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Home My WebLink AboutSPOONS-LIGHTFIELD ENTERPRISES, INC. - PDP/FDP - FDP150003 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTDRAINAGE REPORT FOR Lightfield Enterprises, Inc. 2600 Midpoint Drive Fort Collins, CO 80525 Prepared for: SDP Architecture 633 Agate Court Fort Collins, CO 80525 Prepared by: www.quality-engineering.com 1501 Academy Court, #201 Fort Collins, Colorado 80524 (970) 416-7891 QE Project No: 7025-002 Date: January 21, 2015 Lightfield Enterprises, Inc. FINAL DRAINAGE REPORT ENGINEER’S CERTIFICATION I hereby certify that this Final Drainage Report for the design of stormwater management facilities for the Vogel Concrete Project was prepared by me, or under my direct supervision, in accordance with the provisions of the City of Fort Collins Storm Drainage Design Criteria and Construction Standards for the owners thereof. Cody Geisendorfer, P.E. Registered Professional Engineer State of Colorado No. 41326 I. Table of Contents I. GENERAL LOCATION AND DESCRIPTION ......................................... 1 A. Location .................................................................................................................... 1 B. Description of Property ........................................................................................... 1 II. DRAINAGE BASINS AND SUB-BASINS .................................................. 2 A. Major Basin Description ......................................................................................... 2 B. Sub-Basin Description ............................................................................................. 2 III. DRAINAGE CRITERIA ............................................................................... 2 A. Regulations ............................................................................................................... 2 B. Implementation of the “Four Step Process” .......................................................... 2 C. Development Criteria Reference and Constraints ................................................ 4 D. Hydrological Criteria............................................................................................... 4 E. Hydraulic Criteria ................................................................................................... 5 F. Modifications of Criteria ......................................................................................... 5 IV. DRAINAGE FACILITY DESIGN ............................................................... 5 A. General Concept....................................................................................................... 5 B. Specific Details ......................................................................................................... 6 C. Rain Garden/Detention Pond.................................................................................. 7 V. CONCLUSIONS ............................................................................................. 8 A. Compliance with Standards .................................................................................... 8 B. Drainage Concept..................................................................................................... 8 VI. REFERENCES ............................................................................................... 8 VII. APPENDICES A. Hydrologic Computations Vicinity Map FEMA FIRM Exhibit USGS Soil Map Fort Collins Rainfall Intensity Curve Fort Collins Rainfall Intensity Table Table RO-3 Recommended Percentage Imperviousness Values Rational Method Calculated Composite C Tables Rational Method Calculated Imperviousness Rational Method Calculated Flows B. Hydraulic Computations Table 3-8 Effective Imperviousness Adjustments for Level 2 MDCIA Detention Volume by the Modified FAA Method Reduced Detention Volume by the Modified FAA Method (Via Table 3-8) Stage-Discharge Sizing of Orifice 12" RCP Flow Calculation C. Water Quality Design Calculations UD BMP Rain Garden Calculations I. GENERAL LOCATION AND DESCRIPTION A. Location The proposed site is located in the southeast quarter (SE ¼) of the northwest quarter (NW ¼) of Section 20, Township 7 North, Range 68 West of the 6th P.M. in Larimer County, Colorado. Specifically, the property is located on the north side of Midpoint Drive, about halfway between South Timberline Road and Sharp Point Drive. More generally, southeast of South Timberline Road and East Prospect Road. The property address is 2600 Midpoint Drive, Fort Collins, Colorado, 80525. (Please see the vicinity map located in the Appendix A). B. Description of Property The property is Lot 17 of the Prospect Industrial Park and is currently 0.86 acres of undeveloped land surrounded by commercial and industrial properties to the northeast, northwest and southwest as well as a vacant lot to the southeast. Midpoint Drive is located directly southwest of the property and acts as its only access. South Timberline Road is positioned further southwest while East Prospect Road is located equidistance to the northeast. All surrounding roads are both currently paved with curb, gutter, sidewalk, and utilities installed. The existing property is mainly re-seeded overlot grading that drains generally to the southeast towards Midpoint Drive at approximately a 0.5 percent slope. Midpoint Drive, then attenuates the flow via gutter towards the intersection of Midpoint Drive and Sharp Point Drive where it is met by an area inlet and eventually makes its way to the Poudre River. There are generally no offsite flows that drain towards the property. The entire site is located in FEMA Flood Zone X, entirely outside of any 100-year flood plain (see FIRMETTE in Appendix A). According to the NRCS soils map survey, the native soils consist of the Type “D” soils. These soils consist of deep, poorly drained soils that formed in alluvium. These soils produce high runoff rates and low infiltration. There are no irrigation facilities located within the proposed site area. The proposed development will consist of the construction of two buildings that will act as office and storage and maintenance space. The two buildings (4,900 and 2,218) S.F. will be connected via a sister wall and will act as one (7,118) S.F. building. A drive aisle will be constructed and will include asphalt and impervious pavers. The northern portion of the site will be a gravel road-base surface and will act as site storage. II. DRAINAGE BASINS AND SUB-BASINS A. Major Basin Description The Vogel Concrete proposed site is located within the Poudre River Drainage Basin. The basin is a major tributary to the South Platte River and the major confluence of many of Fort Collins’ sub basins. Water quality and detention are required to attenuate developed flows to a 2-yr historic release rate. B. Sub-Basin Description Historically, the entire existing site drains to the southeast side of the property via sheet flow at a slope of 0.5 percent. This flow then exists the property to Midpoint Drive where it is then transported southeast until it is met by an area inlet. This flow is eventually carried via storm pipe to the Poudre River approximately 0.24 miles downstream. The developed site is delineated into one sub-basin with a rain garden/detention basin designed to provide both the required water quality capture volume and 100-year detention volume. Sub-basin B1, (0.86 acres), consists of roof, asphalt/concrete, gravel base course and landscaped area. Rainfall is carried away from the buildings in every direction into valley pans, swales and soft pans. From there, flow travels into L.I.D. rain garden/detention ponds. The WQCV is treated via the rain garden/dry well area while the 100-year flow is released at the 2-year historic rate. This sub-basin is conveyed out to Midpoint Drive, as it does historically, eventually making its way to the Poudre River. Currently, offsite flows do not enter the site property. This will not change after the site has been developed. III. DRAINAGE CRITERIA A. Regulations Drainage design criteria specified in the City of Fort Collins Storm Drainage Design Criteria and Construction Standards manual (FCSDCM) and the Urban Storm Drainage Criteria Manual, Volume 3 by the Urban Drainage and Flood Control District (UDFCD) have been referenced in the preparation of this study. B. Implementation of the “Four Step Process” The overall stormwater management strategy employed with the Vogel Concrete project 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 selecting a site with historically undetained runoff, the burden of development will be significantly less with a WQCV and detention pond. Also, for Basin B1, grass swales, soft pans and pavers are used to convey the runoff from impervious surfaces, reducing the effects of imperviousness. Step 2 – Implement BMPs That Provide a Water Quality Capture Volume (WQCV) with Slow Release. Urban development will cause stormwater runoff to increase from the site. The primary water quality will occur in the combined rain garden/detention pond on the southeast side of the lot. Refer to the map pocket for rain garden and detention pond details and cross-sections. The pond will reduce the release rate to equal or less than the historic 2-Yr release rate, while improving water quality. Step 3 – Stabilize Drainageways. The Poudre River is the governing drainageway for the Vogel Concrete site. While the project doesn’t affect the river directly, the proposed project indirectly helps achieve a better stabilized drainageway nonetheless. By improving the water quality and lowering the developed runoff to lower than the historic rate, the likelihood of bed and bank erosion from this site is greatly reduced. Step 4 – Implement Site Specific and Other Source Control BMPs. The Vogel Concrete site contains a plethora of source control BMPs. Permeable Pavement Systems: Flow from the roof will directly flow into the void area of the pavers avoiding any extra pollutant-flow contact time. Additional flow from the sidewalks and drive aisle will be captured by the pavers and be treated before and underdrain system transfers flow to the Rain Garden. Rain Garden/Dry Well: All Unconnected Impervious Areas (UIA) are drained through the on-site rain garden, reducing the impact of the impervious areas on water quality. Since the site contains poorly draining soils, two, 10 feet by 10 feet dry wells have been added to aid in the infiltration of the WQCV. Soft Pan: Before UIA flows are captured by the rain garden they are attenuated via pans, gutters, swales and soft pans. Some of these flows will travel through the soft pan on the northeast corner of the lot at a 1-2% slope and be the first defense against pollutants. C. Development Criteria Reference and Constraints The criteria used as the basis for analysis and design of stormwater management improvements for this site are those found in the references cited. To the knowledge of the author, there are no other capital drainage improvements planned for this portion of Prospect Industrial Park, aside from those referred to above, that would constrain or otherwise influence the design of the stormwater improvements for this site. D. Hydrological Criteria Stormwater runoff from the respective sub-basins of the Vogel Concrete site is analyzed for storms with 2-year and 100-year return frequencies. Due to the relatively small aggregate area of the tributary drainage sub-basins, the Rational Method was chosen for use in the design of the stormwater management improvements. The Rational Method provides that: Q = CIA, where: Q = Design flow in cubic feet per second (cfs) C = Coefficient of runoff for the area under consideration I = Rainfall intensity for the design storm duration (in/hr) A = Area of the drainage sub-basin under consideration (ac) Peak flows were calculated using the Rational Method for the 2-year and 100-year storm events. This software uses the local 1-hour rainfall depth and Fort Collins rainfall intensities developed calculate rainfall intensities as a function of the time of concentration. These values were obtained by the City of Fort Collins Rainfall Intensity-Duration- Frequency (IDF) curve/table; Figure 3-1 and Table 3-1a, and can be found in the Appendix. Additionally, per City of Fort Collins, the coefficients have been multiplied by the appropriate storm factors. Percent imperviousness values were taken from Table RO-3, Recommended Percentage Imperviousness Values, UDCM (See Appendix). Soils of hydrologic soil type “D” dominate the site. Onsite runoff was calculated to determine the runoff differential between existing and developed conditions for use in sizing the rain garden as required by the FCSDM.. The hydrologic basin parameters and runoff rates are included in the Appendices and include quantification of the allowable volume reduction. The USDFCD software UD-BMP v3.03 was used to calculate the required WQCV and the size for the proposed rain garden. The Urban Drainage, Table 3-8 Effective Imperviousness Adjustments for Level 2 MDCIA was used to determine the effective imperviousness of the site. The Modified FAA Detention Method as outlined in the UDCM Control was used to compute the required 100-year storage volume requirement for the site. The UDFCD software UD-Detention v2.34 was used to calculate the required detention storage volume as well as tabulate a stage-discharge relationship for the water quality capture volume and outlet structure. The design worksheets included in the Appendices to this Final Drainage Report present documentation of the hydrologic calculations for the on-site storm drainage systems. E. Hydraulic Criteria Within this development, all runoff will be conveyed on the surface, initially as sheet flow and subsequently as concentrated flow in shallow pans and gutters, as well as in grassed swales and soft pans. The west portion of the site will drain under the driveway through a culvert. The assessment of required capacity and the sizing of the respective components of the drainage system are based on the anticipated runoff from the 100-year storm event. The surface runoff will culminate into the rain garden/detention pond at the southeast portion of the site. The pond outlet will consist of a spillway weir with a water quality structure and an orifice plate restricting the ultimate release rate to equal or less than the allowable release rate of 0.16 cfs per acre. An emergency spillway with a crest elevation set greater than the required 100-year water surface elevation and sized to convey the 100-year developed flow and offsite flows at an operating head not exceeding half of the available freeboard is implemented in the detention pond. F. Modifications of Criteria There are no modifications or variances requested in connection with the design of the stormwater management for the Vogel Concrete site development. IV. DRAINAGE FACILITY DESIGN A. General Concept The storm drainage system is designed to safely convey developed storm flows by sheet flow and concentrated pan, underdrain, gutter, swale and soft pan flow to the rain garden/detention pond located at the southeast corner of the property. The rain garden/detention pond has been sized for the total required 100-year storage volume and the WQCV requirements for the entire site. The pond outlet structure is the ultimate release point off of the site and will be releasing the flow at the historic 2-year release rate of 0.16 cfs per acre, or 0.14 cfs, as required by the FCSDCM. The design worksheets included in the Appendices to this Final Drainage Report present details of the hydrologic and hydraulic calculations pertinent to the design of the on-site storm drainage system. A drainage plan, showing the proposed development of the site and developed drainage patterns is included in the map pocket following the Appendices. B. Specific Details There are a number of collection and conveyance scenarios within the drainage regime associated with this development. The respective scenarios are described below. Sub-basin B1, (0.86 acres), generally conveys flow away from the buildings until it is concentrated and eventually attenuated into the rain garden. Northwestern flows start initially as sheet flow over the concrete pad and road base material to the north of the building. They continue north until they are met by a 2 foot valley pan. This valley pan runs parallel to the northern property line and transfers the flow at 0.5% to the soft pan on the eastern side of the lot. The soft pan carries flows south to the rain garden at 1.0% and acts as both a means of conveyance as well as a primary treatment area. Once the flows are within the rain garden area, they are initially infiltrated while excess flows above the WQCV are detained and released out to Midpoint Drive and eventually into the Poudre River as described in the rain garden/detention pond section below. Northeastern flows are much like the northwestern flows described above. They start initially as sheet flow over the concrete pad and road base material traveling in two directions. First, flows travel north into the 2 foot valley pan and continue on exactly as the northwestern flows. The second travel path attenuates flows directly into the soft pan and proceeds as described by the northwestern flows. Southwestern flows start initially as sheet flow over the roofs and sidewalk area. Half of the northern building’s roof will drain to the west while the other half will drain to the east. Western flows will flow via gutter directly into the swale on the west side of the building. This flow eventually makes it way into the detention pond area in the southwest portion of the lot. Flow will accumulate and concentrate into the soft pan within the pond and flow towards the 12 inch culvert. This culvert allows for flow captured in the southwest detention pond to travel underneath the drive aisle to the rain garden where it can infiltrate and continue on as previously described. The eastern portion of the northern building’s roof flows will flow via gutter and sub-drain directly into the void space of the permeable pavers located within the western most parking spots. From there, flow is transferred via a 6 inch sub-drain to the rain garden where it proceeds just as the northwestern and northeastern flows. The southern building’s roof will drain directly into the detention pond located on the southwest quarter of the lot and proceed into the culvert and into the rain garden. The rest of the area encompassed by the southwestern portion of the lot will flow initially as sheet flow toward the pervious pavers located within the southeast parking spots. A portion of this flow is infiltrated through the pavers and is eventually transferred to the rain garden via a 6 inch sub-drain, while the remaining flow is transferred directly to the rain garden through a 2 foot curb cut. Southeastern flows include the drive aisle and the rain garden. Flow starts as sheet flow and proceed to the pervious pavers and continue just as the latter portion of the southwestern flows do. The rain garden is located in this quarter of the lot and acts as the ultimate release point for the entire site. C. Rain Garden/Detention Pond The rain garden/detention pond has been designed to accommodate volume and release requirements for the Vogel Concrete site in its entirety. The 100-year detention requirement for the site is 5,238 cubic feet, while the WQCV required is 533 cubic feet. The total detention volume required including 100-year detention and water quality is 5,771 cubic feet. The WQCV infiltrates completely through the rain garden media. Since the soils are poorly draining, two, 10 feet by 10 feet dry wells have been designed to assure the flow fully infiltrates the surface and does not adversely affect the site drainage. The outlet structure has been designed to release the flows above the WQCV at a maximum allowable release rate for the site of 0.16 cfs per acre. 0.012 0.12 0.132 0.134 4897.26 4896.17 4897.26 0.14 Orifice (1) 3 1/8” hole 100-Yr Release Rate (cfs) Outlet Type Outlet Size WQCV+100 Yr Req'd (ac-ft) Rain Garden Detention Pond Summary WQCV Required (ac-ft) 100-YR Volume Required (ac-ft) Total Volume Provided (ac-ft) 100-YR Elevation WQCV Elevation Spillway Elevation The drive aisle will also act as a utility and access easement along the entire west side of the detention pond to allow for maintenance access. There will be no new facilities required offsite for the conveyance of the minor or major flows to the Poudre River. V. CONCLUSIONS A. Compliance with Standards The drainage design for the Vogel Concrete Project is in compliance with the requirements of the City of Fort Collins Storm Drainage Design Criteria and Construction Standards Manual as well as the City’s floodplain regulations. The criteria and recommendations of the Urban Storm Drainage Criteria Manual are also reflected in the design of the drainage systems. B. Drainage Concept The drainage design for the Vogel Concrete Project will be adequate to safely convey onsite and offsite flows through the development. The design will attenuate the 100-year developed site flow down to the 0.16 cfs per acre release rate as required by the City of Fort Collins. Development of the site, as proposed, should have a beneficial impact on water quality in downstream drainage facilities and drainage ways by reducing and delaying the initial discharge of runoff from the site such that sediments and other potential pollutants typically carried by this first flush are removed from the flow. VI. REFERENCES “City of Fort Collins Stormwater Criteria Manual”, City of Fort Collins, Adopted December 2011 “City of Fort Collins Municipal Code”, Chapter 10 – Flood Protection and Prevention City of Fort Collins, 1987 Urban Storm Drainage Criteria Manual, Volumes 1, 2, and 3, Urban Drainage and Flood Control District, April 2008 VII. APPENDICES A. Hydrologic Computations Vicinity Map FEMA FIRM Exhibit USGS Soil Map Fort Collins Rainfall Intensity Curve Fort Collins Rainfall Intensity Table Table RO-3 Recommended Percentage Imperviousness Values Rational Method Calculated Composite C Tables Rational Method Calculated Imperviousness Rational Method Calculated Flows RIVERSIDE AVE PROSPECT ROAD LEMAY AVE RIVENDAL DR Hydrologic Soil Group—Larimer County Area, Colorado (TOUCHSTONE HEALTH) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/25/2014 Page 1 of 4 4491510 4491550 4491590 4491630 4491670 4491710 4491750 4491510 4491550 4491590 4491630 4491670 4491710 4491750 495080 495120 495160 495200 495240 495280 495320 495360 495400 495440 495080 495120 495160 495200 495240 495280 495320 495360 495400 495440 40° 34' 35'' N 105° 3' 29'' W 40° 34' 35'' N 105° 3' 13'' W 40° 34' 27'' N 105° 3' 29'' W 40° 34' 27'' N 105° 3' 13'' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 50 100 200 300 Feet 0 25 50 100 150 Meters Map Scale: 1:1,760 if printed on A landscape (11" x 8.5") 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 53 Kim loam, 1 to 3 percent slopes B 1.4 12.1% 94 Satanta loam, 0 to 1 percent slopes B 10.4 87.9% Totals for Area of Interest 11.8 100.0% 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 Hydrologic Soil Group—Larimer County Area, Colorado TOUCHSTONE HEALTH Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/25/2014 Page 3 of 4 Component Percent Cutoff: None Specified Tie-break Rule: Higher Hydrologic Soil Group—Larimer County Area, Colorado TOUCHSTONE HEALTH Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/25/2014 Page 4 of 4 DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF Table RO-3—Recommended Percentage Imperviousness Values Land Use or Surface Characteristics Percentage Imperviousness Business: Commercial areas 95 Neighborhood areas 85 Residential: Single-family * Multi-unit (detached) 60 Multi-unit (attached) 75 Half-acre lot or larger * Apartments 80 Industrial: Light areas 80 Heavy areas 90 Parks, cemeteries 5 Playgrounds 10 Schools 50 Railroad yard areas 15 Undeveloped Areas: Historic flow analysis 2 Greenbelts, agricultural 2 Off-site flow analysis (when land use not defined) 45 Streets: Paved 100 Gravel (packed) 40 Drive and walks 90 Roofs 90 Lawns, sandy soil 0 Lawns, clayey soil 0 * See Figures RO-3 through RO-5 for percentage imperviousness. C K 1 . 31 i 3 1 . 44 i 2 1 . 135 i 0 . 12 A A for CA 0, otherwise CA = 0 (RO-6) C K 0 . 858 i 3 0 . 786 i 2 0 . 774 i 0 . 04 CD CD (RO-7) C 2 B A CD C C 2007-01 RO-9 Urban Drainage and Flood Control District Composite C Values Touchstone Addition Asphalt Area (acres) Concrete Area (acres) Gravel (acres) Roofs (acres) Lawns (acres) Total Area Minor (2-YR) Major (100-YR) (C = 0.95) (C = 0.95) (C = 0.50) (C = 0.95) (C = 0.15) (acres) Composite "C" Composite "C" (Cf x C) E1 E1 0.000 0.0000 0.0816 0.0000 0.0000 0.0816 0.50 0.63 E 1a E 1a 0.000 0.000 0.0367 0.0000 0.0000 0.0367 0.50 0.63 P1 B1 0.000 0.0191 0.0159 0.0367 0.0100 0.0816 0.76 0.96 P 1a B 1a 0.000 0.0000 0.0000 0.0367 0.0000 0.0367 0.95 1.00 Notes: Composite C values obtained from Table R0-11 Major Storm Runoff factored per Table R0-12 Developed Design Point Basin(s) Existing CAG City of Fort Collins Rational Method 12/11/2014 Percent Impevious Values Touchstone Addition Asphalt Area (acres) Concrete Area (acres) Gravel (acres) Roofs (acres) Lawns (acres) Total Area Percent (I = 100) (I = 100) (I = 40) (I = 90) (I = 0) (acres) Imperviousness E1 E1 0.000 0.000 0.0816 0.0000 0.0000 0.0816 40% E 1a E 1a 0.000 0.000 0.0367 0.0000 0.0000 0.0367 40% P1 B1 0.000 0.019 0.0159 0.0367 0.0100 0.0816 72% P 1a B 1a 0.000 0.000 0.0000 0.0367 0.0000 0.0367 90% Notes: Percent Impervious Values per Table R0-3, Urban Drainage Manual Developed Design Point Basin (s) Existing CAG City of Fort Collins Rational Method 12/11/2014 Basin Flow Calculations Touchstone Addition Area Minor Major (acres) Composite "C" Composite "C" Length (ft) Slope (%) Minor tov (min)a Major tov (min)a Length (ft) Slope (%) Channel Type Velocity (fps)c tt (min) Minor TC (min) Major TC (min) 2-yr 10-yr 100-yr 2-yr 10-yr 100-yr E1 E1 0.0816 0.50 0.63 52 2.83 5.72 4.53 0 0.00 PL 0.00 0.00 5.72 5.00 2.76 4.72 9.95 0.11 0.19 0.51 E 1a E 1a 0.0367 0.50 0.63 52 2.83 5.72 4.53 0 0.00 PL 0.00 0.00 5.72 5.00 2.76 4.72 9.95 0.05 0.09 0.23 P1 B1 0.0816 0.76 0.96 46 0.50 5.37 2.31 2 4.60 PL 1.50 0.0222 5.39 5.00 2.76 4.72 9.95 0.17 0.29 0.78 P 1a B 1a 0.0367 0.95 1.00 46 0.50 2.40 1.60 2 4.60 PL 1.50 0.0222 5.00 5.00 2.85 4.87 9.95 0.10 0.17 0.36 Notes: a b HM = Heavy Meadow, TF = Tillage/field, PL = Short pasture and lawns, BG = Nearly bare ground, GW = Grassed Waterway, PA = Paved Areas c Velocity alues from Figure 3-3/Table RO-2 Estimate of Average Flow Velocity for use with the Rational Method Design Point Developed Existing Initial/Overland Time Final TC Intensity (in/hr) Basin Flows (cfs) Basin (s) Travel Time 1 / 3 1 . 87 ( 1 . 1 ) 1 / 2 S CC D t f ov − = CAG City of Fort Collins Rational Method 12/11/2014 APPENDIX B: Hydraulic Computations Table 3-8 Effective Imperviousness Adjustments for Level 2 MDCIA Detention Volume by the Modified FAA Method Reduced Detention Volume by the Modified FAA Method (Via Table 3-8) Stage-Discharge Sizing of Orifice 12” RCP Flow Calculation Calculating the WQCV and Volume Reduction Chapter 3 3-14 Urban Drainage and Flood Control District August 2011 Urban Storm Drainage Criteria Manual Volume 3 Figure 3-8. Effective Imperviousness Adjustments for Level 2 MDCIA 4.3 Site-level Volume Reduction Methods For site-level planning, whether at a conceptual level or a more advanced stage of design, it is not necessary to use default D and R values if the various area fractions of a site (i.e., DCIA, UIA, RPA, and SPA) can be defined. Two options are available for quantification of volume reduction at the site level when these fractions have been identified: 1. SWMM modeling using the cascading plane approach, or 2. UDFCD Imperviousness Reduction Factor (IRF) charts and spreadsheet (located within the UD-BMP workbook available at www.udfcd.org) The UDFCD IRF charts and spreadsheet were developed using a dimensionless SWMM modeling approach developed by Guo et al. (2010) that determines the effective imperviousness of a site based on the total area-weighted imperviousness and the ratio of the infiltration rate (average infiltration rate based on Green-Ampt ), f, to the rainfall intensity, I. Because the IRF is based on cascading plane CUHP/SWMM modeling, it will yield results that are generally consistent with creation of a site-specific SWMM model. WQCV Reduced Imperviousness = 52.5% 100-Yr Reduced Imperviousness = 59.1% Vogel Concrete: Quality Engineering Impervious Reductions Project: Basin ID: Design Information (Input): Design Information (Input): Catchment Drainage Imperviousness Ia = 64.00 percent Catchment Drainage Imperviousness I a = 64.00 percent Catchment Drainage Area A = 0.861 acres Catchment Drainage Area A = 0.861 acres Predevelopment NRCS Soil Group Type = D A, B, C, or D Predevelopment NRCS Soil Group Type = D A, B, C, or D Return Period for Detention Control T = 2 years (2, 5, 10, 25, 50, or 100) Return Period for Detention Control T = 100 years (2, 5, 10, 25, 50, or 100) Time of Concentration of Watershed Tc = 5.71 minutes Time of Concentration of Watershed Tc = 5.71 minutes Allowable Unit Release Rate q = 0.16 cfs/acre Allowable Unit Release Rate q = 0.16 cfs/acre One-hour Precipitation P1 = 0.82 inches One-hour Precipitation P 1 = 2.83 inches Design Rainfall IDF Formula i = C1* P 1/(C2 +Tc)^C 3 Design Rainfall IDF Formula i = C1 * P1/(C 2+Tc )^C3 Coefficient One C1 = 28.50 Coefficient One C 1 = 28.50 Coefficient Two C2 = 10 Coefficient Two C 2 = 10 Coefficient Three C3 = 0.789 Coefficient Three C 3 = 0.789 Determination of Average Outflow from the Basin (Calculated): Determination of Average Outflow from the Basin (Calculated): Runoff Coefficient C = 0.44 Runoff Coefficient C = 0.65 Inflow Peak Runoff Qp-in = 1.01 cfs Inflow Peak Runoff Qp-in = 5.14 cfs Allowable Peak Outflow Rate Qp-out = 0.14 cfs Allowable Peak Outflow Rate Qp-out = 0.14 cfs Mod. FAA Minor Storage Volume = 840 cubic feet Mod. FAA Major Storage Volume = 5,413 cubic feet Mod. FAA Minor Storage Volume = 0.019 acre-ft Mod. FAA Major Storage Volume = 0.124 acre-ft 1 <- Enter Rainfall Duration Incremental Increase Value Here (e.g. 5 for 5-Minutes) Rainfall Rainfall Inflow Adjustment Average Outflow Storage Rainfall Rainfall Inflow Adjustment Average Outflow Storage Duration Intensity Volume Factor Outflow Volume Volume Duration Intensity Volume Factor Outflow Volume Volume minutes inches / hr acre-feet "m" cfs acre-feet acre-feet minutes inches / hr acre-feet "m" cfs acre-feet acre-feet (input) (output) (output) (output) (output) (output) (output) (input) (output) (output) (output) (output) (output) (output) 0 0.00 0.000 0.00 0.00 0.000 0.000 0 0.00 0.000 0.00 0.00 0.000 0.000 1 3.52 0.002 1.00 0.14 0.000 0.002 1 12.16 0.009 1.00 0.14 0.000 0.009 2 3.29 0.003 1.00 0.14 0.000 0.003 2 11.35 0.018 1.00 0.14 0.000 0.017 3 3.09 0.005 1.00 0.14 0.001 0.004 3 10.66 0.025 1.00 0.14 0.001 0.024 4 2.91 0.006 1.00 0.14 0.001 0.005 4 10.05 0.031 1.00 0.14 0.001 0.030 5 2.76 0.007 1.00 0.14 0.001 0.006 5 9.52 0.037 1.00 0.14 0.001 0.036 6 2.62 0.008 0.98 0.14 0.001 0.007 6 9.05 0.042 0.98 0.14 0.001 0.041 7 2.50 0.009 0.91 0.13 0.001 0.008 7 8.63 0.047 0.91 0.13 0.001 0.045 8 2.39 0.010 0.86 0.12 0.001 0.009 8 8.25 0.051 0.86 0.12 0.001 0.050 9 2.29 0.011 0.82 0.11 0.001 0.009 9 7.90 0.055 0.82 0.11 0.001 0.053 10 2.20 0.011 0.79 0.11 0.002 0.010 10 7.59 0.058 0.79 0.11 0.002 0.057 11 2.12 0.012 0.76 0.11 0.002 0.011 11 7.30 0.062 0.76 0.11 0.002 0.060 12 2.04 0.013 0.74 0.10 0.002 0.011 12 7.04 0.065 0.74 0.10 0.002 0.063 13 1.97 0.013 0.72 0.10 0.002 0.012 13 6.80 0.068 0.72 0.10 0.002 0.066 14 1.90 0.014 0.70 0.10 0.002 0.012 14 6.57 0.071 0.70 0.10 0.002 0.069 15 1.84 0.014 0.69 0.10 0.002 0.012 15 6.36 0.074 0.69 0.10 0.002 0.072 16 1.79 0.015 0.68 0.09 0.002 0.013 16 6.17 0.076 0.68 0.09 0.002 0.074 17 1.74 0.015 0.67 0.09 0.002 0.013 17 5.99 0.078 0.67 0.09 0.002 0.076 18 1.69 0.016 0.66 0.09 0.002 0.014 18 5.82 0.081 0.66 0.09 0.002 0.078 19 1.64 0.016 0.65 0.09 0.002 0.014 19 5.66 0.083 0.65 0.09 0.002 0.081 20 1.60 0.017 0.64 0.09 0.002 0.014 20 5.51 0.085 0.64 0.09 0.002 0.082 21 1.56 0.017 0.64 0.09 0.003 0.014 21 5.37 0.087 0.64 0.09 0.003 0.084 22 1.52 0.017 0.63 0.09 0.003 0.015 22 5.24 0.089 0.63 0.09 0.003 0.086 23 1.48 0.018 0.62 0.09 0.003 0.015 23 5.11 0.091 0.62 0.09 0.003 0.088 Project: Basin ID: Design Information (Input): Design Information (Input): Catchment Drainage Imperviousness Ia = 59.10 percent Catchment Drainage Imperviousness I a = 59.10 percent Catchment Drainage Area A = 0.861 acres Catchment Drainage Area A = 0.861 acres Predevelopment NRCS Soil Group Type = D A, B, C, or D Predevelopment NRCS Soil Group Type = D A, B, C, or D Return Period for Detention Control T = 2 years (2, 5, 10, 25, 50, or 100) Return Period for Detention Control T = 100 years (2, 5, 10, 25, 50, or 100) Time of Concentration of Watershed Tc = 5.71 minutes Time of Concentration of Watershed Tc = 5.71 minutes Allowable Unit Release Rate q = 0.16 cfs/acre Allowable Unit Release Rate q = 0.16 cfs/acre One-hour Precipitation P1 = 0.82 inches One-hour Precipitation P 1 = 2.83 inches Design Rainfall IDF Formula i = C1* P 1/(C2 +Tc)^C 3 Design Rainfall IDF Formula i = C1 * P1/(C 2+Tc )^C3 Coefficient One C1 = 28.50 Coefficient One C 1 = 28.50 Coefficient Two C2 = 10 Coefficient Two C 2 = 10 Coefficient Three C3 = 0.789 Coefficient Three C 3 = 0.789 Determination of Average Outflow from the Basin (Calculated): Determination of Average Outflow from the Basin (Calculated): Runoff Coefficient C = 0.40 Runoff Coefficient C = 0.63 Inflow Peak Runoff Qp-in = 0.92 cfs Inflow Peak Runoff Qp-in = 4.98 cfs Allowable Peak Outflow Rate Qp-out = 0.14 cfs Allowable Peak Outflow Rate Qp-out = 0.14 cfs Mod. FAA Minor Storage Volume = 738 cubic feet Mod. FAA Major Storage Volume = 5,238 cubic feet Mod. FAA Minor Storage Volume = 0.017 acre-ft Mod. FAA Major Storage Volume = 0.120 acre-ft 1 <- Enter Rainfall Duration Incremental Increase Value Here (e.g. 5 for 5-Minutes) Rainfall Rainfall Inflow Adjustment Average Outflow Storage Rainfall Rainfall Inflow Adjustment Average Outflow Storage Duration Intensity Volume Factor Outflow Volume Volume Duration Intensity Volume Factor Outflow Volume Volume minutes inches / hr acre-feet "m" cfs acre-feet acre-feet minutes inches / hr acre-feet "m" cfs acre-feet acre-feet (input) (output) (output) (output) (output) (output) (output) (input) (output) (output) (output) (output) (output) (output) 0 0.00 0.000 0.00 0.00 0.000 0.000 0 0.00 0.000 0.00 0.00 0.000 0.000 1 3.52 0.002 1.00 0.14 0.000 0.001 1 12.16 0.009 1.00 0.14 0.000 0.009 2 3.29 0.003 1.00 0.14 0.000 0.003 2 11.35 0.017 1.00 0.14 0.000 0.017 3 3.09 0.004 1.00 0.14 0.001 0.004 3 10.66 0.024 1.00 0.14 0.001 0.023 4 2.91 0.006 1.00 0.14 0.001 0.005 4 10.05 0.030 1.00 0.14 0.001 0.029 5 2.76 0.007 1.00 0.14 0.001 0.006 5 9.52 0.036 1.00 0.14 0.001 0.035 6 2.62 0.007 0.98 0.14 0.001 0.006 6 9.05 0.041 0.98 0.14 0.001 0.039 7 2.50 0.008 0.91 0.13 0.001 0.007 7 8.63 0.045 0.91 0.13 0.001 0.044 8 2.39 0.009 0.86 0.12 0.001 0.008 8 8.25 0.049 0.86 0.12 0.001 0.048 9 2.29 0.010 0.82 0.11 0.001 0.008 9 7.90 0.053 0.82 0.11 0.001 0.052 10 2.20 0.010 0.79 0.11 0.002 0.009 10 7.59 0.057 0.79 0.11 0.002 0.055 11 2.12 0.011 0.76 0.11 0.002 0.009 11 7.30 0.060 0.76 0.11 0.002 0.058 12 2.04 0.012 0.74 0.10 0.002 0.010 12 7.04 0.063 0.74 0.10 0.002 0.061 13 1.97 0.012 0.72 0.10 0.002 0.010 13 6.80 0.066 0.72 0.10 0.002 0.064 14 1.90 0.013 0.70 0.10 0.002 0.011 14 6.57 0.069 0.70 0.10 0.002 0.067 15 1.84 0.013 0.69 0.10 0.002 0.011 15 6.36 0.071 0.69 0.10 0.002 0.069 16 1.79 0.014 0.68 0.09 0.002 0.011 16 6.17 0.074 0.68 0.09 0.002 0.072 17 1.74 0.014 0.67 0.09 0.002 0.012 17 5.99 0.076 0.67 0.09 0.002 0.074 18 1.69 0.014 0.66 0.09 0.002 0.012 18 5.82 0.078 0.66 0.09 0.002 0.076 19 1.64 0.015 0.65 0.09 0.002 0.012 19 5.66 0.080 0.65 0.09 0.002 0.078 20 1.60 0.015 0.64 0.09 0.002 0.013 20 5.51 0.082 0.64 0.09 0.002 0.080 21 1.56 0.015 0.64 0.09 0.003 0.013 21 5.37 0.084 0.64 0.09 0.003 0.082 22 1.52 0.016 0.63 0.09 0.003 0.013 22 5.24 0.086 0.63 0.09 0.003 0.083 23 1.48 0.016 0.62 0.09 0.003 0.013 23 5.11 0.088 0.62 0.09 0.003 0.085 Project: Basin ID: Design Information (Input): #1 Horiz. #2 Horiz. #1 Vert. #2 Vert. Circular Opening: Diameter in Inches Dia. = 0.00 0.00 3.13 0.00 inches OR Rectangular Opening: Width in Feet W = ft. Length (Height for Vertical) L or H = ft. Percentage of Open Area After Trash Rack Reduction % open = 50 % Orifice Coefficient Co = 0.65 Weir Coefficient Cw = Orifice Elevation (Bottom for Vertical) Eo = 96.17 ft. Calculation of Collection Capacity: Net Opening Area (after Trash Rack Reduction) Ao = 0.00 0.00 0.03 0.00 sq. ft. OPTIONAL: User-Overide Net Opening Area Ao = sq. ft. Perimeter as Weir Length Lw = 0.00 0.00 ft. OPTIONAL: User-Overide Weir Length Lw = ft. Top Elevation of Vertical Orifice Opening, Top = 96.43 0.00 ft. Center Elevation of Vertical Orifice Opening, Cen = 96.30 0.00 ft. Horizontal Orifices Vertical Orifices Labels Water WQCV #1 Horiz. #1 Horiz. #2 Horiz. #2 Horiz. #1 Vert. #2 Vert. Total Target Volumes for WQCV, Minor, Surface Plate/Riser Weir Orifice Weir Orifice Collection Collection Collection for WQCV, Minor, & Major Storage Elevation Flow Flow Flow Flow Flow Capacity Capacity Capacity & Major Storage W.S. Elevations ft cfs cfs cfs cfs cfs cfs cfs cfs Volumes (input) (linked) (User-linked) (output) (output) (output) (output) (output) (output) (output) (link for goal seek) 95.78 0.00 0.00 0.00 0.00 0.00 0.00 0.00 96.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 WQCV 96.17 0.00 0.00 0.00 0.00 0.00 0.00 0.00 96.25 0.00 0.00 0.00 0.00 0.01 0.00 0.00 96.50 0.00 0.00 0.00 0.00 0.06 0.00 0.00 96.75 0.00 0.00 0.00 0.00 0.09 0.00 0.00 97.00 0.00 0.00 0.00 0.00 0.12 0.00 0.00 97.25 0.00 0.00 0.00 0.00 0.14 0.00 0.00 Spillway Elev. 97.26 0.00 0.00 0.00 0.00 0.14 0.00 0.00 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A Hydraulic Analysis Report Project Data Project Title: Designer: Project Date: Tuesday, January 13, 2015 Project Units: U.S. Customary Units Notes: Channel Analysis: 12" RCP Notes: Input Parameters Channel Type: Circular Pipe Diameter: 1.0000 ft Longitudinal Slope: 0.0025 ft/ft Manning's n: 0.0130 Flow: 1.7700 cfs Result Parameters Depth: 0.8139 ft Area of Flow: 0.6845 ft^2 Wetted Perimeter: 2.2495 ft Average Velocity: 2.5857 ft/s Top Width: 0.7784 ft Froude Number: 0.4859 Critical Depth: 0.5659 ft Critical Velocity: 3.8610 ft/s Critical Slope: 0.0066 ft/ft Critical Top Width: 0.9913 ft Calculated Max Shear Stress: 0.1270 lb/ft^2 Calculated Avg Shear Stress: 0.0475 lb/ft^2 C. Water Quality Design Calculations UD BMP Rain Garden Calculations Sheet 1 of 2 Designer: Company: Date: Project: Location: 1. Basin Storage Volume A) Effective Imperviousness of Tributary Area, Ia Ia = 90.0 % (100% if all paved and roofed areas upstream of rain garden) B) Tributary Area's Imperviousness Ratio (i = Ia/100) i = 0.900 C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.32 watershed inches (WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i) D) Contributing Watershed Area (including rain garden area) Area = 1,600 sq ft E) Water Quality Capture Volume (WQCV) Design Volume VWQCV = cu ft Vol = (WQCV / 12) * Area F) For Watersheds Outside of the Denver Region, Depth of d6 = 0.43 in Average Runoff Producing Storm G) For Watersheds Outside of the Denver Region, VWQCV OTHER = 42.8 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 = 29 sq ft D) Actual Flat Surface Area AActual = 55 sq ft E) Area at Design Depth (Top Surface Area) ATop = 370 sq ft F) Rain Garden Total Volume VT= 212 cu ft (VT= ((ATop + AActual) / 2) * Depth) 3. Growing Media 4. Underdrain System A) Are underdrains provided? B) Underdrain system orifice diameter for 12 hour drain time i) Distance From Lowest Elevation of the Storage y = N/A ft Volume to the Center of the Orifice ii) Volume to Drain in 12 Hours Vol12 = N/A cu ft iii) Orifice Diameter, 3/8" Minimum DO = N/A in Design Procedure Form: Rain Garden (RG) GLF QUALITY ENGINEERING December 11, 2014 1217 RIVERSIDE AVE (One rg north) FORT COLLINS, COLORADO Choose One Choose One 18" Rain Garden Growing Media Other (Explain): YES NO UD-BMP_RAIN GARDEN (North RG with vertical walls), RG 12/11/2014, 1:24 PM 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) GLF QUALITY ENGINEERING December 11, 2014 1217 RIVERSIDE AVE (One rg north) FORT COLLINS, COLORADO 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 UD-BMP_RAIN GARDEN (North RG with vertical walls), RG 12/11/2014, 1:24 PM LIGHTFIELD ENTERPRISES, INC 2600 MIDPOINT DRIVE FORT COLLINS, CO GRADING PLAN 00 10' 20' 40' 1"=20' FOR BURIED UTILITY INFORMATION THREE (3) BUSINESS DAYS BEFORE YOU DIG CALL 811 (OR 1-800-922-1987) UTILITY NOTIFICATION CENTER OF COLORADO (UNCC) WWW.UNCC.ORG R CITY OF FORT COLLINS, COLORADO UTILITY PLAN APPROVAL C4.0 INV = 97.06 INV = 96.20 6" PVC UNDERDRAIN INV = 96.20 00 10' 20' 40' 1"=20' DRAINAGE & L.I.D. PLAN CITY OF FORT COLLINS, COLORADO UTILITY PLAN APPROVAL LIGHTFIELD ENTERPRISES, INC 2600 MIDPOINT DRIVE FORT COLLINS, CO FOR BURIED UTILITY INFORMATION THREE (3) BUSINESS DAYS BEFORE YOU DIG CALL 811 (OR 1-800-922-1987) UTILITY NOTIFICATION CENTER OF COLORADO (UNCC) WWW.UNCC.ORG R C5.0 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A Routing 2: Water flows through WQCV plate and #1 vertical opening and #1 horizontal opening into #2 vertical opening (#2 horizontal opening is not used). STAGE-DISCHARGE SIZING OF THE WEIRS AND ORIFICES (INLET CONTROL) Urban Box-Storage 100-YR Detention Current Routing Order is #2 W.S. EL. WQ W.S. EL. Minor W.S. EL. Major WQ H1 H2 V1 V2 Routing Order #1 (Standard) V1 W.S. EL. WQ W.S. EL. Design Storm WQ H1 Routing Order #3 (Single Stage) Routing Order #4 V2 V1 H1 WQ W.S. EL. Major W.S. EL. Minor W.S. EL. WQ W.S. EL. Emergency Spillway Emergency Overflow into Pipe- H2 V2 H1 WQ W.S. EL. Major W.S. EL. Minor W.S. EL. WQ V1 Routing Order #2 100-Year Developed UD-Detention_v2.33_USEME, Outlet 1/19/2015, 4:17 PM 24 1.45 0.016 0.62 0.09 0.003 0.014 24 4.99 0.090 0.62 0.09 0.003 0.087 25 1.41 0.017 0.61 0.09 0.003 0.014 25 4.88 0.091 0.61 0.09 0.003 0.088 26 1.38 0.017 0.61 0.09 0.003 0.014 26 4.77 0.093 0.61 0.09 0.003 0.090 27 1.35 0.017 0.61 0.08 0.003 0.014 27 4.67 0.094 0.61 0.08 0.003 0.091 28 1.32 0.018 0.60 0.08 0.003 0.014 28 4.57 0.096 0.60 0.08 0.003 0.092 29 1.30 0.018 0.60 0.08 0.003 0.015 29 4.48 0.097 0.60 0.08 0.003 0.094 30 1.27 0.018 0.60 0.08 0.003 0.015 30 4.39 0.098 0.60 0.08 0.003 0.095 31 1.25 0.018 0.59 0.08 0.004 0.015 31 4.31 0.100 0.59 0.08 0.004 0.096 32 1.22 0.019 0.59 0.08 0.004 0.015 32 4.23 0.101 0.59 0.08 0.004 0.097 33 1.20 0.019 0.59 0.08 0.004 0.015 33 4.15 0.102 0.59 0.08 0.004 0.099 34 1.18 0.019 0.58 0.08 0.004 0.015 34 4.07 0.103 0.58 0.08 0.004 0.100 35 1.16 0.019 0.58 0.08 0.004 0.015 35 4.00 0.105 0.58 0.08 0.004 0.101 36 1.14 0.019 0.58 0.08 0.004 0.015 36 3.93 0.106 0.58 0.08 0.004 0.102 37 1.12 0.020 0.58 0.08 0.004 0.016 37 3.87 0.107 0.58 0.08 0.004 0.103 38 1.10 0.020 0.58 0.08 0.004 0.016 38 3.80 0.108 0.58 0.08 0.004 0.104 39 1.08 0.020 0.57 0.08 0.004 0.016 39 3.74 0.109 0.57 0.08 0.004 0.105 40 1.07 0.020 0.57 0.08 0.004 0.016 40 3.68 0.110 0.57 0.08 0.004 0.106 41 1.05 0.020 0.57 0.08 0.005 0.016 41 3.63 0.111 0.57 0.08 0.005 0.107 42 1.03 0.021 0.57 0.08 0.005 0.016 42 3.57 0.112 0.57 0.08 0.005 0.107 43 1.02 0.021 0.57 0.08 0.005 0.016 43 3.52 0.113 0.57 0.08 0.005 0.108 44 1.00 0.021 0.56 0.08 0.005 0.016 44 3.47 0.114 0.56 0.08 0.005 0.109 45 0.99 0.021 0.56 0.08 0.005 0.016 45 3.42 0.115 0.56 0.08 0.005 0.110 46 0.98 0.021 0.56 0.08 0.005 0.016 46 3.37 0.116 0.56 0.08 0.005 0.111 47 0.96 0.021 0.56 0.08 0.005 0.016 47 3.32 0.117 0.56 0.08 0.005 0.112 48 0.95 0.022 0.56 0.08 0.005 0.016 48 3.28 0.117 0.56 0.08 0.005 0.112 49 0.94 0.022 0.56 0.08 0.005 0.016 49 3.23 0.118 0.56 0.08 0.005 0.113 50 0.92 0.022 0.56 0.08 0.005 0.017 50 3.19 0.119 0.56 0.08 0.005 0.114 51 0.91 0.022 0.56 0.08 0.005 0.017 51 3.15 0.120 0.56 0.08 0.005 0.114 52 0.90 0.022 0.55 0.08 0.006 0.017 52 3.11 0.121 0.55 0.08 0.006 0.115 53 0.89 0.022 0.55 0.08 0.006 0.017 53 3.07 0.122 0.55 0.08 0.006 0.116 54 0.88 0.022 0.55 0.08 0.006 0.017 54 3.03 0.122 0.55 0.08 0.006 0.117 55 0.87 0.023 0.55 0.08 0.006 0.017 55 2.99 0.123 0.55 0.08 0.006 0.117 56 0.86 0.023 0.55 0.08 0.006 0.017 56 2.96 0.124 0.55 0.08 0.006 0.118 57 0.85 0.023 0.55 0.08 0.006 0.017 57 2.92 0.124 0.55 0.08 0.006 0.118 58 0.84 0.023 0.55 0.08 0.006 0.017 58 2.89 0.125 0.55 0.08 0.006 0.119 59 0.83 0.023 0.55 0.08 0.006 0.017 59 2.86 0.126 0.55 0.08 0.006 0.120 60 0.82 0.023 0.55 0.08 0.006 0.017 60 2.82 0.127 0.55 0.08 0.006 0.120 Mod. FAA Minor Storage Volume (cubic ft.) = 738 Mod. FAA Major Storage Volume (cubic ft.) = 5,238 Mod. FAA Minor Storage Volume (acre-ft.) = 0.0170 Mod. FAA Major Storage Volume (acre-ft.) = 0.1202 Determination of MAJOR Detention Volume Using Modified FAA Method (For catchments less than 160 acres only. For larger catchments, use hydrograph routing method) (NOTE: for catchments larger than 90 acres, CUHP hydrograph and routing are recommended) UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.33, Released August 2013 Determination of MINOR Detention Volume Using Modified FAA Method DETENTION VOLUME BY THE MODIFIED FAA METHOD Vogel Concrete LID Reduced Developed 100-YR 100-Year Developed UD-Detention_v2.33_USEME, Modified FAA 1/16/2015, 12:32 PM 24 1.45 0.018 0.62 0.09 0.003 0.015 24 4.99 0.092 0.62 0.09 0.003 0.089 25 1.41 0.018 0.61 0.09 0.003 0.015 25 4.88 0.094 0.61 0.09 0.003 0.091 26 1.38 0.019 0.61 0.09 0.003 0.016 26 4.77 0.096 0.61 0.09 0.003 0.093 27 1.35 0.019 0.61 0.08 0.003 0.016 27 4.67 0.097 0.61 0.08 0.003 0.094 28 1.32 0.019 0.60 0.08 0.003 0.016 28 4.57 0.099 0.60 0.08 0.003 0.095 29 1.30 0.020 0.60 0.08 0.003 0.016 29 4.48 0.100 0.60 0.08 0.003 0.097 30 1.27 0.020 0.60 0.08 0.003 0.016 30 4.39 0.102 0.60 0.08 0.003 0.098 31 1.25 0.020 0.59 0.08 0.004 0.017 31 4.31 0.103 0.59 0.08 0.004 0.099 32 1.22 0.020 0.59 0.08 0.004 0.017 32 4.23 0.104 0.59 0.08 0.004 0.101 33 1.20 0.021 0.59 0.08 0.004 0.017 33 4.15 0.106 0.59 0.08 0.004 0.102 34 1.18 0.021 0.58 0.08 0.004 0.017 34 4.07 0.107 0.58 0.08 0.004 0.103 35 1.16 0.021 0.58 0.08 0.004 0.017 35 4.00 0.108 0.58 0.08 0.004 0.104 36 1.14 0.021 0.58 0.08 0.004 0.017 36 3.93 0.109 0.58 0.08 0.004 0.105 37 1.12 0.022 0.58 0.08 0.004 0.018 37 3.87 0.110 0.58 0.08 0.004 0.106 38 1.10 0.022 0.58 0.08 0.004 0.018 38 3.80 0.111 0.58 0.08 0.004 0.107 39 1.08 0.022 0.57 0.08 0.004 0.018 39 3.74 0.112 0.57 0.08 0.004 0.108 40 1.07 0.022 0.57 0.08 0.004 0.018 40 3.68 0.114 0.57 0.08 0.004 0.109 41 1.05 0.022 0.57 0.08 0.005 0.018 41 3.63 0.115 0.57 0.08 0.005 0.110 42 1.03 0.023 0.57 0.08 0.005 0.018 42 3.57 0.116 0.57 0.08 0.005 0.111 43 1.02 0.023 0.57 0.08 0.005 0.018 43 3.52 0.117 0.57 0.08 0.005 0.112 44 1.00 0.023 0.56 0.08 0.005 0.018 44 3.47 0.118 0.56 0.08 0.005 0.113 45 0.99 0.023 0.56 0.08 0.005 0.018 45 3.42 0.118 0.56 0.08 0.005 0.114 46 0.98 0.023 0.56 0.08 0.005 0.018 46 3.37 0.119 0.56 0.08 0.005 0.114 47 0.96 0.024 0.56 0.08 0.005 0.019 47 3.32 0.120 0.56 0.08 0.005 0.115 48 0.95 0.024 0.56 0.08 0.005 0.019 48 3.28 0.121 0.56 0.08 0.005 0.116 49 0.94 0.024 0.56 0.08 0.005 0.019 49 3.23 0.122 0.56 0.08 0.005 0.117 50 0.92 0.024 0.56 0.08 0.005 0.019 50 3.19 0.123 0.56 0.08 0.005 0.118 51 0.91 0.024 0.56 0.08 0.005 0.019 51 3.15 0.124 0.56 0.08 0.005 0.118 52 0.90 0.024 0.55 0.08 0.006 0.019 52 3.11 0.125 0.55 0.08 0.006 0.119 53 0.89 0.025 0.55 0.08 0.006 0.019 53 3.07 0.125 0.55 0.08 0.006 0.120 54 0.88 0.025 0.55 0.08 0.006 0.019 54 3.03 0.126 0.55 0.08 0.006 0.120 55 0.87 0.025 0.55 0.08 0.006 0.019 55 2.99 0.127 0.55 0.08 0.006 0.121 56 0.86 0.025 0.55 0.08 0.006 0.019 56 2.96 0.128 0.55 0.08 0.006 0.122 57 0.85 0.025 0.55 0.08 0.006 0.019 57 2.92 0.128 0.55 0.08 0.006 0.122 58 0.84 0.025 0.55 0.08 0.006 0.019 58 2.89 0.129 0.55 0.08 0.006 0.123 59 0.83 0.025 0.55 0.08 0.006 0.019 59 2.86 0.130 0.55 0.08 0.006 0.124 60 0.82 0.026 0.55 0.08 0.006 0.019 60 2.82 0.131 0.55 0.08 0.006 0.124 Mod. FAA Minor Storage Volume (cubic ft.) = 840 Mod. FAA Major Storage Volume (cubic ft.) = 5,413 Mod. FAA Minor Storage Volume (acre-ft.) = 0.0193 Mod. FAA Major Storage Volume (acre-ft.) = 0.1243 DETENTION VOLUME BY THE MODIFIED FAA METHOD Vogel Concrete Developed 100-Year Determination of MAJOR Detention Volume Using Modified FAA Method (For catchments less than 160 acres only. For larger catchments, use hydrograph routing method) (NOTE: for catchments larger than 90 acres, CUHP hydrograph and routing are recommended) UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.33, Released August 2013 Determination of MINOR Detention Volume Using Modified FAA Method BEFORE_REDUCTION_100-Year Developed UD-Detention_v2.33_USEME, Modified FAA 1/16/2015, 2:08 PM 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—Nov 18, 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 (TOUCHSTONE HEALTH) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/25/2014 Page 2 of 4