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Home My WebLink AboutEAST RIDGE THIRD FILING (FORMERLY EAST RIDGE - RESIDENTIAL) - PDP - PDP170006 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTPRELIMINARY DRAINAGE REPORT East Ridge Third Filing Montage Townhomes Fort Collins, Colorado Prepared for: Hartford Homes 4801 Goodman Road Timnath, Colorado 80547 Phone: (970) 674-1109 Prepared by: Galloway & Company, Inc. 3760 East 15th Street, Suite 202 Loveland, Colorado 80538 Phone: (970) 800-3300 Contact: Herman Feissner, PE Original Preparation: February 8th, 2017 1 TABLE OF CONTENTS TABLE OF CONTENTS.......................................................................................................................... 1 I. CERTIFICATIONS .......................................................................................................................... 2 II. GENERAL LOCATION AND DESCRIPTION .................................................................................. 5 III. DRAINAGE BASINS AND SUB-BASINS ........................................................................................ 7 IV. DRAINAGE DESIGN CRITERIA ..................................................................................................... 8 V. DRAINAGE FACILITY DESIGN .................................................................................................... 15 VI. EROSION AND SEDIMENT CONTROL MEASURES ................................................................... 17 VII. CONCLUSIONS ............................................................................................................................ 18 VIII. REFERENCES .............................................................................................................................. 19 APPENDIX A - REFERENCE MATERIALS VICINITY MAP NRCS SOILS MAP FEMA FIRMETTE APPENDIX B - HYDROLOGY CALCULATIONS PROPOSED COMPOSITE RUNOFF COEFFICIENTS PROPOSED STANDARD FORM SF-2 TIME OF CONCENTRATION CALCULATIONS PROPOSED STANDARD FORM SF-3 STORM DRAINAGE SYSTEM DESIGN 2-YEAR STORM EVENT PROPOSED STANDARD FORM SF-3 STORM DRAINAGE SYSTEM DESIGN 100-YEAR STORM EVENT APPENDIX C - HYDRAULIC CALCULATIONS AREA INLET CALCULATIONS STREET CAPACITY CALCULATIONS ALLEY SECTION MINOR AND MAJOR STORM EVENTS SWALE CAPACITY CALCULATIONS – at FINAL DESIGN STORM DRAIN SIZING CALCULATIONS – at FINAL DESIGN APPENDIX D – SUPPORTING DOCUMENTATION DEVELOPED CONDITION DRAINAGE MAP EXCERPTS FROM FINAL DRAINAGE REPORT EAST RIDGE SECOND FILING, DATED: JUNE 30TH, 2016 BY GALLOWAY & COMPANY, INC. 2 I. CERTIFICATIONS CERTIFICATION OF ENGINEER “I hereby certify that this report for the preliminary drainage design of East Ridge Third Filing Montage Townhomes was prepared by me (or under my direct supervision) in accordance with the provisions of the Fort Collins Amendments to the Urban Drainage and Flood Control District Criteria Manual for the owners thereof.” ______________________________________ Herman Feissner, PE Registered Professional Engineer State Of Colorado No. 38066 For and on behalf of Galloway & Company, Inc. CERTIFICATION OF OWNER “Hartford Homes hereby certifies that the drainage facilities for the East Ridge Third Filing Montage Townhomes shall be constructed according to the design presented in this report. We understand that the City of Fort Collins does not and will not assume liability for drainage facilities designed and/or certified by our engineer. We also understand that the City of Fort Collins relies on the representation of others to establish that drainage facilities are designed and constructed in compliance with City of Fort Collins guidelines, standards or specifications. Review by the City of Fort Collins can therefore in no way limit or diminish any liability, which we or any other party may have with respect to the design or construction of such facilities.” ____________________________________ Hartford Homes Attest: ___________________________________ (Name of Responsible Party) __________________________________ Notary Public __________________________________ Authorized Signature AT FINAL DESIGN ` 5 II. GENERAL LOCATION AND DESCRIPTION LOCATION East Ridge Third Filing Montage Townhomes (hereafter referred to as “the site” or “project site”) will be located in the northeast and southwest corners of East Ridge Second Filing (ERSF). The sites are not contiguous but part of the larger ERSF project. The northern the project site is bounded on the north by the Burlington Northern Railroad and East Vine Drive; on the south by Barnstormer Street; on the east by undeveloped land and on the west by an undeveloped portion of ERSF (i.e., basin Fut-G1). The southwest portion of the project site is bounded on the north by Sykes Drive; on the south by an undeveloped portion of ERSF (basin J1); on the east by Vicot Way and on the west by Timberline Road. The larger ERSF project is located in the Northeast Quarter of Section 8, Township 7 North, Range 68 West in the City of Fort Collins, County of Larimer and State of Colorado. Refer to Appendix A for a Vicinity Map showing the larger ERSF project and Montage Townhomes project site. DESCRIPTION OF PROPERTY The project site encompasses several basins delineated in the Final Drainage Report East Ridge Second Filing, dated: June 30th, 2016 by Galloway & Company, Inc. (Report). The north portion of the project site will develop basins Fut-A and Fut-B. These contiguous basins comprise ±9.73 acres and were overlot graded per the approved East Ridge Second Filing grading design. Fut-A drains to a low point and flared end section (FES C9.1) at the north end of Storm Drain C. Fut-B drains to a low point and flared end section (FES D18) at the north end of Storm Drain D. The southwest portion of the project site will develop basins Fut-H, Fut-I1 and Fut-I2. Fut-H and Fut-I1 are contiguous and comprise ±8.74 acres. Fut-H drains to a low point and flared end section (FES B6.2) to the west of Vicot Way. Fut-I1 drains to a low point and flared end section (FES A8) north of Crusader Street. Fut-I2 is located south of Crusader Street and comprises 1.81 acres. It was designed to flow into Storm Drain A south of SDMH A6. Refer to Appendix D for copies of the approved construction documents associated with storm drain and inflow point. ` 6 Each site will develop with an alley-loaded single-family attached product type. Improvements associated with the development include local wet and dry utilities, concrete paving and landscaping. There are no major drainage ways passing through the project site. According to the USDA NRCS Web Soil Survey, ‘Fort Collins loam, 0 to 3 percent slopes’ covers roughly two-thirds of the project site. This soil is associated with Hydrologic Soil Group (HSG) ‘C’. HSG ‘C’ soils have a slow infiltration rate when thoroughly wet, and 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. The remainder of the site consists of a mix of HSG ‘B’ and ‘C’ soils. Refer to Appendixes A and D for additional soils information. CTL | Thompson conducted a geotechnical investigation on May 16th, 2015. The results of the preliminary geotechnical investigation are summarized in Preliminary Geotechnical InvestigationEast Ridge Subdivision Fort Collins, Colorado (Project No. FC06953-115 | Dated: June 19, 2015). The soils encountered across the site “generally consisted of 9½ feet of interlayered clay and sand over relatively clean sands and gravels to the depths explored. No bedrock was encountered.” For reference, Figure 1 – Locations of Exploratory Borings and Figure 2 – Summary Logs of Exploratory Borings are provided in Appendix D, Supporting Documentation. ` 7 III. DRAINAGE BASINS AND SUB-BASINS MAJOR BASIN DESCRIPTION The project site is located in the Cooper Slough/Boxelder drainage basins. According to the City of Fort Collins website (http://www.fcgov.com/utilities/what-we-do/stormwater/drainage-basins/boxelder-creek-cooper- slough), these basins “encompass 265 square miles, beginning north of the Colorado/Wyoming border and extend southward into east Fort Collins, where they end at the Cache la Poudre River. The basins are primarily characterized by farmland with isolated areas of mixed-use residential development and limited commercial development.” The basin hydrology was studied as part of the Boxelder Creek/Cooper Slough watershed by the City of Fort Collins and Larimer County in 1981 and 2002. In addition, a drainage master plan was prepared for the portion of the basin owned by Anheuser-Busch, Inc. in 1984 in conjunction with development of the brewery site. The 2003 update to the City of Fort Collins stormwater master plans adopted improvements for the Lower Cooper Slough Basin and identified the need for the Upper Cooper Slough as an area to be further studied. The project site is shown on FEMA Map Numbers 08069C0982F and 080690982H (refer to Appendix A for FEMA Firmettes). Neither map indicates the project impacted by an existing floodplain/floodway. Refer to Appendix A for a firmette of each larger map. SUB- BASIN DESCRIPTION At the sub-basin level, a ±1.5 acre off-site area along the length of the north property line should have a negligible impact on the developed drainage design. This area spans the length of the north property line and is comprised of native vegetation and coarse aggregate typical of a railroad grade. We do not expect this area to develop in the future. This area is delineated in herein as basins OS1 through OS5. ` 8 IV. DRAINAGE DESIGN CRITERIA REGULATIONS This preliminary drainage design presented herein is prepared in accordance with the Fort Collins Amendments to the Urban Drainage and Flood Control District Criteria Manual (i.e., Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manuals Volumes 1, 2 and 3 [Manual]). Collectively, the requirements are referred to as the Fort Collins Stormwater Criteria Manual [FCSCM]. DIRECTLY CONNECTED IMPERVIOUS AREA (DCIA) The Report included a strategy for implementing ‘The Four-Step Process’ for stormwater quality management. Each step, as it pertains to the project site, is listed below along with a brief narrative describing the implementation strategy. Specific LID and EDB sizing calculations are not provided herein, only a comparison between the volume estimated in the Report and the volume calculated based on the proposed condition presented in this work. The LID Exhibit (refer to Appendix D, sheet DR03) shows the location and type of each stormwater quality strategy, its water surface limits and tributary area. The following table, which is included on the LID Exhibit, summarizes basic information about each stormwater quality strategy. The bold number preceding each strategy keys to its location on the LID Exhibit. This table was resented in the Report and those strategies which do not apply to the development of basins Fut-A, Fut-B, Fut-H, Fut-I1 and Fut-I2 were removed. Stormwater Quality Strategy/Detention Tributary Basins Tributary Area WS Elev. Volume Release Rate acres ac-ft cfs 1 - Bioswale A Basins (Includes: Fut-A) 21.92 N/A N/A N/A 2 - Sand Filter (SF) B, E and F Basins (Includes: Fut-B) 37.46 4933.96 0.75 N/A 4 - Extended Detention Basin (EDB) G and H Basins (Includes: Fut- G, Fut-H and Fut-TL2) 30.61 4931.59 0.94 40-Hour Drain Time 5 - Sand Filter (SF) I Basins (Includes Fut-I1, Fut- I2 and Fut-TL3) 14.28 4930.36 0.33 N/A 7 - Detention Pond | 2-Year Site 153.29 4929.28 2.43 5 7 - Detention Pond | 100-Year Site 153.29 4935.89 35.41 5 ` 9 Step 1 - Employ runoff reduction practices Several different stormwater quality strategies were designed with Step 1 in mind. Developed runoff from the A Basins of ERSF and the west half of the north portion of the project site will flow through a bioswale before entering the on-site detention facility. The UDFCD defines the bioswale as a “densely vegetated drainage way with low-pitched side slopes that collects and slowly conveys runoff. The design of the longitudinal slope and cross-section size forces the flow to be slow and shallow, thereby facilitating sedimentation while limiting erosion”. The proposed grass swale has low longitudinal and side slopes and a wide flat bottom (e.g., 0.25%, 5:1 and 30’, respectively). It is designed to convey 2-year storm event runoff in a slow (i.e., <1 ft/sec) and shallow manner (i.e., normal depth <1 foot). This design encourages settling and infiltration. Developed runoff from the I Basins and future developed runoff from Fut-I1, Fut-I2 and Fut- TL3 (portion of future Timberline Road alignment) will drain into a Sand Filter (SF). The UDFCD defines a Sand Filter as “a stormwater quality BMP consisting of a sand bed and underdrain system. Above the vegetated sand bed is an extended detention basin sized to capture the WQCV. A Sand Filter extended detention basin provides pollutant removal through settling and filtering and is generally suited to off-line, on-site configurations where there is no base flow and the sediment load is relatively low”. During storm events exceeding the water quality event, the sand filters are designed to fill to the design volume and spill excess runoff into the detention pond. The incoming runoff to each will spill through a weir designed to pass the 100-year incoming flows at a flow depth of 0.5’. The downstream face of each spillway will be protected with North American Green (NAG) SC250 Turf Reinforcement Mat (TRM). This is a composite TRM of 70% straw and 30% coconut fiber matrix incorporated into permanent three-dimensional turf reinforcement matting. The spillway and downstream protection are designed for peak 100-year developed runoff entering the sand filter and passing through the respective LID/EDB weir. The downstream spillway slope is exposed because the water surface elevation in the detention pond has not reached the weir elevation. ` 10 The following table presents the EDB/LID volumes associated with each future area defined in the Report and the proposed condition presented here. In summary, less volume is required in each case based on the imperviousness of the proposed condition. Basin Area acres Imperviousness (Report) % Imperviousness Proposed % Volume (Report) ft3 or ac-ft Volume Proposed ft3 Fut A 4.59 88% 55% N/A N/A Fut B 5.14 75% 57% 5034 ft3 3293 ft3 Fut H 4.51 75% 52% 0.135 ac-ft 0.096 ac-ft Fut I1 and Fut I2 6.03 75% 55% 5904 ft3 4345 ft3 Refer to Appendix D for an e-mail summarizing the basis for the LID strategy employed here. This e-mail summarizes a meeting on January 6th, 2017 between Heather McDowell (City of Fort Collins) and Herman Feissner (Galloway & Company, Inc.). Step 2 - Implement BMPs that provide a Water Quality Capture Volume (WQCV) The developed runoff from Fut-H will drain into an Extended Detention Basin (EDB). The UDFCD defines an Extended Detention Basin as “an engineered basin with an outlet structure designed to slowly release urban runoff over an extended time period to provide water quality benefits and control peak flows for frequently occurring storm events. The basins are sometimes called "dry ponds" because they are designed not to have a significant permanent pool of water remaining between storm runoff events. Outlet structures for extended detention basins are sized to control more frequently occurring storm events”. During storm events exceeding the water quality event, the Extended Detention Basins (EDBs) are designed to fill to the design volume and spill excess runoff into the detention pond. The incoming runoff to each will spill through a weir designed to pass the 100-year incoming flows at a flow depth of 0.5’. The downstream face of each spillway will be protected with North American Green (NAG) SC250 Turf Reinforcement Mat (TRM). This is a composite TRM of 70% straw and 30% coconut fiber matrix incorporated into permanent three-dimensional turf reinforcement matting. The spillway and downstream protection are designed for peak 100- year developed runoff entering the EDB and passing through the respective LID/EDB weir. The downstream spillway slope is exposed because the water surface elevation in the detention pond has not reached the weir elevation. ` 11 Step 3 - Stabilize drainageways Planting within the grass swale will stabilize the drainage way and prevent erosion during storm events exceeding the 2-year recurrence level. Additionally, measures will be implemented to protect the Lake Canal receiving outflow from the on-site detention pond. Step 4 - Implement site specific and other source control BMPS Site specific considerations such as material storage and other site operations are addressed in the Stormwater Management Plan (SWMP). DEVELOPMENT CRITERIA REFERENCE AND CONSTRAINTS Nothing at this time. HYDROLOGICAL CRITERIA For urban catchments that are not complex and are generally 160 acres or less in size, it is acceptable that the design storm runoff be analyzed using the Rational Method. The Rational Method is often used when only the peak flow rate or total volume of runoff is needed (e.g., storm sewer sizing or simple detention basin sizing). The Rational Method was used to estimate the peak flow at each design point. Routing calculations (i.e., time attenuation) that aggregate the basins draining to a specific design point are include in the Rational Method calculations in Appendix B. The Rational Method is based on the Rational Formula: Q = CiA Where: Q = the maximum rate of runoff, cfs C = a runoff coefficient that is the ratio between the runoff volume from an area and the average rate of rainfall depth over a given duration for that area i = average intensity of rainfall in inches per hour for a duration equal to the Time of Concentration (Tc) A = area, acres ` 12 The one-hour rainfall Intensity-Duration-Frequency tables for use with the Rational Method of runoff analysis are provided in Table RA-7 and Table RA-8 (refer to Appendix B). The 2-year and 100-year storm events serve as the basis for the drainage system design. The 2-year storm is considered the minor storm event. It has a fifty percent probability of exceedance during any given year. The 100-year storm is considered the major storm event. It has a one percent probability of exceedance during any given year. The 2-year drainage system, at a minimum, must be designed to transport runoff from the 2- year recurrence interval storm event with minimal disruption to the urban environment. The 100-year drainage system, as a minimum, must be designed to convey runoff from the 100- year recurrence interval flood to minimize life hazards and health, damage to structures, and interruption to traffic and services. HYDRAULIC CRITERIA The on-site developed runoff from each tributary area begins its journey to one of the stormwater quality features and, ultimately, the ERSF detention pond as overland flow. It then flows into a swale or street section/private alley. From here, the stormwater combines with runoff in a downstream basin or is intercepted by an area inlet or grated inlet in the vee- shaped alleys. These inlets discharge to existing on-site storm drain systems. Six storm drain systems were designed in ERSF: A, B, C, D, E and G; four of them will receive runoff from the project site: A, D, C and D. Street Capacity Analysis The maximum encroachment for gutter flow in each of the respective street sections and during the minor storm (Q2) event was used to establish the street capacity. The maximum pavement encroachment standards are presented below in Table ST-2. For example, the minor storm flows within local streets cannot overtop the curb (dmax=0.395’ w/Drive-over C&G) or the crown of the street. During the major storm event (Q100), the street capacities were estimated based on the maximum street encroachment standards presented below in Table ST-3. As an example, the depth of water, for local streets, cannot six-(6) inches at the street crown. Street capacity calculations for four-(4) different proposed ½ street sections and a ` 13 range of longitudinal grades are presented in Appendix C. The street capacities presented in ERSF will be re-evaluated at locations where the project site discharges directly to them (e.g., overland flow). · Alley (Local) · Mixed Drive-Over 15’ CL to FL (Local) and Vertical C&G 15’ CL to FL (Local) · Vertical C&G 18’ CL to FL (Local) · Vertical C&G 25’ CL to FL (Collector) Table ST-2 - Pavement Encroachment Standards for the Minor Storm Street Classification Maximum Encroachment Local No curb overtopping. Flow may spread to crown of street. Collector No curb overtopping. Flow spread must leave at least one lane free of water. Table ST-3 - Street Inundation Standards for the Major (i.e., 100-Year) Storm Street Classification Maximum Depth and Inundated Area Local and Collector The depth of water must not exceed the bottom of the gutter at the median to allow operation of emergency vehicles, the depth of water over the gutter flow line shall not exceed twelve-(12) inches, and the flow must be contained within the right-of- way or easements paralleling the right-of-way. The most restrictive of the three criteria shall govern. Table ST-4 – Allowable Cross-Street Flow Street Classification Initial Storm Flow Major (100-Year) Storm Flow Local 6 inches of depth in cross pan. 18 inches of depth above gutter flow line. Collector Where cross pans allowed, depth of flow should not exceed 6 inches. 12 inches of depth above gutter flow line. The minor storm event street capacity calculations were estimated with the Modified Manning Equation and Excel and Bentley FlowMaster. The major storm event street capacity calculations were completed using Bentley FlowMaster. Refer to Appendix C for the alley and street capacity calculations. ` 14 Inlet Capacity Analysis Neenah R-3362-L CDOT inlets are proposed throughout the project site within the alleys. In the landscaped areas, an ADS Nyloplast product will likely be used. Appendix C includes a preliminary capacity calculation for three Neenah R-3362-L inlet grates. This is an approximate condition used to determine the feasibility of the proposed inlet type and grading design. The allowable ponding depth will vary between 0.30 feet and 0.50 feet. At final design, an inlet capacity calculation that considers the local fine grading and ponding depth limits will be provided for each inlet. Storm Drain Capacity Analysis The storm drain system hydraulic analysis presented in the Report was completed using Bentley StormCAD V8i. This software routes flows based on the tc corresponding intensity (i.e., i2 and i100) and CA at each junction. The original model will be extended to include the project site. Each area set aside for future development was included in the StormCAD model and modeled using reasonable but mildly conservative estimates for time of concentration (tc) and runoff coefficient (C). The proposed conditions compare favorably with the estimates presented in the Report. For example, Fut-A drains into Storm Drain B. The basin was modeled in the report assuming a future C100 of 1.00; the proposed C100 is ±0.76. ` 15 V. DRAINAGE FACILITY DESIGN GENERAL CONCEPT This preliminary design presents an overview of the design for a system to collect and convey developed runoff from the project site to infrastructure designed and constructed with East Ridge Second Filing (ERSF). This infrastructure includes several EDB/LID stormwater quality features receiving runoff from the water quality storm event. During larger storm events, these features fill and spill into a detention pond in the south central region of the project site. SPECIFIC DETAILS K Basins These basins generally overlay Fut-A. The proposed development is consistent with the assumptions presented in the Report. The developed runoff will be collected in a local storm drain system that will be connected to Storm Drain C. Refer to sheet DR01. L Basins These basins generally overlay Fut-B. The proposed development is consistent with the assumptions presented in the Report. The developed runoff will be collected in a local storm drain system that will be connected to Storm Drain D. Refer to sheet DR01. M Basins These basins generally overlay the periphery of Fut-H and Fut-I1. Basin M3 will likely flow to the Sykes Drive right-of-way. Preliminary adjustments to the hydraulic modeling in the Report indicate this is feasible. We will explore this in detail during final design. Part of all of basin M4 will drain into the local storm drain system that will connect to existing Storm Drain B. The specifics will be determined at a later date when the building finished floor elevations are finalized (i.e., internal steps between the main living area and the garage vs. the same elevation in both spaces). The finished floor elevations drive finished site grading design. Basin M5 is similar to basin M4 except that it drains to Storm Drain A. Basin M1, M2, M6, M7 and M8 all drain to the adjacent right-of-way. As with basin M3, we will explore the impacts of the additional runoff on the adjacent street section during final design. ` 16 N Basins These basins generally overlay basin Fut-H. The proposed development is consistent with the assumptions presented in the Report. The developed runoff will be collected in a local storm drain system that will be connected to Storm Drain B. Refer to sheet DR02. O Basins These basins generally overlay basins Fut-I1 and Fut-I2. The proposed development is consistent with the assumption presented in the Report. The developed runoff will be collected in a local storm drain system that will be connected to Storm Drain A. Refer to sheet DR02. OS Basins These basins are located north of the K and L basins. These comprise a narrow off-site area along the north property boundary which was described in the Report. ` 17 VI. EROSION AND SEDIMENT CONTROL MEASURES A General Permit for Stormwater Discharge Associated with Construction Activities issued by the Colorado Department of Public Health and Environment (CDPHE), Water Quality Control Division (WQCD), will be acquired for the site. A Stormwater Management Plan (SWMP) will be prepared at final design and presented under separate cover. It will identify the Best Management Practices (BMPs) which, when implemented, will meet the requirements of the General Permit. ` 18 VII. CONCLUSIONS COMPLIANCE WITH STANDARDS The design presented in this preliminary drainage report for East Ridge Third Filing Montage Townhomes has been prepared in accordance with the design standards and guidelines presented in the Fort Collins Stormwater Criteria Manual. VARIANCES No variances are being requested with the proposed improvements described herein. DRAINAGE CONCEPT The proposed East Ridge Third Filing Montage Townhomes storm drainage improvements should provide adequate protection for the developed site. The proposed drainage design for the site should not negatively impact the existing downstream storm drainage system. ` 19 VII. REFERENCES 1. Fort Collins Stormwater Criteria Manual (Addendum to the Urban Storm Drainage Criteria Manuals Volumes 1, 2 and 3), prepared by City of Fort Collins. 2. Urban Drainage and Flood Control District, Drainage Criteria Manual Volumes 1 and 2, prepared by Wright-McLaughlin Engineers, dated June 2001 (revised April 2008), and the Volume 3, prepared by Wright-McLaughlin Engineers, dated September 1992 and revised November 2010. 3. Final Drainage Report East Ridge Second Filing, dated June 30th, 2016 by Galloway & Company, Inc. ` APPENDIX A REFERENCE MATERIAL ` VICINITY MAP ` NRCS SOILS MAP Hydrologic Soil Group—Larimer County Area, Colorado (East Ridge Subdivision) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/24/2015 Page 1 of 4 4492900 4493000 4493100 4493200 4493300 4493400 4493500 4493600 4493700 4493800 4493900 4494000 4494100 4492900 4493000 4493100 4493200 4493300 4493400 4493500 4493600 4493700 4493800 4493900 4494000 4494100 497500 497600 497700 497800 497900 498000 498100 498200 498300 497500 497600 497700 497800 497900 498000 498100 498200 498300 40° 35' 52'' N 105° 1' 49'' W 40° 35' 52'' N 105° 1' 8'' W 40° 35' 10'' N 105° 1' 49'' W 40° 35' 10'' N 105° 1' 8'' W N 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: 1:6,220 if printed on A portrait (8.5" x 11") sheet. 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: http://websoilsurvey.nrcs.usda.gov 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 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 11.7 6.4% 7 Ascalon sandy loam, 0 to 3 percent slopes B 5.8 3.2% 34 Fort Collins loam, 0 to 1 percent slopes B 6.0 3.3% 35 Fort Collins loam, 0 to 3 percent slopes C 109.7 60.3% 42 Gravel pits A 10.8 5.9% 53 Kim loam, 1 to 3 percent slopes B 17.2 9.5% 73 Nunn clay loam, 0 to 1 percent slopes C 6.8 3.7% 74 Nunn clay loam, 1 to 3 percent slopes C 6.4 3.5% 94 Satanta loam, 0 to 1 percent slopes B 0.1 0.0% 102 Stoneham loam, 3 to 5 percent slopes B 7.3 4.0% Totals for Area of Interest 181.8 100.0% Hydrologic Soil Group—Larimer County Area, Colorado East Ridge Subdivision Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/24/2015 Page 3 of 4 Description 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. 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. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher Hydrologic Soil Group—Larimer County Area, Colorado East Ridge Subdivision Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/24/2015 Page 4 of 4 ` FEMA FIRMETTE ` APPENDIX B HYDROLOGY CALCULATIONS ` PROPOSED COMPOSITE RUNOFF COEFFICIENTS 41 Table RO-11 Rational Method Runoff Coefficients for Composite Analysis Character of Surface Runoff Coefficient Streets, Parking Lots, Drives: Asphalt 0.95 Concrete 0.95 Gravel 0.5 Roofs 0.95 Recycled Asphalt 0.8 Lawns, Sandy Soil: Flat <2% 0.1 Average 2 to 7% 0.15 Steep >7% 0.2 Lawns, Heavy Soil: Flat <2% 0.2 Average 2 to 7% 0.25 Steep >7% 0.35 (4) A new Section 2.9 is added, to read as follows: 2.9 Composite Runoff Coefficient Drainage sub-basins are frequently composed of land that has multiple surfaces or zoning classifications. In such cases a composite runoff coefficient must be calculated for any given drainage sub-basin. The composite runoff coefficient is obtained using the following formula: ( ) t n i i i A C A C ∑ = = 1 * (RO-8) Where: C = Composite Runoff Coefficient Ci = Runoff Coefficient for Specific Area (Ai) Ai = Area of Surface with Runoff Coefficient of Ci, acres or feet2 n = Number of different surfaces to be considered At = Total Area over which C is applicable, acres or feet2 (5) A new Section 2.10 is added, to read as follows: 42 2.10 Runoff Coefficient Adjustment for Infrequent Storms The runoff coefficients provided in tables RO-10 and RO-11 are appropriate for use with the 2-year storm event. For storms with higher intensities, an adjustment of the runoff coefficient is required due to the lessening amount of infiltration, depression retention, evapo-transpiration and other losses that have a proportionally smaller effect on storm runoff. This adjustment is applied to the composite runoff coefficient. These frequency adjustment factors are found in Table RO-12. Table RO-12 Rational Method Runoff Coefficients for Composite Analysis Storm Return Period (years) Frequency Factor Cf 2 to 10 11 to 25 26 to 50 51 to 100 1.00 1.10 1.20 1.25 Note: The product of C times Cf cannot exceed the value of 1, in the cases where it does a value of 1 must be used (6) Section 3.1 is deleted in its entirety. (7) Section 3.2 is deleted in its entirety. (8) Section 3.3 is deleted in its entirety. (9) A new Section 4.3 is added, to read as follows: 4.3 Computer Modeling Practices (a) For circumstances requiring computer modeling, the design storm hydrographs must be determined using the Stormwater Management Model (SWMM). Basin and conveyance element parameters must be computed based on the physical characteristics of the site. (b) Refer to the SWMM Users’ Manual for appropriate modeling methodology, practices and development. The Users’ Manual can be found on the Environmental Protection Agency (EPA) website (http://www.epa.gov/ednnrmrl/models/swmm/index.htm). (c) It is the responsibility of the design engineer to verify that all of the models used in the design meet all current City criteria and regulations. 4.3.1 Surface Storage, Resistance Factors, and Infiltration Table RO-13 provides values for surface storage for pervious and impervious surfaces and the infiltration rates to be used with SWMM. Table RO-13 also lists the appropriate infiltration decay rate, zero detention depth and resistance factors, or Manning’s “n” values, for pervious and impervious surfaces to be used for SWMM modeling in the city of Fort Collins. Subdivision: East Ridge Third Filing Project Name: Montage Townhomes Location: CO, Fort Collins Project No.: Calculated By: H. Feissner Checked By: J. Prelog INPUT User Input Date: 2/6/17 INPUT User Input Single-Family Alley-Loaded SF Duplex/AttachedMulti-Family Townhome Roof 95% 5% 62.5% 70% 75% 80% 100% K1 1.13 95 0.08 7 20 0.84 15 100 0.21 19 0.40 K2 0.86 95 0.08 8 20 0.61 14 100 0.17 20 0.42 K3 0.77 95 0.29 35 20 0.14 4 100 0.34 44 0.83 K4 0.97 95 0.31 31 20 0.23 5 100 0.43 44 0.80 K5 0.77 95 0.10 13 20 0.29 7 100 0.38 50 0.70 ΣK 4.50 L1 1.21 95 0.38 30 20 0.40 7 100 0.43 35 0.72 L2 0.80 95 0.08 9 20 0.51 13 100 0.21 27 0.49 L3 1.16 95 0.11 9 20 0.80 14 100 0.25 22 0.45 L4 1.12 95 0.40 34 20 0.20 4 100 0.52 46 0.84 L5 0.95 95 0.09 10 20 0.39 8 100 0.47 49 0.67 ΣL 5.23 M1 0.18 95 0.05 27 20 0.11 12 100 0.02 9 0.49 M2 0.02 95 0.00 0 20 0.02 20 100 0.00 0 0.20 M3 0.43 95 0.07 15 20 0.18 8 100 0.18 43 0.66 M4 0.57 95 0.08 13 20 0.31 11 100 0.18 32 0.56 M5 1.15 95 0.20 16 20 0.60 10 100 0.36 31 0.58 M6 0.21 95 0.02 11 20 0.11 10 100 0.08 37 0.59 M7 0.06 95 0.02 26 20 0.05 15 100 0.00 0 0.40 M8 0.12 95 0.02 16 20 0.08 13 100 0.02 17 0.47 ΣM 2.76 N1 0.85 95 0.29 33 20 0.26 6 100 0.30 35 0.74 N2 1.59 95 0.13 8 20 1.12 14 100 0.34 21 0.43 N3 0.63 95 0.20 30 20 0.12 4 100 0.31 50 0.84 ΣN 3.07 O1 0.72 95 0.23 31 20 0.17 5 100 0.31 43 0.79 O2 0.98 95 0.11 10 20 0.65 13 100 0.22 23 0.46 O3 1.11 95 0.42 36 20 0.29 5 100 0.40 36 0.77 O4 0.16 95 0.01 6 20 0.07 9 100 0.08 50 0.65 O5 0.09 95 0.01 5 20 0.04 8 100 0.05 54 0.67 O6 1.18 95 0.32 26 20 0.61 10 100 0.24 21 0.57 O7 0.30 95 0.02 7 20 0.14 9 100 0.14 45 0.62 O8 0.08 95 0.00 3 20 0.08 19 100 0.00 0 0.22 ΣO 4.53 Area Weighted Basin ID Total Area (ac) Runoff C2 Coefficient Area (ac) Townhomes (i.e., roof area) Runoff Coefficient COMPOSITE RUNOFF COEFFICIENTS Area (ac) Area Weighted Asphalt + Concrete Walks Lawns, Heavy Soil: Flat <2% Area Weighted Runoff Coefficient Area (ac) HFHLV0001.02 H:\Hartford Homes\CO, Timnath - HFHLV0001.02_Timberline Vine Multi-Family\3.04 Grading-Drainage Studies\3.04.2 Proposed Drainage Reports-Info\Hydrology\Rational\HFHLV01.02_ERSF Rational.xls Page 1 of 2 2/6/2017 95% 5% 62.5% 70% 75% 80% 100% Area Weighted Basin ID Total Area (ac) Runoff C2 Coefficient Area (ac) Townhomes (i.e., roof area) Runoff Coefficient Area (ac) Area Weighted Asphalt + Concrete Walks Lawns, Heavy Soil: Flat <2% Area Weighted Runoff Coefficient Area (ac) OS1 0.54 95 0.10 18 20 0.43 16 100 0.00 0 0.34 OS2 0.21 95 0.00 0 20 0.21 20 100 0.00 0 0.20 OS3 0.27 95 0.00 0 20 0.27 20 100 0.00 0 0.20 OS4 0.40 95 0.00 0 20 0.40 20 100 0.00 0 0.20 OS5 0.38 95 0.00 0 20 0.38 20 100 0.00 0 0.20 ΣOS H:\Hartford Homes\CO, Timnath - HFHLV0001.02_Timberline Vine Multi-Family\3.04 Grading-Drainage Studies\3.04.2 Proposed Drainage Reports-Info\Hydrology\Rational\HFHLV01.02_ERSF Rational.xls Page 2 of 2 2/6/2017 ` PROPOSED STANDARD FORM SF-2 TIME OF CONCENTRATION CALCULATIONS Subdivision: East Ridge Third Filing Project Name: Montage Townhomes Location: CO, Fort Collins Project No.: Calculated By: H. Feissner Checked By: J. Prelog Date: 2/6/17 1 2 3 4 5 6 7 8 9 10 13 15 16 17 18 19 20 21 22 23 24 BASIN D.A. Hydrologic C2 C5 C100 L S Ti | 2-Year Ti | 100-Year L S Cv VEL. Tt COMP. Tc | 2-Year COMP. Tc | 100-Year TOTAL Urbanized Tc Tc | 2-Year Tc | 100-Year ID (AC) Soils Group Cf=1.00 Cf=1.00 Cf=1.25 (FT) (%) (MIN) (MIN) (FT) (%) (FPS) (MIN) (MIN) (MIN) LENGTH(FT) (MIN) (MIN) (MIN) K1 1.13 C 0.40 0.40 0.51 39 10.00 3.8 3.2 240 1.00 15 1.5 2.7 6.4 5.9 279 11.6 6.4 5.9 K2 0.86 C 0.42 0.42 0.53 40 3.00 5.5 4.7 279 1.00 15 1.5 3.1 8.6 7.8 319 11.8 8.6 7.8 K3 0.77 C 0.83 0.83 1.00 48 2.00 2.7 1.0 277 0.70 20 1.7 2.8 5.5 3.8 325 11.8 5.5 5.0 K4 0.97 C 0.80 0.80 1.00 48 2.00 3.1 1.1 226 0.50 20 1.4 2.7 5.8 3.7 274 11.5 5.8 5.0 K5 0.77 C 0.70 0.70 0.87 40 2.00 3.8 2.2 0 0.00 20 0.0 0.0 3.8 2.2 40 10.2 5.0 5.0 L1 1.21 C 0.72 0.72 0.90 89 2.30 5.1 2.7 412 0.90 20 1.9 3.6 8.7 6.3 501 12.8 8.7 6.3 L2 0.80 C 0.49 0.49 0.61 20 24.00 1.8 1.4 321 1.00 15 1.5 3.6 5.4 5.0 341 11.9 5.4 5.0 L3 1.16 C 0.45 0.45 0.56 28 3.00 4.5 3.7 288 1.00 15 1.5 3.2 7.7 6.9 316 11.8 7.7 6.9 L4 1.12 C 0.84 0.84 1.00 48 2.00 2.7 1.0 275 0.62 20 1.6 2.9 5.6 3.9 323 11.8 5.6 5.0 L5 0.95 C 0.67 0.67 0.84 40 2.00 4.0 2.5 0 0.00 15 0.0 0.0 4.0 2.5 40 10.2 5.0 5.0 M1 0.18 C 0.49 0.49 0.61 56 2.00 6.8 5.5 47 1.65 20 2.6 0.3 7.1 5.8 103 10.6 7.1 5.8 M2 0.02 C 0.20 0.20 0.25 26 2.00 6.8 6.4 0 0.00 15 0.0 0.0 6.8 6.4 26 10.1 6.8 6.4 M3 0.43 C 0.66 0.66 0.83 50 3.30 3.9 2.4 0 0.00 15 0.0 0.0 3.9 2.4 50 10.3 5.0 5.0 M4 0.57 C 0.56 0.56 0.70 73 2.00 6.9 5.1 0 0.00 15 0.0 0.0 6.9 5.1 73 10.4 6.9 5.1 M5 1.15 C 0.58 0.58 0.72 66 20.00 2.9 2.1 0 0.00 15 0.0 0.0 2.9 2.1 66 10.4 5.0 5.0 M6 0.21 C 0.59 0.59 0.73 74 2.00 6.5 4.7 0 0.00 15 0.0 0.0 6.5 4.7 74 10.4 6.5 5.0 M7 0.06 C 0.40 0.40 0.51 23 10.00 2.9 2.5 0 0.00 15 0.0 0.0 2.9 2.5 23 10.1 5.0 5.0 M8 0.12 C 0.47 0.47 0.59 40 2.00 5.9 4.8 0 0.00 15 0.0 0.0 5.9 4.8 40 10.2 5.9 5.0 N1 0.85 C 0.74 0.74 0.92 63 2.00 4.2 2.1 190 0.75 20 1.7 1.8 6.1 3.9 253 11.4 6.1 5.0 N2 1.59 C 0.43 0.43 0.54 78 2.00 8.8 7.4 179 1.00 15 1.5 2.0 10.8 9.3 257 11.4 10.8 9.3 N3 0.63 C 0.84 0.84 1.00 56 2.00 2.9 1.1 123 0.75 20 1.7 1.2 4.1 2.3 179 11.0 5.0 5.0 O1 0.72 C 0.79 0.79 0.99 46 2.00 3.1 1.1 229 0.75 20 1.7 2.2 5.3 3.3 275 11.5 5.3 5.0 O2 0.98 C 0.46 0.46 0.58 101 2.00 9.5 7.8 279 0.95 15 1.5 3.2 12.7 11.0 380 12.1 12.1 11.0 O3 1.11 C 0.77 0.77 0.97 57 2.00 3.6 1.5 315 0.75 20 1.7 3.0 6.7 4.5 372 12.1 6.7 5.0 O4 0.16 C 0.65 0.65 0.81 63 2.00 5.3 3.4 0 0.00 15 0.0 0.0 5.3 3.4 63 10.4 5.3 5.0 O5 0.09 C 0.67 0.67 0.84 64 2.00 5.1 3.1 0 0.00 15 0.0 0.0 5.1 3.1 64 10.4 5.1 5.0 O6 1.18 C 0.57 0.57 0.71 57 2.00 5.9 4.3 372 0.75 20 1.7 3.6 9.5 7.9 429 12.4 9.5 7.9 O7 0.30 C 0.62 0.62 0.77 64 2.00 5.7 3.9 0 0.00 0 0.0 0.0 5.7 3.9 64 10.4 5.7 5.0 O8 0.08 C 0.22 0.22 0.28 53 7.80 6.0 5.6 0 0.00 0 0.0 0.0 6.0 5.6 53 10.3 6.0 5.6 OS1 0.54 C 0.34 0.34 0.43 23 4.80 4.0 3.6 360 1.50 5 0.6 9.8 13.8 13.4 383 12.1 12.1 12.1 OS2 0.21 C 0.20 0.20 0.25 22 40.00 2.3 2.2 0 0.00 5 0.0 0.0 2.3 2.2 22 10.1 5.0 5.0 OS3 0.27 C 0.20 0.20 0.25 32 37.00 2.9 2.7 0 0.00 5 0.0 0.0 2.9 2.7 32 10.2 5.0 5.0 OS4 0.40 C 0.20 0.20 0.25 33 22.00 3.5 3.3 0 0.00 5 0.0 0.0 3.5 3.3 33 10.2 5.0 5.0 OS5 0.38 C 0.20 0.20 0.25 35 18.00 3.8 3.6 0 0.00 5 0.0 0.0 3.8 3.6 35 10.2 5.0 5.0 NOTES: Ti = (1.87*(1.1 - CCf)*(L)^0.5)/((S)^0.33), S in % Cv Tt=L/60V (Velocity From Fig. 501) 2.5 Velocity V=Cv*S^0.5, S in ft/ft 5 Tc Check = 10+L/180 7 For Urbanized basins a minimum Tc of 5.0 minutes is required. 10 For non-urbanized basins a minimum Tc of 10.0 minutes is required 15 20 STANDARD FORM SF-2 TIME OF CONCENTRATION SUB-BASIN Tc CHECK HFHLV0001.02 DATA (Tt) (URBANIZED BASINS) INITIAL/OVERLAND FINAL (Ti) TRAVEL TIME Paved areas and shallow paved swales Type of Land Surface ` PROPOSED STANDARD FORM SF-3 STORM DRAINAGE SYSTEM DESIGN 2-YEAR STORM EVENT 36 RAINFALL INTENSITY-DURATION-FREQUENCY CURVE 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 0.00 10.00 20.00 30.00 40.00 50.00 60.00 STORM DURATION (minutes) RAINFALL INTENSITY (inches/hour) 2-Year Storm 10-Year Storm 100-Year Storm Figure RA-16 City of Fort Collins Rainfall Intensity-Duration-Frequency Curves (13) Section 5.0 is deleted in its entirety. (14) Section 6.0 is deleted in its entirety. (15) Section 7.0 is deleted in its entirety. (16) Section 7.1 is deleted in its entirety. (17) Section 7.2 is deleted in its entirety. (18) Section 7.3 is deleted in its entirety. (19) Section 8.0 is deleted in its entirety. (20) Table RA-1 is deleted in its entirety. Project Name: Montage Townhomes Subdivision: East Ridge Third Filing Project No.: HFHLV0001.02 Location: CO, Fort Collins Calculated By: H. Feissner Design Storm: Checked By: J. Prelog Date: TRAVEL TIME STREET Design Point Basin ID Area (Ac) Runoff Coeff. | C 2 Tc | 2-Year (min) C*A (Ac) I (in/hr) Q (cfs) Tc (min) C*A (Ac) I (in/hr) Q (cfs) Slope (%) Street Flow (cfs) Design Flow (cfs) Slope (%) Pipe Size (inches) Length (ft) Velocity (fps) Tt (min) REMARKS K1 K1 1.13 0.40 6.4 0.46 2.65 1.2 K2 K2 0.86 0.42 8.6 0.36 2.39 0.9 K3 K3 0.77 0.83 5.5 0.64 2.78 1.8 K4 K4 0.97 0.80 5.8 0.77 2.74 2.1 K5 K5 0.77 0.70 5.0 0.54 2.86 1.5 L1 L1 1.21 0.72 8.7 0.87 2.39 2.1 L2 L2 0.80 0.49 5.4 0.39 2.81 1.1 L3 L3 1.16 0.45 7.7 0.52 2.50 1.3 L4 L4 1.12 0.84 5.6 0.94 2.77 2.6 L5 L5 0.95 0.67 5.0 0.63 2.86 1.8 M1 M1 0.18 0.49 7.1 0.09 2.57 0.2 M2 M2 0.02 0.20 6.8 0.00 2.60 0.0 M3 M3 0.43 0.66 5.0 0.29 2.86 0.8 M4 M4 0.57 0.56 6.9 0.32 2.60 0.8 M5 M5 1.15 0.58 5.0 0.67 2.86 1.9 M6 M6 0.21 0.59 6.5 0.12 2.64 0.3 M7 M7 0.06 0.40 5.0 0.03 2.86 0.1 M8 M8 0.12 0.47 5.9 0.06 2.72 0.2 N1 N1 0.85 0.74 6.1 0.63 2.70 1.7 N2 N2 1.59 0.43 10.8 0.68 2.19 1.5 N3 N3 0.63 0.84 5.0 0.53 2.86 1.5 O1 O1 0.72 0.79 5.3 0.57 2.81 1.6 O2 O2 0.98 0.46 12.1 0.45 2.08 0.9 O3 O3 1.11 0.77 6.7 0.86 2.62 2.3 O4 O4 0.16 0.65 5.3 0.10 2.81 0.3 O5 O5 0.09 0.67 5.1 0.06 2.85 0.2 O6 O6 1.18 0.57 9.5 0.67 2.30 1.5 O7 O7 0.30 0.62 5.7 0.18 2.75 0.5 OS1 OS1 0.54 0.34 12.1 0.18 2.08 0.4 OS2 OS2 0.21 0.20 5.0 0.04 2.86 0.1 OS3 OS3 0.27 0.20 5.0 0.05 2.86 0.2 OS4 OS4 0.40 0.20 5.0 0.08 2.86 0.2 ` PROPOSED STANDARD FORM SF-3 STORM DRAINAGE SYSTEM DESIGN 100-YEAR STORM EVENT STANDARD FORM SF-3 STORM DRAINAGE SYSTEM DESIGN (RATIONAL METHOD PROCEDURE) Project Name: Montage Townhomes Subdivision: East Ridge Third Filing Project No.: HFHLV0001.02 Location: CO, Fort Collins Calculated By: H. Feissner Design Storm: Checked By: J. Prelog Date: TRAVEL TIME STREET Design Point Basin ID Area (Ac) Runoff Coeff. | C 100 Tc | 100-Year (min) C*A (Ac) I (in/hr) Q (cfs) Tc (min) C*A (Ac) I (in/hr) Q (cfs) Slope (%) Street Flow (cfs) Design Flow (cfs) Slope (%) Pipe Size (inches) Length (ft) Velocity (fps) Tt (min) REMARKS K1 K1 1.13 0.51 5.9 0.57 9.52 5.5 K2 K2 0.86 0.53 7.8 0.45 8.68 3.9 K3 K3 0.77 1.00 5.0 0.77 9.98 7.7 K4 K4 0.97 1.00 5.0 0.96 9.98 9.6 K5 K5 0.77 0.87 5.0 0.67 9.98 6.7 0.76 L1 L1 1.21 0.90 6.3 1.09 9.32 10.1 L2 L2 0.80 0.61 5.0 0.48 9.98 4.8 L3 L3 1.16 0.56 6.9 0.65 9.03 5.8 L4 L4 1.12 1.00 5.0 1.12 9.98 11.2 L5 L5 0.95 0.84 5.0 0.79 9.98 7.9 0.79 M1 M1 0.18 0.61 5.8 0.11 9.58 1.1 M2 M2 0.02 0.25 6.4 0.01 9.26 0.05 M3 M3 0.43 0.83 5.0 0.36 9.98 3.6 M4 M4 0.57 0.70 5.1 0.40 9.93 4.0 M5 M5 1.15 0.72 5.0 0.83 9.98 8.3 M6 M6 0.21 0.73 5.0 0.15 9.98 1.5 M7 M7 0.06 0.51 5.0 0.03 9.98 0.3 M8 M8 0.12 0.59 5.0 0.07 9.98 0.7 0.71 N1 N1 0.85 0.92 5.0 0.78 9.98 7.8 N2 N2 1.59 0.54 9.3 0.85 8.09 6.9 N3 N3 0.63 1.00 5.0 0.63 9.98 6.3 0.74 O1 O1 0.72 0.99 5.0 0.71 9.98 7.1 O2 O2 0.98 0.58 11.0 0.57 7.58 4.3 O3 O3 1.11 0.97 5.0 1.08 9.98 10.8 O4 O4 0.16 0.81 5.0 0.13 9.98 1.3 ` APPENDIX C HYDRAULIC CALCULATIONS ` AREA INLET CALCULATIONS 186 3 COMBINATION INLETS g Note: When specifying/ordering grates, refer to “Choosing the Proper Inlet Grate” on pages 125-126. For a complete listing of FREE OPEN AREAS and WEIR PERIMETERS of all NEENAH grates, refer to pages 327-332. R-3362-L Concave Gutter Inlet Frame, Grate Heavy Duty Can be furnished as double unit with side flanges removed as shown in R-3363-1. R-3363-1 Double Unit Inlet Frame, Grate, Curb Box Light Duty Standard Grate (shown): Type C Type L grate available. R-3382 Concave Gutter Inlet Frame, Grate Heavy Duty R-3381 Concave Gutter Inlet Frame, Grate Heavy Duty WEIR SQ. PERIMETER CATALOG GRATE FT. LINEAL NUMBER TYPE OPEN FEET R-3362-L L 2.9 10.3 WEIR SQ. PERIMETER CATALOG GRATE FT. LINEAL NUMBER TYPE OPEN FEET R-3363-1 C 4.6 10.3 R-3363-1 L 5.8 10.3 WEIR SQ. PERIMETER CATALOG GRATE FT. LINEAL NUMBER TYPE OPEN FEET R-3381 A 1.0 6.8 WEIR SQ. PERIMETER CATALOG GRATE FT. LINEAL NUMBER TYPE OPEN FEET R-3382 C 2.3 10.4 CLICK HERE to return to the Table of Contents Location: General Grate: Neenah R-3362-L Number of Grates: 3 Length: 9.47 ft 113.63 in Width: 1.75 ft 21.00 in Number of Sides: 4 Grate Area: 16.57 sq ft Open Area Ratio: 0.53 Open Area: 8.71 sq ft Clogging factor: 50% n: 26% Weir Length, L 22.44 ft Open Area, A 16.57 sq ft Stage, Dd 0.05 ft Weir Calculation: Orifice Calculation: Qw = nCwLH3/2 Qo =nC0BL(2gH) 1/2 Cw 3.00 C0 0.64 Water Depth, d Elevation QW-INLET QO-INLET Inflow ft ft cfs cfs cfs 0.00 5000.00 0.00 0.00 0.00 0.05 5000.05 0.35 5.00 0.35 0.10 5000.10 0.99 7.07 0.99 0.15 5000.15 1.81 8.66 1.81 0.20 5000.20 2.79 10.00 2.79 0.25 5000.25 3.90 11.18 3.90 0.30 5000.30 5.12 12.24 5.12 0.35 5000.35 6.45 13.23 6.45 0.40 5000.40 7.88 14.14 7.88 0.45 5000.45 9.41 15.00 9.41 0.50 5000.50 11.02 15.81 11.02 0.55 5000.55 12.71 16.58 12.71 0.60 5000.60 14.48 17.32 14.48 0.65 5000.65 16.33 18.02 16.33 0.70 5000.70 18.25 18.70 18.25 0.75 5000.75 20.24 19.36 19.36 Catalog Dimensions 0.0 5.0 10.0 15.0 20.0 25.0 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 Inlet Capacity, cfs Depth of Flow, ft Series1 Series2 Series3 ` STREET CAPACITY CALCULATIONS ` ALLEY SECTION MINOR AND MAJOR STORM EVENTS Project: Montage Townhomes Calculations By: H. Feissner Date: 2/7/2017 2-year 100-year Depth 99.81 Top of Curb Depth 99.91 @Easement Line Street Name Determination Determination K3 Private Alley 10.00 Private Alley 1.8 7.7 0.70% 3.9 1.00 3.9 Okay 9.0 1.00 9.0 Okay K4 Private Alley 10.00 Private Alley 2.1 9.6 0.45% 3.2 1.00 3.2 Okay 7.3 1.00 7.3 Problem L1 Private Alley 10.00 Private Alley 2.1 10.1 0.85% 4.3 1.00 4.3 Okay 10.0 1.00 10.0 Problem L4 Private Alley 10.00 Private Alley 2.6 11.1 0.65% 3.8 1.00 3.8 Okay 8.7 0.98 8.5 Problem N1 Private Alley 10.00 Private Alley 1.7 7.8 0.75% 4.1 1.00 4.1 Okay 9.4 1.00 9.4 Okay N3 Private Alley 10.00 Private Alley 1.5 6.3 0.75% 4.1 1.00 4.1 Okay 9.4 1.00 9.4 Okay O1 Private Alley 10.00 Private Alley 1.6 7.1 0.75% 4.1 1.00 4.1 Okay 9.4 1.00 9.4 Okay O3 Private Alley 10.00 Private Alley 2.3 10.8 0.75% 4.1 1.00 4.1 Okay 9.4 0.92 8.6 Problem O6 Private Alley 10.00 Private Alley 1.5 7.3 0.60% 3.6 1.00 3.6 Okay 8.4 0.98 8.2 Okay Notes: 1. DP K4: Capacity is Okay because flows approach inlet from the east (60%) and west (40%). 2. DP L1: Capacity is very close (i.e., available capacity is 0.1 cfs less than estimated Q100). 3. DP L4: Capacity is Okay because flows approach inlet from the east (50%) and west (50%). 4. DP O3: Capacity is Okay because flows approach inlet from the north, south and east. Street Capacity Calculations Drive-Over Curb & Gutter - ALLEY w/Vee Sectioin Minor Storm Event Major Storm Event Major Storm Reduction Factor (UDFCD Figure 7-4) Allowable Capacity cfs Developed Q100 cfs Design Point Width FL to BOC ft Street Classification Developed Q2 cfs Longitudinal Grade, S0 % Calculated Capacity (FlowMaster)1 cfs Minor Storm Reduction Factor (UDFCD Figure 7-4) Allowable Capacity cfs Calculated Capacity (FlowMaster)1 cfs In several cases noted to the left, the 'Determination' column shows Problem. However, in several basins the alley section approaches the design point from more than one direction. In this case, the developed runoff should be divided proportionally (assuming the composition is similar) to determine if sufficient capacity exists. For example, Q100 is estimated at 12 cfs and two alleys (S=0.45%) each capture 50% of the basin; therefore, Q100 in each alley is 6 cfs and within the capacity limits. Project Description Friction Method Manning Formula Solve For Discharge Input Data Channel Slope 0.0075 ft/ft Normal Depth 0.27 ft Section Definitions Station (ft) Elevation (ft) 0+00.00 100.00 0+07.50 99.81 0+17.50 99.59 0+27.50 99.81 0+35.00 100.00 Roughness Segment Definitions Start Station Ending Station Roughness Coefficient (0+00.00, 100.00) (0+07.50, 99.81) 0.025 (0+07.50, 99.81) (0+27.50, 99.81) 0.016 (0+27.50, 99.81) (0+35.00, 100.00) 0.025 Channel Slope (ft/ft) Water Surface Elevation (ft) Discharge (ft³/s) Velocity (ft/s) Flow Area (ft²) Wetted Perimeter (ft) Top Width (ft) 0.0040 99.81 2.97 1.35 2.20 20.00 20.00 0.0040 99.86 4.64 1.41 3.30 23.95 23.95 0.0040 99.91 6.83 1.49 4.59 27.90 27.89 0.0040 99.96 9.57 1.57 6.09 31.85 31.84 0.0045 99.81 3.15 1.43 2.20 20.00 20.00 0.0045 99.86 4.93 1.49 3.30 23.95 23.95 0.0045 99.91 7.25 1.58 4.59 27.90 27.89 Rating Table for Private Alley | Vee X-Section 2/6/2017 4:19:02 PM Bentley Systems, Inc. Haestad Methods Solution BentleCyenter FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 5 Rating Table for Private Alley | Vee X-Section Input Data Channel Slope (ft/ft) Water Surface Elevation (ft) Discharge (ft³/s) Velocity (ft/s) Flow Area (ft²) Wetted Perimeter (ft) Top Width (ft) 0.0045 99.96 10.15 1.67 6.09 31.85 31.84 0.0050 99.81 3.32 1.51 2.20 20.00 20.00 0.0050 99.86 5.19 1.57 3.30 23.95 23.95 0.0050 99.91 7.64 1.66 4.59 27.90 27.89 0.0050 99.96 10.70 1.76 6.09 31.85 31.84 0.0055 99.81 3.48 1.58 2.20 20.00 20.00 0.0055 99.86 5.45 1.65 3.30 23.95 23.95 0.0055 99.91 8.01 1.74 4.59 27.90 27.89 0.0055 99.96 11.23 1.84 6.09 31.85 31.84 0.0060 99.81 3.63 1.65 2.20 20.00 20.00 0.0060 99.86 5.69 1.72 3.30 23.95 23.95 0.0060 99.91 8.37 1.82 4.59 27.90 27.89 0.0060 99.96 11.73 1.93 6.09 31.85 31.84 0.0065 99.81 3.78 1.72 2.20 20.00 20.00 0.0065 99.86 5.92 1.79 3.30 23.95 23.95 0.0065 99.91 8.71 1.90 4.59 27.90 27.89 0.0065 99.96 12.20 2.00 6.09 31.85 31.84 0.0070 99.81 3.92 1.78 2.20 20.00 20.00 0.0070 99.86 6.14 1.86 3.30 23.95 23.95 0.0070 99.91 9.04 1.97 4.59 27.90 27.89 0.0070 99.96 12.67 2.08 6.09 31.85 31.84 0.0075 99.81 4.06 1.85 2.20 20.00 20.00 0.0075 99.86 6.36 1.93 3.30 23.95 23.95 0.0075 99.91 9.36 2.04 4.59 27.90 27.89 0.0075 99.96 13.11 2.15 6.09 31.85 31.84 0.0080 99.81 4.19 1.91 2.20 20.00 20.00 0.0080 99.86 6.57 1.99 3.30 23.95 23.95 0.0080 99.91 9.66 2.10 4.59 27.90 27.89 0.0080 99.96 13.54 2.22 6.09 31.85 31.84 0.0085 99.81 4.32 1.97 2.20 20.00 20.00 0.0085 99.86 6.77 2.05 3.30 23.95 23.95 0.0085 99.91 9.96 2.17 4.59 27.90 27.89 0.0085 99.96 13.96 2.29 6.09 31.85 31.84 0.0090 99.81 4.45 2.02 2.20 20.00 20.00 0.0090 99.86 6.97 2.11 3.30 23.95 23.95 0.0090 99.91 10.25 2.23 4.59 27.90 27.89 0.0090 99.96 14.36 2.36 6.09 31.85 31.84 Bentley Systems, Inc. Haestad Methods Solution BentleCyenter FlowMaster V8i (SELECTseries 1) [08.11.01.03] Rating Table for Private Alley | Vee X-Section Input Data Channel Slope (ft/ft) Water Surface Elevation (ft) Discharge (ft³/s) Velocity (ft/s) Flow Area (ft²) Wetted Perimeter (ft) Top Width (ft) 0.0095 99.81 4.57 2.08 2.20 20.00 20.00 0.0095 99.86 7.16 2.17 3.30 23.95 23.95 0.0095 99.91 10.53 2.29 4.59 27.90 27.89 0.0095 99.96 14.75 2.42 6.09 31.85 31.84 0.0100 99.81 4.69 2.13 2.20 20.00 20.00 0.0100 99.86 7.34 2.23 3.30 23.95 23.95 0.0100 99.91 10.80 2.35 4.59 27.90 27.89 0.0100 99.96 15.14 2.49 6.09 31.85 31.84 0.0105 99.81 4.81 2.18 2.20 20.00 20.00 0.0105 99.86 7.52 2.28 3.30 23.95 23.95 0.0105 99.91 11.07 2.41 4.59 27.90 27.89 0.0105 99.96 15.51 2.55 6.09 31.85 31.84 0.0110 99.81 4.92 2.24 2.20 20.00 20.00 0.0110 99.86 7.70 2.33 3.30 23.95 23.95 0.0110 99.91 11.33 2.47 4.59 27.90 27.89 0.0110 99.96 15.88 2.61 6.09 31.85 31.84 0.0115 99.81 5.03 2.29 2.20 20.00 20.00 0.0115 99.86 7.88 2.39 3.30 23.95 23.95 0.0115 99.91 11.59 2.52 4.59 27.90 27.89 0.0115 99.96 16.23 2.67 6.09 31.85 31.84 0.0120 99.81 5.14 2.34 2.20 20.00 20.00 0.0120 99.86 8.04 2.44 3.30 23.95 23.95 0.0120 99.91 11.84 2.58 4.59 27.90 27.89 0.0120 99.96 16.58 2.72 6.09 31.85 31.84 0.0125 99.81 5.24 2.38 2.20 20.00 20.00 0.0125 99.86 8.21 2.49 3.30 23.95 23.95 0.0125 99.91 12.08 2.63 4.59 27.90 27.89 0.0125 99.96 16.92 2.78 6.09 31.85 31.84 0.0130 99.81 5.35 2.43 2.20 20.00 20.00 0.0130 99.86 8.37 2.54 3.30 23.95 23.95 0.0130 99.91 12.32 2.68 4.59 27.90 27.89 0.0130 99.96 17.26 2.83 6.09 31.85 31.84 0.0135 99.81 5.45 2.48 2.20 20.00 20.00 0.0135 99.86 8.53 2.59 3.30 23.95 23.95 0.0135 99.91 12.55 2.73 4.59 27.90 27.89 0.0135 99.96 17.59 2.89 6.09 31.85 31.84 0.0140 99.81 5.55 2.52 2.20 20.00 20.00 Bentley Systems, Inc. Haestad Methods Solution BentleCyenter FlowMaster V8i (SELECTseries 1) [08.11.01.03] Rating Table for Private Alley | Vee X-Section Input Data Channel Slope (ft/ft) Water Surface Elevation (ft) Discharge (ft³/s) Velocity (ft/s) Flow Area (ft²) Wetted Perimeter (ft) Top Width (ft) 0.0140 99.86 8.69 2.63 3.30 23.95 23.95 0.0140 99.91 12.78 2.78 4.59 27.90 27.89 0.0140 99.96 17.91 2.94 6.09 31.85 31.84 0.0145 99.81 5.65 2.57 2.20 20.00 20.00 0.0145 99.86 8.84 2.68 3.30 23.95 23.95 0.0145 99.91 13.01 2.83 4.59 27.90 27.89 0.0145 99.96 18.23 2.99 6.09 31.85 31.84 0.0150 99.81 5.74 2.61 2.20 20.00 20.00 0.0150 99.86 8.99 2.73 3.30 23.95 23.95 0.0150 99.91 13.23 2.88 4.59 27.90 27.89 0.0150 99.96 18.54 3.05 6.09 31.85 31.84 0.0155 99.81 5.84 2.65 2.20 20.00 20.00 0.0155 99.86 9.14 2.77 3.30 23.95 23.95 0.0155 99.91 13.45 2.93 4.59 27.90 27.89 0.0155 99.96 18.85 3.10 6.09 31.85 31.84 0.0160 99.81 5.93 2.70 2.20 20.00 20.00 0.0160 99.86 9.29 2.82 3.30 23.95 23.95 0.0160 99.91 13.67 2.97 4.59 27.90 27.89 0.0160 99.96 19.15 3.15 6.09 31.85 31.84 0.0165 99.81 6.02 2.74 2.20 20.00 20.00 0.0165 99.86 9.43 2.86 3.30 23.95 23.95 0.0165 99.91 13.88 3.02 4.59 27.90 27.89 0.0165 99.96 19.44 3.19 6.09 31.85 31.84 0.0170 99.81 6.11 2.78 2.20 20.00 20.00 0.0170 99.86 9.57 2.90 3.30 23.95 23.95 0.0170 99.91 14.09 3.07 4.59 27.90 27.89 0.0170 99.96 19.74 3.24 6.09 31.85 31.84 0.0175 99.81 6.20 2.82 2.20 20.00 20.00 0.0175 99.86 9.71 2.94 3.30 23.95 23.95 0.0175 99.91 14.29 3.11 4.59 27.90 27.89 0.0175 99.96 20.03 3.29 6.09 31.85 31.84 0.0180 99.81 6.29 2.86 2.20 20.00 20.00 0.0180 99.86 9.85 2.99 3.30 23.95 23.95 0.0180 99.91 14.50 3.15 4.59 27.90 27.89 0.0180 99.96 20.31 3.34 6.09 31.85 31.84 0.0185 99.81 6.38 2.90 2.20 20.00 20.00 0.0185 99.86 9.99 3.03 3.30 23.95 23.95 Bentley Systems, Inc. Haestad Methods Solution BentleCyenter FlowMaster V8i (SELECTseries 1) [08.11.01.03] Rating Table for Private Alley | Vee X-Section Input Data Channel Slope (ft/ft) Water Surface Elevation (ft) Discharge (ft³/s) Velocity (ft/s) Flow Area (ft²) Wetted Perimeter (ft) Top Width (ft) 0.0185 99.91 14.70 3.20 4.59 27.90 27.89 0.0185 99.96 20.59 3.38 6.09 31.85 31.84 0.0190 99.81 6.46 2.94 2.20 20.00 20.00 0.0190 99.86 10.12 3.07 3.30 23.95 23.95 0.0190 99.91 14.89 3.24 4.59 27.90 27.89 0.0190 99.96 20.87 3.43 6.09 31.85 31.84 0.0195 99.81 6.55 2.98 2.20 20.00 20.00 0.0195 99.86 10.25 3.11 3.30 23.95 23.95 0.0195 99.91 15.09 3.28 4.59 27.90 27.89 0.0195 99.96 21.14 3.47 6.09 31.85 31.84 0.0200 99.81 6.63 3.01 2.20 20.00 20.00 0.0200 99.86 10.39 3.15 3.30 23.95 23.95 0.0200 99.91 15.28 3.33 4.59 27.90 27.89 0.0200 99.96 21.41 3.52 6.09 31.85 31.84 2/6/2017 4:19:02 PM Bentley Systems, Inc. Haestad Methods Solution BentleCyenter FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 5 of 5 ` SWALE CAPACITY CALCULATIONS ` STORM DRAIN SIZING CALCULATIONS Project Description Friction Method Manning Formula Solve For Full Flow Capacity Input Data Roughness Coefficient 0.013 Channel Slope 0.0050 ft/ft Normal Depth 1.50 ft Diameter 18 in Discharge 7.43 ft³/s Diameter (in) Normal Depth (ft) Discharge (ft³/s) Velocity (ft/s) Flow Area (ft²) Wetted Perimeter (ft) Top Width (ft) 18 1.50 7.43 4.20 1.77 4.71 0.00 24 2.00 16.00 5.09 3.14 6.28 0.00 30 2.50 29.00 5.91 4.91 7.85 0.00 36 3.00 47.16 6.67 7.07 9.42 0.00 Rating Table for Circular Storm Drain Pipe 2/7/2017 9:02:29 AM Bentley Systems, Inc. Haestad Methods Solution BentleCyenter FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 ` APPENDIX D SUPPORTING DOCUMENTATION ` PRELIMINARY GEOTECHNICAL INVESTIGATION EAST RIDGE SUBDIVISION FORT COLLINS, COLORADO (Project No. FC06953-115 | Dated: June 19, 2015) ` DEVELOPED CONDITION DRAINAGE MAP 0.51 0.40 1.13 K1 0.53 0.42 0.86 K2 1.00 0.80 0.97 K4 0.87 0.70 0.77 K5 1.00 0.83 0.77 K3 0.56 0.45 1.16 L3 1.00 0.84 1.12 L4 0.84 0.67 0.95 L5 0.61 0.49 0.80 L2 0.90 0.72 1.2 L1 K1 K2 L3 L2 L4 K4 K3 K5 L5 0.43 0.34 0.54 OS1 OS1 0.25 0.20 0.21 OS2 0.25 0.20 0.27 OS3 0.83 0.66 0.43 M3 0.54 0.43 1.59 N2 0.61 0.49 0.18 M1 0.25 0.20 0.02 M2 0.70 0.56 0.57 M4 1.00 0.84 0.63 N3 0.92 0.74 0.85 N1 0.59 0.47 0.12 M8 0.58 0.46 0.98 O2 0.97 0.77 1.11 O3 0.51 0.40 0.06 M7 0.73 0.59 0.21 M6 0.72 0.58 1.15 M5 xx xx xx O5 O4 0.99 0.79 0.72 ` EXCERPTS FROM FINAL DRAINAGE REPORT EAST RIDGE SECOND FILING, DATED: JUNE 30TH, 2016 BY GALLOWAY & COMPANY, INC. 1 Herman Feissner From: Herman Feissner Sent: Thursday, January 19, 2017 9:34 AM To: 'Heather McDowell' Cc: James Prelog Subject: East Ridge Townhomes - Montage | Follow-Up Hi Heather, The following is a summary of our meeting about LID requirements for the townhome developments at East Ridge. Several areas labeled as ‘future’ in the approved East Ridge Second Filing (ERSF) documents will be developed as townhomes. Specifically, the areas labeled: Fut-A, Fut-B, Fut-H and Fut-I. Refer to the attached copy of sheet DR01 from the ERSF CDs. · East Ridge Second Filing was designed to meet City of Fort Collins (CoFC) Ordinance No. 152, 2012. Specifically, Section 3.1.a (1) and (2) reads: o No less than fifty percent (50%) of any newly added impervious area must be treated using one or a combination of LID techniques; and o No less than twenty five percent (25%) of any newly added pavement areas must be treated using permeable pavement technology that is considered an LID technique. · At the time of approval, 58% of the project site was treating using at least one LID technique. · Since ERSF was approved the aforementioned ordinance has been revised. Section 3.1.b of Ordinance No. 007, 2016 reads: o No less than fifty percent (50%) of any newly developed or redeveloped area, and any modification on a previously developed area for which a construction permit is required under City codes and regulations, must be treated using one or a combination of LID techniques, when a permeable pavement area covering at least twenty five (25%) of the drivable surface area on private development property is constructed as one of the components of the LID treatment techniques used on that site. · The townhome sites are being re-platted; therefore, each site is required to meet the LID requirements of Ordinance No. 007, 2016, Section 3.1.b. · The townhomes are considered single-family attached and required to meet the 50% criteria mentioned above. The 25% permeable pavement required is waived for the single-family attached product type. The future areas in ERSF were designed to flow into the following LID/WQ features: North Townhomes · Fut-A (4.59 acres) was designed to flow into a Bioswale · Fut-B (5.14 acres) was designed to flow into a Sand Filter · Summary: 100% of the newly added area flows in an LID feature West Townhomes · Fut-H (4.51 acres) was designed to flow into an EDB · The newly added impervious area in Fut-H is ±2.14 acres · Fut-I1 and Fut-I2 (6.03 acres combined) were designed to flow into a Sand Filter · The newly added impervious area in Fut-I1 and Fut-I2 is ±3.03 acres · The total newly added impervious area is 5.17 acres · Summary: ±59% (>50%) of the newly added impervious area is treated using LID techniques. 57% of the newly added area is treated using LID techniques Let me know what you think. Regards, Herman 2 Galloway Planning. Architecture. Engineering. HERMAN FEISSNER, PE, SR. CIVIL PROJECT ENGINEER 3760 E. 15th Street, Suite 202 Loveland, CO 80538 970.800.3300 O 970.800.3313 D HermanFeissner@GallowayUS.com www.GallowayUS.com Denver, CO - Loveland, CO - Salt Lake City, UT - Fresno, CA Licensed in more than 40 states to better serve you. This message and any attachments are intended only for the recipient named. If you are not the intended recipient you are notified that any dissemination, disclosing, copying, distributing or taking any action in reliance on the contents of this information is strictly prohibited. Galloway & Company, Inc. considers any design data to be in final form only when plotted, stamped and signed. Galloway & Company, Inc. assumes no responsibility for the unauthorized use of this data. 11 BARNSTORMER STREET BIPLANE STREET COLEMAN STREET SUPERCUB LANE CONQUEST STREET SYKES DRIVE COMET STREET (B) RELIANT STREET CRUSADER STREET (B) VICOT WAY PRIVATE DRIVEAA ZEPPELINWAY PRIVATE DRIVE TIGERCATWAY NAVION LANE VICOT WAY YEAGER STREET MARQUISESTREET FAIRCHILD STREET QUINBYSTREET FAIRCHILD STREET DASSAULT STREET DELOZIERROAD SYKES DRIVE BARNSTORMER STREET BIPLANE STREET COLEMAN STREET VICOT WAY VICOT WAY CONQUEST STREET CONQUEST STREET CONQUESTWAY ALLEY A ALLEY A ALLEY A ALLEYA ALLEY A ALLEY A QUINBY STREET MARQUISESTREET CRUSADER STREET (A) ZEPPELINWAY Z EPPELINWAY SYKES DRIVE ALLEY B COMETSTRE ET (A) PRIVATE DRIVEC PRIVATE DRIVED PRIVATE DRIVE E PRIVATE D RIVEC PRIVATE DRIVE TIGERCATWAY FUTURE NEIGHBORHOOD PARK (±8.0 AC) 1 A Basins (Includes: Fut-A) Tributary Area: 21.92 ac B, E and F Basins (Includes: Fut-B) Tributary Area: 37.46 ac C and D Basins Tributary Area: 23.74 ac G and H Basins (Includes: Fut-G, Fut-H and Fut-TL2) Tributary Area: 30.61 ac I- and J-Basins (Includes: Fut-I and Fut-TL-4) Tributary Area: 14.28 ac 5 4 2 3 7 2-YEAR WATER SURFACE ELEVATION 6 6 9 10 8 11 11 11 CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU DIG, GRADE, OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES. CALL UTILITY NOTIFICATION CENTER OF COLORADO R # THESE PLANS ARE AN INSTRUMENT OF SERVICE AND ARE THE PROPERTY OF GALLOWAY, AND MAY NOT BE DUPLICATED, DISCLOSED, OR REPRODUCED WITHOUT THE WRITTEN CONSENT OF THE ARCHITECT. COPYRIGHTS AND INFRINGEMENTS WILL BE ENFORCED AND PROSECUTED. 3760 E. 15th Street, Suite 202 Loveland, CO 80538 970.800.3300 O www.gallowayUS.com C 2015. Galloway & Company, Inc. All Rights Reserved SHEET TITLE: Date: Drawn By: Project No: Checked By: HFHLV0001.01 03/23/16 EAST RIDGE HOLDINGS 4801 Goodman Rd. Timnath, CO 80547 970.674.1109 NOT FOR CONSTRUCTION 03/23/16 DESIGN POINT MAJOR BASIN BOUNDARY SUB-BASIN BOUNDARY OVERLAND FLOW DIRECTION (I.E., LANDSCAPING) 1. BIOSWALE - LID | SEE SHEET DT07 FOR CROSS SECTIONI TRIBUTARY AREA: A-BASINS (INCLUDES FUT-A) DESIGN FLOW: Q2 ~ 27.1 CFS LENGTH: 450 FT, CHANNEL SLOPE: 0.0025 FT/FT, CHANNEL SIDE SLOPES: 5:1, BOTTOM WIDTH: 30 FT 2. SAND FILTER (SF) - LID: TRIBUTARY AREA: B-, E- AND F-BASINS (INCLUDES FUT-B) DESIGN VOLUME: 0.75 AC-FT 3. EXTENDED DETENTION BASIN (EDB) - WQCV: TRIBUTARY AREA: C- AND D-BASINS DESIGN VOLUME: 0.61 AC-FT 4. EXTENDED DETENTION BASIN (EDB) - WQCV: TRIBUTARY AREA: G- AND H-BASINS (INCLUDES FUT-G, FUT-H AND FUT-TL2) DESIGN VOLUME: 0.94 AC-FT 5. SAND FILTER (SF) - LID: TRIBUTARY AREA: I-BASINS (INCLUDES FUT-I BASINS AND FUT-TL3) DESIGN VOLUME: 0.33 AC-FT GRASS BUFFER (GB) - LID: TRIBUTARY AREA: VARIES LENGTH: 14 FT (MIN.), MAX. SLOPE=10% DETENTION POND WATER SURFACE ELEVATION: EXTENDED DETENTION BASIN (EDB) WATER QUALITY OUTLET STRUCTURE (WQOS). SEE SHEET DT04 FOR DETAIL 3 (C AND D BASINS) EXTENDED DETENTION BASIN (EDB) WATER QUALITY OUTLET STRUCTURE (WQOS). SEE SHEET DT04 FOR DETAIL 4 (G AND H BASINS) 10' x 20' x 8.5' CONCRETE VAULT W/PUMPIING INFRASTRUCTURE. ADDITIONAL DETAIL IS PROVIDED IN THE FINAL DRAINAGE REPORT EAST RIDGE SECOND FILING, DATED MARCH 23, 2016. NORTH AMERICAN GREEN C125BN ROLLED EROSION CONTROL PRODUCT (RECP). SEE SHEET DT07 FOR ADDITIONAL INFORMATION. NOTES: 1 DRAINAGE SYMBOLS: LEGEND: 2 3 4 5 6 DIRECT FLOW DIRECTION (I.E., PAVEMENT, CURB AND GUTTER) PROPOSED RIGHT-OF-WAY PROPOSED STORM SEWER EXISTING STORM SEWER PROPOSED STORM INLET PROPOSED LOTLINE EASEMENT LINE FUTURE LOTLINE FUTURE RIGHT-OF-WAY BASIN ID MINOR (2-year) RUNOFF COEFFICIENT MAJOR (100-year) RUNOFF COEFFICIENT BASIN AREA (ACRES) EXISTING MINOR CONTOUR EXISTING MAJOR CONTOUR PROPOSED MINOR CONTOUR PROPOSED MAJOR CONTOUR 4900 4900 35 7 **FOR 2,3,4 AND 5 - EACH CORRESPONDING HATCH PATTERN INDICATES THE LIMITS OF THE WATER QUALITY STORM EVENT WATER SURFACE ELEVATION. 8 9 10 2-YEAR WSEL=4933.96 WSEL=4930.99 WSEL=4931.59 WSEL=4930.36 11 Stormwater Quality Strategy/Detention Tributary Basins Tributary Area WS Elev. (Event Noted) Volume Release Rate acres ac-ft cfs 1 - Bioswale A Basins (Includes: Fut-A) 21.92 N/A N/A N/A 2 - Sand Filter (SF) B, E and F Basins (Includes: Fut-B) 37.46 WQ=4933.96 0.75 N/A 3 - Extended Detention Basin (EDB) C and D Basins 23.74 WQ=4930.99 0.61 40-Hour Drain Time 4 - Extended Detention Basin (EDB) G and H Basins (Includes: Fut-G, Fut-H and Fut-TL2) 30.61 WQ=4931.59 0.94 40-Hour Drain Time 5 - Sand Filter (SF) I Basins (Includes Fut-I and Fut-TL3) 14.28 WQ=4930.36 0.33 N/A 6 - Grass Buffer LID feature for Neighborhood Park future parking lot and impervious area around perimeter 21.31 N/A N/A N/A 7 - Detention Pond | 2-Year Site 153.29 2year =4929.17 2.57 5 7 - Detention Pond | 100-Year Site 153.29 100year =4935.88 35.77 5 LID/EDB AND DETENTION SUMMARY CityDate Engineer Date Date Date Date Stormwater Utility Parks & Recreation Traffic Engineer Date APPROVED: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: Water & Wastewater Utility City of Fort Collins, Colorado UTILITY PLAN APPROVAL Environmental Planner O1 G6 I6 I5 I2 I4 G7 I3 I7 Fut-TL3 O7 1.00 0.83 0.49 G6 7 1.00 0.81 0.42 H1 1 2 2 2 1 2 1.00 0.90 1.57 Fut-TL3 0.97 0.78 1.04 I2 Fut-TL4 1.00 0.81 0.10 I3 I7 1.00 0.80 0.17 I4 1.00 0.81 0.17 I5 11 11 11 11 PRIVATE DRIVE BB PRIVATE DRIVE DD FF TIMBERLINE ROAD CRUSADER STREET VICOT WAY VICOT WAY 12''SS 12''SS 12''SS 12''SS 12''SS 0.28 0.22 0.08 O8 0.71 0.57 1.18 O6 xx xx xx O5 0.81 0.65 0.16 O4 I6 I5 I2 J1 I4 I3 I9 I7 Fut-TL3 0.28 0.22 0.08 O7 1.00 0.90 0.28 Fut-TL4 2 1.00 0.81 0.10 I3 1.00 0.84 0.10 I7 1.00 0.80 0.17 I4 0.25 0.20 0.48 J1 0.89 0.71 0.12 I9 1.00 0.81 0.17 I5 11 PRIVATE DRIVE EE PRIVATE DRIVE FF CRUSADER STREET 3760 E. 15th Street, Suite 202 Loveland, CO 80538 970.800.3300 O www.gallowayUS.com 2016. Galloway & Company, Inc. All Rights Reserved Date: Drawn By: Project No: Checked By: H:\Hartford Homes\CO, Timnath - HFHLV0001.02_Timberline & Vine Multi-Family\CADD\3-CD\HFHLV1.02_Townhomes\HFHLV1.02_DR01.dwg - Nate Whitcomb - 2/7/2017 HFHLV0001.02 02.08.2017 # DateDescription Issue / Init. EAST RIDGE THIRD FILING MONTAGE TOWNHOMES FORT COLLINS, CO THESE PLANS ARE AN INSTRUMENT OF SERVICE AND ARE THE PROPERTY OF GALLOWAY, AND MAY NOT BE DUPLICATED, DISCLOSED, OR REPRODUCED WITHOUT THE WRITTEN CONSENT OF GALLOWAY. COPYRIGHTS AND INFRINGEMENTS WILL BE ENFORCED AND PROSECUTED. COPYRIGHT PRELIMINARY NOT FOR BIDDING NOT FOR CONSTRUCTION EAST RIDGE HOLDINGS 4801 Goodman Rd. Timnath, CO 80547 970.674.1109 CAUTION - NOTICE TO CONTRACTOR 1. ALL UTILITY LOCATIONS SHOWN ARE BASED ON MAPS PROVIDED BY THE APPROPRIATE UTILITY COMPANY AND FIELD SURFACE EVIDENCE AT THE TIME OF SURVEY AND IS TO BE CONSIDERED AN APPROXIMATE LOCATION ONLY. IT IS THE CONTRACTOR'S RESPONSIBILITY TO FIELD VERIFY THE FIELD LOCATION OF ALL UTILITIES, PUBLIC OR PRIVATE, WHETHER SHOWN ON THE PLANS OR NOT, PRIOR TO CONSTRUCTION. REPORT ANY DISCREPANCIES TO THE ENGINEEER PRIOR TO CONSTRUCTION. 2. WHERE A PROPOSED UTILITY CROSSES AN EXISTING UTILITY, IT IS THE CONTRACTOR'S RESPONSIBILITY TO FIELD VERIFY THE HORIZONTAL AND VERTICAL LOCATION OF SUCH EXISTING UTILITY, EITHER THROUGH POTHOLING OR ALTERNATIVE METHOD. REPORT INFORMATION TO THE ENGINEER PRIOR TO CONSTRUCTION. CityDate Engineer Date Date Date Date Stormwater Utility Parks & Recreation Traffic Engineer Date APPROVED: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: Water & Wastewater Utility City of Fort Collins, Colorado UTILITY PLAN APPROVAL Environmental Planner DR01 KEYMAP DESIGN POINT MAJOR BASIN BOUNDARY PROPOSED BASIN BOUNDARY OVERLAND FLOW DIRECTION (I.E., LANDSCAPING) DRAINAGE SYMBOLS: LEGEND: DIRECT FLOW DIRECTION (I.E., PAVEMENT, CURB AND GUTTER) PROPOSED RIGHT-OF-WAY PROPOSED STORM SEWER EXISTING STORM SEWER PROPOSED STORM INLET PROPOSED LOTLINE EASEMENT LINE FUTURE LOTLINE FUTURE RIGHT-OF-WAY BASIN ID MINOR (2-year) RUNOFF COEFFICIENT MAJOR (100-year) RUNOFF COEFFICIENT BASIN AREA (ACRES) EXISTING MINOR CONTOUR EXISTING MAJOR CONTOUR PROPOSED MINOR CONTOUR PROPOSED MAJOR CONTOUR 4900 4900 35 EXISTING BASIN BOUNDARY (PER PROPOSED UTILITY PLANS FOR EAST RIDGE SECOND FILING DATED: 6.30.16) Tributary Area C2 C 100 tc | 2-Year tc | 100-Year Q 2 Q100 Sub-basin (acres) (min) (min) (cfs) (cfs) K1 1.13 0.40 0.51 6.4 5.9 1.2 5.5 K2 0.86 0.42 0.53 8.6 7.8 0.9 3.9 K3 0.77 0.83 1.00 5.5 5.0 1.8 7.7 K4 0.97 0.80 1.00 5.8 5.0 2.1 9.6 K5 0.77 0.70 0.87 5.0 5.0 1.5 6.7 L1 1.21 0.72 0.90 8.7 6.3 2.1 10.1 L2 0.80 0.49 0.61 5.4 5.0 1.1 4.8 L3 1.16 0.45 0.56 7.7 6.9 1.3 5.8 L4 1.12 0.84 1.00 5.6 5.0 2.6 11.2 L5 0.95 0.67 0.84 5.0 5.0 1.8 7.9 M1 0.18 0.49 0.61 7.1 5.8 0.2 1.1 M2 0.02 0.20 0.25 6.8 6.4 0.01 0.05 M3 0.43 0.66 0.83 5.0 5.0 0.8 3.6 M4 0.57 0.56 0.70 6.9 5.1 0.8 4.0 M5 1.15 0.58 0.72 5.0 5.0 1.9 8.3 M6 0.21 0.59 0.73 6.5 5.0 0.3 1.5 M7 0.06 0.40 0.51 5.0 5.0 0.1 0.3 M8 0.12 0.47 0.59 5.9 5.0 0.2 0.7 N1 0.85 0.74 0.92 6.1 5.0 1.7 7.8 N2 1.59 0.43 0.54 10.8 9.3 1.5 6.9 N3 0.63 0.84 1.00 5.0 5.0 1.5 6.3 O1 0.72 0.79 0.99 5.3 5.0 1.6 7.1 O2 0.98 0.46 0.58 12.1 11.0 0.9 4.3 O3 1.11 0.77 0.97 6.7 5.0 2.3 10.8 O4 0.16 0.65 0.81 5.3 5.0 0.3 1.3 O5 0.09 0.67 0.84 5.1 5.0 0.2 0.8 O6 1.18 0.57 0.71 9.5 7.9 1.5 7.3 O7 0.30 0.62 0.77 5.7 5.0 0.5 2.3 O8 0.08 0.22 0.28 6.0 5.6 0.0 0.2 OS1 0.54 0.34 0.43 12.1 12.1 0.4 1.7 OS2 0.21 0.20 0.25 5.0 5.0 0.1 0.5 OS3 0.27 0.20 0.25 5.0 5.0 0.2 0.7 OS4 0.40 0.20 0.25 5.0 5.0 0.2 1.0 OS5 0.38 0.20 0.25 5.0 5.0 0.2 1.0 DR02 ( IN FEET ) 1 inch = ft. 60Feet 0 60 60 DEVELOPED RUNOFF TABLE 120 180 DRAINAGE NOTES PROPOSED AREA INLET PROPOSED VALLEY PAN INLET(S) - NEENAH R-3362-L EXISTING STORM DRAIN A (CONSTRUCTED W/EAST RIDGE SECOND FILING) EXISTING STORM DRAIN B (CONSTRUCTED W/EAST RIDGE SECOND FILING) EXISTING STORM DRAIN C (CONSTRUCTED W/EAST RIDGE SECOND FILING) EXISTING STORM DRAIN D (CONSTRUCTED W/EAST RIDGE SECOND FILING) CONNECT TO EXISTING STORM DRAIN IN EAST RIDGE SECOND FILING PROPOSED SWALE EXISTING TYPE 'R' INLET EXISTING NO. 16 COMBINATION INLET EXISTING IRRIGATION LINE MATCHLINE-SEE THIS SHEET MATCHLINE-SEE THIS SHEET ROTATION: 0° 0.25 0.20 0.40 OS4 0.25 0.20 0.38 OS5 OS2 OS3 OS4 OS5 1 1 2 2 5 7 6 7 8 8 8 8 8 2 2 8 1 1 PRIVATE DRIVE A PRIVATE DRIVE B PRIVATE DRIVE D PRIVATE DRIVE C BARNSTORMER STREET NAVION LANE YEAGER STREET MARQUISE STREET VINE DRIVE PROPOSED UTILITY PLANS FOR: EAST RIDGE SECOND FILING DATED: 6.30.16 3760 E. 15th Street, Suite 202 Loveland, CO 80538 970.800.3300 O www.gallowayUS.com 2016. Galloway & Company, Inc. All Rights Reserved Date: Drawn By: Project No: Checked By: H:\Hartford Homes\CO, Timnath - HFHLV0001.02_Timberline & Vine Multi-Family\CADD\3-CD\HFHLV1.02_Townhomes\HFHLV1.02_DR01.dwg - Nate Whitcomb - 2/7/2017 HFHLV0001.02 02.08.2017 # DateDescription Issue / Init. EAST RIDGE THIRD FILING MONTAGE TOWNHOMES FORT COLLINS, CO THESE PLANS ARE AN INSTRUMENT OF SERVICE AND ARE THE PROPERTY OF GALLOWAY, AND MAY NOT BE DUPLICATED, DISCLOSED, OR REPRODUCED WITHOUT THE WRITTEN CONSENT OF GALLOWAY. COPYRIGHTS AND INFRINGEMENTS WILL BE ENFORCED AND PROSECUTED. COPYRIGHT PRELIMINARY NOT FOR BIDDING NOT FOR CONSTRUCTION EAST RIDGE HOLDINGS 4801 Goodman Rd. Timnath, CO 80547 970.674.1109 CAUTION - NOTICE TO CONTRACTOR 1. ALL UTILITY LOCATIONS SHOWN ARE BASED ON MAPS PROVIDED BY THE APPROPRIATE UTILITY COMPANY AND FIELD SURFACE EVIDENCE AT THE TIME OF SURVEY AND IS TO BE CONSIDERED AN APPROXIMATE LOCATION ONLY. IT IS THE CONTRACTOR'S RESPONSIBILITY TO FIELD VERIFY THE FIELD LOCATION OF ALL UTILITIES, PUBLIC OR PRIVATE, WHETHER SHOWN ON THE PLANS OR NOT, PRIOR TO CONSTRUCTION. REPORT ANY DISCREPANCIES TO THE ENGINEEER PRIOR TO CONSTRUCTION. 2. WHERE A PROPOSED UTILITY CROSSES AN EXISTING UTILITY, IT IS THE CONTRACTOR'S RESPONSIBILITY TO FIELD VERIFY THE HORIZONTAL AND VERTICAL LOCATION OF SUCH EXISTING UTILITY, EITHER THROUGH POTHOLING OR ALTERNATIVE METHOD. REPORT INFORMATION TO THE ENGINEER PRIOR TO CONSTRUCTION. CityDate Engineer Date Date Date Date Stormwater Utility Parks & Recreation Traffic Engineer Date APPROVED: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: Water & Wastewater Utility City of Fort Collins, Colorado UTILITY PLAN APPROVAL Environmental Planner ( IN FEET ) 1 inch = ft. 60Feet 0 60 60 120 180 KEYMAP DESIGN POINT MAJOR BASIN BOUNDARY PROPOSED BASIN BOUNDARY OVERLAND FLOW DIRECTION (I.E., LANDSCAPING) DRAINAGE SYMBOLS: LEGEND: DIRECT FLOW DIRECTION (I.E., PAVEMENT, CURB AND GUTTER) PROPOSED RIGHT-OF-WAY PROPOSED STORM SEWER EXISTING STORM SEWER PROPOSED STORM INLET PROPOSED LOTLINE EASEMENT LINE FUTURE LOTLINE FUTURE RIGHT-OF-WAY BASIN ID MINOR (2-year) RUNOFF COEFFICIENT MAJOR (100-year) RUNOFF COEFFICIENT BASIN AREA (ACRES) EXISTING MINOR CONTOUR EXISTING MAJOR CONTOUR PROPOSED MINOR CONTOUR PROPOSED MAJOR CONTOUR 4900 4900 35 EXISTING BASIN BOUNDARY (PER PROPOSED UTILITY PLANS FOR EAST RIDGE SECOND FILING DATED: 6.30.16) DRAINAGE NOTES PROPOSED AREA INLET PROPOSED VALLEY PAN INLET(S) - NEENAH R-3362-L EXISTING STORM DRAIN A (CONSTRUCTED W/EAST RIDGE SECOND FILING) EXISTING STORM DRAIN B (CONSTRUCTED W/EAST RIDGE SECOND FILING) EXISTING STORM DRAIN C (CONSTRUCTED W/EAST RIDGE SECOND FILING) EXISTING STORM DRAIN D (CONSTRUCTED W/EAST RIDGE SECOND FILING) CONNECT TO EXISTING STORM DRAIN IN EAST RIDGE SECOND FILING PROPOSED SWALE EXISTING TYPE 'R' INLET EXISTING NO. 16 COMBINATION INLET DR01 DR02 Tributary Area C2 C 100 tc | 2-Year tc | 100-Year Q 2 Q100 Sub-basin (acres) (min) (min) (cfs) (cfs) K1 1.13 0.40 0.51 6.4 5.9 1.2 5.5 K2 0.86 0.42 0.53 8.6 7.8 0.9 3.9 K3 0.77 0.83 1.00 5.5 5.0 1.8 7.7 K4 0.97 0.80 1.00 5.8 5.0 2.1 9.6 K5 0.77 0.70 0.87 5.0 5.0 1.5 6.7 L1 1.21 0.72 0.90 8.7 6.3 2.1 10.1 L2 0.80 0.49 0.61 5.4 5.0 1.1 4.8 L3 1.16 0.45 0.56 7.7 6.9 1.3 5.8 L4 1.12 0.84 1.00 5.6 5.0 2.6 11.2 L5 0.95 0.67 0.84 5.0 5.0 1.8 7.9 M1 0.18 0.49 0.61 7.1 5.8 0.2 1.1 M2 0.02 0.20 0.25 6.8 6.4 0.01 0.05 M3 0.43 0.66 0.83 5.0 5.0 0.8 3.6 M4 0.57 0.56 0.70 6.9 5.1 0.8 4.0 M5 1.15 0.58 0.72 5.0 5.0 1.9 8.3 M6 0.21 0.59 0.73 6.5 5.0 0.3 1.5 M7 0.06 0.40 0.51 5.0 5.0 0.1 0.3 M8 0.12 0.47 0.59 5.9 5.0 0.2 0.7 N1 0.85 0.74 0.92 6.1 5.0 1.7 7.8 N2 1.59 0.43 0.54 10.8 9.3 1.5 6.9 N3 0.63 0.84 1.00 5.0 5.0 1.5 6.3 O1 0.72 0.79 0.99 5.3 5.0 1.6 7.1 O2 0.98 0.46 0.58 12.1 11.0 0.9 4.3 O3 1.11 0.77 0.97 6.7 5.0 2.3 10.8 O4 0.16 0.65 0.81 5.3 5.0 0.3 1.3 O5 0.09 0.67 0.84 5.1 5.0 0.2 0.8 O6 1.18 0.57 0.71 9.5 7.9 1.5 7.3 O7 0.30 0.62 0.77 5.7 5.0 0.5 2.3 O8 0.08 0.22 0.28 6.0 5.6 0.0 0.2 OS1 0.54 0.34 0.43 12.1 12.1 0.4 1.7 OS2 0.21 0.20 0.25 5.0 5.0 0.1 0.5 OS3 0.27 0.20 0.25 5.0 5.0 0.2 0.7 OS4 0.40 0.20 0.25 5.0 5.0 0.2 1.0 OS5 0.38 0.20 0.25 5.0 5.0 0.2 1.0 ROTATION: 0° O5 O5 0.09 0.84 5.0 0.08 9.98 0.8 O6 O6 1.18 0.71 7.9 0.84 8.63 7.3 O7 O7 0.30 0.77 5.0 0.23 9.98 2.3 0.80 OS1 OS1 0.54 0.43 12.1 0.23 7.24 1.7 OS2 OS2 0.21 0.25 5.0 0.05 9.98 0.5 OS3 OS3 0.27 0.25 5.0 0.07 9.98 0.7 OS4 OS4 0.40 0.25 5.0 0.10 9.98 1.0 OS5 OS5 0.38 0.25 5.0 0.10 9.98 1.0 PIPE 100-Year DIRECT RUNOFF TOTAL RUNOFF STREET 2/6/17 H:\Hartford Homes\CO, Timnath - HFHLV0001.02_Timberline Vine Multi-Family\3.04 Grading-Drainage Studies\3.04.2 Proposed Drainage Reports-Info\Hydrology\Rational\HFHLV01.02_ERSF Rational.xls Page 1 of 1 2/6/2017 OS5 OS5 0.38 0.20 5.0 0.08 2.86 0.2 DIRECT RUNOFF TOTAL RUNOFF STREET PIPE STANDARD FORM SF-3 STORM DRAINAGE SYSTEM DESIGN (RATIONAL METHOD PROCEDURE) 2-Year 2/6/17 H:\Hartford Homes\CO, Timnath - HFHLV0001.02_Timberline Vine Multi-Family\3.04 Grading-Drainage Studies\3.04.2 Proposed Drainage Reports-Info\Hydrology\Rational\HFHLV01.02_ERSF Rational.xls Page 1 of 1 2/6/2017 Heavy Meadow Tillage/field Short pasture and lawns Nearly bare ground Grassed waterway H:\Hartford Homes\CO, Timnath - HFHLV0001.02_Timberline Vine Multi-Family\3.04 Grading-Drainage Studies\3.04.2 Proposed Drainage Reports-Info\Hydrology\Rational\HFHLV01.02_ERSF Rational.xls Page 1 of 1 2/6/2017 Survey Area Data: Version 9, Sep 22, 2014 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Apr 22, 2011—Apr 28, 2011 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. Hydrologic Soil Group—Larimer County Area, Colorado (East Ridge Subdivision) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/24/2015 Page 2 of 4