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TRANSFORT FACILITY EXPANSION - FDP - FDP110003 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORT
FINAL DRAINAGE REPORT FOR TRANSFORT FACILITY EXPANSION FORT COLLINS, COLORADO Prepared for: ALLER-LINGLE-MASSEY ARCHITECTS PROJECT MANAGER: MATT NEWMAN 712 WHALERS WAY, BLDG B, SUITE 100 FORT COLLINS, CO 80525 PHONE: (970) 223-1820 JSD PROJECT NO. 2598 MARCH 30, 2011 Prepared by: 153 West Mountain Avenue Fort Collins, Colorado 80524 Fax 970.484.2443 970.484.1921 F:\JSD PROJECTS\2598 TRANSFORT FACILITY EXPANSION\03 DESIGN CALCULATIONS\DRAINAGE\REPORT\2598 COVER LETTER.DOC March 30, 2011 Wes Lamarque City of Fort Collins – Storm Water Utility 700 Wood Street Fort Collins, CO 80522 RE: Transfort Facility Expansion Project JSD Project No.: 2598 Mr. Larmarque: Please refer to our enclosed submittal for the “Final Drainage & Erosion Control Report for the Transfort Facility Expansion Project.” This report has been prepared in accordance with the drainage guidelines presented in the City of Fort Collins’ Storm Drainage Criteria and Construction Standards along with the Urban Storm Drainage Criteria Manual. Please feel free to contact our office at (970) 484-1921 at your convenience if you have any questions regarding this report. We thank you for your time and consideration in reviewing the drainage and erosion control report. Sincerely, Jim Sell Design, Inc. Jason Claeys, PE Project Engineer JIM SELL DESIGN, INC. Landscape Architecture, Engineering & Planning 153 West Mountain Avenue Fort Collins, CO 80524 Tele: 970.484.1921 Fax: 970.484-2443 Page i TABLE OF CONTENTS Table of Contents............................................................................................................................. i Engineer’s Certification Block ....................................................................................................... ii General Description and Location .................................................................................................. 1 Site Description and Location ..................................................................................................... 1 Site Soils...................................................................................................................................... 1 Storm Drainage Criteria.................................................................................................................. 2 Hydrologic Criteria...................................................................................................................... 2 Hydraulic Criteria........................................................................................................................ 2 Drainage Basins and Historic Runoff ............................................................................................. 4 Historic Basin .............................................................................................................................. 4 Developed Basins ........................................................................................................................ 4 Drainage Facility Design ................................................................................................................ 6 Drainage Conveyance Design ..................................................................................................... 6 Detention/Water Quality Pond Design........................................................................................ 6 Stormwater Pollution Prevention.................................................................................................... 7 Temporary Erosion Control......................................................................................................... 7 Permanent Erosion Control ......................................................................................................... 7 Conclusions..................................................................................................................................... 8 References....................................................................................................................................... 9 Appendix....................................................................................................................................... 10 Site Descriptions and Characteristics ...................................................................................... A-1 Pond Calculations.................................................................................................................... A-2 Historic & Proposed Rational Calculations............................................................................. A-3 Conveyance Element Sizing.................................................................................................... A-4 Erosion Control Details ........................................................................................................... A-5 Page ii ENGINEER’S CERTIFICATION BLOCK I hereby certify that this Drainage Report for the Transfort Facility Expansion Project was prepared by me (or under my direct supervision) for the Owners thereof and meets or exceeds the City of Fort Collins’ Storm Drainage Design Criteria and Construction Standards. ________________________________________ Jason Thomas Claeys Registered Professional Engineer State of Colorado No. 42122 Page 1 GENERAL DESCRIPTION AND LOCATION SITE DESCRIPTION AND LOCATION The Transfort Facility Expansion is a proposed addition to the current Transfort Operations Headquarters to house the future Mason Street BRT bus fleet and an associated bus training area. The Transfort Operations Headquarters is located at 6570 Portner Road, between College (Hwy 287) and Lemay, just off of Trilby. The site is bound by Trilby to the south, Portner Road and a natural drainage way to the west, open space and the Prairie Dog Meadow Natural Area to the North, and the residential subdivision Brittany Knolls to the east. Access to the site is off of Portner Road and no new accesses are proposed with this project. The total site area included the existing facility and the area defined associated with the proposed improvements, is approximately 10.40 acres. For the intent of this drainage report and calculations, the area analyzed consists of the proposed improvements that contribute to the increase in impervious area, which is approximately 3.24 acres. The site area currently consists of a portion of the existing Transfort site and the remaining is undeveloped open space. It appears that the past use of the site has been open space seeded with non-native grasses. The naturalized drainage way to the west does contain wetland species but is not going to be affected with this project with the exception of the installation of the pond outlet pipe. An Ecological Characterization Study has been completed and discusses the naturalized drainage way and also discusses a remnant stock pond wetland. To maintain this small wetland area and trees, the drainage patterns to this area will be modified to accommodate the proposed improvements but will not divert runoff away from this wetland. The site general slopes 1% to 2% from the southeast to the northwest. The site is proposed to be constructed with an approx 16,240 sf bus storage facility and approximately 62,500 sf concrete paved vehicle access and training area. The detention pond is proposed to be located in the northwest corner of the site and outlets into the western naturalized drainage way. The pond is designed to detain the increase 100-yr runoff rates, while releasing at the historic 2-yr runoff rate. This drainage way along the west side of the site has been included in a drainage study as a tributary to Stone Creek. The HEC-RAS models have been provided by the City of Fort Collins and reviewed. It appears that cross sections 1512 thru 1200 would be located near the facility expansion and does not breach the drainage way during a 100-yr event. The Transfort Facility is located along a tributary to the Fossil Creek Drainage Basin. The Transfort Facility is not located within a FEMA regulated floodplain or floodway. SITE SOILS According to the National Cooperative Soil Survey-Web Soil Survey 1.1, the area of improvements for the Transfort Facility Expansion site soils consist of clay loam soils. These soils are classified as being in the Type C hydrologic group with a slow infiltration rate. Supporting figures can be found in the appendix. Page 2 STORM DRAINAGE CRITERIA This report was prepared to meet or exceed the City of Fort Collins Storm Drainage Design Criteria & Construction Standards. Urban Drainage Flood Control District’s (UDFCD) Drainage Criteria Manual (USDCM) Volumes 1, 2 and 3 were also referenced as guidelines for this design. HYDROLOGIC CRITERIA The City of Fort Collins’ (CoFC) criteria is used to determine the allowed release rate and required detention volume. It is required that the developed storm water runoff rate shall not be released from developments at a rate greater than the 2-year historic runoff rate. The rational method is used to calculate the 2-yr and 100-yr peak runoff rates under both historic and developed conditions. A combination of runoff coefficients from the CoFC criteria and the time of concentration and intensity equations from the USDCM were referenced to calculate the peak runoff rates for the 2-yr and 100-yr storm events. The UDFCD’s UD-Detention_v2.2 spreadsheet is utilized to calculate the required detention volume. This spreadsheet uses the rational formula-based modified FAA Procedure to determine the detention volume based on a certain release rate. To account for the City of Fort Collins’ IDF Curve, Coefficient 3 of the UDFCD’s intensity formula was adjusted to 0.7867. The City of Fort Collins uses a 1-hr rainfall depth of 2.86 inches for the 100-yr storm, which is the 1997 adjusted rainfall depth. The percent impervious is obtained using USDCM Table RO-3 and Figure RO-5. Using the weighted average of surface characteristics, a composite percent impervious was calculated for each basin under both historic and developed conditions. Using the percent impervious, the runoff coefficients were calculated reflecting the soil characteristics of Type C soils, as defined by the Natural Resources Conservation Service’s Web Soil Survey 2.0. The longest time of concentration was calculated for each basin. All of these site calculations, site characteristics and rainfall depths were used as inputs in the detention calculations and are attached for reference. All supporting references and calculations can be found in the appendix. HYDRAULIC CRITERIA The hydraulic elements conveying runoff to the pond is limited to the site’s grading design and curb and gutters. The site is graded to drain from the south to the north and west along the curb and gutter, to a curb cut that drains directly into the detention pond. The rational method was performed to calculate the peak runoff rates for each basin. Weighted percent imperviousness and weighted runoff coefficients were calculated for each basin using USDCM Tables RO-3 and RO-5 and the City of Fort Collins runoff coefficients. The Natural Resources Conservation Service (NRCS) classifies the site with majority Type C hydrologic soil classification with a slow infiltration rate. The time of concentration was calculated using Page 3 USDCM Equation RO-3 and the intensity was calculated using the corresponding storm rainfall depth and USDCM Equation RA-3 The pond was sized as described above in the hydrologic criteria. The outlet structure was designed with an orifice plate that limited the release rate to the 2-yr historic runoff rate. The water quality control feature is based off of USDCM’s design requirements with a 40-hour release rate. The spillway is sized using the equation for trapezoidal broad-crested weirs and sized to allow the combination of site’s developed 100-yr and any offsite 100-yr flows conveyed to the pond and through the spillway with 1’ of freeboard. The pond’s outlet pipe is analyzed using Bentley’s StormCAD storm sewer modeling program to design the pipe size and slopes. StormCAD conducts a steady state simulation and creates flow profiles based on pipe capacities and backwater analysis. The program accounts for head losses within manholes, bends, and head losses associated with pipe friction. Bentley’s FlowMaster was used to compute the open channel hydraulics and verify the capacities of the drainage elements throughout the site. Flow velocities within these elements were reviewed and if flow were found to be supercritical, the appropriate erosion control is sized and proposed to accordingly to protect from erosion. All swale and pipe outlets are protected with riprap. Storm sewer pipe outlets are protected using the requirements set by the USDCM for the protection downstream of culverts. All supporting calculations are located in the appendix. Page 4 DRAINAGE BASINS AND HISTORIC RUNOFF HISTORIC BASIN The historic were analyzed using the rational method as 2 sub-basins. The two basins are: Basin H01 and Basin H02. The basin descriptions are below: Basin H01 is approximately 2.55 acres and consists of the existing open space north of the existing Transfort Facility. The boundary of this basin is determined by the extent of proposed impervious area and the proposed detention pond. This basin is 2.0% impervious with 2-yr and 100-yr peak runoff rates of 1.27 cfs and 5.55 cfs, respectively. This 2-yr runoff rate is used as the allowed release rate of the detention pond. Basin H02 is approximately 0.69 acres. This basin contains the northern access around the current facility and the landscape areas adjacent building. There are 5 area inlets located within the access drive. These basin ultimately drains to a type R inlet and into the western drainage way. This basin is 68.6% impervious with 2-yr and 100-yr peak runoff rates of 1.18 cfs and 5.15 cfs, respectively. Currently, the total basin containing the entire proposed impervious improvements and detention pond has an overall imperviousness of 16.2% with a 2-yr and 100-yr peak runoff rate of 2.46 cfs and 10.70 cfs, respectively, and is approximately 3.24 acres. Reference the exhibits and calculations located in the appendix. DEVELOPED BASINS The developed basin is divided into 3 sub-basins for the developed evaluation. The runoff flow path is determined for each basin, from the furthest point to a design point. The peak 2-yr and 100-yr values were determined for these various design point locations using the rational method. All calculations can be found in the appendix. The sub-basin descriptions are below: Basin D01 is approximately 1.07 acres and consists of the detention pond located in the northwest portion of the site. The basin is 2.0% impervious with a 2-yr and 100-yr peak runoff rate of 0.56 cfs and 2.43 cfs, respectively. Basin D02 is approximately 1.50 acres and consists of the proposed building expansion and the concrete access and training area. This basin was analyzed separate to Basin D01 to verify the capacities of the curb cut which directs runoff to the pond. This basin is 95.5% impervious with 2-yr and 100-yr peak runoff rates of 3.84 cfs and 14.31 cfs, respectively. Page 5 Basin D03 is the remaining areas of Basin H02. The Basin H02 is reduced with the removal of the proposed expansion roof area. Though these appear detached, the existing storm sewer and inlet are going to remain. The reduced area will still drain to the type R inlet and into the drainage way. The one inlet located under the proposed canopy will have a cover placed on it. The basin is 0.66 acres, 93.2% impervious with a 2-yr and 100-yr peak runoff rates of 1.51 cfs and 5.83 cfs, respectively. The total developed basins have an overall imperviousness of 64.1% with a 2-yr and 100-yr peak runoff rate of 5.90 cfs and 22.57 cfs, respectively. Reference the exhibits and calculations located in the appendix. Page 6 DRAINAGE FACILITY DESIGN DRAINAGE CONVEYANCE DESIGN Storm infrastructure to convey runoff will include overland grass-lined swales, existing inlets, and existing storm sewer and the curb and gutter grading of the training area. Storm water detention and water quality enhancement will be achieved through the use of an extended detention basin. Supporting calculations and exhibits can be found in the appendix of this report. DETENTION/WATER QUALITY POND DESIGN An extended detention basin (EDB) with a dry bottom is to be utilized as the detention and water quality facility for the Transfort Facility Expansion site. The pond provides open space in addition to reducing the peak runoff rate and improving the water quality. The pond is located adjacent to the existing naturalized drainage way and within the 50 ft buffer and is allowed because of the compatible uses. The design criteria and procedures in the USDCM Vol. 3 were used as the basis of this design. The EDB water quality capture volume is based off of the required 40-hr drain time. The total detention volume is based on the allowable release rate of the historic 2-yr storm event in addition to the required water quality capture volume. The pond has been designed with maintenance to the outlet structure from the irrigation maintenance road. Water Quality Capture Volume (WQCV): The water quality capture volume required is 0.06 acre-ft with a 40-hr drain time. The WQCV water surface elevation is 4940.38 ft. 100-yr Detention Volume: The peak historic 2-yr runoff rate is equal to 1.27 cfs. The developed peak flow entering the pond from the Transfort Facility Expansion is 16.74 cfs. The combination of the WQCV and the 100-yr detention volume gives the required pond volume of 0.57 acre-ft and a 100-yr WSEL of 4943.45 ft. All supporting calculations are included in the appendix. Page 7 STORMWATER POLLUTION PREVENTION TEMPORARY EROSION CONTROL A temporary erosion control plan is to be implemented for the site during construction. Temporary erosion control measures include, but not limited to, slope and swale protection provided by the use of erosion control wattles/sediment control logs, silt fence placed around areas of disturbance, construction vehicle tracking pads at entrances, designated concrete truck washout basins, designated vehicle fueling areas, inlet protection, etc. All temporary erosion control measures are to be removed after they are deemed unnecessary. The Town of Parker’s Storm Drainage and Environmental Criteria Manual was referenced for construction best management practice details and can be found in the appendix. PERMANENT EROSION CONTROL Permanent erosion control measures include, but not limited to, the constructed detention/water quality pond, riprap pads placed for culvert outlet protection, seeding and mulch placed to enable and established vegetative growth, etc. Long-term maintenance of these erosion control measures shall be the responsibility of the Owner of the property. Reference the attached erosion control plan. Page 8 CONCLUSIONS This Drainage Report has been prepared to comply with the City of Fort Collins’ Storm Drainage Design Criteria and Construction Standards. The drainage system presented in this report is designed to convey the developed stormwater runoff through the site to the proposed detention pond and provide water quality treatment prior to discharging offsite. The 100-yr peak flow release from the site under the proposed conditions is less than or equal to the 2-yr historical peak runoff. It can therefore be concluded that development of the Transfort Facility Expansion Project will not have an adverse impact on the current runoff conditions. Best management practices are proposed for erosion control during construction, and permanent landscaping, riprap, and a water quality/detention pond are proposed for long-term stormwater management. Page 9 REFERENCES 1. Urban Storm Drainage Criteria Manual (Volumes 1, 2, and 3), Urban Drainage and Flood Control District, June 2001. 2. City of Fort Collins’ “Storm Drainage Design Criteria and Construction Standards,” Storm Drainage Volume II. Department of Public Works and Water Utilities – Storm Drainage Division, Updated April 1999. 3. “Hydrologic Group Rating for Weld County, Colorado, Southern Part.” USDA-Natural Resources Conservation Service, National Cooperative Soil Survey. Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov. [July 11, 2010] 4. Bentley StormCAD Version 5.6 [Computer Software]. Bentley Systems, Inc. 5. Bentley FlowMaster [Computer Software]. Bentley Systems, Inc. 6. Grading, Erosion, and Sediment Control Manual (GESC), Douglas County Department of Public Works – Engineering Division, March 2004 7. Storm Drainage and Environmental Criteria Manual, Construction Best Management Practices, Standard Details, Town of Parker, Colorado, December 2002 Page 10 APPENDIX Site Descriptions and Characteristics Pond Calculations Historic & Proposed Rational Calculations Conveyance Element Sizing Erosion Control Page A-1 SITE DESCRIPTIONS AND CHARACTERISTICS Trilby Rd Portner Dr Westbourn Cir Autumn Ridge Dr Compton Rd Desert Willow Way 90 54 27 63 106 27 106 494340 494340 494400 494400 494460 494460 494520 494520 494580 494580 494640 494640 494700 494700 4482540 4482540 4482600 4482600 4482660 4482660 4482720 4482720 4482780 4482780 4482840 4482840 4482900 4482900 4482960 4482960 4483020 4483020 0 50 100 200 300 Feet 0 20 40 80 120 Meters 40° 29' 53'' 105° 3' 45'' 40° 29' 35'' 105° 3' 45'' 40° 29' 35'' 40° 29' 53'' 105° 4' 2'' 105° 4' 2'' Map Scale: 1:2,590 if printed on A size (8.5" x 11") sheet. Hydrologic Soil Group—Larimer County Area, Colorado (Transfort Facility Expansion) Natural Resources MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Units Soil Ratings A A/D B B/D C C/D D Not rated or not available Political Features Cities Water Features Oceans Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Map Scale: 1:2,590 if printed on A size (8.5" × 11") sheet. The soil surveys that comprise your AOI were mapped at 1:24,000. Please rely on the bar scale on each map sheet for accurate map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: UTM Zone 13N NAD83 This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Larimer County Area, Colorado Survey Area Data: Version 7, May 1, 2009 Date(s) aerial images were photographed: 8/6/2005 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 (Transfort Facility Expansion) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/11/2010 Page 2 of 4 Hydrologic Soil Group Hydrologic Soil Group— Summary by Map Unit — Larimer County Area, Colorado Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 27 Cushman fine sandy loam, 3 to 9 percent slopes C 4.0 14.2% 54 Kim loam, 3 to 5 percent slopes B 10.3 36.6% 63 Longmont clay, 0 to 3 percent slopes C 1.0 3.7% 90 Renohill clay loam, 3 to 9 percent slopes C 11.3 40.0% 106 Tassel sandy loam, 3 to 25 percent slopes D 1.5 5.5% Totals for Area of Interest 28.1 100.0% 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. Hydrologic Soil Group–Larimer County Area, Colorado Transfort Facility Expansion Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/11/2010 Page 3 of 4 Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Lower Hydrologic Soil Group–Larimer County Area, Colorado Transfort Facility Expansion Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/11/2010 Page 4 of 4 40 5.0 6.0 7.0 8.0 9.0 10.0 11.0 Duration (min) City of Fort Collins IDF Curve 2-yr (FTC) 10-yr (FTC) 100-yr (FTC) 2-yr (UD) 10-yr (UD) 100-yr (UD) 0.0 1.0 2.0 3.0 4.0 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0 55.0 60.0 65.0 Intensity (in/hr) Duration (minutes) 2-yr Intensity (in/hr) 10-yr Intensity (in/hr) 100-yr Intensity (in/hr) Duration (minutes) 2-yr Intensity (in/hr) 10-yr Intensity (in/hr) 100-yr Intensity (in/hr) 5 2.85 4.87 9.95 33 1.22 2.08 4.24 6 2.67 4.56 9.31 34 1.19 2.04 4.16 7 2.52 4.31 8.80 35 1.17 2.00 4.08 8 2.40 4.10 8.38 36 1.15 1.96 4.01 9 2.30 3.93 8.03 37 1.13 1.93 3.93 10 2.21 3.78 7.72 38 1.11 1.89 3.87 11 2.13 3.63 7.42 39 1.09 1.86 3.80 12 2.05 3.50 7.16 40 1.07 1.83 3.74 13 1.98 3.39 6.92 41 1.05 1.80 3.68 14 1.92 3.29 6.71 42 1.04 1.77 3.62 15 1.87 3.19 6.52 43 1.02 1.74 3.56 16 1.81 3.08 6.30 44 1.01 1.72 3.51 17 1.75 2.99 6.10 45 0.99 1.69 3.46 18 1.70 2.90 5.92 46 0.98 1.67 3.41 19 1.65 2.82 5.75 47 0.96 1.64 3.36 20 1.61 2.74 5.60 48 0.95 1.62 3.31 21 1.56 2.67 5.46 49 0.94 1.60 3.27 22 1.53 2.61 5.32 50 0.92 1.58 3.23 23 1.49 2.55 5.20 51 0.91 1.56 3.18 24 1.46 2.49 5.09 52 0.90 1.54 3.14 25 1.43 2.44 4.98 53 0.89 1.52 3.10 26 1.40 2.39 4.87 54 0.88 1.50 3.07 27 1.37 2.34 4.78 55 0.87 1.48 3.03 28 1.34 2.29 4.69 56 0.86 1.47 2.99 29 1.32 2.25 4.60 57 0.85 1.45 2.96 30 1.30 2.21 4.52 58 0.84 1.43 2.92 31 1.27 2.16 4.42 59 0.83 1.42 2.89 32 1.24 2.12 4.33 60 0.82 1.40 2.86 Figure 3-1a City of Fort Collins Rainfall Intensity-Duration-Frequency Table for using the Rational Method Duration 2-yr 10-yr 100-yr 2-yr Δ 10-yr Δ 100-yr Δ 5 2.85 4.87 9.95 2.78 0.07 4.74 0.13 9.68 0.27 6 2.67 4.56 9.31 2.64 0.03 4.51 0.05 9.20 0.11 7 2.52 4.31 8.80 2.52 0.00 4.30 0.01 8.78 0.02 8 2.40 4.10 8.38 2.41 -0.01 4.11 -0.01 8.39 -0.01 9 2.30 3.93 8.03 2.31 -0.01 3.94 -0.01 8.04 -0.01 10 2.21 3.78 7.72 2.21 0.00 3.78 0.00 7.72 0.00 11 2.13 3.63 7.42 2.13 0.00 3.64 -0.01 7.43 -0.01 2-yr 0.82 12 2.05 3.50 7.16 2.05 0.00 3.51 -0.01 7.16 0.00 10-yr 1.4 13 1.98 3.39 6.92 1.98 0.00 3.39 0.00 6.92 0.00 100-yr 2.86 14 1.92 3.29 6.71 1.92 0.00 3.28 0.01 6.69 0.02 15 1.87 3.19 6.52 1.86 0.01 3.17 0.02 6.48 0.04 16 1.81 3.08 6.30 1.80 0.01 3.08 0.00 6.28 0.02 C1 28.5 17 1.75 2.99 6.10 1.75 0.00 2.99 0.00 6.10 0.00 C2 10 18 1.70 2.90 5.92 1.70 0.00 2.90 0.00 5.93 -0.01 C3 0.786651 19 1.65 2.82 5.75 1.65 0.00 2.82 0.00 5.77 -0.02 20 1.61 2.74 5.60 1.61 0.00 2.75 -0.01 5.61 -0.01 21 1.56 2.67 5.46 1.57 -0.01 2.68 -0.01 5.47 -0.01 22 1.53 2.61 5.32 1.53 0.00 2.61 0.00 5.34 -0.02 23 1.49 2.55 5.20 1.49 0.00 2.55 0.00 5.21 -0.01 24 1.46 2.49 5.09 1.46 0.00 2.49 0.00 5.09 0.00 25 1.43 2.44 4.98 1.43 0.00 2.43 0.01 4.97 0.01 26 1.40 2.39 4.87 1.39 0.01 2.38 0.01 4.86 0.01 27 1.37 2.34 4.78 1.36 0.01 2.33 0.01 4.76 0.02 28 1.34 2.29 4.69 1.34 0.00 2.28 0.01 4.66 0.03 29 1.32 2.25 4.60 1.31 0.01 2.24 0.01 4.57 0.03 30 1.30 2.21 4.52 1.28 0.02 2.19 0.02 4.48 0.04 31 1.27 2.16 4.42 1.26 0.01 2.15 0.01 4.39 0.03 32 1.24 2.12 4.33 1.24 0.00 2.11 0.01 4.31 0.02 33 1.22 2.08 4.24 1.21 0.01 2.07 0.01 4.23 0.01 34 1.19 2.04 4.16 1.19 0.00 2.03 0.01 4.15 0.01 35 1.17 2.00 4.08 1.17 0.00 2.00 0.00 4.08 0.00 36 1.15 1.96 4.01 1.15 0.00 1.96 0.00 4.01 0.00 37 1.13 1.93 3.93 1.13 0.00 1.93 0.00 3.94 -0.01 38 1.11 1.89 3.87 1.11 0.00 1.90 -0.01 3.88 -0.01 39 1.09 1.86 3.80 1.09 0.00 1.87 -0.01 3.82 -0.02 40 1.07 1.83 3.74 1.08 -0.01 1.84 -0.01 3.76 -0.02 41 1.05 1.80 3.68 1.06 -0.01 1.81 -0.01 3.70 -0.02 42 1.04 1.77 3.62 1.04 0.00 1.78 -0.01 3.64 -0.02 43 1.02 1.74 3.56 1.03 -0.01 1.76 -0.02 3.59 -0.03 44 1.01 1.72 3.51 1.01 0.00 1.73 -0.01 3.54 -0.03 45 0.99 1.69 3.46 1.00 -0.01 1.71 -0.02 3.48 -0.02 46 0.98 1.67 3.41 0.99 -0.01 1.68 -0.01 3.44 -0.03 Rainfall Depth Coefficients Intensity (in/hr) Urban Drainage Intensity (in/hr) City of Fort Collins Urban Drainage Inputs This cell was determined using solver to best match intensities given from the Fort Collins IDF values. C 3 2 1 1 ( C t c ) I C P 2-year 5-yr 10-yr 25-yr 50-yr 100-yr 5 0.29 0.40 0.49 0.63 0.79 1.00 10 0.33 0.45 0.56 0.72 0.90 1.14 15 0.38 0.53 0.65 0.84 1.05 1.33 20 0.64 0.89 1.09 1.41 1.77 2.23 25 0.81 1.13 1.39 1.80 2.25 2.84 30 1.57 2.19 2.69 3.48 4.36 5.49 35 2.85 3.97 4.87 6.30 7.90 9.95 40 1.18 1.64 2.02 2.61 3.27 4.12 45 0.71 0.99 1.21 1.57 1.97 2.48 50 0.42 0.58 0.71 0.92 1.16 1.46 55 0.35 0.49 0.60 0.77 0.97 1.22 60 0.30 0.42 0.52 0.67 0.84 1.06 65 0.20 0.28 0.39 0.62 0.79 1.00 70 0.19 0.27 0.37 0.59 0.75 0.95 75 0.18 0.25 0.35 0.56 0.72 0.91 80 0.17 0.24 0.34 0.54 0.69 0.87 85 0.17 0.23 0.32 0.52 0.66 0.84 90 0.16 0.22 0.31 0.50 0.64 0.81 95 0.15 0.21 0.30 0.48 0.62 0.78 100 0.15 0.20 0.29 0.47 0.60 0.75 105 0.14 0.19 0.28 0.45 0.58 0.73 110 0.14 0.19 0.27 0.44 0.56 0.71 115 0.13 0.18 0.26 0.42 0.54 0.69 120 0.13 0.18 0.25 0.41 0.53 0.67 2-year 5-yr 10-yr 25-yr 50-yr 100-yr 1-hr 0.82 1.14 1.40 1.81 2.27 2.86 2-hr 0.98 1.36 1.71 2.31 2.91 3.67 Note: The City of Fort Collins SWWM input hyetopgrah is used to calculate the 1-hr and 2-hr storm rainfall depths for the different storm events. Storm Rainfall Depth (in) Duration Time Intensity (in/hr) (min) City of Fort Collins Design Storms for using SWMM Figure 3-1c Page A- 2 POND CALCULATIONS Transfort Facility Expansion Pond Summary Design Engineer: Design Firm: Project Number: Date: Pond Summary Table 0.06 4940.38 16.74 4 1/2 1.27 0.57 4943.45 16.74 17.00 1.5 4943.50 4945.00 J.Claeys Jim Sell Design, Inc. 2598.1 September 15, 2010 100-yr Detention Volume (acre-ft) 100-yr Water Surface Elev. (ft) Detention Pond Summary Table Water Quality Capture Volume (acre-ft) WQCV Water Surface Elev. (ft) 100-yr Pond Max Inflow (cfs) 100-yr Site Release Rate (cfs) Outlet Orifice Size (in) Spillway Summary Table Top of Berm Elev. (ft) 100-yr Pond Max Inflow (cfs) Length (ft) Spillway Depth, including 1 ft freeboard (ft) Spillway Crest Elev. (ft) 2598 PondCalcs.xls - Pond Summary Page 1 of 7 Jim Sell Design, Inc. Project: Basin ID: Design Information (Input): Design Information (Input): Catchment Drainage Imperviousness Ia = 57.00 percent Catchment Drainage Imperviousness I a = 57.00 percent Catchment Drainage Area A = 2.573 acres Catchment Drainage Area A = 2.573 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 = 15 minutes Time of Concentration of Watershed Tc = 15 minutes Allowable Unit Release Rate q = 0.10 cfs/acre Allowable Unit Release Rate q = 0.49 cfs/acre One-hour Precipitation P1 = 0.82 inches One-hour Precipitation P 1 = 2.86 inches Design Rainfall IDF Formula i = C1* P1 /(C2+Tc )^C3 Design Rainfall IDF Formula i = C1 * P1/(C2 +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 = 0.787 Coefficient Three C 3 = 0.787 Determination of Average Outflow from the Basin (Calculated): Determination of Average Outflow from the Basin (Calculated): Runoff Coefficient C = 0.65 Runoff Coefficient C = 0.81 Inflow Peak Runoff Qp-in = 3.16 cfs Inflow Peak Runoff Qp-in = 13.72 cfs Allowable Peak Outflow Rate Qp-out = 0.27 cfs Allowable Peak Outflow Rate Qp-out = 1.27 cfs Mod. FAA Minor Storage Volume = 5,273 cubic feet Mod. FAA Major Storage Volume = 22,202 cubic feet Mod. FAA Minor Storage Volume = 0.121 acre-ft Mod. FAA Major Storage Volume = 0.510 acre-ft 25 <- 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 cubic feet "m" cfs cubic feet cubic feet minutes inches / hr cubic feet "m" cfs cubic feet cubic feet (input) (output) (output) (output) (output) (output) (output) (input) (output) (output) (output) (output) (output) (output) 5 2.78 1,393 1.00 0.27 80 1,313 5 9.68 6,055 1.00 1.27 381 5,674 30 1.28 3,864 0.74 0.20 357 3,507 30 4.48 16,794 0.74 0.94 1,695 15,098 55 0.88 4,835 0.63 0.17 558 4,277 55 3.06 21,015 0.63 0.80 2,648 18,367 80 0.68 5,444 0.59 0.16 759 4,686 80 2.37 23,663 0.59 0.75 3,601 20,062 105 0.56 5,893 0.57 0.15 959 4,933 105 1.95 25,611 0.57 0.72 4,553 21,058 130 0.48 6,250 0.56 0.15 1,160 5,090 130 1.67 27,163 0.56 0.71 5,506 21,657 155 0.42 6,548 0.55 0.15 1,361 5,187 155 1.47 28,460 0.55 0.69 6,458 22,002 180 0.38 6,805 0.54 0.14 1,561 5,244 180 1.31 29,578 0.54 0.69 7,411 22,168 205 0.34 7,032 0.54 0.14 1,762 5,270 205 1.19 30,565 0.54 0.68 8,363 22,202 230 0.31 7,236 0.53 0.14 1,963 5,273 230 1.09 31,450 0.53 0.68 9,316 22,134 255 0.29 7,421 0.53 0.14 2,163 5,257 255 1.01 32,254 0.53 0.67 10,268 21,985 280 0.27 7,591 0.53 0.14 2,364 5,226 280 0.94 32,991 0.53 0.67 11,221 21,770 305 0.25 7,748 0.52 0.14 2,565 5,183 305 0.88 33,674 0.52 0.67 12,173 21,500 330 0.24 7,894 0.52 0.14 2,766 5,128 330 0.83 34,309 0.52 0.66 13,126 21,183 355 0.23 8,031 0.52 0.14 2,966 5,065 355 0.79 34,905 0.52 0.66 14,078 20,827 380 0.21 8,160 0.52 0.14 3,167 4,993 380 0.75 35,466 0.52 0.66 15,031 20,435 405 0.20 8,282 0.52 0.14 3,368 4,914 405 0.71 35,996 0.52 0.66 15,983 20,012 430 0.19 8,398 0.52 0.14 3,568 4,829 430 0.68 36,499 0.52 0.66 16,936 19,563 455 0.19 8,508 0.52 0.14 3,769 4,739 455 0.65 36,978 0.52 0.66 17,888 19,090 480 0.18 8,613 0.52 0.14 3,970 4,643 480 0.62 37,435 0.52 0.65 18,841 18,595 505 0.17 8,714 0.51 0.14 4,170 4,543 505 0.60 37,873 0.51 0.65 19,793 18,080 530 0.17 8,810 0.51 0.14 4,371 4,439 530 0.58 38,293 0.51 0.65 20,746 17,547 555 0.16 8,903 0.51 0.14 4,572 4,332 555 0.56 38,697 0.51 0.65 21,699 16,999 580 0.15 8,993 0.51 0.14 4,773 4,220 580 0.54 39,086 0.51 0.65 22,651 16,435 605 0.15 9,079 0.51 0.14 4,973 4,106 605 0.52 39,461 0.51 0.65 23,604 15,858 630 0.14 9,163 0.51 0.14 5,174 3,989 630 0.51 39,824 0.51 0.65 24,556 15,268 Project: Basin ID: DETENTION VOLUME BY THE MODIFIED FAA METHOD (See USDCM Volume 2 Storage Chapter for description of method) Transfort Facility Expansion UDFCD DETENTION VOLUME ESTIMATING WORKBOOK Version 2.2, Released January 2010 -20,000 -10,000 0 10,000 20,000 30,000 40,000 50,000 60,000 70,000 0 200 400 600 800 1000 1200 1400 1600 Volume (Cubic Feet) Duration (Minutes) Inflow and Outflow Volumes vs. Rainfall Duration Minor Storm Inflow Volume Minor Storm Outflow Volume Minor Storm Storage Volume Major Storm Inflow Volume Major Storm Outflow Volume Major Storm Storage Volume 2598 UD_Detention_2.2.xls, Modified FAA 9/15/2010, 7:53 AM Transfort Facility Expansion Water Quality Pond and Outlet Sizing (Per USDCM) Design Engineer: Design Firm: Project Number: Date: DESIGN CRITERIA: REQUIRED WATER QUALITY CAPTURE VOLUME (WQCV): Tributary Area, A 2.57 acres Composite. Imperviousness, I 57.0% WQCV (watershed inches) 0.226 inches 40-Hour Drain Time (Fig SQ-2) Required WQCV 0.058 acre-feet Including 20% for Sedimentation WATER QUALITY OUTLET SIZING (Per USDCM, Volume 3): Design Water Quality Depth, DWQ 1.28 ft Determine K40 K40 = 0.013DWQ 2 + 0.22DWQ - 0.10 0.203 Maximum Area per Row, a a = WQCV / K40 0.287 square inches Number of Rows, nr 3 rows Number of Columns, nc (See Table 6a-1 for Max.) 1 columns Choose Hole Diameter 9/16 inches Use USDCM Volume 3, Figure 5 0.563 inches Total Area per Row, Ao 0.25 square inches J.Claeys Jim Sell Design, Inc. 2598.1 September 15, 2010 Urban Storm Drainage Criteria Manual (USDCM) Volume III, Urban Drainage and Flood Control District, June 2001 Circular Perforation Sizing * * 1 . 2 12 WQCV Area Volume ⎟ ⎠ ⎞ ⎜ ⎝ = ⎛ Total Outlet Area, Aot 0.75 square inches Does design work? Yes Minimum Steel Plate Thickness 1/4 inch (Not Used) Number of Rows, nr 2 rows Choose Rectangular Hole Width (w/ 2" Height) 0 inches Use USDCM Volume 3, Figure 5 0.000 inches Total Outlet Area, Aot 0.00 square inches Does design work? Yes Minimum Steel Plate Thickness 1/4 inch Rectangular Perforation Sizing * * 1 . 2 12 WQCV Area Volume ⎟ ⎠ ⎞ ⎜ ⎝ = ⎛ 2598 PondCalcs.xls - WQCV & Outlet Structure Page 2 of 7 Jim Sell Design, Inc. Transfort Facility Expansion Water Quality Pond and Outlet Sizing (Per USDCM) Design Engineer: Design Firm: Project Number: Date: J.Claeys Jim Sell Design, Inc. 2598.1 September 15, 2010 WATER QUALITY TRASH RACK SIZING (Per USDCM, Volume 3) Required Open Area, At At=0.5*[77(e-0.124D)]*Aot 27 square inches Min. Distance between Columns, Sc 3 inches Width of Trash Rack and Concrete Opening per Column 3 inches Use USDCM Volume 3, Table 6a-1 Total Width, Wconc 3 inches Height of Trash Rack Screen, Htr 15 6/16 inches Check - Larger than Required Type of Screen S.S. #93 VEE Wire (US Filter) Screen Opening Slot Dimension 0.139" (US Filter) Support Rod Type (See Table 6a-2) Spacing of Support Rod (O.C.) 3/4 inches O.C. Total Screen Thickness (See Table 6a-2) 0.31 inches Carbon Steel Frame Type (See Table 6a-2) (Not Used) Required Open Area, At (including 50% clogging) At=0.5*[77(e-0.124D)]*Aot 0 square inches Width of Trash Rack Opening, Wopening 1 inches Rectangular Perforation Trash Rack Sizing #156 VEE 3/8in x 1.0in flat bar Circular Perforation Trash Rack Sizing Width of Trash Rack Opening, Wopening 1 inches Use USDCM Volume 3, Table 6b-1 Width of Concrete Opening, Wconc 12 inches Min Height of Trash Rack Screen, Htr (including 2' 4" below lowest openings) 28.00 inches Type of Screen Kelmp KRP Series Aluminum Bar Gate (or Equal) Screen Opening Slot Dimension 3/16" Bars on 1-3/16" Centers Minimum Bearing Bar Size (See Table 6b-2) 1 in x 3/16 in 2598 PondCalcs.xls - WQCV & Outlet Structure Page 3 of 7 Jim Sell Design, Inc. Transfort Facility Expansion Critical Pond Elevations Design Engineer: Design Firm: Project Number: Date: DESIGN CRITERIA Urban Storm Drainage Criteria Manual, Urban Drainage and Flood Control District, June 2001 Stage Storage Volume (pond volume calculated using the prismoidal formula): CONTOUR (FT) AREA (FT2) AREA (ACRE) VOLUME (ACRE-FT) DEPTH (FT) CUMULATIVE VOLUME (ACRE-FT) 4939.10 0.000 0.000 0.00 0.000 4940.0 3260.37 0.075 0.022 0.90 0.022 4941.0 4973.785 0.114 0.094 1.90 0.116 4942.0 7243.862 0.166 0.139 2.90 0.256 4943.0 9882.058 0.227 0.196 3.90 0.452 4944.0 12965.129 0.298 0.261 4.90 0.713 4945.0 16171.518 0.371 0.334 5.90 1.047 0.06 4940.38 ft 0.57 4943.45 ft J.Claeys Jim Sell Design, Inc. 2598.1 Acre-Ft Interpolates to an Elev. of Acre-Ft Interpolates to an Elev. of Required Water Quality Capture Volume = Required 100-yr Detention Volume (including WQCV) = September 15, 2010 ( ) 3 AAAADepth 1 2 1 2 V + + = 2598 PondCalcs.xls - Pond Stage Storage Page 4 of 7 Jim Sell Design, Inc. 4938.00 4939.00 4940.00 4941.00 4942.00 4943.00 4944.00 4945.00 4946.00 0.0 0.2 0.4 0.6 0.8 1.0 1.2 ELEVATION (FT) DETENTION POND VOLUME (AC-FT) DETENTION POND VOLUME VERSUS ELEVATION ( ) 3 AAAADepth 1 2 1 2 V + + = 2598 PondCalcs.xls - Pond Stage Storage Page 4 of 7 Jim Sell Design, Inc. Transfort Facility Expansion Emergency Overflow Spillway Calculations Design Engineer: Design Firm: Project Number: Date: Broad-Crested Weir Equation-Trapezoidal Shape where: Q = Discharge (cfs) C = Weir Coeffecient L = Weir Length (ft) H = Average Weir Head (ft) H:V =Side Slope Calculations Knowns: 4.00 0.50 ft 2.6 4943.50 ft 16.74 cfs *Total Offsite/Onsite Runnoff 16.21 ft 17 ft 1.50 ft Side Slopes (H:V) Desired Spillway Head Weir Coefficient Spillway Elevation J.Claeys Jim Sell Design, Inc. 2598.1 September 15, 2010 100-yr Pond Inflow Calculated Spillway Length Use Spillway Length Spillway Depth 2 5 2 3 H V Q CLH C H ⎟ ⎠ ⎞ ⎜ ⎝ = + ⎛ Topft of Berm Elevation 4945.0 (including 1' freeboard) 4943.00 4943.50 4944.00 4944.50 4945.00 4945.50 4946.00 0.00 50.00 100.00 150.00 200.00 ELEVATION (ft) DISCHARGE (cfs) STAGE - DISCHARGE CURVE FOR THE PROPOSED DETENTION POND OVERFLOW SPILLWAY FOR SOUTH Transfort Facility Expansion Emergency Overflow Spillway Calculations Design Engineer: Design Firm: Project Number: Date: J.Claeys Jim Sell Design, Inc. 2598.1 September 15, 2010 Ponding Depth (ft) Spillway Head (ft) QTotal (CFS) 4943.50 0.00 0.00 4943.60 0.10 1.43 4943.70 0.20 4.14 4943.80 0.30 7.78 4943.90 0.40 12.23 4944.00 0.50 17.47 4944.10 0.60 23.44 4944.20 0.70 30.15 4944.30 0.80 37.58 4944.40 0.90 45.73 4944.50 1.00 54.60 4944.60 1.10 64.19 4944.70 1.20 74.51 4944.80 1.30 85.55 4944.90 1.40 97.34 4945.00 1.50 109.86 4945.10 1.60 123.13 4945.20 1.70 137.16 4945.30 1.80 151.95 4945.40 1.90 167.51 4945.50 2.00 183.85 2598 PondCalcs.xls - Spillway Page 6 of 7 Jim Sell Design, Inc. Transfort Facility Expansion Circular Orifice Plate Sizing Design Engineer: Design Firm: Project Number: Date: Orifice Equation where: C = Orifice Discharge Coefficient A o = Orifice Area (ft 2 ) g = Gravity (32.2 ft/s 2 ) Δh = Difference in Elevation Head (ft) D o = Orifice Diameter (in) Calculations 100-yr Orifice Sizing 100-yr Orifice Rating Table Knowns: 100-yr Release Rate 1.27 cfs 100-yr WSEL 4943.45 ft 4939.10 0.00 0.000 4940.00 0.52 0.022 Pond Outlet Invert 4939.10 ft 4941.00 0.81 0.116 4942.00 1.02 0.256 Discharge Coefficient 0.65 4943.00 1.20 0.452 4944.00 1.35 0.713 Tailwater Elevation 4938.00 ft 4945.00 1.49 1.047 Orifice Diameter 4 11/16 in Pond Volume (ac-ft) J.Claeys Jim Sell Design, Inc. 2598.1 September 15, 2010 Elevation (ft) Discharge (cfs) C g h Q CA o g h A o Q Δ = Δ ⇒ = 2 2 π o o D A 576 = 2598 PondCalcs.xls - Outlet Orifice Plate Sizing Page 7 of 7 Jim Sell Design, Inc. Orifice Area 0.119 ft 2 Centroid Elevation 4939.29 ft Actual Release Rate 1.27 cfs C g h Q CA o g h A o Q Δ = Δ ⇒ = 2 2 π o Page A- 3 HISTORIC & PROPOSED RATIONAL CALCULATIONS Transfort Facility Expansion DRAINAGE SUMMARY Design Engineer: Design Firm: Project Number: Date: DRAINAGE SUMMARY: Area (acres) % Impervious 2-yr Peak Runoff (cfs) 100-yr Peak Runoff (cfs) H01 2.547 2.0% 1.27 5.55 H02 0.688 68.6% 1.18 5.15 Overall 3.235 16.2% 2.46 10.70 Area (acres) % Impervious 2-yr Peak Runoff (cfs) 100-yr Peak Runoff (cfs) DO1 1.070 2.0% 0.56 2.43 DO2 1.503 95.5% 3.84 14.31 Total to Pond 2.573 56.6% 4.40 16.74 DO3 0.662 93.2% 1.51 5.83 Overall 3.235 64.1% 5.90 22.57 Basin J.Claeys Jim Sell Design, Inc. 2598.1 September 15, 2010 Basin Historical Proposed Page 1 of 7 Transfort Facility Expansion HISTORIC IMPERVIOUS AREA CALCULATION Design Engineer: Design Firm: Project Number: Date: DESIGN CRITERIA: Storm Drainage Design Criteria and Constructions Standards, City of Fort Collins, 1999 Urban Storm Drainage Criteria Manual by Urban Drainage and Flood Control District, June 2001 (Revised August 2006) BASINS: % Impervious Runoff Coefficient C Return Period Frequency Adjustment Factor (Cf) 100% 0.95 2-year & 5-year 1.00 90% 0.95 100-year 1.25 40% 0.50 2% 0.25 Atotal A total Apaved Aroof A gravel Agreen (sq feet) (acres (sq feet) (sq feet) (sq feet) (sq feet) C2 / C5 C100 H01 110,939 2.547 0 0 0 110,939 2.0% 0.25 0.31 H02 29,961 0.688 20,347 0 0 9,613 68.6% 0.73 0.91 Overall 140,900 3.235 20,347 0 0 120,553 16.2% 0.35 0.44 J.Claeys Jim Sell Design, Inc. 2598.1 September 15, 2010 % Impervious values from Table RO-3 in the Urban Storm Drainage Criteria Manual for Hydrologic Soil Classification C Sub-basin Designation COMPOSITE Land Use Paved Roof Gravel Greenbelt Weighted % Impervious Page 2 of 7 Transfort Facility Expansion HISTORIC TIME OF CONCENTRATION Design Engineer: Design Firm: Project Number: Date: DESIGN CRITERIA: Urban Storm Drainage Criteria Manual by Urban Drainage and Flood Control District, June 2001 (Revised August 2006) EQUATIONS: -Equation RO-3 -Equation RO-4 -Urbanized Check Equation RO-5 -Equation RO-3 CONSTRAINTS: 300 ft - Overland flow shall not exceed for developed condition 500 ft - Overland flow shall not exceed for undeveloped condition Final t c = minimum of t i + t t and urbanized basin check recommended minimum t c = 5 min for urbanized basins J.Claeys Jim Sell Design, Inc. 2598.1 September 15, 2010 () 0 . 33 0 . 395 1 . 1 5 S C L ti − = t c = t i + t t 0 . 5 VCvS = w 10 180 = + tc L V tt 60 L = Page 3 of 7 BASINS: Type of Travel Surface C v H1 H01 0.25 2.547 498 0.0228 26.43 0 0.0000 Grassed Waterway 15 0.05 0.00 26.43 12.77 12.77 H2 H02 0.73 0.688 73 0.0705 3.06 492 0.0060 Paved Areas 20 1.55 5.30 8.35 13.14 8.35 SUB-BASIN DATA INITIAL/OVERLAND TIME (ti) DESIGN POINT Sub-basin C5 AREA (acres) LENGTH (ft) SLOPE (ft/ft) ti (min) LENGTH Table RO-2 (ft) TRAVEL TIME (tt) REMARKS Transfort Facility Expansion HISTORIC PEAK RUNOFF Design Engineer: Design Firm: Project Number: Date: DESIGN CRITERIA: Storm Drainage Design Criteria and Constructions Standards, City of Fort Collins, 1999 (Rainfall Depths) Urban Storm Drainage Criteria Manual by Urban Drainage and Flood Control District, June 2001 (Revised August 2006) EQUATIONS: Q n = n -yr peak discharge (cfs) I = rainfall intensity (in/hr) C n = n -yr runoff coefficient P 1 = one-hour point rainfall depth (in) I n = n -yr rainfall intensity (in/hr) t c = time of concentration (min) A n = Basin drainage area (ac) P 1-2yr = 0.82 in P 1-100yr = 2.86 in BASINS: R noff Coeff C(A) It it R noff Coeff C(A) It it J.Claeys Jim Sell Design, Inc. 2598.1 September 15, 2010 100-yr Peak Runoff Design Sub basin Area (acres) t (min) 2-yr Peak Runoff Q n = C n I n A n 0.7867 1 ( 10 ) 28 . 5 t c I P + = Page 4 of 7 Runoff Coeff. (C2) C(A) (acres) Intensity (in/hr) Q (ft 3 /s) Runoff Coeff. (C100) C(A) (acres) Intensity (in/hr) Q (ft 3 /s) H1 H01 2.547 12.77 0.25 0.64 2.00 1.27 0.31 0.80 6.97 5.55 H2 H02 0.688 8.35 0.73 0.50 2.37 1.18 0.91 0.62 8.26 5.15 es g Point Sub-basin Area (acres) tc (min) Q n = C n I n A n 0.7867 1 ( 10 ) Transfort Facility Expansion DEVELOPED IMPERVIOUS AREA CALCULATION Design Engineer: Design Firm: Project Number: Date: DESIGN CRITERIA: Storm Drainage Design Criteria and Constructions Standards, City of Fort Collins, 1999 Urban Storm Drainage Criteria Manual by Urban Drainage and Flood Control District, June 2001 (Revised August 2006) BASINS: % Impervious Runoff Coefficient C Return Period Frequency Adjustment Factor (Cf) 100% 0.95 2-year & 5- year 1.00 90% 0.95 100-year 1.25 40% 0.50 2% 0.25 Atotal Atotal Apaved Aroof Agravel Agreen (sq feet) (acres (sq feet) (sq feet) (sq feet) (sq feet) C2 / C5 C100 DO1 46,589 1.070 0 0 0 46,589 2.0% 0.25 0.31 DO2 65,483 1.503 47,885 16,240 0 1,358 95.5% 0.94 1.00 Total to Pond 112,072 2.573 47,885 16,240 0 47,947 56.6% 0.65 0.81 DO3 28,828 0.662 26,842 0 0 1,986 93.2% 0.90 1.00 Overall 140,900 3.235 74,727 16,240 0 49,932 64.1% 0.70 0.88 % Impervious values from Table RO-3 in the Urban Storm Drainage Criteria Manual for Hydrologic Soil Classification C Roof Paved J.Claeys Jim Sell Design, Inc. 2598.1 September 15, 2010 Sub-basin Designation Greenbelt Weighted % COMPOSITE Impervious Land Use Gravel Page 5 of 7 Transfort Facility Expansion DEVELOPED TIME OF CONCENTRATION Design Engineer: Design Firm: Project Number: Date: DESIGN CRITERIA: Urban Storm Drainage Criteria Manual by Urban Drainage and Flood Control District, June 2001 (Revised August 2006) EQUATIONS: -Equation RO-3 -Equation RO-4 -Urbanized Check Equation RO-5 -Equation RO-3 CONSTRAINTS: 300 ft - Overland flow shall not exceed for developed condition 500 ft - Overland flow shall not exceed for undeveloped condition Final t c = minimum of t i + t t and urbanized basin check recommended minimum t c = 5 min for urbanized basins J.Claeys Jim Sell Design, Inc. 2598.1 September 15, 2010 () 0 . 33 0 . 395 1 . 1 5 S C L ti − = t c = t i + t t 0 . 5 VCvS = w 10 180 = + tc L V tt 60 L = Page 6 of 7 BASINS: Type of Travel Surface C v D1 DO1 0.25 1.070 127 0.0916 8.40 291 0.0100 Grassed Waterway 15 1.50 3.23 11.63 12.32 11.63 D2 DO2 0.94 1.503 100 0.0129 2.77 298 0.0094 Paved Areas 20 1.94 2.56 5.32 12.21 5.32 D3 DO3 0.90 0.662 73 0.0705 1.62 492 0.0060 Paved Areas 20 1.55 5.30 6.91 13.14 6.91 TRAVEL TIME (tt) REMARKS tc Urban Check Final tc (min) tc=t i+tt SLOPE (min) (ft/ft) VEL. (ft/s) tt (min) DESIGN POINT Sub-basin C5 Transfort Facility Expansion DEVELOPED PEAK RUNOFF Design Engineer: Design Firm: Project Number: Date: DESIGN CRITERIA: Storm Drainage Design Criteria and Constructions Standards, City of Fort Collins, 1999 (Rainfall Depths) Urban Storm Drainage Criteria Manual by Urban Drainage and Flood Control District, June 2001 (Revised August 2006) EQUATIONS: Q n = n -yr peak discharge (cfs) I = rainfall intensity (in/hr) C n = n -yr runoff coefficient P 1 = one-hour point rainfall depth (in) I n = n -yr rainfall intensity (in/hr) t c = time of concentration (min) A n = Basin drainage area (ac) P 1-2yr = 0.82 in P 1-100yr = 2.86 in BASINS: R noff Coeff C(A) It it R noff Coeff C(A) It it J.Claeys Jim Sell Design, Inc. 2598.1 September 15, 2010 100-yr Peak Runoff Design Sub basin Area (acres) t (min) 2-yr Peak Runoff Q n = C n I n A n 0.7867 1 ( 10 ) 28 . 5 t c I P + = Page 7 of 7 Runoff Coeff. (C2) C(A) (acres) Intensity (in/hr) Q (ft 3 /s) Runoff Coeff. (C100) C(A) (acres) Intensity (in/hr) Q (ft 3 /s) D1 DO1 1.070 11.63 0.25 0.27 2.08 0.56 0.31 0.33 7.26 2.43 D2 DO2 1.503 5.32 0.94 1.41 2.73 3.84 1.00 1.50 9.52 14.31 D3 DO3 0.662 6.91 0.90 0.60 2.53 1.51 1.00 0.66 8.81 5.83 es g Point Sub-basin Area (acres) tc (min) Q n = C n I n A n 0.7867 1 Page A- 4 CONVEYANCE ELEMENT SIZING Project Description Friction Method Manning Formula Solve For Discharge Input Data Roughness Coefficient 0.012 Channel Slope 0.10000 ft/ft Normal Depth 0.50 ft Bottom Width 3.00 ft Results Discharge 30.54 ft³/s Flow Area 1.50 ft² Wetted Perimeter 4.00 ft Top Width 3.00 ft Critical Depth 1.48 ft Critical Slope 0.00460 ft/ft Velocity 20.36 ft/s Velocity Head 6.44 ft Specific Energy 6.94 ft Froude Number 5.08 Flow Type Supercritical GVF Input Data Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Downstream Velocity Infinity ft/s Upstream Velocity Infinity ft/s Normal Depth 0.50 ft Critical Depth 1.48 ft Channel Slope 0.10000 ft/ft Critical Slope 0.00460 ft/ft Worksheet for Parking Lot Chase 9/15/2010 9:13:52 AM Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.01.071.00] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 Project Description Friction Method Manning Formula Solve For Discharge Input Data Channel Slope 0.01000 ft/ft Normal Depth 0.50 ft Section Definitions Station (ft) Elevation (ft) 0+00.00 0.50 0+16.67 0.17 0+18.67 0.00 0+18.67 0.50 0+19.17 0.50 Roughness Segment Definitions Start Station Ending Station Roughness Coefficient (0+00.00, 0.50) (0+16.67, 0.17) 0.013 (0+16.67, 0.17) (0+18.67, 0.00) 0.012 (0+18.67, 0.00) (0+19.17, 0.50) 0.012 Results Discharge 13.50 ft³/s Elevation Range 0.00 to 0.50 ft Flow Area 3.58 ft² Wetted Perimeter 19.18 ft Top Width 18.67 ft Normal Depth 0.50 ft Critical Depth 0.56 ft Critical Slope 0.00401 ft/ft Velocity 3.77 ft/s Velocity Head 0.22 ft Specific Energy 0.72 ft Worksheet for Parking Lot C&G Capacity 9/15/2010 9:15:22 AM Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.01.071.00] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 2 Results Froude Number 1.52 Flow Type Supercritical GVF Input Data Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Downstream Velocity Infinity ft/s Upstream Velocity Infinity ft/s Normal Depth 0.50 ft Critical Depth 0.56 ft Channel Slope 0.01000 ft/ft Critical Slope 0.00401 ft/ft Worksheet for Parking Lot C&G Capacity 9/15/2010 9:15:22 AM Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.01.071.00] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 2 of 2 Project Description Friction Method Manning Formula Solve For Discharge Input Data Roughness Coefficient 0.030 Channel Slope 0.01000 ft/ft Normal Depth 1.00 ft Left Side Slope 8.00 ft/ft (H:V) Right Side Slope 4.00 ft/ft (H:V) Results Discharge 18.53 ft³/s Flow Area 6.00 ft² Wetted Perimeter 12.19 ft Top Width 12.00 ft Critical Depth 0.90 ft Critical Slope 0.01746 ft/ft Velocity 3.09 ft/s Velocity Head 0.15 ft Specific Energy 1.15 ft Froude Number 0.77 Flow Type Subcritical GVF Input Data Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Downstream Velocity Infinity ft/s Upstream Velocity Infinity ft/s Normal Depth 1.00 ft Critical Depth 0.90 ft Channel Slope 0.01000 ft/ft Critical Slope 0.01746 ft/ft Worksheet for Eastern Drainage Swale 9/15/2010 9:15:56 AM Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.01.071.00] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 Scenario: Base JSD Custom Table Title: Transfort Facility Expansion f:\...\drainage\2598 stormcad.stm 09/15/10 09:46:05 AM Jim Sell Design IncFort Collin © Bentley Systems, Inc. Haestad Methods Solution Center Watertown, CT 06795 USA +1-203-755-1666 Project Engineer: jasonc StormCAD v5.6 [05.06.014.00] Page 1 of 1 Label Structure Diameter (ft) Section Size Number of Sections Rim Elevation (ft) Sump Elevation (ft) Upstream Invert Elevation (ft) Downstream Invert Elevation (ft) Length (ft) Constructed Slope (ft/ft) Headloss Method Headloss Coefficient Hydraulic Grade Line In (ft) Hydraulic Grade Line Out (ft) Energy Grade Line In (ft) Energy Grade Line Out (ft) Additional Flow (cfs) Scenario: Base Title: Transfort Facility Expansion f:\...\drainage\2598 stormcad.stm 09/15/10 09:34:41 AM Jim Sell Design IncFort Collin © Bentley Systems, Inc. Haestad Methods Solution Center Watertown, CT 06795 USA +1-203-755-1666 Project Engineer: jasonc StormCAD v5.6 [05.06.014.00] Page 1 of 1 P-1 O-1 I-1 Profile Scenario: Base Title: Transfort Facility Expansion f:\...\drainage\2598 stormcad.stm 09/15/10 09:35:49 AM Jim Sell Design IncFort Collin © Bentley Systems, Inc. Haestad Methods Solution Center Watertown, CT 06795 USA +1-203-755-1666 Project Engineer: jasonc StormCAD v5.6 [05.06.014.00] Page 1 of 1 Elevation (ft) Station (ft) Profile: Outlet Pipe Scenario: Base 0+00 1+00 4,935.00 4,940.00 4,945.00 Sump: 4,938.00 ft Rim: 4,939.50 ft Label: O-1 Sump: 4,939.10 ft Rim: 4,941.10 ft Label: I-1 S: 0.014667 ft/ft Size: 18 inch L: 75.00 ft Dn. Invert: 4,938.00 ft Up. Invert: 4,939.10 ft Label: P-1 Page A- 5 EROSION CONTROL DETAILS Total Flow (cfs) Tailwater Elevation (ft) I-1 4,941.10 4,939.10 Absolute 4,939.52 4,939.52 4,939.67 4,939.67 1.27 1.27 P-1 18 inch 1 4,939.10 4,938.00 75.00 0.014667 4,939.52 4,938.75 4,939.67 4,938.78 1.27 O-1 4,939.50 4,938.00 4,938.75 4,938.75 4,938.75 4,938.75 1.27 4,938.75 ( 10 ) 28 . 5 t c I P + = Page 7 of 7 AREA (acres) LENGTH (ft) SLOPE (ft/ft) ti (min) LENGTH Table RO-2 (ft) SUB-BASIN DATA INITIAL/OVERLAND TIME (ti) () 0 . 33 0 . 395 1 . 1 5 S C L ti − = t c = t i + t t 0 . 5 VCvS = w 10 180 = + tc L V tt 60 L = Page 6 of 7 28 . 5 t c I P + = Page 4 of 7 tc Urban Check Final tc (min) tc=t i+tt SLOPE (min) (ft/ft) VEL (ft/s) tt (min) () 0 . 33 0 . 395 1 . 1 5 S C L ti − = t c = t i + t t 0 . 5 VCvS = w 10 180 = + tc L V tt 60 L = Page 3 of 7 o D A 576 = 2598 PondCalcs.xls - Outlet Orifice Plate Sizing Page 7 of 7 Jim Sell Design, Inc. POND 2 5 2 3 H V Q CLH C H ⎟ ⎠ ⎞ ⎜ ⎝ = + ⎛ 2598 PondCalcs.xls - Spillway Page 5 of 7 Jim Sell Design, Inc. 655 0.14 9,243 0.51 0.14 5,375 3,869 655 0.49 40,175 0.51 0.65 25,509 14,666 680 0.14 9,322 0.51 0.14 5,575 3,746 680 0.48 40,515 0.51 0.65 26,461 14,054 705 0.13 9,397 0.51 0.14 5,776 3,621 705 0.46 40,845 0.51 0.65 27,414 13,431 730 0.13 9,471 0.51 0.14 5,977 3,494 730 0.45 41,165 0.51 0.65 28,366 12,799 755 0.13 9,543 0.51 0.14 6,177 3,365 755 0.44 41,476 0.51 0.65 29,319 12,158 780 0.12 9,613 0.51 0.14 6,378 3,234 780 0.43 41,779 0.51 0.65 30,271 11,508 805 0.12 9,680 0.51 0.14 6,579 3,102 805 0.42 42,074 0.51 0.65 31,224 10,851 830 0.12 9,747 0.51 0.14 6,779 2,967 830 0.41 42,362 0.51 0.65 32,176 10,186 855 0.11 9,811 0.51 0.14 6,980 2,831 855 0.40 42,643 0.51 0.65 33,129 9,514 880 0.11 9,874 0.51 0.14 7,181 2,693 880 0.39 42,917 0.51 0.65 34,081 8,836 905 0.11 9,936 0.51 0.14 7,382 2,554 905 0.38 43,185 0.51 0.65 35,034 8,151 930 0.11 9,996 0.51 0.14 7,582 2,414 930 0.37 43,447 0.51 0.64 35,986 7,460 955 0.10 10,055 0.51 0.14 7,783 2,272 955 0.37 43,703 0.51 0.64 36,939 6,764 980 0.10 10,113 0.51 0.14 7,984 2,129 980 0.36 43,954 0.51 0.64 37,891 6,062 1005 0.10 10,169 0.51 0.14 8,184 1,985 1005 0.35 44,199 0.51 0.64 38,844 5,355 1030 0.10 10,225 0.51 0.14 8,385 1,840 1030 0.35 44,440 0.51 0.64 39,796 4,643 1055 0.10 10,279 0.51 0.14 8,586 1,693 1055 0.34 44,676 0.51 0.64 40,749 3,927 1080 0.10 10,332 0.51 0.14 8,786 1,546 1080 0.33 44,907 0.51 0.64 41,702 3,206 1105 0.09 10,384 0.51 0.14 8,987 1,397 1105 0.33 45,134 0.51 0.64 42,654 2,480 1130 0.09 10,436 0.51 0.14 9,188 1,248 1130 0.32 45,357 0.51 0.64 43,607 1,751 1155 0.09 10,486 0.51 0.14 9,388 1,098 1155 0.32 45,577 0.51 0.64 44,559 1,017 1180 0.09 10,536 0.51 0.14 9,589 947 1180 0.31 45,792 0.51 0.64 45,512 280 1205 0.09 10,584 0.51 0.14 9,790 795 1205 0.31 46,003 0.51 0.64 46,464 -461 1230 0.09 10,632 0.51 0.14 9,991 642 1230 0.30 46,211 0.51 0.64 47,417 -1,205 1255 0.08 10,679 0.51 0.14 10,191 488 1255 0.30 46,416 0.51 0.64 48,369 -1,953 1280 0.08 10,726 0.51 0.14 10,392 334 1280 0.29 46,617 0.51 0.64 49,322 -2,704 1305 0.08 10,771 0.51 0.14 10,593 179 1305 0.29 46,816 0.51 0.64 50,274 -3,459 1330 0.08 10,816 0.51 0.14 10,793 23 1330 0.28 47,011 0.51 0.64 51,227 -4,216 1355 0.08 10,860 0.51 0.14 10,994 -134 1355 0.28 47,203 0.51 0.64 52,179 -4,976 1380 0.08 10,904 0.51 0.14 11,195 -291 1380 0.27 47,393 0.51 0.64 53,132 -5,739 1405 0.08 10,947 0.51 0.14 11,395 -448 1405 0.27 47,579 0.51 0.64 54,084 -6,505 1430 0.08 10,989 0.51 0.14 11,596 -607 1430 0.27 47,763 0.51 0.64 55,037 -7,274 1455 0.08 11,031 0.50 0.14 11,797 -766 1455 0.26 47,945 0.50 0.64 55,989 -8,045 1480 0.07 11,072 0.50 0.14 11,997 -925 1480 0.26 48,124 0.50 0.64 56,942 -8,818 1505 0.07 11,113 0.50 0.14 12,198 -1,085 1505 0.26 48,300 0.50 0.64 57,894 -9,594 Mod. FAA Minor Storage Volume (cubic ft.) = 5,273 Mod. FAA Major Storage Volume (cubic ft.) = 22,202 Mod. FAA Minor Storage Volume (acre-ft.) = 0.1211 Mod. FAA Major Storage Volume (acre-ft.) = 0.5097 DETENTION VOLUME BY THE MODIFIED FAA METHOD (See USDCM Volume 2 Storage Chapter for description of method) Transfort Facility Expansion 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 VOLUME ESTIMATING WORKBOOK Version 2.2, Released January 2010 Determination of MINOR Detention Volume Using Modified FAA Method 2598 UD_Detention_2.2.xls, Modified FAA 9/15/2010, 7:53 AM + = 47 0.96 1.64 3.36 0.97 -0.01 1.66 -0.02 3.39 -0.03 48 0.95 1.62 3.31 0.96 -0.01 1.64 -0.02 3.34 -0.03 49 0.94 1.60 3.27 0.95 -0.01 1.61 -0.01 3.30 -0.03 50 0.92 1.58 3.23 0.93 -0.01 1.59 -0.01 3.25 -0.02 51 0.91 1.56 3.18 0.92 -0.01 1.57 -0.01 3.21 -0.03 52 0.90 1.54 3.14 0.91 -0.01 1.55 -0.01 3.17 -0.03 53 0.89 1.52 3.10 0.90 -0.01 1.53 -0.01 3.13 -0.03 54 0.88 1.50 3.07 0.89 -0.01 1.51 -0.01 3.09 -0.02 55 0.87 1.48 3.03 0.88 -0.01 1.50 -0.02 3.06 -0.03 56 0.86 1.47 2.99 0.87 -0.01 1.48 -0.01 3.02 -0.03 57 0.85 1.45 2.96 0.86 -0.01 1.46 -0.01 2.98 -0.02 58 0.84 1.43 2.92 0.85 -0.01 1.44 -0.01 2.95 -0.03 59 0.83 1.42 2.89 0.84 -0.01 1.43 -0.01 2.92 -0.03 60 0.82 1.40 2.86 0.83 -0.01 1.41 -0.01 2.88 -0.02 0.00 0.02 0.00 C 3 2 1 1 ( C t c ) I C P + = Conservation Service Web Soil Survey National Cooperative Soil Survey 7/11/2010 Page 1 of 4