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Home My WebLink About112 W. MAGNOLIA STREET PARKING LOT - PDP - PDP160040 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTDRAINAGE REPORT FOR Wells Fargo Parking Lot Improvements 112 West Magnolia Street Fort Collins, CO 80524 Prepared for: Cox Pavement Consulting, LLC 228 Stratton Park Road Bellvue, CO, 80512 Prepared by: www.quality-engineering.com 2637 Midpoint Drive, Suite E Fort Collins, Colorado 80524 (970) 416-7891 QE Project No: 7060-001 Date: December 8, 2016 Parking at 112 West Magnolia Street FINAL DRAINAGE REPORT ENGINEER’S CERTIFICATION I hereby certify that this Final Drainage Report for the design of stormwater management facilities for the Parking at 112 West Magnolia Street 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 ................................................ 3 D. Hydrological Criteria............................................................................................... 3 E. Hydraulic Criteria ................................................................................................... 4 F. Modifications of Criteria ......................................................................................... 4 IV. DRAINAGE FACILITY DESIGN ............................................................... 5 A. General Concept....................................................................................................... 5 B. Specific Details ......................................................................................................... 5 V. CONCLUSIONS ............................................................................................. 5 A. Compliance with Standards .................................................................................... 5 B. Drainage Concept..................................................................................................... 5 VI. REFERENCES ............................................................................................... 6 VII. APPENDICES A. Hydrologic Computations Vicinity Map Fort Collins Flood Map 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 Modified FAA Method Permeable Paver Sub-Base Detention Calculation Orifice Sizing Calculation C. Map Pocket Drainage Plan I. GENERAL LOCATION AND DESCRIPTION A. Location The proposed site is located in the northeast quarter (NE ¼) of Section 11, Township 7 North, Range 69 West of the 6th P.M. in Larimer County, Colorado. Specifically, the property is located at the southeast corner of West Magnolia Street and College Avenue. The property address is 112 West Magnolia Street, Fort Collins, Colorado, 80524. (Please see the vicinity map located in the Appendix A). B. Description of Property The property’s parcel number is 9711424001. The site is located on Lots 1 and 2, Block 113 Fort Collins Subdivision and is currently 0.436 acres of undeveloped land surrounded by the clock tower building to the north, Wells Fargo to the south, and office buildings to the east and west. West Magnolia is located directly south, College Avenue is located directly east, and an alley is located west of the property. There is an existing access to the site on all three roadways. The existing accesses on College Avenue and Magnolia Street are to be abandoned and replaced by a new access on Magnolia Street. Both existing West Magnolia Street and College Avenue are paved with curb, gutter, sidewalk, and utilities installed. The existing property is a gravel parking lot that drains south to West Magnolia Street and College Avenue. Existing West Magnolia Street drains west to the existing inlet, where it is conveyed to the Poudre River. Existing College Avenue drains north towards the existing storm inlet, where it conveyed to the Poudre River. There are generally no offsite flows that drain toward the property. The entire site is located within the 100-year floodplain. The northern half of the site is located in a moderate risk area, and the southern half of the site is located within the city flood fringe (see City Flood Risk Map in Appendix A). According to the NRCS soils map survey, the native soils consist of the Type “C” soils. These soils 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. There are no irrigation facilities located within the proposed site area. The proposed development will consist of the construction of a 35 space off-street parking lot that will act as employee parking for the Wells Fargo directly across West Magnolia Street. The parking lot will be paved asphalt with curb and gutter. Seven on- street parking stalls will be added to West Magnolia Street. II. DRAINAGE BASINS AND SUB-BASINS A. Major Basin Description The proposed site is located within the Old Town Basin. The Old Town Drainage Basin is located in north-central Fort Collins. The basin has a drainage area of approximately 2,120 acres, including approximately 400 acres of the Colorado State University campus. The entire basin is urbanized, with some development dating back to the late 1800s. Generally, the basin drains from west to east. The Old Town Basin receives some runoff water from the Canal Importation Basin directly west of Old Town. Most of the water from Old Town drains to the Poudre River, just to the east. B. Sub-Basin Description Historically, most of the site drains south to West Magnolia Street. The developed site is delineated into one sub-basin, with underground detention designed to provide the required water quality capture volume. Sub-basin B1, (0.436 acres), consists of an asphalt/concrete parking lot, landscaped area, and permeable pavers. Rainfall travels via overland flow from north to south, where it will concentrate in the gutter flowlines. Once the flow is concentrated into the gutter flowline it is conveyed to the flowline of West Magnolia Street through a 2’ u-channel. Overland flow will also infiltrate the permeable pavers in the parking stalls, where it will be treated and piped into the existing storm inlet. 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 this parking lot expansion 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 underground detention. Also, permeable pavers are used to reduce the area of 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 permeable pavers, located in the parking spaces of the lot. Refer to the map pocket for permeable paver details and cross-sections. The permeable pavers will increase water quality and promote infiltration. Water quality treatment for 50% of the site is provided for in the Udall Natural Area water treatment facility. Step 3 – Stabilize Drainageways. The Poudre River is the governing drainageway for the proposed site. The proposed project indirectly helps achieve a better stabilized drainageway nonetheless. By improving the water quality and increasing infiltration, the likelihood of bed and bank erosion from this site is greatly reduced. Step 4 – Implement Site Specific and Other Source Control BMPs. The Parking at 112 West Magnolia Street site contains a plethora of source control BMPs. Permeable Pavement Systems: Flow from the parking lot will directly flow into the void area of the pavers avoiding any extra pollutant-flow contact time. 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 the site; 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 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 “C” dominate the site. Onsite runoff was calculated to determine the runoff differential between existing and developed conditions for use in sizing the WQCV 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 detention and orifice sizing. 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. 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 permeable pavers. F. Modifications of Criteria There are no modifications or variances requested in connection with the design of the stormwater management for the Parking at 112 West Magnolia site development. IV. DRAINAGE FACILITY DESIGN A. General Concept The storm drainage system is designed to safely convey developed storm flows by sheet flow, concentrated pan, underdrain, and gutter flow to the permeable pavers and street flowlines. 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, (0.436 acres), consists of an asphalt/concrete parking lot, landscaped area, and permeable pavers. Rainfall travels via overland flow from north to south to the gutter flowline of the parking area, where it will concentrate into a 2’ u-channel and will be conveyed to Magnolia Street at a minimum of 0.6% slope. The Magnolia Street flowline conveys runoff to an existing storm inlet to the west. Overland flow will also infiltrate the permeable pavers in the parking stalls, where it will be treated. The 100-year flow is released at the 2-year historic rate, via an 8” pipe with an orifice plate with a 4.5” opening into the back of an existing storm inlet. After treatment within the permeable pavers, the WQCV will also be released into the back of the curb inlet, where it will be eventually be conveyed to the Poudre River. Sub-basin B1 produces a 100-year flow of 3.03 cfs. If the paver system overflows due to clogging, the runoff will be directed to Magnolia Street. V. CONCLUSIONS A. Compliance with Standards The drainage design for the Parking at 112 West Magnolia Street 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 Parking at 112 West Magnolia Street will be adequate to safely convey onsite flows through the development. 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. APPENDICIES APPENDIX A: Hydrologic Computations Vicinity Map Fort Collins Flood Map USGS Soil Map Loveland Rainfall Intensity Curve Loveland Rainfall Intensity Table Table RO-3 Recommended Percentage Imperviousness Values Rational Method Calculated Runoff Coefficients Rational Method Calculated Imperviousness Rational Method Calculated Flows S COLLEGE AVE W MAGNOLIA ST . Printed: 03/25/2016 All floodplain boundaries are approximate. This information is based on the Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map (FIRM) and the City of Fort Collins Master Drainageway Plans. This letter does not imply that the referenced property will or will not be free from flooding or damage. A property not in the Special Flood Hazard Area or in a City Designated Floodplain may be damaged by a flood greater than that predicted on the map or from a local drainage problem not shown on the map. This map does not create liability on the part of the City, or any officer or employee thereof, for any damage that results from reliance on this information. City Flood Risk Map Moderate Risk May include: - Areas of FEMA 500-year floodplain (FEMA Zone X-shaded). - Areas of FEMA or City 100-year floodplain (sheet flow) with average depths of less than 1 foot. - Areas protected by levees from the 100-year flood. Low Risk Areas outside of FEMA and City mapped 100-year and 500-year floodplains. Local drainage problems may still exist. City Flood Fringe - May Include: - Areas of FEMA 100-year floodplain (FEMA Zones A, AE, AO, and AH) - Areas of City 100-year floodplain including ponding areas and sheet flow areas with average depths of 1-3 feet. There is a 1% annual chance that these areas will be flooded. High Risk City Floodway - Area of 100-year floodplain with greatest depths and fastest velocities. 0 15 30 60 90 120 Feet 35 C 0.5 0.5 112 W Magnolia Street 8/18/2016 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 WELLS FARGO PARKING EXPANSION 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) P1 E1 0.00 0.00 0.44 0.00 0.00 0.44 0.50 0.63 D1 B1 0.21 0.01 0.00 0.00 0.21 0.44 0.56 0.70 Notes: Composite C values obtained from Table R0-11 Major Storm Runoff factored per Table R0-12 Developed Design Point Basin(s) Existing MAP Wells Fargo Rational Method.xlsx 8/31/2016 Impeviousness WELLS FARGO PARKING EXPANSION 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 P1 E1 0.000 0.000 0.4360 0.0000 0.0000 0.4360 40% D1 B1 0.21 0.01 0.00 0.00 0.21 0.436 51% Notes: Percent Impervious Values per Table R0-3, Urban Drainage Manual Developed Design Point Basin (s) Existing CAG Wells Fargo Rational Method.xlsx 8/31/2016 Basin Flow Calculations WELLS FARGO PARKING EXPANSION 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 P1 E1 0.4360 0.50 0.63 117 1.77 10.03 7.94 71 0.60 PA 1.55 0.76 10.80 8.71 2.13 3.63 8.21 0.46 0.79 2.24 D1 B1 0.4354 0.56 0.70 69 2.00 6.67 4.95 0 1.00 PA 2.00 0.0000 6.67 5.00 2.60 4.44 9.95 0.63 1.08 3.03 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 Wells Fargo Rational Method.xlsx 8/31/2016 APPENDIX B: Hydraulic Computations Modified FAA Method Permeable Paver Sub-Base Detention Calculation Orifice Sizing Calculation Project: Basin ID: Design Information (Input): Design Information (Input): Catchment Drainage Imperviousness Ia = 51.00 percent Catchment Drainage Imperviousness I a = 51.00 percent Catchment Drainage Area A = 0.436 acres Catchment Drainage Area A = 0.436 acres Predevelopment NRCS Soil Group Type = C A, B, C, or D Predevelopment NRCS Soil Group Type = C 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 = 11 minutes Time of Concentration of Watershed Tc = 11 minutes Allowable Unit Release Rate q = 1.05 cfs/acre Allowable Unit Release Rate q = 1.05 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 = 0.34 Runoff Coefficient C = 0.61 Inflow Peak Runoff Qp-in = 0.32 cfs Inflow Peak Runoff Qp-in = 1.96 cfs Allowable Peak Outflow Rate Qp-out = 0.46 cfs Allowable Peak Outflow Rate Qp-out = 0.46 cfs Mod. FAA Minor Storage Volume = 4 cubic feet Mod. FAA Major Storage Volume = 1,732 cubic feet Mod. FAA Minor Storage Volume = 0.000 acre-ft Mod. FAA Major Storage Volume = 0.040 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) 1 3.52 0.001 1.00 0.46 0.001 0.000 1 12.16 0.004 1.00 0.46 0.001 0.004 2 3.29 0.001 1.00 0.46 0.001 0.000 2 11.35 0.008 1.00 0.46 0.001 0.007 3 3.09 0.002 1.00 0.46 0.002 0.000 3 10.66 0.012 1.00 0.46 0.002 0.010 4 2.91 0.002 1.00 0.46 0.003 0.000 4 10.05 0.015 1.00 0.46 0.003 0.012 5 2.76 0.003 1.00 0.46 0.003 0.000 5 9.52 0.017 1.00 0.46 0.003 0.014 6 2.62 0.003 1.00 0.46 0.004 -0.001 6 9.05 0.020 1.00 0.46 0.004 0.016 7 2.50 0.004 1.00 0.46 0.004 -0.001 7 8.63 0.022 1.00 0.46 0.004 0.018 8 2.39 0.004 1.00 0.46 0.005 -0.001 8 8.25 0.024 1.00 0.46 0.005 0.019 9 2.29 0.004 1.00 0.46 0.006 -0.001 9 7.90 0.026 1.00 0.46 0.006 0.020 10 2.20 0.004 1.00 0.46 0.006 -0.002 10 7.59 0.028 1.00 0.46 0.006 0.021 11 2.12 0.005 0.99 0.45 0.007 -0.002 11 7.30 0.029 0.99 0.45 0.007 0.023 12 2.04 0.005 0.95 0.43 0.007 -0.002 12 7.04 0.031 0.95 0.43 0.007 0.024 13 1.97 0.005 0.92 0.42 0.008 -0.002 13 6.80 0.032 0.92 0.42 0.008 0.025 14 1.90 0.005 0.89 0.41 0.008 -0.002 14 6.57 0.034 0.89 0.41 0.008 0.026 15 1.84 0.006 0.86 0.39 0.008 -0.002 15 6.36 0.035 0.86 0.39 0.008 0.027 16 1.79 0.006 0.84 0.38 0.008 -0.003 16 6.17 0.036 0.84 0.38 0.008 0.028 17 1.74 0.006 0.82 0.37 0.009 -0.003 17 5.99 0.037 0.82 0.37 0.009 0.029 18 1.69 0.006 0.80 0.37 0.009 -0.003 18 5.82 0.038 0.80 0.37 0.009 0.029 19 1.64 0.006 0.78 0.36 0.009 -0.003 19 5.66 0.039 0.78 0.36 0.009 0.030 20 1.60 0.007 0.77 0.35 0.010 -0.003 20 5.51 0.040 0.77 0.35 0.010 0.031 21 1.56 0.007 0.76 0.35 0.010 -0.003 21 5.37 0.041 0.76 0.35 0.010 0.031 22 1.52 0.007 0.75 0.34 0.010 -0.004 22 5.24 0.042 0.75 0.34 0.010 0.032 23 1.48 0.007 0.73 0.34 0.011 -0.004 23 5.11 0.043 0.73 0.34 0.011 0.032 24 1.45 0.007 0.73 0.33 0.011 -0.004 24 4.99 0.044 0.73 0.33 0.011 0.033 Project: Basin ID: Design Information (Input): Width of Basin Bottom, W = ft Right Triangle OR… Length of Basin Bottom, L = ft Isosceles Triangle OR… Dam Side-slope (H:V), Zd = ft/ft Rectangle OR… Circle / Ellipse OR… Irregular (Use Overide values in cells G32:G52) MINOR MAJOR Storage Requirement from Sheet 'Modified FAA': 0.00 0.04 acre-ft. Stage-Storage Relationship: Storage Requirement from Sheet 'Hydrograph': acre-ft. Storage Requirement from Sheet 'Full-Spectrum': acre-ft. Labels Water Side Basin Basin Surface Surface Volume Surface Volume Target Volumes for WQCV, Minor, Surface Slope Width at Length at Area at Area at Below Area at Below for WQCV, Minor, & Major Storage Elevation (H:V) Stage Stage Stage Stage Stage Stage Stage & Major Storage Stages ft ft/ft ft ft ft 2 ft 2 User ft 3 acres acre-ft Volumes (input) (input) Below El. (output) (output) (output) Overide (output) (output) (output) (for goal seek) 93.33 (input) 720 0 0.017 0.000 93.58 0.00 0.00 1,440 270 0.033 0.006 93.64 0.00 0.00 1,716 365 0.039 0.008 93.78 0.00 0.00 2,264 643 0.052 0.015 94.03 0.00 0.00 2,264 1,209 0.052 0.028 94.28 0.00 0.00 2,264 1,775 0.052 0.041 100-YR 94.53 0.00 0.00 2,264 2,341 0.052 0.054 94.66 0.00 0.00 1,544 2,589 0.035 0.059 94.91 0.00 0.00 824 2,885 0.019 0.066 94.98 0.00 0.00 548 2,933 0.013 0.067 95.12 0.00 0.00 548 3,010 0.013 0.069 #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 Project: Basin ID: Design Information (Input): #1 Horiz. #2 Horiz. #1 Vert. #2 Vert. Circular Opening: Diameter in Inches Dia. = 4.50 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 = 100 % Orifice Coefficient Co = 0.60 Weir Coefficient Cw = Orifice Elevation (Bottom for Vertical) Eo = 93.33 ft. Calculation of Collection Capacity: Net Opening Area (after Trash Rack Reduction) Ao = 0.11 sq. ft. OPTIONAL: User-Overide Net Opening Area Ao = sq. ft. Perimeter as Weir Length Lw = ft. OPTIONAL: User-Overide Weir Length Lw = ft. Top Elevation of Vertical Orifice Opening, Top = 93.71 ft. Center Elevation of Vertical Orifice Opening, Cen = 93.52 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) 93.33 #N/A 0.00 0.00 0.00 0.00 0.00 0.00 #N/A 93.58 #N/A 0.00 0.00 0.00 0.00 0.13 0.00 #N/A 93.64 #N/A 0.00 0.00 0.00 0.00 0.17 0.00 #N/A 93.78 #N/A 0.00 0.00 0.00 0.00 0.27 0.00 #N/A 94.03 #N/A 0.00 0.00 0.00 0.00 0.38 0.00 #N/A 94.28 #N/A 0.00 0.00 0.00 0.00 0.46 0.00 #N/A 100-YR 94.53 #N/A 0.00 0.00 0.00 0.00 0.54 0.00 #N/A 94.66 #N/A 0.00 0.00 0.00 0.00 0.57 0.00 #N/A 94.91 #N/A 0.00 0.00 0.00 0.00 0.63 0.00 #N/A 94.98 #N/A 0.00 0.00 0.00 0.00 0.64 0.00 #N/A 95.12 #N/A 0.00 0.00 0.00 0.00 0.67 0.00 #N/A Routing 3: Single Stage - Water flows through WQCV plate and #1 horizontal opening into #1 vertical opening. This flow will be applied to culvert sheet (#2 vertical & horizontal openings is not used). Wells Fargo Parking Improvements Current Routing Order is #3 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 APPENDIX C: Map Pocket Drainage Plan PLANTING AREA 7 8 5 MAGNOLIA STREET UNDERDRAIN INV: 93.58' UNDERDRAIN INV: 93.33' UNDERDRAIN INV: 93.77' UNDERDRAIN INV: 93.51' UNDERDRAIN INV: 93.75' UNDERDRAIN INV: 94.06' PROPOSED 18" CATCH BASIN UNDER DRAIN INV: 93.13' UNDERDRAIN INV: 93.79' UNDERDRAIN INV: 93.60' C5.0 10' SCALE: 1" = 10' 0 20' WELLS FARGO PARKING LOT IMPROVEMENTS 112 WEST MAGNOLIA STREET FORT COLLINS CO, 80525 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 BASIN ID MINOR "C" COEFFICIENT MAJOR "C" COEFFICIENT DRAINAGE AREA CITY OF FORT COLLINS, COLORADO UTILITY PLAN APPROVAL 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 UD-Detention_v2.34 underground.xls, Outlet 8/31/2016, 10:03 AM #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 STAGE-STORAGE SIZING FOR DETENTION BASINS Wells Fargo Parking Improvements Check Basin Shape Underground Storage UD-Detention_v2.34 underground.xls, Basin 8/31/2016, 9:59 AM 25 1.41 0.007 0.72 0.33 0.011 -0.004 25 4.88 0.045 0.72 0.33 0.011 0.033 26 1.38 0.007 0.71 0.32 0.012 -0.004 26 4.77 0.045 0.71 0.32 0.012 0.034 27 1.35 0.007 0.70 0.32 0.012 -0.004 27 4.67 0.046 0.70 0.32 0.012 0.034 28 1.32 0.008 0.69 0.32 0.012 -0.005 28 4.57 0.047 0.69 0.32 0.012 0.035 29 1.30 0.008 0.69 0.31 0.013 -0.005 29 4.48 0.048 0.69 0.31 0.013 0.035 30 1.27 0.008 0.68 0.31 0.013 -0.005 30 4.39 0.048 0.68 0.31 0.013 0.035 31 1.25 0.008 0.67 0.31 0.013 -0.005 31 4.31 0.049 0.67 0.31 0.013 0.036 32 1.22 0.008 0.67 0.31 0.013 -0.005 32 4.23 0.050 0.67 0.31 0.013 0.036 33 1.20 0.008 0.66 0.30 0.014 -0.006 33 4.15 0.050 0.66 0.30 0.014 0.036 34 1.18 0.008 0.66 0.30 0.014 -0.006 34 4.07 0.051 0.66 0.30 0.014 0.037 35 1.16 0.008 0.65 0.30 0.014 -0.006 35 4.00 0.051 0.65 0.30 0.014 0.037 36 1.14 0.008 0.65 0.30 0.015 -0.006 36 3.93 0.052 0.65 0.30 0.015 0.037 37 1.12 0.008 0.65 0.30 0.015 -0.007 37 3.87 0.052 0.65 0.30 0.015 0.037 38 1.10 0.009 0.64 0.29 0.015 -0.007 38 3.80 0.053 0.64 0.29 0.015 0.038 39 1.08 0.009 0.64 0.29 0.016 -0.007 39 3.74 0.053 0.64 0.29 0.016 0.038 40 1.07 0.009 0.64 0.29 0.016 -0.007 40 3.68 0.054 0.64 0.29 0.016 0.038 41 1.05 0.009 0.63 0.29 0.016 -0.008 41 3.63 0.054 0.63 0.29 0.016 0.038 42 1.03 0.009 0.63 0.29 0.017 -0.008 42 3.57 0.055 0.63 0.29 0.017 0.038 43 1.02 0.009 0.63 0.29 0.017 -0.008 43 3.52 0.055 0.63 0.29 0.017 0.038 44 1.00 0.009 0.62 0.29 0.017 -0.008 44 3.47 0.056 0.62 0.29 0.017 0.039 45 0.99 0.009 0.62 0.28 0.018 -0.008 45 3.42 0.056 0.62 0.28 0.018 0.039 46 0.98 0.009 0.62 0.28 0.018 -0.009 46 3.37 0.057 0.62 0.28 0.018 0.039 47 0.96 0.009 0.61 0.28 0.018 -0.009 47 3.32 0.057 0.61 0.28 0.018 0.039 48 0.95 0.009 0.61 0.28 0.019 -0.009 48 3.28 0.058 0.61 0.28 0.019 0.039 49 0.94 0.009 0.61 0.28 0.019 -0.009 49 3.23 0.058 0.61 0.28 0.019 0.039 50 0.92 0.009 0.61 0.28 0.019 -0.010 50 3.19 0.058 0.61 0.28 0.019 0.039 51 0.91 0.009 0.61 0.28 0.019 -0.010 51 3.15 0.059 0.61 0.28 0.019 0.039 52 0.90 0.010 0.60 0.28 0.020 -0.010 52 3.11 0.059 0.60 0.28 0.020 0.039 53 0.89 0.010 0.60 0.28 0.020 -0.010 53 3.07 0.060 0.60 0.28 0.020 0.039 54 0.88 0.010 0.60 0.27 0.020 -0.011 54 3.03 0.060 0.60 0.27 0.020 0.040 55 0.87 0.010 0.60 0.27 0.021 -0.011 55 2.99 0.060 0.60 0.27 0.021 0.040 56 0.86 0.010 0.60 0.27 0.021 -0.011 56 2.96 0.061 0.60 0.27 0.021 0.040 57 0.85 0.010 0.59 0.27 0.021 -0.012 57 2.92 0.061 0.59 0.27 0.021 0.040 58 0.84 0.010 0.59 0.27 0.022 -0.012 58 2.89 0.061 0.59 0.27 0.022 0.040 59 0.83 0.010 0.59 0.27 0.022 -0.012 59 2.86 0.062 0.59 0.27 0.022 0.040 60 0.82 0.010 0.59 0.27 0.022 -0.012 60 2.82 0.062 0.59 0.27 0.022 0.040 61 0.81 0.010 0.59 0.27 0.023 -0.013 61 2.79 0.062 0.59 0.27 0.023 0.040 Mod. FAA Minor Storage Volume (cubic ft.) = 4 Mod. FAA Major Storage Volume (cubic ft.) = 1,732 Mod. FAA Minor Storage Volume (acre-ft.) = 0.0001 Mod. FAA Major Storage Volume (acre-ft.) = 0.0398 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 2.34, Released November 2013 Determination of MINOR Detention Volume Using Modified FAA Method DETENTION VOLUME BY THE MODIFIED FAA METHOD Wells Fargo Parking Lot Improvements UD-Detention_v2.34 underground.xls, Modified FAA 8/31/2016, 9:57 AM