 1.03 Tc100 (min) Intensity, i2 (in/hr) Intensity, i100 (in/hr) DEVELOPED RUNOFF COMPUTATIONS Design Point Basin(s)Area, A (acres) Tc2 (min) Flow, Q2 (cfs) Flow, Q100 (cfs) C2 C100 IDF Table for Rational Method - Table 3.4-1 FCSCM Intensity, i10 (in/hr) Flow, Q10 (cfs) ()()()AiCCQf= NORTHERNENGINEERING.COM | 970.221.4158 FORT COLLINS | GREELEY FINAL DRAINAGE REPORT: THE FLATS AT HANSEN FARM APPENDIX APPENDIX B HYDRAULIC COMPUTATIONS NORTHERNENGINEERING.COM | 970.221.4158 FORT COLLINS | GREELEY FINAL DRAINAGE REPORT: THE FLATS AT HANSEN FARM APPENDIX B.1 – Detention Ponds Project: 1916-001 By: CLU Date: 1/17/2023 Pond ID Tributary Area (Ac) Ave Percent Imperviousness (%) Extended Detention WQCV (Ac-Ft) 100-Yr. Detention Vol. (Ac-Ft) 100-Yr. Detention WSEL(Ft) Peak Release (cfs) Pond 3 8.00 60 0.092 2.17 4958.55 9.30 POND SUMMARY TABLE Project: Date: Outlet Elevation:4953.19 2.17 ac-ft Grate Elevation:4959.0 2.53 ac-ft Crest of Pond Elev.:4959.8 4958.6 4954.2 0.092 ac-ft Maximum Elevation Minimum Elevation cu. ft. acre ft cu. ft. acre ft 4,952.80 N/A 24.52 0 0 0.00 0 0.00 4,953.00 4952.8 321.07 0.2 28.96 0.00 28.96 0.00 4,953.20 4953.0 940.68 0.2 120.75 0.00 149.71 0.00 4,953.40 4953.2 1,843.49 0.2 124.68 0.00 274.39 0.01 4,953.60 4953.4 2,973.08 0.2 477.18 0.01 751.57 0.02 4,953.80 4953.6 4,308.82 0.2 724.07 0.02 1475.64 0.03 4,954.00 4953.8 5,717.52 0.2 999.32 0.02 2474.96 0.06 4,954.20 4954.0 7,023.51 0.2 1271.87 0.03 3746.82 0.09 4,954.40 4954.2 8,496.66 0.2 1549.68 0.04 5296.51 0.12 4,954.60 4954.4 10,235.95 0.2 1870.56 0.04 7167.07 0.16 4,954.80 4954.6 11,930.41 0.2 2214.47 0.05 9381.54 0.22 4,955.00 4954.8 13,532.98 0.2 2544.66 0.06 11926.2 0.27 4,955.20 4955.0 14,622.75 0.2 2814.87 0.06 14741.07 0.34 4,955.40 4955.2 15,645.34 0.2 3026.23 0.07 17767.3 0.41 4,955.60 4955.4 16,669.15 0.2 3230.91 0.07 20998.21 0.48 4,955.80 4955.6 17,694.99 0.2 3435.9 0.08 24434.12 0.56 4,956.00 4955.8 18,724.32 0.2 3641.45 0.08 28075.56 0.64 4,956.20 4956.0 19,755.66 0.2 3847.54 0.09 31923.1 0.73 4,956.40 4956.2 20,789.25 0.2 4054.05 0.09 35977.15 0.83 4,956.60 4956.4 21,825.03 0.2 4261.01 0.10 40238.16 0.92 4,956.80 4956.6 22,863.76 0.2 4468.48 0.10 44706.64 1.03 4,957.00 4956.8 23,905.74 0.2 4676.56 0.11 49383.2 1.13 4,957.20 4957.0 24,945.36 0.2 4884.74 0.11 54267.94 1.25 4,957.40 4957.2 25,983.30 0.2 5092.51 0.12 59360.45 1.36 4,957.60 4957.4 28,961.87 0.2 5491.82 0.13 64852.28 1.49 4,957.80 4957.6 29,891.81 0.2 5885.12 0.14 70737.4 1.62 4,958.00 4957.8 30,829.57 0.2 6071.9 0.14 76809.3 1.76 4,958.20 4958.0 31,777.69 0.2 6260.49 0.14 83069.78 1.91 4,958.40 4958.2 32,728.35 0.2 6450.37 0.15 89520.15 2.06 4,958.60 4958.4 33,680.69 0.2 6640.68 0.15 96160.83 2.21 4,958.80 4958.6 34,627.92 0.2 6830.64 0.16 102991.47 2.36 4,959.00 4958.8 35,584.34 0.2 7021.01 0.16 110012.48 2.53 4,959.20 4959.0 36,542.58 0.2 7212.48 0.17 117224.96 2.69 4,959.40 4959.2 37,512.17 0.2 7405.26 0.17 124630.23 2.86 4,959.60 4959.4 38,524.80 0.2 7603.47 0.17 132233.7 3.04 4,959.70 4959.6 39,058.95 0.1 3879.16 0.09 136112.85 3.12 Pond Outlet and Volume Data Design Volume: Volume at Grate: Project Number: Project Location: Calculations By: Pond No.: Water Quality Elev.:Water Quality Volume: Detention Pond Stage Storage Curve Contour Contour Surface Area (ft2) Depth Incremental Volume Cummalitive Volume Pond Stage Storage Curve 1916-001 Fort Collins, Colorado C. Ungerman Pond 3 Elev at Design Volume: The Flats at Hansen Farm 1/11/2023 1 NORTHERNENGINEERING.COM | 970.221.4158 FORT COLLINS | GREELEY FINAL DRAINAGE REPORT: THE FLATS AT HANSEN FARM APPENDIX B.2 – Water Quality Project Number:1916-001 Project:The Flats at Hansen Farm Date:1/11/2023 Prepared By:C. Ungerman 3.770 <-- INPUT from impervious calcs 74.00 <-- INPUT from impervious calcs 0.7400 <-- CALCULATED 0.294 <-- CALCULATED from UDFCD Figure 3-2 WQCV (ac-ft) =0.092 <-- CALCULATED from UDFCD DCM V.3 Section 3.0 WQ Depth (ft) =1.040 <-- INPUT from stage-storage table 0.364 <-- CALCULATED from Figure EDB-3 dia (in) =3/4 <-- INPUT from Figure 5 number of holes =3 <-- INPUT from Figure 5 t (in) =0.500 <-- INPUT from Figure 5 number of rows =1.000 <-- CALCULATED from WQ Depth and row spacing WQCV (watershed inches) = AREA REQUIRED PER ROW, a (in 2) = CIRCULAR PERFORATION SIZING: WATER QUALITY POND DESIGN CALCULATIONS Pond 3 REQUIRED STORAGE & OUTLET WORKS: BASIN AREA = BASIN IMPERVIOUSNESS PERCENT = BASIN IMPERVIOUSNESS RATIO = NORTHERNENGINEERING.COM | 970.221.4158 FORT COLLINS | GREELEY FINAL DRAINAGE REPORT: THE FLATS AT HANSEN FARM APPENDIX B.3 – Storm Sewers NORTHERNENGINEERING.COM | 970.221.4158 FORT COLLINS | GREELEY FINAL DRAINAGE REPORT: THE FLATS AT HANSEN FARM APPENDIX B.4 – Inlets Project:1916-001 Calculations By:Cassandra Ungerman Date: Design Point Design Inlet Label Q2 (cfs) Q100 (cfs) Q100 (cfs)Total Q100 (cfs) Intercepted Q100 (cfs) Unintercepted Inlet Type Inlet Size Notes C1 Inlet 2-2 2.23 4.75 4.75 4.80 0.00 Combo Single D2 Inlet 3-3 1.16 4.84 4.84 4.84 0.00 Type R Single D1 Inlet 3-6 1.39 5.51 5.51 5.51 0.00 Nyloplast 2'x3' (24" Basin)2'x3' F Inlet 4-4 0.21 0.92 0.92 0.92 0.00 Type R Single INLET CAPACITY SUMMARY January 23, 2023 P:\1916-001\Drainage\Inlets\Inlet Summary Table\inlet summary Project: Inlet ID: Gutter Geometry: Maximum Allowable Width for Spread Behind Curb TBACK =24.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.057 ft/ft Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.020 Height of Curb at Gutter Flow Line HCURB =6.00 inches Distance from Curb Face to Street Crown TCROWN =26.0 ft Gutter Width W =1.00 ft Street Transverse Slope SX =0.025 ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft Street Longitudinal Slope - Enter 0 for sump condition SO =0.000 ft/ft Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.013 Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm TMAX =26.0 26.0 ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 6.0 inches Check boxes are not applicable in SUMP conditions MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow =SUMP SUMP cfs MHFD-Inlet, Version 5.01 (April 2021) ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) The Flats at Hansen Farm Inlet 4-4 1 Design Information (Input)MINOR MAJOR Type of Inlet Type = Local Depression (additional to continuous gutter depression 'a' from above)alocal =3.00 3.00 inches Number of Unit Inlets (Grate or Curb Opening)No =1 1 Water Depth at Flowline (outside of local depression)Ponding Depth =6.0 6.0 inches Grate Information MINOR MAJOR Length of a Unit Grate Lo (G) =N/A N/A feet Width of a Unit Grate Wo =N/A N/A feet Area Opening Ratio for a Grate (typical values 0.15-0.90)Aratio =N/A N/A Clogging Factor for a Single Grate (typical value 0.50 - 0.70)Cf (G) =N/A N/A Grate Weir Coefficient (typical value 2.15 - 3.60)Cw (G) =N/A N/A Grate Orifice Coefficient (typical value 0.60 - 0.80)Co (G) =N/A N/A Curb Opening Information MINOR MAJOR Length of a Unit Curb Opening Lo (C) =5.00 5.00 feet Height of Vertical Curb Opening in Inches Hvert =6.00 6.00 inches Height of Curb Orifice Throat in Inches Hthroat =6.00 6.00 inches Angle of Throat (see USDCM Figure ST-5)Theta =63.40 63.40 degrees Side Width for Depression Pan (typically the gutter width of 2 feet)Wp =1.00 1.00 feet Clogging Factor for a Single Curb Opening (typical value 0.10)Cf (C) =0.10 0.10 Curb Opening Weir Coefficient (typical value 2.3-3.7)Cw (C) =3.60 3.60 Curb Opening Orifice Coefficient (typical value 0.60 - 0.70)Co (C) =0.67 0.67 Low Head Performance Reduction (Calculated)MINOR MAJOR Depth for Grate Midwidth dGrate =N/A N/A ft Depth for Curb Opening Weir Equation dCurb =0.42 0.42 ft Combination Inlet Performance Reduction Factor for Long Inlets RFCombination =0.77 0.77 Curb Opening Performance Reduction Factor for Long Inlets RFCurb =1.00 1.00 Grated Inlet Performance Reduction Factor for Long Inlets RFGrate =N/A N/A MINOR MAJOR Total Inlet Interception Capacity (assumes clogged condition)Qa =5.9 5.9 cfs Inlet Capacity IS GOOD for Minor and Major Storms(>Q PEAK)Q PEAK REQUIRED =0.2 0.9 cfs CDOT Type R Curb Opening INLET IN A SUMP OR SAG LOCATION MHFD-Inlet, Version 5.01 (April 2021) H-VertH-Curb W Lo (C) Lo (G) Wo WP CDOT Type R Curb Opening Override Depths 1 Project: Inlet ID: Gutter Geometry: Maximum Allowable Width for Spread Behind Curb TBACK =10.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.250 ft/ft Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.020 Height of Curb at Gutter Flow Line HCURB =6.00 inches Distance from Curb Face to Street Crown TCROWN =29.0 ft Gutter Width W =3.20 ft Street Transverse Slope SX =0.018 ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft Street Longitudinal Slope - Enter 0 for sump condition SO =0.000 ft/ft Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.013 Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm TMAX =29.0 29.0 ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 6.0 inches Check boxes are not applicable in SUMP conditions MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow =SUMP SUMP cfs MHFD-Inlet, Version 5.01 (April 2021) ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) The Flats at Hansen Farm Inlet 2-2 1 Design Information (Input)MINOR MAJOR Type of Inlet Type = Local Depression (additional to continuous gutter depression 'a' from above)alocal =2.00 2.00 inches Number of Unit Inlets (Grate or Curb Opening)No =1 1 Water Depth at Flowline (outside of local depression)Ponding Depth =7.3 7.3 inches Grate Information MINOR MAJOR Length of a Unit Grate Lo (G) =3.00 3.00 feet Width of a Unit Grate Wo =1.73 1.73 feet Area Opening Ratio for a Grate (typical values 0.15-0.90)Aratio =0.43 0.43 Clogging Factor for a Single Grate (typical value 0.50 - 0.70)Cf (G) =0.50 0.50 Grate Weir Coefficient (typical value 2.15 - 3.60)Cw (G) =3.30 3.30 Grate Orifice Coefficient (typical value 0.60 - 0.80)Co (G) =0.60 0.60 Curb Opening Information MINOR MAJOR Length of a Unit Curb Opening Lo (C) =3.00 3.00 feet Height of Vertical Curb Opening in Inches Hvert =6.50 6.50 inches Height of Curb Orifice Throat in Inches Hthroat =5.25 5.25 inches Angle of Throat (see USDCM Figure ST-5)Theta =0.00 0.00 degrees Side Width for Depression Pan (typically the gutter width of 2 feet)Wp =3.20 3.20 feet Clogging Factor for a Single Curb Opening (typical value 0.10)Cf (C) =0.10 0.10 Curb Opening Weir Coefficient (typical value 2.3-3.7)Cw (C) =3.70 3.70 Curb Opening Orifice Coefficient (typical value 0.60 - 0.70)Co (C) =0.66 0.66 Low Head Performance Reduction (Calculated)MINOR MAJOR Depth for Grate Midwidth dGrate =0.658 0.658 ft Depth for Curb Opening Weir Equation dCurb =0.34 0.34 ft Combination Inlet Performance Reduction Factor for Long Inlets RFCombination =1.00 1.00 Curb Opening Performance Reduction Factor for Long Inlets RFCurb =1.00 1.00 Grated Inlet Performance Reduction Factor for Long Inlets RFGrate =1.00 1.00 MINOR MAJOR Total Inlet Interception Capacity (assumes clogged condition)Qa =4.8 4.8 cfs Inlet Capacity IS GOOD for Minor and Major Storms(>Q PEAK)Q PEAK REQUIRED =2.2 4.8 cfs CDOT/Denver 13 Combination INLET IN A SUMP OR SAG LOCATION MHFD-Inlet, Version 5.01 (April 2021) H-VertH-Curb W Lo (C) Lo (G) Wo WP CDOT/Denver 13 Combination Override Depths 1 Project: Inlet ID: Gutter Geometry: Maximum Allowable Width for Spread Behind Curb TBACK =16.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.020 Height of Curb at Gutter Flow Line HCURB =6.00 inches Distance from Curb Face to Street Crown TCROWN =16.0 ft Gutter Width W =1.00 ft Street Transverse Slope SX =0.014 ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft Street Longitudinal Slope - Enter 0 for sump condition SO =0.000 ft/ft Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.013 Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm TMAX =16.0 16.0 ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 6.0 inches Check boxes are not applicable in SUMP conditions MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow =SUMP SUMP cfs MHFD-Inlet, Version 5.01 (April 2021) ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) The Flats at Hansen Farm Inlet 3-3 1 Design Information (Input)MINOR MAJOR Type of Inlet Type = Local Depression (additional to continuous gutter depression 'a' from above)alocal =2.00 2.00 inches Number of Unit Inlets (Grate or Curb Opening)No =1 1 Water Depth at Flowline (outside of local depression)Ponding Depth =3.5 3.5 inches Grate Information MINOR MAJOR Length of a Unit Grate Lo (G) =3.00 3.00 feet Warning 5 Width of a Unit Grate Wo =1.73 1.73 feet Area Opening Ratio for a Grate (typical values 0.15-0.90)Aratio =0.43 0.43 Clogging Factor for a Single Grate (typical value 0.50 - 0.70)Cf (G) =0.50 0.50 Grate Weir Coefficient (typical value 2.15 - 3.60)Cw (G) =3.30 3.30 Grate Orifice Coefficient (typical value 0.60 - 0.80)Co (G) =0.60 0.60 Curb Opening Information MINOR MAJOR Length of a Unit Curb Opening Lo (C) =3.00 3.00 feet Height of Vertical Curb Opening in Inches Hvert =6.50 6.50 inches Height of Curb Orifice Throat in Inches Hthroat =5.25 5.25 inches Angle of Throat (see USDCM Figure ST-5)Theta =0.00 0.00 degrees Side Width for Depression Pan (typically the gutter width of 2 feet)Wp =1.00 1.00 feet Clogging Factor for a Single Curb Opening (typical value 0.10)Cf (C) =0.10 0.10 Curb Opening Weir Coefficient (typical value 2.3-3.7)Cw (C) =3.70 3.70 Curb Opening Orifice Coefficient (typical value 0.60 - 0.70)Co (C) =0.66 0.66 Low Head Performance Reduction (Calculated)MINOR MAJOR Depth for Grate Midwidth dGrate =0.244 0.244 ft Depth for Curb Opening Weir Equation dCurb =0.21 0.21 ft Combination Inlet Performance Reduction Factor for Long Inlets RFCombination =0.55 0.55 Curb Opening Performance Reduction Factor for Long Inlets RFCurb =1.00 1.00 Grated Inlet Performance Reduction Factor for Long Inlets RFGrate =0.55 0.55 MINOR MAJOR Total Inlet Interception Capacity (assumes clogged condition)Qa =0.8 0.8 cfs WARNING: Inlet Capacity less than Q Peak for Minor and Major Storms Q PEAK REQUIRED =1.2 4.8 cfs Warning 5: The width of unit is greater than the gutter width. CDOT/Denver 13 Combination INLET IN A SUMP OR SAG LOCATION MHFD-Inlet, Version 5.01 (April 2021) H-VertH-Curb W Lo (C) Lo (G) Wo WP CDOT/Denver 13 Combination Override Depths 1 CDOT Type R Curb Opening Denver No. 14 Curb Opening Colorado Springs D-10-R CDOT/Denver 13 Valley Grate CDOT/Denver 13 Combination Denver No. 16 Combination Wheat Ridge Combination Inlet Denver No. 16 Valley Grate Directional Cast Vane Grate Directional 30-Degree Bar Grate (courtesy HEC-22) Directional 45-Degree Bar Grate Reticuline Riveted Grate 1-7/8" Bar Grate, Crossbars @ 8" 1-7/8" Bar Grate, Crossbars @ 4" (courtesy HEC-22) 1-1/8 in. Bar Grate, Crossbars @ 8 in. (courtesy HEC-22) Slotted Inlet Parallel to Flow CDOT Type C Grate (Close Mesh)CDOT Type C Grate CDOT Type C Inlet CDOT Type C Inlet in Depression CDOT Type D Inlet In Series (Flat & Depressed) CDOT Type D Inlet In Series (10° Incline & Depressed) CDOT Type D Inlet In Series (20° Incline & Depressed) CDOT Type D Inlet In Series (30° Incline & Depressed) CDOT Type D Inlet Parallel (Flat & Depressed) CDOT Type D Inlet Parallel (10° Incline & Depressed) CDOT Type D Inlet Parallel (20° Incline & Depressed) CDOT Type D Inlet Parallel (30° Incline & Depressed) INLET PICTURES 1916-001_MHFD-Inlet_v5.01, Inlet Pictures 1/18/2023, 10:26 AM Area Inlet Performance Curve: Hansen Multifamily Inlet 6-6 Governing Equations: At low flow depths, the inlet will act like a weir governed by the following equation: * where P = 2(L + W) * where H corresponds to the depth of water above the flowline At higher flow depths, the inlet will act like an orifice governed by the following equation: * where A equals the open area of the inlet grate * where H corresponds to the depth of water above the centroid of the cross-sectional area (A) The exact depth at which the inlet ceases to act like a weir, and begins to act like an orifice is unknown. However, what is known, is that the stage-discharge curves of the weir equation and the orifice equation will cross at a certain flow depth. The two curves can be found below: If H > 1.792 (A/P), then the grate operates like an orifice; otherwise it operates like a weir. Input Parameters: Type of Grate: Nyloplast 2'X3' Grate w/ 24" Basin Length of Grate (ft): 3.00 Width of Grate (ft): 2.00 Open Area of Grate (ft2):7.65 Flowline Elevation (ft): 4960.14 Clogging Factor: 0.60 Depth vs. Flow: Depth Above Inlet (ft) Elevation (ft) Shallow Weir Flow (cfs) Orifice Flow (cfs) Actual Flow (cfs) 0.05 4960.19 0.20 5.52 0.20 0.10 4960.24 0.57 7.80 0.57 0.15 4960.290 1.05 9.55 1.05 0.20 4960.34 1.61 11.03 1.61 0.25 4960.390 2.25 12.33 2.25 0.30 4960.44 2.96 13.51 2.96 0.35 4960.49 3.73 14.59 3.73 0.40 4960.540 4.55 15.60 4.55 0.45 4960.59 5.43 16.55 5.43 Q100 0.50 4960.64 6.36 17.44 6.36 0.55 4960.690 7.34 18.29 7.34 0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 0.00 0.10 0.20 0.30 0.40 0.50 0.60Discharge (cfs)Stage (ft) Stage - Discharge Curves Weir Flow Orifice Flow 5.10.3 HPQ= 5.0)2(67.0 gHAQ= Input Type of Grate 8" Standard Head (ft)0.5 Properties Orifice Flow Area (in)18.77 Orifice Flow Area (ft)0.13 Weir Flow Perimeter (in)21.30 Weir Flow Perimeter (ft)1.78 Solution Capacity (cfs)0.44 Capacity (gpm)197.82 REV 2.1.21 Nyloplast Inlet Capacity Table DISCLAIMER: SAFETY FACTORS ARE NOT INCLUDED IN THESE CALCULATIONS. ACTUAL CALCULATIONS SHOULD BE CARRIED OUT AND VERIFIED BY THE DESIGN ENGINEER TAKING INTO ACCOUNT ALL LOCAL CONDITIONS. NYLOPLAST RECOMMENDS USING A MINIMUM SAFETY FACTOR OF 1.25 FOR PAVED AREAS AND 2.0 FOR TURF AREAS. ADS/NYLOPLAST IS NOT RESPONSIBLE FOR MISUSE OF THIS TOOL. Project:1916-001 By:CLU Date:5/17/2023 Inlet Inlet Inlet LID Inlet Design Design Inlet Capacity Comments ID Size Type TYPE Condition Storm Flow (CFS) (CFS) Inlet 2-2.1 8-in 8-in Nyloplast Basin Standard Grate Sump 100-Yr <0.3 See Nyloplast Capacity 0.5-ft ponding depth above inlet Inlet 2-3.1 8-in 8-in Nyloplast Basin Standard Grate Sump 100-Yr <0.3 See Nyloplast Capacity 0.5-ft ponding depth above inlet Inlet 2-4.1 8-in 8-in Nyloplast Basin Standard Grate Sump 100-Yr <0.3 See Nyloplast Capacity 0.5-ft ponding depth above inlet Inlet 2-5.1-1 8-in 8-in Nyloplast Basin Standard Grate Sump 100-Yr <0.3 See Nyloplast Capacity 0.6-ft ponding depth above inlet Inlet 2-5.3 8-in 8-in Nyloplast Basin Standard Grate Sump 100-Yr <0.3 See Nyloplast Capacity 0.4-ft ponding depth above inlet Inlet 2-6.1 8-in 8-in Nyloplast Basin Standard Grate Sump 100-Yr <0.3 See Nyloplast Capacity 0.4-ft ponding depth above inlet Inlet 2-7.1 8-in 8-in Nyloplast Basin Standard Grate Sump 100-Yr <0.3 See Nyloplast Capacity 0.7-ft ponding depth above inlet Inlet 2-8.1-1 8-in 8-in Nyloplast Basin Standard Grate Sump 100-Yr <0.3 See Nyloplast Capacity 0.6-ft ponding depth above inlet Inlet 2-8.1-2 8-in 8-in Nyloplast Basin Standard Grate Sump 100-Yr <0.3 See Nyloplast Capacity 0.1-ft ponding depth above inlet Inlet 2-8.2 8-in 8-in Nyloplast Basin Standard Grate Sump 100-Yr <0.3 See Nyloplast Capacity 0.15-ft ponding depth above inlet Inlet 2-8.4 8-in 8-in Nyloplast Basin Standard Grate Sump 100-Yr <0.3 See Nyloplast Capacity 0.1-ft ponding depth above inlet Inlet 2-9.1 8-in 8-in Nyloplast Basin Standard Grate Sump 100-Yr <0.3 See Nyloplast Capacity 0.2-ft ponding depth above inlet Inlet 2-11.1 8-in 8-in Nyloplast Basin Standard Grate Sump 100-Yr <0.3 See Nyloplast Capacity 0.4-ft ponding depth above inlet Inlet 2-12.1 8-in 8-in Nyloplast Basin Standard Grate Sump 100-Yr <0.4 See Nyloplast Capacity 0.3-ft ponding depth above inlet Inlet 2-14.1 8-in 8-in Nyloplast Basin Standard Grate Sump 100-Yr <0.3 See Nyloplast Capacity 0.3-ft ponding depth above inlet Inlet 2-17 8-in 8-in Nyloplast Basin Standard Grate Sump 100-Yr <0.3 See Nyloplast Capacity 0.1-ft ponding depth above inlet BASIN SUMMARY STORM 2 NORTHERNENGINEERING.COM | 970.221.4158 FORT COLLINS | GREELEY FINAL DRAINAGE REPORT: THE FLATS AT HANSEN FARM APPENDIX B.5 – Erosion Control Mat Calculations Project Number:1916-001 Project: Date:1/23/2023 Prepared By: Storm Outlet Pipe Dia. (in) Flowrate (cfs) Velocity (ft/s) Protection1 Dimensions1 # of Mats1 RG PIPE END A 4 ScourStop 4' x 4' 1 RG PIPE END B 4 ScourStop 4' x 4' 1 RG PIPE END D 4 ScourStop 4' x 4' 1 RG PIPE END E 18 ScourStop 4' x 4' 1 FES 4 30 31.92 7.88 ScourStop 8' x 12' 4 STORM OUTLET PROTECTION The Flats at Hansen Farm C. Ungerman Notes: 1) ScourStop dimensions and number of mats are per the ScourStop Design Guide for Circular Culvert Outlet Protection provided by Hanes Geo Components (https://hanesgeo.com/Catalog/Product?id=2879). ScourStop® DESIGN GUIDE Circular Culvert Outlet Protection scourstop.com PERFORMANCE AESTHETICS NPDES-COMPLIANT COST-EFFECTIVE the green solution to riprap ® ScourStop transition mats protect against erosion and scour at culvert outlets with a vegetated solution in areas traditionally protected with rock or other hard armor. ScourStop is part of a system that includes semi-rigid transition mats installed over sod or turf reinforcement mats. Each 4’ x 4’ x 1/2” mat is made of high-density polyethylene and secured tightly to the ground with anchors. why use the SCOURSTOP SYSTEM? - If velocity is greater than 16 fps, contact manufacturer for design assistance. - ScourStop mats have been shown to at least double the effectiveness of turf reinforcement mats. - ScourStop fully vegetated channel (2:1 slope): velocity = 31 fps, shear stress = 16 psf. PIPE DIAMETER VELOCITY < 10 FT/SEC 10 < VELOCITY < 16 FT/SEC TRANSITION MAT W x L QUANTITY OF MATS TRANSITION MAT W x L QUANTITY OF MATS 12”4’ x 4’1 4’ x 8’2 24”8’ x 8’4 8’ x 12’6 36”8’ x 12’6 12’ x 20’15 48”12’ x 16’12 12’ x 24’18 60”12’ x 20’15 16’ x 32’32 72”16’ x 24’24 20’ x 36’45 Circular Culvert Outlet Protection These are minimum recommendations. More ScourStop protection may be needed depending upon site and soil conditions, per project engineer. 1. ScourStop mats must be installed over a soil cover: sod, seeded turf reinforcement mat (TRM), geotextile, or a combination thereof. 2. For steep slopes (>10%) or higher velocities (>10 ft/sec), sod is the recommended soil cover. 3. Follow manufacturer’s ScourStop Installation Guidelines to ensure proper installation. 4. Install ScourStop mats at maximum 1-2” below flowline of culvert or culvert apron. (No waterfall impacts onto ScourStop mats.) 5. Performance of protected area assumes stable downstream conditions. Transition mat apron protects culvert outlet. *Width of protection: Bottom width of channel and up both side slopes to a depth at least half the culvert diameter. Protect bare/disturbed downstream soils from erosion with appropriate soil cover. Use normal-depth calculator to compute for downstream protection. Install anchors per ScourStop Installation Guidelines. Minimum depth 24” in compacted, cohesive soil. Minimum depth 30” in loose, sandy, or wet soil. Extra anchors as needed to secure mat tightly over soil cover. Abut transition mats to end of culvert or culvert apron. Adjacent mats abut together laterally and longitudinally. Minimum 8 anchors per mat. Extra anchors as needed for loose or wet soils. Extra anchors as needed for uneven soil surface. ScourStop® Installation Recommendations A A MAX. 1"-2" DROP FROM CULVERT FLOWLINE ONTO SCOURSTOP MATSCULVERT FLOWLINE PROFILE VIEW A LEADER in the GEOSYNTHETIC and EROSION CONTROL industries Learn more about our products at: HanesGeo.com | 888.239.4539 the green solution to riprap ©2014 Leggett & Platt, Incorporated | 16959_1114 AA NORTHERNENGINEERING.COM | 970.221.4158 FORT COLLINS | GREELEY FINAL DRAINAGE REPORT: THE FLATS AT HANSEN FARM APPENDIX APPENDIX C LID EXHIBIT Project Number:Project: Project Location: Calculations By:Date: Sq. Ft. Acres A 60,121 1.38 71%Rain Garden A Rain Garden 1,121 42,686 B 25,267 0.58 63%Rain Garden B Rain Garden 647 15,918 C 30,650 0.70 72% Rain Garden C Rain Garden 1,294 22,068 C1 43,772 1.00 62% Rain Garden C Rain Garden 1,294 27,139 C2 3,107 0.07 2% n/a n/a 0 62 D 55,183 1.27 16% n/a n/a 0 8,829 D1 24,133 0.55 87% Rain Garden D Rain Garden 1,094 20,996 D2 21,173 0.49 82% Rain Garden D Rain Garden 1,094 17,362 E 93,655 2.15 72% Rain Garden E Rain Garden 2,181 67,432 E1 9,948 0.23 86% Rain Garden E Rain Garden 2,181 8,555 E2 15,348 0.35 48% Rain Garden E Rain Garden 2,181 7,367 F 5,782 0.13 45% n/a n/a 0 2,602 O1 6,774 0.16 31% n/a n/a 0 2,100 O2 13,496 0.31 74% n/a n/a 0 9,987 O3 2,537 0.06 21% n/a n/a 0 533 O4 6,404 0.15 17% n/a n/a 0 1,089 O5 2,536 0.06 39% n/a n/a 0 989 O6 18,348 0.42 61% n/a n/a 0 11,192 O7 10,618 0.24 61% n/a n/a 0 6,477 O8 4,959 0.11 62% Rain Garden B Rain Garden 647 3,075 O9 6,776 0.16 87% Rain Garden B Rain Garden 647 5,895 Total 460,587 10.57 282,352 LID Summary Project Number: Project: Project Location: Calculations By: Date: LID Summary per LID Structure Sq. Ft. Acres Rain Garden A 60,121 1.38 71%A Rain Garden 1,121 42,686 Rain Garden B 37,002 0.85 67%B Rain Garden 647 24,888 Rain Garden C 77,529 1.78 64%C Rain Garden 1,294 49,269 Rain Garden D 45,306 1.04 85%D Rain Garden 1,094 38,358 Rain Garden E 118,951 2.73 70%E Rain Garden 2,181 83,354 Total 338,909 7.78 238,554 460,587 ft2 282,352 ft2 43,798 ft2 211,764 ft3 238,554 ft2 84.49% LID ID Volume per UD-BMP (ft3) Total Treated Area Percent Impervious Treated by LID D, F, O1-O7 75% Requried Minimum Area to be Treated LID Site Summary - New Impervious Area Total Area of Current Development Total Impervious Area Total Impervious Area without LID Treatment Impervious Area (ft2) The Flats at Hansen Farm 3/8/2023 Subbasin ID Treatment Type Area Weighted % Impervious 1916-001 Fort Collins, Colorado C. Ungerman LID Summary AreaBasin ID Treatment Type Percent Impervious LID ID The Flatrs at Hansen Farm 3/8/2023 1916-001 Fort Collins, Colorado C. Ungerman Total Impervious Area (ft2) Required Volume (ft3) LID Summary per Basin FMELEC ELEC ELECELECG G G GGGGG GGG / / / / / / / / ELECELECELEC ELECNYLOPLAST DO NOT POLLUTE DRAINS TO WATERW A Y S FDCFDCFDCFDC FDCFDC FDCFDCWEREVSE EVR EVR EVR EVR EVR EVR EVR EVR EVR EVR EVR EVR HC EVR EVSE WEREVSE EVR EVR EVR EVR EVR EVR EVR EVR EVR EVR EVR EVR HC EVR EVSE WER EVSE EVSE EVSE EVR EVR EVR EVR XXXXXXXXXXXXXXXXX X X XXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXX X X BBBBBBBBBBBBBBBBBBB B B B BB BB B B BBBB BBB B BB BBBBBBBBBB BBB B BBBBBB B BBB BBB B BBBB B BBBBB BBB BB B BBBB BB BBB BBB BBB BB BB BB BB BBBBBBBB BBB B BB B B B BB BB B B BBB BB BB BBB B BBBBBBBBBBB B B B BBBB B B B B BBBBB BB B BBB BB BB B B B B BBBB BBB C C1 F E D D2 E2 O4 B A DETENTION POND 3 RAIN GARDEN D RAIN GARDEN E RAIN GARDEN B RAIN GARDEN A RAIN GARDEN C EXISTING DETENTION POND 1 KNOBBY PINE DRIVE ZEPHYR ROADBURLY TREE DRIVETWISTED ROOT DRIVE SOUTH TIMBERLINE ROADD1 E1 O3 O1 A B C D E C1 O6 O3 E2 O4 O1 D1 D2 E1 F O2 O7 O7 C2 C2 O5 O2 O5 O6 O9 O9 O8 O8 EXISTING DETENTION POND 2 PROPOSED STORM SEWER PROPOSED CURB & GUTTER PROPERTY BOUNDARY PROPOSED INLET ADESIGN POINT DRAINAGE BASIN LABEL DRAINAGE BASIN BOUNDARY A LEGEND: DRAWN BY: SCALE: ISSUED: THE FLATS AT HANSEN FARM SHEET NO: FORT COLLINS: 301 North Howes Street, Suite 100, 80521 GREELEY: 820 8th Street, 80631 E N G I N E E R N GI EHTRON R N 970.221.4158 northernengineering.com LID EXHIBIT C. Ungerman 1in=120ft 5/17/2023 ( IN FEET ) 1 inch = ft. Feet0120120 120 RAIN GARDEN LIMITS STORMTECH CHAMBERS FOR DRAINAGE REVIEW ONLY NOT FOR CONSTRUCTION LID Site Summary - New Impervious Area Total Area of Current Development 460,587 ft2 Total Impervious Area 282,352 ft2 Total Impervious Area without LID Treatment 43,798 ft2 D, F, O1-O7 75% Requried Minimum Area to be Treated 211,764 Total Treated Area 238,554 ft2 Percent Impervious Treated by LID 84.49% Sheet 1 of 2 Designer: Company: Date: Project: Location: 1. Basin Storage Volume A) Effective Imperviousness of Tributary Area, Ia Ia =71.0 % (100% if all paved and roofed areas upstream of rain garden) B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 0.710 C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.22 watershed inches (WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i) D) Contributing Watershed Area (including rain garden area) Area = 60,121 sq ft E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =1,121 cu ft Vol = (WQCV / 12) * Area F) For Watersheds Outside of the Denver Region, Depth of d6 = in Average Runoff Producing Storm G) For Watersheds Outside of the Denver Region, VWQCV OTHER =cu ft Water Quality Capture Volume (WQCV) Design Volume H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER =cu ft (Only if a different WQCV Design Volume is desired) 2. Basin Geometry A) WQCV Depth (12-inch maximum)DWQCV =12 in B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 4.00 ft / ft (Use "0" if rain garden has vertical walls) C) Mimimum Flat Surface Area AMin =854 sq ft D) Actual Flat Surface Area AActual =1031 sq ft E) Area at Design Depth (Top Surface Area)ATop =2113 sq ft F) Rain Garden Total Volume VT=1,572 cu ft (VT= ((ATop + AActual) / 2) * Depth) 3. Growing Media 4. Underdrain System A) Are underdrains provided?1 B) Underdrain system orifice diameter for 12 hour drain time i) Distance From Lowest Elevation of the Storage y =ft Volume to the Center of the Orifice ii) Volume to Drain in 12 Hours Vol12 =cu ft iii) Orifice Diameter, 3/8" Minimum DO = in Design Procedure Form: Rain Garden (RG) C. Ungerman May 17, 2023 The Flats at Hansen Farm Rain Garden A UD-BMP (Version 3.07, March 2018) Choose One Choose One 18" Rain Garden Growing Media Other (Explain): YES NO Rain Garden A_UD-BMP_v3.07, RG 5/17/2023, 8:44 AM Sheet 2 of 2 Designer: Company: Date: Project: Location: 5. Impermeable Geomembrane Liner and Geotextile Separator Fabric A) Is an impermeable liner provided due to proximity of structures or groundwater contamination? 6. Inlet / Outlet Control A) Inlet Control 7. Vegetation 8. Irrigation A) Will the rain garden be irrigated? Notes: Design Procedure Form: Rain Garden (RG) C. Ungerman May 17, 2023 The Flats at Hansen Farm Rain Garden A Choose One Choose One Choose One Sheet Flow- No Energy Dissipation Required Concentrated Flow- Energy Dissipation Provided Plantings Seed (Plan for frequent weed control) Sand Grown or Other High Infiltration Sod Choose One YES NO YES NO Rain Garden A_UD-BMP_v3.07, RG 5/17/2023, 8:44 AM Sheet 1 of 2 Designer: Company: Date: Project: Location: 1. Basin Storage Volume A) Effective Imperviousness of Tributary Area, Ia Ia =67.0 % (100% if all paved and roofed areas upstream of rain garden) B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 0.670 C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.21 watershed inches (WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i) D) Contributing Watershed Area (including rain garden area) Area = 37,002 sq ft E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =647 cu ft Vol = (WQCV / 12) * Area F) For Watersheds Outside of the Denver Region, Depth of d6 = in Average Runoff Producing Storm G) For Watersheds Outside of the Denver Region, VWQCV OTHER =cu ft Water Quality Capture Volume (WQCV) Design Volume H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER =cu ft (Only if a different WQCV Design Volume is desired) 2. Basin Geometry A) WQCV Depth (12-inch maximum)DWQCV =12 in B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 4.00 ft / ft (Use "0" if rain garden has vertical walls) C) Mimimum Flat Surface Area AMin =496 sq ft D) Actual Flat Surface Area AActual =756 sq ft E) Area at Design Depth (Top Surface Area)ATop =1430 sq ft F) Rain Garden Total Volume VT=1,093 cu ft (VT= ((ATop + AActual) / 2) * Depth) 3. Growing Media 4. Underdrain System A) Are underdrains provided?1 B) Underdrain system orifice diameter for 12 hour drain time i) Distance From Lowest Elevation of the Storage y =ft Volume to the Center of the Orifice ii) Volume to Drain in 12 Hours Vol12 =cu ft iii) Orifice Diameter, 3/8" Minimum DO = in Design Procedure Form: Rain Garden (RG) C. Ungerman May 17, 2023 The Flats at Hansen Farm Rain Garden B UD-BMP (Version 3.07, March 2018) Choose One Choose One 18" Rain Garden Growing Media Other (Explain): YES NO Rain Garden B_UD-BMP_v3.07, RG 5/17/2023, 8:45 AM Sheet 2 of 2 Designer: Company: Date: Project: Location: 5. Impermeable Geomembrane Liner and Geotextile Separator Fabric A) Is an impermeable liner provided due to proximity of structures or groundwater contamination? 6. Inlet / Outlet Control A) Inlet Control 7. Vegetation 8. Irrigation A) Will the rain garden be irrigated? Notes: Design Procedure Form: Rain Garden (RG) C. Ungerman May 17, 2023 The Flats at Hansen Farm Rain Garden B Choose One Choose One Choose One Sheet Flow- No Energy Dissipation Required Concentrated Flow- Energy Dissipation Provided Plantings Seed (Plan for frequent weed control) Sand Grown or Other High Infiltration Sod Choose One YES NO YES NO Rain Garden B_UD-BMP_v3.07, RG 5/17/2023, 8:45 AM Sheet 1 of 2 Designer: Company: Date: Project: Location: 1. Basin Storage Volume A) Effective Imperviousness of Tributary Area, Ia Ia =64.0 % (100% if all paved and roofed areas upstream of rain garden) B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 0.640 C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.20 watershed inches (WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i) D) Contributing Watershed Area (including rain garden area) Area = 77,529 sq ft E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =1,294 cu ft Vol = (WQCV / 12) * Area F) For Watersheds Outside of the Denver Region, Depth of d6 = in Average Runoff Producing Storm G) For Watersheds Outside of the Denver Region, VWQCV OTHER =cu ft Water Quality Capture Volume (WQCV) Design Volume H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER =cu ft (Only if a different WQCV Design Volume is desired) 2. Basin Geometry A) WQCV Depth (12-inch maximum)DWQCV =12 in B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 4.00 ft / ft (Use "0" if rain garden has vertical walls) C) Mimimum Flat Surface Area AMin =992 sq ft D) Actual Flat Surface Area AActual =1117 sq ft E) Area at Design Depth (Top Surface Area)ATop =2693 sq ft F) Rain Garden Total Volume VT=1,905 cu ft (VT= ((ATop + AActual) / 2) * Depth) 3. Growing Media 4. Underdrain System A) Are underdrains provided?1 B) Underdrain system orifice diameter for 12 hour drain time i) Distance From Lowest Elevation of the Storage y =ft Volume to the Center of the Orifice ii) Volume to Drain in 12 Hours Vol12 =cu ft iii) Orifice Diameter, 3/8" Minimum DO = in Design Procedure Form: Rain Garden (RG) C. Ungerman May 17, 2023 The Flats at Hansen Farm Rain Garden C UD-BMP (Version 3.07, March 2018) Choose One Choose One 18" Rain Garden Growing Media Other (Explain): YES NO Rain Garden C_UD-BMP_v3.07, RG 5/17/2023, 8:48 AM Sheet 2 of 2 Designer: Company: Date: Project: Location: 5. Impermeable Geomembrane Liner and Geotextile Separator Fabric A) Is an impermeable liner provided due to proximity of structures or groundwater contamination? 6. Inlet / Outlet Control A) Inlet Control 7. Vegetation 8. Irrigation A) Will the rain garden be irrigated? Notes: Design Procedure Form: Rain Garden (RG) C. Ungerman May 17, 2023 The Flats at Hansen Farm Rain Garden C Choose One Choose One Choose One Sheet Flow- No Energy Dissipation Required Concentrated Flow- Energy Dissipation Provided Plantings Seed (Plan for frequent weed control) Sand Grown or Other High Infiltration Sod Choose One YES NO YES NO Rain Garden C_UD-BMP_v3.07, RG 5/17/2023, 8:48 AM Sheet 1 of 2 Designer: Company: Date: Project: Location: 1. Basin Storage Volume A) Effective Imperviousness of Tributary Area, Ia Ia =85.0 % (100% if all paved and roofed areas upstream of rain garden) B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 0.850 C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.29 watershed inches (WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i) D) Contributing Watershed Area (including rain garden area) Area = 45,306 sq ft E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =1,094 cu ft Vol = (WQCV / 12) * Area F) For Watersheds Outside of the Denver Region, Depth of d6 = in Average Runoff Producing Storm G) For Watersheds Outside of the Denver Region, VWQCV OTHER =cu ft Water Quality Capture Volume (WQCV) Design Volume H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER =cu ft (Only if a different WQCV Design Volume is desired) 2. Basin Geometry A) WQCV Depth (12-inch maximum)DWQCV =12 in B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 4.00 ft / ft (Use "0" if rain garden has vertical walls) C) Mimimum Flat Surface Area AMin =770 sq ft D) Actual Flat Surface Area AActual =845 sq ft E) Area at Design Depth (Top Surface Area)ATop =1797 sq ft F) Rain Garden Total Volume VT=1,321 cu ft (VT= ((ATop + AActual) / 2) * Depth) 3. Growing Media 4. Underdrain System A) Are underdrains provided?1 B) Underdrain system orifice diameter for 12 hour drain time i) Distance From Lowest Elevation of the Storage y =ft Volume to the Center of the Orifice ii) Volume to Drain in 12 Hours Vol12 =cu ft iii) Orifice Diameter, 3/8" Minimum DO = in Design Procedure Form: Rain Garden (RG) C. Ungerman May 17, 2023 The Flats at Hansen Farm Rain Garden D UD-BMP (Version 3.07, March 2018) Choose One Choose One 18" Rain Garden Growing Media Other (Explain): YES NO Rain Garden D_UD-BMP_v3.07, RG 5/17/2023, 8:50 AM Sheet 2 of 2 Designer: Company: Date: Project: Location: 5. Impermeable Geomembrane Liner and Geotextile Separator Fabric A) Is an impermeable liner provided due to proximity of structures or groundwater contamination? 6. Inlet / Outlet Control A) Inlet Control 7. Vegetation 8. Irrigation A) Will the rain garden be irrigated? Notes: Design Procedure Form: Rain Garden (RG) C. Ungerman May 17, 2023 The Flats at Hansen Farm Rain Garden D Choose One Choose One Choose One Sheet Flow- No Energy Dissipation Required Concentrated Flow- Energy Dissipation Provided Plantings Seed (Plan for frequent weed control) Sand Grown or Other High Infiltration Sod Choose One YES NO YES NO Rain Garden D_UD-BMP_v3.07, RG 5/17/2023, 8:50 AM NORTHERNENGINEERING.COM | 970.221.4158 FORT COLLINS | GREELEY FINAL DRAINAGE REPORT: THE FLATS AT HANSEN FARM APPENDIX APPENDIX D USDA SOILS REPORT United States Department of Agriculture A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Larimer County Area, ColoradoNatural Resources Conservation Service September 12, 2017 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/ portal/nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid=nrcs142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require 2 alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface....................................................................................................................2 How Soil Surveys Are Made..................................................................................5 Soil Map.................................................................................................................. 8 Soil Map................................................................................................................9 Legend................................................................................................................10 Map Unit Legend................................................................................................ 11 Map Unit Descriptions.........................................................................................11 Larimer County Area, Colorado......................................................................14 5—Aquepts, loamy......................................................................................14 22—Caruso clay loam, 0 to 1 percent slope............................................... 15 34—Fort Collins loam, 0 to 1 percent slopes.............................................. 16 35—Fort Collins loam, 0 to 3 percent slopes.............................................. 17 36—Fort Collins loam, 3 to 5 percent slopes.............................................. 19 37—Fort Collins loam, 5 to 9 percent slopes.............................................. 20 55—Kim loam, 5 to 9 percent slopes.......................................................... 21 63—Longmont clay, 0 to 3 percent slopes.................................................. 23 73—Nunn clay loam, 0 to 1 percent slopes.................................................24 74—Nunn clay loam, 1 to 3 percent slopes.................................................25 76—Nunn clay loam, wet, 1 to 3 percent slopes.........................................27 79—Otero sandy loam, 5 to 9 percent slopes.............................................28 Soil Information for All Uses...............................................................................30 Soil Properties and Qualities..............................................................................30 Soil Qualities and Features.............................................................................30 Hydrologic Soil Group................................................................................. 30 References............................................................................................................35 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 44833004483400448350044836004483700448380044839004484000448410044842004484300448440044845004483300448340044835004483600448370044838004483900448400044841004484200448430044844004484500495900 496000 496100 496200 496300 496400 496500 496600 496700 495900 496000 496100 496200 496300 496400 496500 496600 496700 40° 30' 41'' N 105° 2' 58'' W40° 30' 41'' N105° 2' 16'' W40° 29' 58'' N 105° 2' 58'' W40° 29' 58'' N 105° 2' 16'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 300 600 1200 1800 Feet 0 50 100 200 300 Meters Map Scale: 1:6,420 if printed on A portrait (8.5" x 11") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Larimer County Area, Colorado Survey Area Data: Version 11, Sep 23, 2016 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Mar 20, 2015—Oct 15, 2016 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 Larimer County Area, Colorado (CO644) Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 5 Aquepts, loamy 15.4 8.8% 22 Caruso clay loam, 0 to 1 percent slope 4.0 2.3% 34 Fort Collins loam, 0 to 1 percent slopes 1.9 1.1% 35 Fort Collins loam, 0 to 3 percent slopes 8.6 4.9% 36 Fort Collins loam, 3 to 5 percent slopes 30.9 17.6% 37 Fort Collins loam, 5 to 9 percent slopes 1.1 0.6% 55 Kim loam, 5 to 9 percent slopes 4.4 2.5% 63 Longmont clay, 0 to 3 percent slopes 6.6 3.8% 73 Nunn clay loam, 0 to 1 percent slopes 23.5 13.4% 74 Nunn clay loam, 1 to 3 percent slopes 67.6 38.5% 76 Nunn clay loam, wet, 1 to 3 percent slopes 3.8 2.2% 79 Otero sandy loam, 5 to 9 percent slopes 7.7 4.4% Totals for Area of Interest 175.6 100.0% 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. Custom Soil Resource Report 11 Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. 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 Custom Soil Resource Report 12 of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. Custom Soil Resource Report 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: Depressions, draws, stream terraces 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 Natural 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: Rare Frequency of ponding: None Interpretive groups Land capability classification (irrigated): 5w Land capability classification (nonirrigated): 3w Hydrologic Soil Group: A/D Hydric soil rating: Yes Minor Components Fort collins Percent of map unit: 5 percent Hydric soil rating: No Nunn Percent of map unit: 5 percent Hydric soil rating: No Custom Soil Resource Report 14 Stoneham Percent of map unit: 5 percent Hydric soil rating: No Kim Percent of map unit: 5 percent 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, sandy loam H2 - 35 to 44 inches: sand, gravelly sand H3 - 44 to 60 inches: H3 - 44 to 60 inches: Properties and qualities Slope: 0 to 1 percent Depth to restrictive feature: More than 80 inches Natural 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: Occasional Frequency of ponding: None Calcium carbonate, maximum in profile: 5 percent Custom Soil Resource Report 15 Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: High (about 9.8 inches) Interpretive groups Land capability classification (irrigated): 3w Land capability classification (nonirrigated): 5w Hydrologic Soil Group: D Hydric soil rating: No Minor Components Loveland Percent of map unit: 9 percent Landform: Terraces Hydric soil rating: Yes Fluvaquents Percent of map unit: 6 percent Landform: Terraces Hydric soil rating: Yes 34—Fort Collins loam, 0 to 1 percent slopes Map Unit Setting National map unit symbol: jpw7 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 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: Terraces, fans Landform position (three-dimensional): Base slope, tread Down-slope shape: Linear Across-slope shape: Linear Parent material: Alluvium Typical profile H1 - 0 to 8 inches: loam H2 - 8 to 18 inches: loam, clay loam H2 - 8 to 18 inches: loam, silt loam, fine sandy loam H3 - 18 to 60 inches: Custom Soil Resource Report 16 H3 - 18 to 60 inches: H3 - 18 to 60 inches: Properties and qualities Slope: 0 to 1 percent Depth to restrictive feature: More than 80 inches Natural 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 in profile: 15 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: Very high (about 26.0 inches) Interpretive groups Land capability classification (irrigated): 2e Land capability classification (nonirrigated): 3c Hydrologic Soil Group: B Ecological site: Loamy Plains (R067XY002CO) Hydric soil rating: No Minor Components Stoneham Percent of map unit: 6 percent Hydric soil rating: No Larim Percent of map unit: 5 percent Hydric soil rating: No Ascalon Percent of map unit: 4 percent Hydric soil rating: No 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: 143 to 154 days Farmland classification: Prime farmland if irrigated Map Unit Composition Fort collins and similar soils: 85 percent Custom Soil Resource Report 17 Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Fort Collins Setting Landform: Interfluves Down-slope shape: Linear Across-slope shape: Linear Parent material: Pleistocene or older alluvium derived from igneous, metamorphic and sedimentary rock and/or eolian deposits Typical profile Ap - 0 to 4 inches: loam Bt1 - 4 to 9 inches: clay loam Bt2 - 9 to 16 inches: clay loam Bk1 - 16 to 29 inches: loam Bk2 - 29 to 80 inches: loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural 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 in profile: 12 percent Salinity, maximum in profile: Nonsaline (0.1 to 1.0 mmhos/cm) Sodium adsorption ratio, maximum in profile: 0.5 Available water storage in profile: High (about 9.1 inches) Interpretive groups Land capability classification (irrigated): 2e Land capability classification (nonirrigated): 4c Hydrologic Soil Group: C Ecological site: Loamy Plains (R067BY002CO) Hydric soil rating: No Minor Components Nunn Percent of map unit: 10 percent Landform: Terraces Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Ecological site: Loamy Plains (R067BY002CO) Hydric soil rating: No Vona Percent of map unit: 5 percent Landform: Interfluves Landform position (two-dimensional): Backslope, footslope Landform position (three-dimensional): Side slope, base slope Custom Soil Resource Report 18 Down-slope shape: Linear Across-slope shape: Linear Ecological site: Sandy Plains (R067BY024CO) Hydric soil rating: No 36—Fort Collins loam, 3 to 5 percent slopes Map Unit Setting National map unit symbol: jpw9 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 Fort collins and similar soils: 90 percent Minor components: 10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Fort Collins Setting Landform: Terraces, fans Landform position (three-dimensional): Base slope, riser Down-slope shape: Linear Across-slope shape: Linear Parent material: Alluvium Typical profile H1 - 0 to 9 inches: loam H2 - 9 to 20 inches: loam, clay loam H2 - 9 to 20 inches: loam, silt loam, fine sandy loam H3 - 20 to 60 inches: H3 - 20 to 60 inches: H3 - 20 to 60 inches: Properties and qualities Slope: 3 to 5 percent Depth to restrictive feature: More than 80 inches Natural 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 in profile: 15 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Custom Soil Resource Report 19 Available water storage in profile: Very high (about 25.5 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 3e Hydrologic Soil Group: B Ecological site: Loamy Plains (R067XY002CO) Hydric soil rating: No Minor Components Ascalon Percent of map unit: 5 percent Hydric soil rating: No Kim Percent of map unit: 3 percent Hydric soil rating: No Stoneham Percent of map unit: 2 percent Hydric soil rating: No 37—Fort Collins loam, 5 to 9 percent slopes Map Unit Setting National map unit symbol: jpwb 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: Farmland of statewide importance 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: Terraces, fans Landform position (three-dimensional): Base slope, riser Down-slope shape: Linear Across-slope shape: Linear Parent material: Alluvium Typical profile H1 - 0 to 6 inches: loam H2 - 6 to 18 inches: loam, clay loam H2 - 6 to 18 inches: loam, silt loam, fine sandy loam H3 - 18 to 60 inches: Custom Soil Resource Report 20 H3 - 18 to 60 inches: H3 - 18 to 60 inches: Properties and qualities Slope: 5 to 9 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Medium 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 in profile: 15 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: Very high (about 26.4 inches) Interpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: B Ecological site: Loamy Plains (R067XY002CO) Hydric soil rating: No Minor Components Larimer Percent of map unit: 8 percent Hydric soil rating: No Kim Percent of map unit: 4 percent Hydric soil rating: No Stoneham Percent of map unit: 3 percent Hydric soil rating: No 55—Kim loam, 5 to 9 percent slopes Map Unit Setting National map unit symbol: jpwz 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 Kim and similar soils: 85 percent Custom Soil Resource Report 21 Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Kim Setting Landform: Fans Landform position (three-dimensional): Base slope, side 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: loam, clay loam, sandy clay loam H2 - 7 to 60 inches: H2 - 7 to 60 inches: Properties and qualities Slope: 5 to 9 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Medium 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 in profile: 15 percent Salinity, maximum in profile: Nonsaline to slightly saline (0.0 to 4.0 mmhos/cm) Available water storage in profile: Very high (about 26.5 inches) Interpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 6e Hydrologic Soil Group: B Ecological site: Loamy Plains (R067XY002CO) Hydric soil rating: No Minor Components Thedalund Percent of map unit: 10 percent Hydric soil rating: No Stoneham Percent of map unit: 5 percent Hydric soil rating: No Custom Soil Resource Report 22 63—Longmont clay, 0 to 3 percent slopes Map Unit Setting National map unit symbol: jpx8 Elevation: 4,800 to 5,800 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 and reclaimed of excess salts and sodium Map Unit Composition Longmont and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Longmont Setting Landform: Flood plains, valleys Landform position (three-dimensional): Base slope, tread Down-slope shape: Linear Across-slope shape: Linear Parent material: Clayey alluvium derived from shale Typical profile H1 - 0 to 60 inches: clay Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: 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 30 inches Frequency of flooding: Occasional Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Gypsum, maximum in profile: 5 percent Salinity, maximum in profile: Slightly saline to strongly saline (4.0 to 16.0 mmhos/cm) Sodium adsorption ratio, maximum in profile: 20.0 Available water storage in profile: Moderate (about 8.4 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 6w Hydrologic Soil Group: D Ecological site: Salt Meadow (R067BY035CO) Custom Soil Resource Report 23 Hydric soil rating: No Minor Components Dacono Percent of map unit: 5 percent Hydric soil rating: No Aquolls Percent of map unit: 5 percent Landform: Swales Hydric soil rating: Yes Heldt Percent of map unit: 5 percent Hydric soil rating: No 73—Nunn clay loam, 0 to 1 percent slopes Map Unit Setting National map unit symbol: 2tlng Elevation: 4,100 to 5,700 feet Mean annual precipitation: 14 to 15 inches Mean annual air temperature: 48 to 52 degrees F Frost-free period: 135 to 152 days Farmland classification: Prime farmland if irrigated Map Unit Composition Nunn and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Nunn Setting Landform: Terraces Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Parent material: Pleistocene aged alluvium and/or eolian deposits Typical profile Ap - 0 to 6 inches: clay loam Bt1 - 6 to 10 inches: clay loam Bt2 - 10 to 26 inches: clay loam Btk - 26 to 31 inches: clay loam Bk1 - 31 to 47 inches: loam Bk2 - 47 to 80 inches: loam Properties and qualities Slope: 0 to 1 percent Depth to restrictive feature: More than 80 inches Custom Soil Resource Report 24 Natural drainage class: Well drained Runoff class: Medium 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: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 7 percent Salinity, maximum in profile: Nonsaline (0.1 to 1.0 mmhos/cm) Sodium adsorption ratio, maximum in profile: 0.5 Available water storage in profile: High (about 9.1 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: C Ecological site: Clayey Plains (R067BY042CO) Hydric soil rating: No Minor Components Heldt Percent of map unit: 10 percent Landform: Terraces Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Ecological site: Clayey Plains (R067BY042CO) Hydric soil rating: No Wages Percent of map unit: 5 percent Landform: Terraces Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Ecological site: Loamy Plains (R067BY002CO) Hydric soil rating: No 74—Nunn clay loam, 1 to 3 percent slopes Map Unit Setting National map unit symbol: 2tlpl Elevation: 3,900 to 5,840 feet Mean annual precipitation: 13 to 17 inches Mean annual air temperature: 50 to 54 degrees F Frost-free period: 135 to 160 days Farmland classification: Prime farmland if irrigated Custom Soil Resource Report 25 Map Unit Composition Nunn and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Nunn Setting Landform: Terraces Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Parent material: Pleistocene aged alluvium and/or eolian deposits Typical profile Ap - 0 to 9 inches: clay loam Bt - 9 to 13 inches: clay loam Btk - 13 to 25 inches: clay loam Bk1 - 25 to 38 inches: clay loam Bk2 - 38 to 80 inches: clay loam Properties and qualities Slope: 1 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Medium 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: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 7 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.1 to 2.0 mmhos/cm) Sodium adsorption ratio, maximum in profile: 0.5 Available water storage in profile: High (about 9.9 inches) Interpretive groups Land capability classification (irrigated): 2e Land capability classification (nonirrigated): 3e Hydrologic Soil Group: C Ecological site: Clayey Plains (R067BY042CO) Hydric soil rating: No Minor Components Heldt Percent of map unit: 10 percent Landform: Terraces Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Ecological site: Clayey Plains (R067BY042CO) Hydric soil rating: No Custom Soil Resource Report 26 Satanta Percent of map unit: 5 percent Landform: Terraces Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Ecological site: Loamy Plains (R067BY002CO) Hydric soil rating: No 76—Nunn clay loam, wet, 1 to 3 percent slopes Map Unit Setting National map unit symbol: jpxq Elevation: 4,800 to 5,600 feet Mean annual precipitation: 13 to 15 inches Mean annual air temperature: 48 to 50 degrees F Frost-free period: 135 to 150 days Farmland classification: Prime farmland if irrigated Map Unit Composition Nunn, wet, and similar soils: 90 percent Minor components: 10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Nunn, Wet Setting Landform: Alluvial fans, stream terraces Landform position (three-dimensional): Base slope, tread Down-slope shape: Linear Across-slope shape: Linear Parent material: Alluvium Typical profile H1 - 0 to 10 inches: clay loam H2 - 10 to 47 inches: clay loam, clay H2 - 10 to 47 inches: clay loam, loam, gravelly sandy loam H3 - 47 to 60 inches: H3 - 47 to 60 inches: H3 - 47 to 60 inches: Properties and qualities Slope: 1 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Somewhat poorly drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat): Moderately low to moderately high (0.06 to 0.60 in/hr) Depth to water table: About 24 to 36 inches Frequency of flooding: Rare Custom Soil Resource Report 27 Frequency of ponding: None Calcium carbonate, maximum in profile: 10 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: Very high (about 19.8 inches) Interpretive groups Land capability classification (irrigated): 2w Land capability classification (nonirrigated): 3s Hydrologic Soil Group: C Hydric soil rating: No Minor Components Heldt Percent of map unit: 6 percent Hydric soil rating: No Dacono Percent of map unit: 3 percent Hydric soil rating: No Mollic halaquepts Percent of map unit: 1 percent Landform: Swales Hydric soil rating: Yes 79—Otero sandy loam, 5 to 9 percent slopes Map Unit Setting National map unit symbol: jpxt 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: Not prime farmland Map Unit Composition Otero and similar soils: 80 percent Minor components: 20 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Otero Setting Landform: Fans Landform position (three-dimensional): Base slope, side slope Down-slope shape: Linear Across-slope shape: Linear Parent material: Alluvium and/or eolian deposits Custom Soil Resource Report 28 Typical profile H1 - 0 to 14 inches: sandy loam H2 - 14 to 60 inches: sandy loam, fine sandy loam, loamy very fine sand H2 - 14 to 60 inches: H2 - 14 to 60 inches: Properties and qualities Slope: 5 to 9 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Somewhat excessively drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): High (2.00 to 6.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 5 percent Salinity, maximum in profile: Nonsaline to slightly saline (0.0 to 4.0 mmhos/cm) Available water storage in profile: Very high (about 15.4 inches) Interpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 6e Hydrologic Soil Group: A Ecological site: Sandy Plains (R067BY024CO) Hydric soil rating: No Minor Components Kim Percent of map unit: 9 percent Hydric soil rating: No Nelson Percent of map unit: 6 percent Hydric soil rating: No Tassel Percent of map unit: 5 percent Hydric soil rating: No Custom Soil Resource Report 29 Soil Information for All Uses Soil Properties and Qualities The Soil Properties and Qualities section includes various soil properties and qualities displayed as thematic maps with a summary table for the soil map units in the selected area of interest. A single value or rating for each map unit is generated by aggregating the interpretive ratings of individual map unit components. This aggregation process is defined for each property or quality. Soil Qualities and Features Soil qualities are behavior and performance attributes that are not directly measured, but are inferred from observations of dynamic conditions and from soil properties. Example soil qualities include natural drainage, and frost action. Soil features are attributes that are not directly part of the soil. Example soil features include slope and depth to restrictive layer. These features can greatly impact the use and management of the soil. Hydrologic Soil Group Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. 30 Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Custom Soil Resource Report 31 32 Custom Soil Resource Report Map—Hydrologic Soil Group 44833004483400448350044836004483700448380044839004484000448410044842004484300448440044845004483300448340044835004483600448370044838004483900448400044841004484200448430044844004484500495900 496000 496100 496200 496300 496400 496500 496600 496700 495900 496000 496100 496200 496300 496400 496500 496600 496700 40° 30' 41'' N 105° 2' 58'' W40° 30' 41'' N105° 2' 16'' W40° 29' 58'' N 105° 2' 58'' W40° 29' 58'' N 105° 2' 16'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 300 600 1200 1800 Feet 0 50 100 200 300 Meters Map Scale: 1:6,420 if printed on A portrait (8.5" x 11") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines A A/D B B/D C C/D D Not rated or not available Soil Rating Points A A/D B B/D C C/D D Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Larimer County Area, Colorado Survey Area Data: Version 11, Sep 23, 2016 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Mar 20, 2015—Oct 15, 2016 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 33 Table—Hydrologic Soil Group Hydrologic Soil Group— Summary by Map Unit — Larimer County Area, Colorado (CO644) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 5 Aquepts, loamy A/D 15.4 8.8% 22 Caruso clay loam, 0 to 1 percent slope D 4.0 2.3% 34 Fort Collins loam, 0 to 1 percent slopes B 1.9 1.1% 35 Fort Collins loam, 0 to 3 percent slopes C 8.6 4.9% 36 Fort Collins loam, 3 to 5 percent slopes B 30.9 17.6% 37 Fort Collins loam, 5 to 9 percent slopes B 1.1 0.6% 55 Kim loam, 5 to 9 percent slopes B 4.4 2.5% 63 Longmont clay, 0 to 3 percent slopes D 6.6 3.8% 73 Nunn clay loam, 0 to 1 percent slopes C 23.5 13.4% 74 Nunn clay loam, 1 to 3 percent slopes C 67.6 38.5% 76 Nunn clay loam, wet, 1 to 3 percent slopes C 3.8 2.2% 79 Otero sandy loam, 5 to 9 percent slopes A 7.7 4.4% Totals for Area of Interest 175.6 100.0% Rating Options—Hydrologic Soil Group Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher Custom Soil Resource Report 34 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 35 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 36 NORTHERNENGINEERING.COM | 970.221.4158 FORT COLLINS | GREELEY FINAL DRAINAGE REPORT: THE FLATS AT HANSEN FARM APPENDIX MAP POCKET DR1 – DRAINAGE EXHIBIT UDUDUDUD UDUDNYLOPLASTDO NOT POLLUTE DRAINS TO WATERWAYS FDC FDC FDC FDCFDCFDC FDC FDCFM FM FM/ / / / / / / // / / / / / / // / / / / / / // / / / / / / /ELECELECELEC ELECXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX BBBBBBBBBBBBBBBBBBBBBBBBB BBBB B B BB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBB BBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBB BBBBBBBBB BBBB BBB BBBBBB BBBBBB B B B B BBBB CC1EDD2E2O4BAO8KNOBBY PINE DRIVEZEPHYR ROADBURLY TREE DRIVE TWISTED ROOT DRIVESOUTH TIMBERLINE ROADEXISTINGSTORM DRAINRAINGARDEN ARAINGARDEN BRAINGARDEN CRAINGARDEN DRAINGARDEN EDETENTIONPOND 3EXISTINGDETENTION POND 2EXISTINGDETENTION POND 1EXISTING DETENTIONPOND 4EXISTINGSTORM DRAINEXISTINGSTORM DRAINEXISTINGSTORM DRAINSEXISTINGSTORM DRAINABCDEC1O6O8O3E2O4O1D1D2E1PROPOSED 2'CONCRETE PANO3E1D1PROPOSED 2'CONCRETE PANO1EXISTINGSTORM DRAININLET 2-2INLET 3-6INLET 4-4O2FO2O5STORM DRAIN LINE 4SEE SHEET 16RAIN GARDEN B UNDERDRAINSEE SHEET 17STORM DRAIN LINE 3SEE SHEET 15RAIN GARDEN A UNDERDRAINSEE SHEET 17RAIN GARDEN D UNDERDRAINSEE SHEET 18RAIN GARDEN E UNDERDRAINSEE SHEET 19BUILDING 1BUILDING 3BUILDING 2BUILDING 4BUILDING 5BUILDING 6BUILDING 7BUILDING 8STORM DRAIN LINE 2SEE SHEET 14O7C2C2RAIN GARDEN C UNDERDRAINSEE SHEET 18INLET 3-3FO9O9SheetTHE FLATS AT HANSEN FARM These drawings are instruments of service provided by Northern Engineering Services, Inc. and are not to be used for any type of construction unless signed and sealed by a Professional Engineer in the employ of Northern Engineering Services, Inc.NOT FOR CO N S T R U C T I O N REVIEW SE T of 36NORTH( IN FEET )1 inch = ft.Feet0505050100150CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOUDIG, GRADE, OR EXCAVATE FOR THE MARKING OFUNDERGROUND MEMBER UTILITIES.CALL UTILITY NOTIFICATION CENTER OFCOLORADOKnow what'sbelow.before you dig.CallRC 803DRAINAGE EXHIBIT 36PROPOSED CONTOURPROPOSED STORM SEWERPROPOSED SWALEEXISTING CONTOURPROPOSED CURB & GUTTERPROPERTY BOUNDARYPROPOSED INLETADESIGN POINTFLOW ARROWDRAINAGE BASIN LABELDRAINAGE BASIN BOUNDARYPROPOSED SWALE SECTION11NOTES:1.REFER TO THE FINAL DRAINAGE REPORT FOR THE FLATS AT HANSEN FARM, DATEDMAY 24, 2023 FOR ADDITIONAL INFORMATION.ALEGEND:FOR DRAINAGE REVIEW ONLYNOT FOR CONSTRUCTIONRational Flow Summary | Developed Basin Flow RatesBASINTOTALAREA(acres)Tc2(min)Tc100(min)C2C100Q2(cfs)Q100(cfs)A1.385.05.00.780.983.0713.39B0.585.05.00.690.861.144.98C0.705.05.00.770.961.546.74C11.005.05.00.780.982.239.75D1.2710.79.60.350.440.964.36D10.555.05.00.881.001.395.51D20.495.05.00.841.001.164.84E2.155.15.00.770.964.7220.59E10.235.05.00.851.000.552.27E20.355.85.00.610.760.592.67O10.165.05.00.460.580.200.89O20.316.15.00.790.990.653.04O30.065.05.00.410.510.070.30O40.155.05.00.390.490.160.71O50.065.05.00.630.790.100.46O60.425.05.00.700.880.843.67O70.245.05.00.720.900.502.18O80.115.05.00.730.910.241.03C20.078.37.60.250.310.040.19Combined BasinsEast Side6.1612.412.40.670.848.4736.97West Side4.4111.211.20.750.947.0430.67On-Site LID TreatmentProject SummaryTotal Impervious Area 282,352sfTarget Treatment Percentage84%Minimum Area to be Treated by LID measures 238,554sfRain Garden AreaRain Garden Area 6,337sfRun-on area for Rain Gardens 338,909sfTotal Rain Garden Treatment Area 345,246sfOverall Run-on Ratio for Rain Garden (50:1 Max) 53:1Total Treatment Area238,554sfPercent Total Project Area Treated84.5%p:\1916-001\Dwg\Drng\1916-001_DRNG.dwg, 5/23/2023 6:36:35 AM, 1:1