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2590 MIDPOINT DRIVE - PDP - PDP160010 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORT
Drainage Report for Hess Land, LLC 2590 Midpoint Drive Fort Collins, CO 80525 Prepared by: Ryan Blades Reviewed by: Mike Beach, P.E. Date: March 14, 2016 5255 Ronald Reagan Blvd, Suite 210 Johnstown, CO 80534 (303) 322-6480 EMAIL: rblades@ridgetopeng.com Project # 16‐015‐002 Page 2 Section Page 1. Project Engineer’s Certification ........................................................................................ 3 2. Project Location & Overview ............................................................................................ 4 3. Drainage Design Criteria ................................................................................................... 5 4. Hydraulic Calculations ....................................................................................................... 6 5. Facility Design .................................................................................................................... 7 6. Conclusion ......................................................................................................................... 8 7. References ......................................................................................................................... 8 Appendix A – Site Vicinity Map Appendix B – Flood Insurance Rate Map Appendix C – NRCS Soils Map Appendix D – Hydrologic Criteria Fort Collins Rainfall Intensity Curve Fort Collins Ranfall Intensity Table Table RO‐3 – Recommended Percentage Imperviousness Values Appendix E – Hydraulic Calculations Weighted Runoff Coefficients & Imperviousness Time of Concentration ‐ SF‐2 Rational Method Runoff Flows – SF‐3 (2‐Year Event) Rational Method Runoff Flows – SF‐3 (100‐Year Event) Figure 3‐8 – Effective Imperviousness Adjustments Detention Volume by Modified FAA Method (both Basins) Detention Basin Stage‐Discharge Table (Basin 1) Detention Basin Outlet Structure Design (Basin 1) Detention Basin Stage‐Discharge Table (Basin 2) Detention Basin Outlet Structure Design (Basin 2) Table of Contents Project # 16‐015‐002 Page 3 Section 1: PROJECT ENGINEER’S CERTIFICATION I hereby attest that this Final Drainage Report for the design of stormwater management facilities for Lot 18 (2590 Midpoint Drive) 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 responsible parties thereof. __________________________ Mike Beach, P.E. Registered Professional Engineer State of Colorado No. 45088 Project # 16‐015‐002 Page 4 Section 2: Project Location & Overview Location The sites address is 2590 Midpoint Drive, Fort Collins, CO; which is in the SE 1/4, of the NW 1/4, of Section 20, TWP 7 N, R 68 W of the 6th PM in Larimer County, CO. Located along the north side of Midpoint Drive and east of South Timberline Road, the site is described as Lot 18 of the Prospect Industrial Pak and contains 0.86 acres of undeveloped vacant land. (See Appendix A – Site Vicinity Map) Existing Condition The existing site is covered by native vegetation and slopes predominately towards Midpoint Drive at approximately 0.5% slope. Stormwater runoff collected into Midpoint Drive is conveyed via gutter towards Sharp Point Drive where it is deposited into an inlet that conveys the water to Poudre River. Proposed Condition The intent of the development is to construct a 4,395 SF building, asphalt concrete parking, landscaping and a stormwater conveyance system for Sherwin Williams on Lot 5 and provide two separate access drives, one for Commercial/Retail users plus a second for deliveries and solid waste collection. Floodplain FEMA Floodplain mapping in this neighborhood is located on map‐panel 08069C0992G, revised May 2, 2012, which indicates the subject property is located in Zone X, which is outside the 100‐year floodplain. (Appendix B – Flood Insurance Rate Map) Existing Soils The Natural Resource Conservation Service mapped the historic soils on the site as part of the Caruso clay loam. The Hydrologic Class is Type ‘D’ Soils. (Appendix C – NRCS Soils Map) Proposed Condition The intent of the development is to construct a new single story pre‐engineered metal building, approximately 9,050 SF, asphalt concrete parking, landscaping and a stormwater detention and conveyance system for Hess Land, LLC. Project # 16‐015‐002 Page 5 Section 3: Drainage Design Criteria Reference Manuals Storm drainage design criteria is defined in the City of Fort Collins “Storm Drainage Design Criteria and Construction Standards manual (FCSDCM), which references to the “Urban Drainage and Flood Control District” (UDFCD) and the “Urban Storm Drainage Criteria Manual” (USDCM), Volumes 1, 2, and 3, dated 2008 with revisions (the Manual), are used and referenced in this report. Four Step Process The City of Fort Collins has adopted the “Four Step Process” that is recommended in Volume 3 of the USDCM for selecting BMP’s in urban redevelopment areas. The goal of this process is to minimize adverse impacts on receiving waters. The following describe how each step of the process are incorporated in the proposed development: Step 1 – Employ Runoff Reduction Practices By selecting a site that is undeveloped that currently does not have detention or water quality treatment, the impacts of the proposed development will be less due to the addition of the detention pond with the water quality capture volume included. The project proposes to install soft pans to aid in conveyance and infiltration opportunities and reduce the effects of the added impervious areas. Step 2 – Water Quality Capture Volume (WQCV) In order to reduce the sediment load and other pollutants leaving the site, it is important to provide WQCV to minimize the downstream impacts. This project proposes to provide rain garden/detention ponds located on the southern side of the site. These ponds are sized to release at the historic 2‐YR release rates. Step 3 – Stabilize Drainageways Since this site is in close proximity to Poudre River it is important to take this Step into consideration. By providing stormwater detention and water quality and lowering the historic runoff and providing a metered outflow the project impacts to the drainageway are essentially reduced. The majority of the drainageway leaving the site is already stabilized. Step 4 – Implement Site Specific and Other Source Control BMP’s The proposed project will contain the following BMP’s: Rain Garden/Dry Wells: All runoff from the site will be directed into and through the proposed BMP facilities prior to leaving the site. As in the adjacent site, we are proposing to install Dry Wells as necessary to aid in infiltration into the existing soil stratum. Soft Pans: As an added measure, soft pans are being added to capture and convey runoff prior to it entering the rain gardens. These will also aid in removal of pollutants. Project # 16‐015‐002 Page 6 Maintenance: In order for BMP’s to remain effective proper maintenance needs are required. Scheduled visual inspections and routine repair after larger storm events are critical in the maintenance and effectiveness of the installed BMP’s. The sites owner will be advised of these practices during installation in order to maximize the efficiency of the installed BMP’s. Section 4: Hydraulic Calculations Criteria Runoff criteria for the proposed sites was analyzed for the 2‐YR and 100‐YR storm events. The Rational Method is being used for the design of the proposed improvements. Rainfall Intensities used in the proposed design were determined as a function of the Time of Concertation for each subbasin. The values used were determined by the City of Fort Collins Rainfall Intensity/Duration/Frequency curve (Figure 3‐1 and Table 3‐1a (see Appendix D). Imperviousness Values from Table RO‐3 (USDCM) were used in determining the sites imperviousness. The proposed site improvements and landscaping equate to a total onsite proposed Imperviousness of 69.4%. The Effective Imperviousness of each of the subbasins was determined using the USDCM Table 3‐8 (see Appendix E). Subbasin one (1) was reduced from 70% to 64%. Subbasin two (2) was reduced from 56.5% to 50% (see Appendix E). Time of Concentration & Runoff Coefficient The onsite area was separated into two (2) subbasins with slopes varying between 0.5% to 4%. The calculated Time of Concentration (TC) for each basin are 11.3 and 10.9 (see Appendix E). WQCV The UD‐BMP (UDFCD) spreadsheet was used to calculated the required water quality capture volume for each of the two subbasins. Detention The USDCM’s Modified FAA Detention Spreadsheet for each of the subbasins was used to analyze the 100‐year storm event with the allowable predeveloped 2‐year release. Project # 16‐015‐002 Page 7 Section 5: Facility Design The proposed improvements will increase the amount of impervious area; however, measures have been included in the design to minimize the amount of stormwater release from the site. Water Quality and Detention are both sized for the 100‐year rainfall event for each of the proposed ponds. The outlet structure was designed to release at the predeveloped 2‐year event at a release of 0.14 cfs per acre. The runoff will sheet flow until a concentrated point and then be conveyed via trickle channel or gutters and then deposited into the respective pond. The site was broken into two developed subbasins; Basin 1 (0.44 acres) and Basin 2 (0.300 acres). See Appendix E for breakdown of the different area types for each subbasin. Basin 1 is primarily the parking and paved areas which drains to the NE to a shared detention/water quality pond. This pond is being reworked to include sufficient volume as necessary for the newly added Basin 1 from Lot 18 (this project), as well as maintaining the required volume from the adjacent site as determined in the Holsinger Drywall (Lot 19) approved plans dated (4‐12‐2007). See Appendix for that design. Basin 2 contains the proposed building and minor areas adjacent to the building. The runoff will be conveyed to the back of the building and outlet into proposed drainage pan behind the building, which will convey the water to the new pond located between the new building and Midpoint Drive. For Water Quality, the project proposes to include the WQCV as part of the detention ponds. The volumes in both of the ponds equate to less than one foot of ponding depth. Also included within the ponds will be drywells to aid in the infiltration and the natural discharge of runoff. Below is a summary of each of subbasins design with supporting calculations within the Appendix of this report. 2‐Year Flow (cfs) 100‐Year Flow (cfs) WQCV (ac‐ft) 100‐Year Vol. (ac‐ ft) Volume Req'd (ac‐ft) Volume Provided (ac‐ft) Release Rate (cfs) Outlet (in) Basin 1 0.51 2.59 0.007 0.101 0.108 0.115 0.14 0.5 (3) Basin 2 0.28 1.61 0.004 0.061 0.065 0.075 0.14 2.0 Project # 16‐015‐002 Page 8 Section 6: Conclusions All computations that have been reviewed or completed within this report are in compliance with the City of Fort Collins Storm Drainage Design Criteria and Construction Standards manual and the Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual Volumes 1 &2. The proposed drainage concepts presented in this report and on the construction plans adequately provide for stormwater detention and water quality treatment of impervious areas by releasing the 100‐Year storm event at the Predeveloped 2‐Year runoff rates. The Water Quality design will benefit the site by reducing the initial discharge from the site and removal of any sediments or other pollutants generated by the developed site. Section 7: References The Natural Resource Conservation Service Soil Survey for Larimer County and the WSS website. FEMA FIRM map‐panel 08069C0992G Effective 05/02/2012. “City of Fort Collins Stormwater Criteria Manual” dated December 2011 Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual (UDFCD), Volumes 1, 2, and 3, dated 2008 with revisions (the Manual). w Appendix A Site Vicinity Map Appendix B Flood Insurance Rate Map Appendix C NRCS Soils Map Soil Map—Larimer County Area, Colorado (Lot 18 - Midpoint Dr) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 2/29/2016 Page 1 of 3 4489990 4490010 4490030 4490050 4490070 4490090 4490110 4490130 4490150 4490170 4489990 4490010 4490030 4490050 4490070 4490090 4490110 4490130 4490150 4490170 497390 497410 497430 497450 497470 497490 497510 497530 497390 497410 497430 497450 497470 497490 497510 497530 40° 33' 44'' N 105° 1' 51'' W 40° 33' 44'' N 105° 1' 45'' W 40° 33' 38'' N 105° 1' 51'' W 40° 33' 38'' N 105° 1' 45'' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 45 90 180 270 Feet 0 10 20 40 60 Meters Map Scale: 1:944 if printed on A portrait (8.5" x 11") sheet. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of Map Unit Legend Larimer County Area, Colorado (CO644) Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 22 Caruso clay loam, 0 to 1 percent slope 1.9 100.0% Totals for Area of Interest 1.9 100.0% Soil Map—Larimer County Area, Colorado Lot 18 - Midpoint Dr Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 2/29/2016 Page 3 of 3 Appendix D Hydrologic Criteria RAINFALL INTENSITY-DURATION-FREQUENCY CURVE 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 0.00 10.00 20.00 30.00 40.00 50.00 60.00 STORM DURATION (minutes) RAINFALL INTENSITY (inches/hour) 2-Year Storm 10-Year Storm 100-Year Storm Figure RA-16 City of Fort Collins Rainfall Intensity-Duration-Frequency Curves (13) Section 5.0 is deleted in its entirety. (14) Section 6.0 is deleted in its entirety. (15) Section 7.0 is deleted in its entirety. (16) Section 7.1 is deleted in its entirety. (17) Section 7.2 is deleted in its entirety. (18) Section 7.3 is deleted in its entirety. (19) Section 8.0 is deleted in its entirety. (20) Table RA-1 is deleted in its entirety. (11) Section 4.0 is amended to read as follows: 4.0 Intensity-Duration-Frequency Curves for Rational Method: The one-hour rainfall Intensity-Duration-Frequency tables for use the Rational Method of runoff analysis are provided in Table RA-7 and in Table RA-8. Table RA-7 -- City of Fort Collins Rainfall Intensity-Duration-Frequency Table for Use with the Rational Method (5 minutes to 30 minutes) 2-Year 10-Year 100-Year Duration (min) Intensity (in/hr) Intensity (in/hr) Intensity (in/hr) 5 2.85 4.87 9.95 6 2.67 4.56 9.31 7 2.52 4.31 8.8 8 2.4 4.1 8.38 9 2.3 3.93 8.03 10 2.21 3.78 7.72 11 2.13 3.63 7.42 12 2.05 3.5 7.16 13 1.98 3.39 6.92 14 1.92 3.29 6.71 15 1.87 3.19 6.52 16 1.81 3.08 6.3 17 1.75 2.99 6.1 18 1.7 2.9 5.92 19 1.65 2.82 5.75 20 1.61 2.74 5.6 21 1.56 2.67 5.46 22 1.53 2.61 5.32 23 1.49 2.55 5.2 24 1.46 2.49 5.09 25 1.43 2.44 4.98 26 1.4 2.39 4.87 27 1.37 2.34 4.78 28 1.34 2.29 4.69 29 1.32 2.25 4.6 30 1.3 2.21 4.52 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 A = K A + ( 1 . 31 i 3 − 1 . 44 i 2 + 1 . 135 i − 0 . 12 ) for CA ≥ 0, otherwise CA = 0 (RO-6) C CD = K CD + ( 0 . 858 i 3 − 0 . 786 i 2 + 0 . 774 i + 0 . 04 ) (RO-7) C B = (CA + C CD ) 2 2007-01 RO-9 Urban Drainage and Flood Control District Appendix E Hydraulic Calculations Weighted Runoff Coefficients Calculated By: RSB Project - Lot 18 - Midpoint Dr Checked By: MRB Job Number: 16-015-002 Date: 2/26/2016 Proposed/ IMP% Soil Types: Caruso Clay loam, 0-1 % Existing Roof 90 Asphalt/Concrete 100 Landscaping 0 Hydrologic Grouping: D Gravel 40 Multi-family (attached) 70 Runoff Coefficients: C = Kc + (.858i^3-.786I^2+.774i+.04) Commercial 95 Kc(2year) = 0 Undeveloped Historical 2 Kc(5year) = -.10i+.11 Kc(10year) = -.18i+.21 Kc(100year) = -.39i+.46 Existing Basins (current conditions) Land Use (Acres) Weighted Runoff Coefficient Total Asphalt/ Landscape Basin Area Roof Concrete Native Grass Gravel Multi-family Commercial C2 C5 C10 C100 %Imp 1.00 0.86 0.00 0.00 0.86 0.00 0.00 0.00 0.04 0.15 0.25 0.50 0.0 Proposed Basins (proposed conditions) Land Use (Acres) Weighted Runoff Coefficient Total Asphalt/ Basin 0.56 Roof Concrete Landscape Gravel Multi-family Commercial C2 C5 C10 C100 %Imp 1.00 0.440 0.000 0.326 0.118 0.000 0.00 0.00 0.53 0.57 0.61 0.70 74.1 2.00 0.300 0.208 0.000 0.087 0.000 0.00 0.00 0.43 0.47 0.52 0.64 62.4 Total Basin Dev 0.740 0.208 0.326 0.118 0.000 0.00 0.00 0.48 0.53 0.57 0.67 69.4 STANDARD FORM SF-2 TIME OF CONCENTRATION SUBDIVISION: Lot 18 CALCULATED BY: RSB DATE: 2/26/2016 REV: SUB-BASIN INITIAL/OVERLAND TRAVEL TIME tc CHECK FINAL REMARKS DATA TIME (ti ) (tt) (URBANIZED BASINS) tc DESIG: C5 AREA LENGTH SLOPE t i LENGTH SLOPE VEL. tt COMP. TOT. LENGTH tc=(L/180)+10 Ac Ft % Min Ft % FPS Min tc Ft Min Min (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) 1.00 0.57 0.44 175 1.0 12.7 50 0.5 4.4 0.2 12.9 225 11.3 11.3 2.00 0.47 0.30 125 1.0 12.6 40 0.5 4.4 0.2 12.8 165 10.9 10.9 P1 0.15 0.86 285 0.5 36.4 0 0 4.4 0.0 36.4 285 11.6 11.6 CALCULATED BY : RSB STANDARD FORM SF-3 JOB NO: 16-015-002 DATE: REV: STORM DRAINAGE SYSTEM DESIGN PROJECT: Lot 18 CHECKED BY: MRB (RATIONAL METHOD PROCEDURE) DESIGN STORM: 2-YEAR DIRECT RUNOFF TOTAL RUNOFF STREET PIPE TRAVEL TIME BASIN DESIGN POINT AREA DESIGN AREA (AC) RUNOFF COEFF tc (MIN) C * A (AC) I IN/HR Q (CFS) tc (MIN) (C * A) (AC) I (IN/HR) Q (CFS) SLOPE (%) STREET FLOW (CFS) DESIGN FLOW (CFS) SLOPE (%) PIPE SIZE LENGTH (FT) VELOCITY (FPS) tt (MIN) REMARKS (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) 2.17 P1 11.6 0.13 1.11 0.14 0.43 10.9 0.13 2/26/2016 1 2 0.30 0.86 0.15 0.44 0.53 11.3 0.23 2.17 0.28 0.51 Page 1 2-YEAR CALCULATED BY : RSB STANDARD FORM SF-3 JOB NO: 16-015-002 DATE: REV: STORM DRAINAGE SYSTEM DESIGN PROJECT: Lot 18 CHECKED BY: MRB (RATIONAL METHOD PROCEDURE) DESIGN STORM: 100-YEAR DIRECT RUNOFF TOTAL RUNOFF STREET PIPE TRAVEL TIME BASIN DESIGN POINT AREA DESIGN AREA (AC) RUNOFF COEFF tc (MIN) C * A (AC) I IN/HR Q (CFS) tc (MIN) (C * A) (AC) I (IN/HR) Q (CFS) SLOPE (%) STREET FLOW (CFS) DESIGN FLOW (CFS) SLOPE (%) PIPE SIZE LENGTH (FT) VELOCITY (FPS) tt (MIN) REMARKS (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) 8.38 P1 11.6 0.16 3.97 0.65 0.64 10.9 0.19 2/26/2016 1 2 0.30 0.86 0.19 0.44 0.70 11.3 0.31 8.38 1.61 2.59 Page 1 100-YEAR Calculating the WQCV and Volume Reduction Chapter 3 3-14 Urban Drainage and Flood Control District August 2011 Urban Storm Drainage Criteria Manual Volume 3 Figure 3-8. Effective Imperviousness Adjustments for Level 2 MDCIA 4.3 Site-level Volume Reduction Methods For site-level planning, whether at a conceptual level or a more advanced stage of design, it is not necessary to use default D and R values if the various area fractions of a site (i.e., DCIA, UIA, RPA, and SPA) can be defined. Two options are available for quantification of volume reduction at the site level when these fractions have been identified: 1. SWMM modeling using the cascading plane approach, or 2. UDFCD Imperviousness Reduction Factor (IRF) charts and spreadsheet (located within the UD-BMP workbook available at www.udfcd.org) The UDFCD IRF charts and spreadsheet were developed using a dimensionless SWMM modeling approach developed by Guo et al. (2010) that determines the effective imperviousness of a site based on the total area-weighted imperviousness and the ratio of the infiltration rate (average infiltration rate based on Green-Ampt ), f, to the rainfall intensity, I. Because the IRF is based on cascading plane CUHP/SWMM modeling, it will yield results that are generally consistent with creation of a site-specific SWMM model. 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Effective Imperviousness Total Imperviousness Directly Connected 2-year Level 2 10-year Level 2 100-year Level 2 Project: Basin ID: Design Information (Input): Design Information (Input): Catchment Drainage Imperviousness Ia = 74.00 percent Catchment Drainage Imperviousness I a = 74.00 percent Catchment Drainage Area A = 0.440 acres Catchment Drainage Area A = 0.440 acres Predevelopment NRCS Soil Group Type = D A, B, C, or D Predevelopment NRCS Soil Group Type = D A, B, C, or D Return Period for Detention Control T = 2 years (2, 5, 10, 25, 50, or 100) Return Period for Detention Control T = 100 years (2, 5, 10, 25, 50, or 100) Time of Concentration of Watershed Tc = 11 minutes Time of Concentration of Watershed Tc = 11 minutes Allowable Unit Release Rate q = 0.1400 cfs/acre Allowable Unit Release Rate q = 0.1400 cfs/acre One-hour Precipitation P1 = 0.82 inches One-hour Precipitation P 1 = 2.83 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 = 0.789 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 = 0.53 Runoff Coefficient C = 0.70 Inflow Peak Runoff Qp-in = 0.49 cfs Inflow Peak Runoff Qp-in = 2.22 cfs Allowable Peak Outflow Rate Qp-out = 0.06 cfs Allowable Peak Outflow Rate Qp-out = 0.06 cfs Mod. FAA Minor Storage Volume = 596 cubic feet Mod. FAA Major Storage Volume = 4,558 cubic feet Mod. FAA Minor Storage Volume = 0.014 acre-ft Mod. FAA Major Storage Volume = 0.105 acre-ft 100 <- 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) 0 0.00 0 0.00 0.00 0 0 0 0.00 0 0.00 0.00 0 0 100 0.57 801 0.56 0.03 206 596 100 1.98 3,653 0.56 0.03 206 3,448 200 0.34 962 0.53 0.03 390 572 200 1.19 4,387 0.53 0.03 390 3,996 300 0.25 1,062 0.52 0.03 575 486 300 0.87 4,839 0.52 0.03 575 4,264 400 0.20 1,135 0.51 0.03 760 375 400 0.70 5,175 0.51 0.03 760 4,415 500 0.17 1,195 0.51 0.03 945 250 500 0.59 5,445 0.51 0.03 945 4,501 600 0.15 1,245 0.51 0.03 1,130 115 600 0.51 5,674 0.51 0.03 1,130 4,544 700 0.13 1,288 0.51 0.03 1,314 -26 700 0.45 5,872 0.51 0.03 1,314 4,558 800 0.12 1,327 0.51 0.03 1,499 -172 800 0.41 6,048 0.51 0.03 1,499 4,549 900 0.11 1,362 0.51 0.03 1,684 -322 900 0.37 6,207 0.51 0.03 1,684 4,523 1000 0.10 1,394 0.51 0.03 1,869 -475 1000 0.34 6,352 0.51 0.03 1,869 4,483 1100 0.09 1,423 0.51 0.03 2,054 -631 1100 0.32 6,486 0.51 0.03 2,054 4,432 1200 0.09 1,450 0.50 0.03 2,238 -788 1200 0.30 6,610 0.50 0.03 2,238 4,371 1300 0.08 1,476 0.50 0.03 2,423 -948 1300 0.28 6,726 0.50 0.03 2,423 4,303 1400 0.08 1,499 0.50 0.03 2,608 -1,109 1400 0.26 6,835 0.50 0.03 2,608 4,227 1500 0.07 1,522 0.50 0.03 2,793 -1,271 1500 0.25 6,938 0.50 0.03 2,793 4,145 1600 0.07 1,543 0.50 0.03 2,978 -1,434 1600 0.24 7,035 0.50 0.03 2,978 4,057 1700 0.07 1,564 0.50 0.03 3,162 -1,599 1700 0.23 7,128 0.50 0.03 3,162 3,965 1800 0.06 1,583 0.50 0.03 3,347 -1,764 1800 0.22 7,216 0.50 0.03 3,347 3,869 1900 0.06 1,602 0.50 0.03 3,532 -1,930 1900 0.21 7,300 0.50 0.03 3,532 3,768 2000 0.06 1,619 0.50 0.03 3,717 -2,098 2000 0.20 7,381 0.50 0.03 3,717 3,665 2100 0.06 1,636 0.50 0.03 3,902 -2,265 2100 0.19 7,459 0.50 0.03 3,902 3,558 2200 0.05 1,653 0.50 0.03 4,086 -2,434 2200 0.19 7,534 0.50 0.03 4,086 3,448 2300 0.05 1,669 0.50 0.03 4,271 -2,603 2300 0.18 7,606 0.50 0.03 4,271 3,335 2400 0.05 1,684 0.50 0.03 4,456 -2,772 2400 0.17 7,676 0.50 0.03 4,456 3,220 2500 0.05 1,699 0.50 0.03 4,641 -2,942 2500 0.17 7,743 0.50 0.03 4,641 3,102 Project: Basin ID: DETENTION VOLUME BY THE MODIFIED FAA METHOD (See USDCM Volume 2 Storage Chapter for description of method) Lot 18 Developed 100-Year (Basin 1) UDFCD DETENTION VOLUME ESTIMATING WORKBOOK Version 2.2, Released January 2010 -15,000 -10,000 -5,000 0 5,000 10,000 15,000 0 1000 2000 3000 4000 5000 6000 7000 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 Storage Modified FAA Detention_Reduced Imp, Modified FAA 2/26/2016, 10:05 AM Project: Basin ID: Design Information (Input): Design Information (Input): Catchment Drainage Imperviousness Ia = 70.00 percent Catchment Drainage Imperviousness I a = 70.00 percent Catchment Drainage Area A = 0.440 acres Catchment Drainage Area A = 0.440 acres Predevelopment NRCS Soil Group Type = D A, B, C, or D Predevelopment NRCS Soil Group Type = D A, B, C, or D Return Period for Detention Control T = 2 years (2, 5, 10, 25, 50, or 100) Return Period for Detention Control T = 100 years (2, 5, 10, 25, 50, or 100) Time of Concentration of Watershed Tc = 11 minutes Time of Concentration of Watershed Tc = 11 minutes Allowable Unit Release Rate q = 0.1400 cfs/acre Allowable Unit Release Rate q = 0.1400 cfs/acre One-hour Precipitation P1 = 0.82 inches One-hour Precipitation P 1 = 2.83 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 = 0.789 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 = 0.49 Runoff Coefficient C = 0.68 Inflow Peak Runoff Qp-in = 0.45 cfs Inflow Peak Runoff Qp-in = 2.16 cfs Allowable Peak Outflow Rate Qp-out = 0.06 cfs Allowable Peak Outflow Rate Qp-out = 0.06 cfs Mod. FAA Minor Storage Volume = 535 cubic feet Mod. FAA Major Storage Volume = 4,390 cubic feet Mod. FAA Minor Storage Volume = 0.012 acre-ft Mod. FAA Major Storage Volume = 0.101 acre-ft 100 <- 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) 0 0.00 0 0.00 0.00 0 0 0 0.00 0 0.00 0.00 0 0 100 0.57 741 0.56 0.03 206 535 100 1.98 3,549 0.56 0.03 206 3,343 200 0.34 890 0.53 0.03 390 499 200 1.19 4,261 0.53 0.03 390 3,871 300 0.25 982 0.52 0.03 575 406 300 0.87 4,701 0.52 0.03 575 4,126 400 0.20 1,050 0.51 0.03 760 290 400 0.70 5,027 0.51 0.03 760 4,267 500 0.17 1,104 0.51 0.03 945 160 500 0.59 5,290 0.51 0.03 945 4,345 600 0.15 1,151 0.51 0.03 1,130 21 600 0.51 5,512 0.51 0.03 1,130 4,382 700 0.13 1,191 0.51 0.03 1,314 -123 700 0.45 5,704 0.51 0.03 1,314 4,390 800 0.12 1,227 0.51 0.03 1,499 -273 800 0.41 5,875 0.51 0.03 1,499 4,376 900 0.11 1,259 0.51 0.03 1,684 -425 900 0.37 6,030 0.51 0.03 1,684 4,346 1000 0.10 1,288 0.51 0.03 1,869 -580 1000 0.34 6,171 0.51 0.03 1,869 4,302 1100 0.09 1,316 0.51 0.03 2,054 -738 1100 0.32 6,301 0.51 0.03 2,054 4,247 1200 0.09 1,341 0.50 0.03 2,238 -898 1200 0.30 6,421 0.50 0.03 2,238 4,183 1300 0.08 1,364 0.50 0.03 2,423 -1,059 1300 0.28 6,534 0.50 0.03 2,423 4,110 1400 0.08 1,386 0.50 0.03 2,608 -1,222 1400 0.26 6,640 0.50 0.03 2,608 4,031 1500 0.07 1,407 0.50 0.03 2,793 -1,386 1500 0.25 6,739 0.50 0.03 2,793 3,947 1600 0.07 1,427 0.50 0.03 2,978 -1,551 1600 0.24 6,834 0.50 0.03 2,978 3,856 1700 0.07 1,446 0.50 0.03 3,162 -1,717 1700 0.23 6,924 0.50 0.03 3,162 3,762 1800 0.06 1,464 0.50 0.03 3,347 -1,884 1800 0.22 7,010 0.50 0.03 3,347 3,663 1900 0.06 1,481 0.50 0.03 3,532 -2,051 1900 0.21 7,092 0.50 0.03 3,532 3,560 2000 0.06 1,497 0.50 0.03 3,717 -2,220 2000 0.20 7,171 0.50 0.03 3,717 3,454 2100 0.06 1,513 0.50 0.03 3,902 -2,389 2100 0.19 7,246 0.50 0.03 3,902 3,344 2200 0.05 1,528 0.50 0.03 4,086 -2,558 2200 0.19 7,319 0.50 0.03 4,086 3,232 2300 0.05 1,543 0.50 0.03 4,271 -2,729 2300 0.18 7,389 0.50 0.03 4,271 3,118 2400 0.05 1,557 0.50 0.03 4,456 -2,899 2400 0.17 7,457 0.50 0.03 4,456 3,001 2500 0.05 1,571 0.50 0.03 4,641 -3,070 2500 0.17 7,522 0.50 0.03 4,641 2,881 Project: Basin ID: DETENTION VOLUME BY THE MODIFIED FAA METHOD (See USDCM Volume 2 Storage Chapter for description of method) Lot 18 Developed 100YR (Basin 1) Reduced Imp UDFCD DETENTION VOLUME ESTIMATING WORKBOOK Version 2.2, Released January 2010 -15,000 -10,000 -5,000 0 5,000 10,000 15,000 0 1000 2000 3000 4000 5000 6000 7000 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 Storage Modified FAA Detention_Reduced Imp, Modified FAA 2/26/2016, 10:19 AM Project: Basin ID: Design Information (Input): Design Information (Input): Catchment Drainage Imperviousness Ia = 62.00 percent Catchment Drainage Imperviousness I a = 62.00 percent Catchment Drainage Area A = 0.300 acres Catchment Drainage Area A = 0.300 acres Predevelopment NRCS Soil Group Type = D A, B, C, or D Predevelopment NRCS Soil Group Type = D A, B, C, or D Return Period for Detention Control T = 2 years (2, 5, 10, 25, 50, or 100) Return Period for Detention Control T = 100 years (2, 5, 10, 25, 50, or 100) Time of Concentration of Watershed Tc = 11 minutes Time of Concentration of Watershed Tc = 11 minutes Allowable Unit Release Rate q = 0.1400 cfs/acre Allowable Unit Release Rate q = 0.1400 cfs/acre One-hour Precipitation P1 = 0.82 inches One-hour Precipitation P 1 = 2.83 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 = 0.789 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 = 0.42 Runoff Coefficient C = 0.64 Inflow Peak Runoff Qp-in = 0.27 cfs Inflow Peak Runoff Qp-in = 1.41 cfs Allowable Peak Outflow Rate Qp-out = 0.04 cfs Allowable Peak Outflow Rate Qp-out = 0.04 cfs Mod. FAA Minor Storage Volume = 293 cubic feet Mod. FAA Major Storage Volume = 2,767 cubic feet Mod. FAA Minor Storage Volume = 0.007 acre-ft Mod. FAA Major Storage Volume = 0.064 acre-ft 100 <- 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) 0 0.00 0 0.00 0.00 0 0 0 0.00 0 0.00 0.00 0 0 100 0.57 433 0.55 0.02 140 293 100 1.98 2,277 0.55 0.02 140 2,138 200 0.34 520 0.53 0.02 266 254 200 1.19 2,735 0.53 0.02 266 2,469 300 0.25 574 0.52 0.02 392 182 300 0.87 3,017 0.52 0.02 392 2,625 400 0.20 613 0.51 0.02 518 96 400 0.70 3,226 0.51 0.02 518 2,708 500 0.17 645 0.51 0.02 644 2 500 0.59 3,395 0.51 0.02 644 2,751 600 0.15 673 0.51 0.02 770 -97 600 0.51 3,537 0.51 0.02 770 2,767 700 0.13 696 0.51 0.02 896 -200 700 0.45 3,660 0.51 0.02 896 2,765 800 0.12 717 0.51 0.02 1,022 -305 800 0.41 3,770 0.51 0.02 1,022 2,749 900 0.11 736 0.51 0.02 1,148 -412 900 0.37 3,869 0.51 0.02 1,148 2,722 1000 0.10 753 0.51 0.02 1,274 -521 1000 0.34 3,960 0.51 0.02 1,274 2,686 1100 0.09 769 0.50 0.02 1,400 -631 1100 0.32 4,043 0.50 0.02 1,400 2,643 1200 0.09 784 0.50 0.02 1,526 -742 1200 0.30 4,120 0.50 0.02 1,526 2,595 1300 0.08 797 0.50 0.02 1,652 -854 1300 0.28 4,193 0.50 0.02 1,652 2,541 1400 0.08 810 0.50 0.02 1,778 -968 1400 0.26 4,261 0.50 0.02 1,778 2,483 1500 0.07 822 0.50 0.02 1,904 -1,081 1500 0.25 4,325 0.50 0.02 1,904 2,421 1600 0.07 834 0.50 0.02 2,030 -1,196 1600 0.24 4,385 0.50 0.02 2,030 2,356 1700 0.07 845 0.50 0.02 2,156 -1,311 1700 0.23 4,443 0.50 0.02 2,156 2,287 1800 0.06 855 0.50 0.02 2,282 -1,426 1800 0.22 4,498 0.50 0.02 2,282 2,217 1900 0.06 865 0.50 0.02 2,408 -1,542 1900 0.21 4,551 0.50 0.02 2,408 2,143 2000 0.06 875 0.50 0.02 2,534 -1,659 2000 0.20 4,601 0.50 0.02 2,534 2,068 2100 0.06 884 0.50 0.02 2,660 -1,776 2100 0.19 4,650 0.50 0.02 2,660 1,990 2200 0.05 893 0.50 0.02 2,786 -1,893 2200 0.19 4,697 0.50 0.02 2,786 1,911 2300 0.05 902 0.50 0.02 2,912 -2,010 2300 0.18 4,742 0.50 0.02 2,912 1,830 2400 0.05 910 0.50 0.02 3,038 -2,128 2400 0.17 4,785 0.50 0.02 3,038 1,747 2500 0.05 918 0.50 0.02 3,164 -2,246 2500 0.17 4,827 0.50 0.02 3,164 1,663 Project: Basin ID: DETENTION VOLUME BY THE MODIFIED FAA METHOD (See USDCM Volume 2 Storage Chapter for description of method) Lot 18 Developed 100YR (Basin 2) UDFCD DETENTION VOLUME ESTIMATING WORKBOOK Version 2.2, Released January 2010 -8,000 -6,000 -4,000 -2,000 0 2,000 4,000 6,000 8,000 10,000 0 1000 2000 3000 4000 5000 6000 7000 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 Storage Modified FAA Detention_Reduced Imp, Modified FAA 2/26/2016, 10:17 AM Project: Basin ID: Design Information (Input): Design Information (Input): Catchment Drainage Imperviousness Ia = 56.50 percent Catchment Drainage Imperviousness I a = 56.50 percent Catchment Drainage Area A = 0.300 acres Catchment Drainage Area A = 0.300 acres Predevelopment NRCS Soil Group Type = D A, B, C, or D Predevelopment NRCS Soil Group Type = D A, B, C, or D Return Period for Detention Control T = 2 years (2, 5, 10, 25, 50, or 100) Return Period for Detention Control T = 100 years (2, 5, 10, 25, 50, or 100) Time of Concentration of Watershed Tc = 11 minutes Time of Concentration of Watershed Tc = 11 minutes Allowable Unit Release Rate q = 0.1400 cfs/acre Allowable Unit Release Rate q = 0.1400 cfs/acre One-hour Precipitation P1 = 0.82 inches One-hour Precipitation P 1 = 2.83 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 = 0.789 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 = 0.38 Runoff Coefficient C = 0.62 Inflow Peak Runoff Qp-in = 0.24 cfs Inflow Peak Runoff Qp-in = 1.36 cfs Allowable Peak Outflow Rate Qp-out = 0.04 cfs Allowable Peak Outflow Rate Qp-out = 0.04 cfs Mod. FAA Minor Storage Volume = 252 cubic feet Mod. FAA Major Storage Volume = 2,657 cubic feet Mod. FAA Minor Storage Volume = 0.006 acre-ft Mod. FAA Major Storage Volume = 0.061 acre-ft 100 <- 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) 0 0.00 0 0.00 0.00 0 0 0 0.00 0 0.00 0.00 0 0 100 0.57 392 0.55 0.02 140 252 100 1.98 2,206 0.55 0.02 140 2,066 200 0.34 470 0.53 0.02 266 205 200 1.19 2,649 0.53 0.02 266 2,383 300 0.25 519 0.52 0.02 392 127 300 0.87 2,922 0.52 0.02 392 2,531 400 0.20 555 0.51 0.02 518 37 400 0.70 3,125 0.51 0.02 518 2,607 500 0.17 584 0.51 0.02 644 -60 500 0.59 3,288 0.51 0.02 644 2,645 600 0.15 608 0.51 0.02 770 -161 600 0.51 3,426 0.51 0.02 770 2,657 700 0.13 630 0.51 0.02 896 -266 700 0.45 3,546 0.51 0.02 896 2,650 800 0.12 649 0.51 0.02 1,022 -373 800 0.41 3,653 0.51 0.02 1,022 2,631 900 0.11 666 0.51 0.02 1,148 -482 900 0.37 3,748 0.51 0.02 1,148 2,601 1000 0.10 681 0.51 0.02 1,274 -592 1000 0.34 3,836 0.51 0.02 1,274 2,562 1100 0.09 696 0.50 0.02 1,400 -704 1100 0.32 3,917 0.50 0.02 1,400 2,517 1200 0.09 709 0.50 0.02 1,526 -817 1200 0.30 3,992 0.50 0.02 1,526 2,466 1300 0.08 721 0.50 0.02 1,652 -930 1300 0.28 4,062 0.50 0.02 1,652 2,410 1400 0.08 733 0.50 0.02 1,778 -1,045 1400 0.26 4,128 0.50 0.02 1,778 2,350 1500 0.07 744 0.50 0.02 1,904 -1,160 1500 0.25 4,190 0.50 0.02 1,904 2,286 1600 0.07 754 0.50 0.02 2,030 -1,275 1600 0.24 4,248 0.50 0.02 2,030 2,219 1700 0.07 764 0.50 0.02 2,156 -1,391 1700 0.23 4,304 0.50 0.02 2,156 2,149 1800 0.06 774 0.50 0.02 2,282 -1,508 1800 0.22 4,358 0.50 0.02 2,282 2,076 1900 0.06 783 0.50 0.02 2,408 -1,625 1900 0.21 4,409 0.50 0.02 2,408 2,001 2000 0.06 792 0.50 0.02 2,534 -1,742 2000 0.20 4,458 0.50 0.02 2,534 1,924 2100 0.06 800 0.50 0.02 2,660 -1,860 2100 0.19 4,505 0.50 0.02 2,660 1,845 2200 0.05 808 0.50 0.02 2,786 -1,978 2200 0.19 4,550 0.50 0.02 2,786 1,764 2300 0.05 816 0.50 0.02 2,912 -2,096 2300 0.18 4,593 0.50 0.02 2,912 1,682 2400 0.05 823 0.50 0.02 3,038 -2,215 2400 0.17 4,635 0.50 0.02 3,038 1,598 2500 0.05 830 0.50 0.02 3,164 -2,333 2500 0.17 4,676 0.50 0.02 3,164 1,512 Project: Basin ID: DETENTION VOLUME BY THE MODIFIED FAA METHOD (See USDCM Volume 2 Storage Chapter for description of method) Lot 18 Developed 100YR (Basin 2) - Reduced Imp UDFCD DETENTION VOLUME ESTIMATING WORKBOOK Version 2.2, Released January 2010 -8,000 -6,000 -4,000 -2,000 0 2,000 4,000 6,000 8,000 10,000 0 1000 2000 3000 4000 5000 6000 7000 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 Storage Modified FAA Detention_Reduced Imp, Modified FAA 2/26/2016, 10:20 AM Project: Basin ID: Depth Increment = 0.25 ft Required Volume Calculation Media Surface 0.00 81.1 4.1 329 0.008 Selected BMP Type = RG 0.25 83.0 6.0 496 0.011 99 0.002 Watershed Area = 0.44 acres 0.50 85.0 8.0 678 0.016 246 0.006 Watershed Length = 175 ft Zone 1 (WQCV) 0.64 86.2 9.2 791 0.018 356 0.008 Watershed Slope = 0.005 ft/ft 0.75 87.0 10.0 868 0.020 439 0.010 Watershed Imperviousness = 70.00% percent 1.00 89.0 12.0 1,066 0.024 680 0.016 Percentage Hydrologic Soil Group A = 0.0% percent 1.25 91.0 14.0 1,272 0.029 973 0.022 Percentage Hydrologic Soil Group B = 0.0% percent 1.50 93.0 16.0 1,486 0.034 1,317 0.030 Percentage Hydrologic Soil Groups C/D = 100.0% percent 1.75 95.0 18.0 1,708 0.039 1,716 0.039 Desired WQCV Drain Time = 12.0 hours 2.00 97.0 20.0 1,938 0.045 2,172 0.050 Location for 1-hr Rainfall Depths = UDFCD Default Zone 2 (100-year) 2.17 98.5 21.4 2,109 0.048 2,536 0.058 Water Quality Capture Volume (WQCV) = 0.008 acre-feet 2.25 99.1 22.1 2,186 0.050 2,708 0.062 Excess Urban Runoff Volume (EURV) = 0.030 acre-feet 2.50 101.1 24.1 2,433 0.056 3,285 0.075 2-yr Runoff Volume (P1 = 0.82 in.) = 0.021 acre-feet 0.82 inches 2.75 103.1 26.1 2,687 0.062 3,925 0.090 5-yr Runoff Volume (P1 = 1.34 in.) = 0.037 acre-feet inches 3.00 105.1 28.1 2,949 0.068 4,629 0.106 10-yr Runoff Volume (P1 = 1.64 in.) = 0.048 acre-feet inches 3.25 107.1 30.1 3,220 0.074 5,400 0.124 25-yr Runoff Volume (P1 = 2.02 in.) = 0.064 acre-feet inches 3.50 109.1 32.1 3,498 0.080 6,240 0.143 50-yr Runoff Volume (P1 = 2.32 in.) = 0.075 acre-feet inches 3.75 111.1 34.1 3,784 0.087 7,150 0.164 100-yr Runoff Volume (P1 = 2.83 in.) = 0.095 acre-feet 2.83 inches 4.00 113.1 36.1 4,079 0.094 8,133 0.187 500-yr Runoff Volume (P1 = 3.29 in.) = 0.115 acre-feet inches 4.25 115.1 38.1 4,381 0.101 9,190 0.211 Approximate 2-yr Detention Volume = 0.019 acre-feet 4.50 117.1 40.1 4,691 0.108 10,324 0.237 Approximate 5-yr Detention Volume = 0.032 acre-feet 4.75 119.1 42.1 5,010 0.115 11,536 0.265 Approximate 10-yr Detention Volume = 0.036 acre-feet 5.00 121.1 44.1 5,336 0.122 12,829 0.295 Approximate 25-yr Detention Volume = 0.041 acre-feet 5.25 123.1 46.1 5,670 0.130 14,205 0.326 Approximate 50-yr Detention Volume = 0.047 acre-feet 5.50 125.1 48.1 6,013 0.138 15,665 0.360 Approximate 100-yr Detention Volume = 0.058 acre-feet 5.75 127.1 50.1 6,363 0.146 17,212 0.395 6.00 129.1 52.1 6,721 0.154 18,848 0.433 Stage-Storage Calculation 6.25 131.1 54.1 7,088 0.163 20,574 0.472 Zone 1 Volume (WQCV) = 0.008 acre-feet 6.50 133.1 56.1 7,462 0.171 22,392 0.514 Zone 2 Volume (100-year - Zone 1) = 0.050 acre-feet 6.75 135.1 58.1 7,845 0.180 24,305 0.558 Select Zone 3 Storage Volume (Optional) = acre-feet 7.00 137.1 60.1 8,235 0.189 26,315 0.604 Total Detention Basin Volume = 0.058 acre-feet 7.25 139.1 62.1 8,633 0.198 28,423 0.653 Initial Surcharge Volume (ISV) = N/A ft^3 7.50 141.1 64.1 9,040 0.208 30,632 0.703 Initial Surcharge Depth (ISD) = N/A ft 7.75 143.1 66.1 9,454 0.217 32,944 0.756 Total Available Detention Depth (Htotal) = 2.25 ft 8.00 145.1 68.1 9,876 0.227 35,360 0.812 Depth of Trickle Channel (HTC) = N/A ft 8.25 147.1 70.1 10,307 0.237 37,883 0.870 Slope of Trickle Channel (STC) = N/A ft/ft 8.50 149.1 72.1 10,745 0.247 40,514 0.930 Slopes of Main Basin Sides (Smain) = 4 H:V 8.75 151.1 74.1 11,191 0.257 43,256 0.993 Basin Length-to-Width Ratio (RL/W) = 20 9.00 153.1 76.1 11,646 0.267 46,110 1.059 9.25 155.1 78.1 12,108 0.278 49,079 1.127 Initial Surcharge Area (AISV) = 0 ft^2 9.50 157.1 80.1 12,578 0.289 52,165 1.198 Surcharge Volume Length (LISV) = 0.0 ft 9.75 159.1 82.1 13,057 0.300 55,369 1.271 Surcharge Volume Width (WISV) = 0.0 ft 10.00 161.1 84.1 13,543 0.311 58,694 1.347 Depth of Basin Floor (HFLOOR) = 0.00 ft 10.25 163.1 86.1 14,037 0.322 62,141 1.427 Length of Basin Floor (LFLOOR) = 81.1 ft 10.50 165.1 88.1 14,540 0.334 65,713 1.509 Width of Basin Floor (WFLOOR) = 4.1 ft 10.75 167.1 90.1 15,050 0.346 69,412 1.593 Area of Basin Floor (AFLOOR) = 329 ft^2 11.00 169.1 92.1 15,569 0.357 73,239 1.681 Volume of Basin Floor (VFLOOR) = 0 ft^3 11.25 171.1 94.1 16,095 0.369 77,197 1.772 Depth of Main Basin (HMAIN) = 2.25 ft 11.50 173.1 96.1 16,629 0.382 81,287 1.866 Length of Main Basin (LMAIN) = 99.1 ft 11.75 175.1 98.1 17,172 0.394 85,512 1.963 Width of Main Basin (WMAIN) = 22.1 ft 12.00 177.1 100.1 17,722 0.407 89,874 2.063 Area of Main Basin (AMAIN) = 2,186 ft^2 12.25 179.1 102.1 18,280 0.420 94,374 2.167 Volume of Main Basin (VMAIN) = 2,523 ft^3 12.50 181.1 104.1 18,847 0.433 99,015 2.273 Calculated Total Basin Volume (Vtotal) = 0.058 acre-feet 12.75 183.1 106.1 19,421 0.446 103,798 2.383 0 User Defined Stage-Area Boolean for Message 0 Equal Stage-Area Inputs Watershed L:W 1 CountA 0Calc_S_TC H_FLOOR 81.1202 L_FLOOR_OTHER 0.00 ISV 0.00 ISV 0.00 Floor 0.00 Floor 0.64 Zone 1 (WQCV) 0.64 Zone 1 (WQCV) 2.17 Zone 2 (100-year 2.17 Zone 2 (100-year) 0.00 Zone 3 0.00 Zone 3 DETENTION BASIN STAGE‐STORAGE TABLE BUILDER 0.000 0.885 1.770 2.655 3.540 0.000 0.145 0.290 0.435 0.580 0.00 4.00 8.00 12.00 16.00 Volume (ac‐ft) Area (acres) Stage (ft.) Area (acres) Volume (ac‐ft) 0 6300 12600 18900 25200 0 55 110 165 220 0.00 4.00 8.00 12.00 16.00 Area (sq.ft.) Length, Width (ft.) Stage (ft) Length (ft) Width (ft) Area (sq.ft.) UD-Detention_v3 01 - Basin 1, Basin 3/14/2016, 12:36 PM Project: Basin ID: Stage (ft) Zone Volume (ac‐ft) Outlet Type Zone 1 (WQCV) 0.64 0.008 Filtration Media Zone 2 (100‐year) 2.17 0.050 Circular Orifice Zone 3 0.058 Total User Input: Orifice at Underdrain Outlet (typically used to drain WQCV in a Filtration BMP) Calculated Parameters for Underdrain Underdrain Orifice Invert Depth = 1.50 ft (distance below the filtration media surface) Underdrain Orifice Area = 0.0 ft2 Underdrain Orifice Diameter = 0.33 inches Underdrain Orifice Centroid = 0.01 feet User Input: Orifice Plate with one or more orifices or Elliptical Slot Weir (typically used to drain WQCV and/or EURV in a sedimentation BMP) Calculated Parameters for Plate Invert of Lowest Orifice = N/A ft (relative to bottom of basin at Stage = 0 ft) WQ Orifice Area per Row = N/A ft2 Depth at top of Zone using Orifice Plate = N/A ft (relative to bottom of basin at Stage = 0 ft) Elliptical Half‐Width = N/A feet Orifice Plate: Orifice Vertical Spacing = N/A inches Elliptical Slot Centroid = N/A feet Orifice Plate: Orifice Area per Row = N/A inches Elliptical Slot Area = N/A ft2 User Input: Stage and Total Area of Each Orifice Row (numbered from lowest to highest) Row 1 (optional) Row 2 (optional) Row 3 (optional) Row 4 (optional) Row 5 (optional) Row 6 (optional) Row 7 (optional) Row 8 (optional) Stage of Orifice Centroid (ft) N/A N/A N/A N/A N/A N/A N/A N/A Orifice Area (sq. inches) N/A N/A N/A N/A N/A N/A N/A N/A Row 9 (optional) Row 10 (optional) Row 11 (optional) Row 12 (optional) Row 13 (optional) Row 14 (optional) Row 15 (optional) Row 16 (optional) Stage of Orifice Centroid (ft) N/A N/A N/A N/A N/A N/A N/A N/A Orifice Area (sq. inches) N/A N/A N/A N/A N/A N/A N/A N/A User Input: Vertical Orifice (Circular or Rectangular) Calculated Parameters for Vertical Orifice Zone 2 Circular Not Selected Zone 2 Circular Not Selected Invert of Vertical Orifice = 0.64 ft (relative to bottom of basin at Stage = 0 ft) Vertical Orifice Area = 0.04 ft2 Depth at top of Zone using Vertical Orifice = 2.17 ft (relative to bottom of basin at Stage = 0 ft) Vertical Orifice Centroid = 0.11 feet Vertical Orifice Diameter = 2.60 inches User Input: Overflow Weir (Dropbox) and Grate (Flat or Sloped) Calculated Parameters for Overflow Weir Not Selected Not Selected Not Selected Not Selected Overflow Weir Front Edge Height, Ho = ft (relative to bottom of basin at Stage = 0 ft) Height of Grate Upper Edge, Ht = feet Overflow Weir Front Edge Length = feet Over Flow Weir Slope Length = feet Overflow Weir Slope = H:V (enter zero for flat grate) Grate Open Area / 100‐yr Orifice Area = should be > 4 Horiz. Length of Weir Sides = feet Overflow Grate Open Area w/o Debris = ft2 Overflow Grate Open Area % = %, grate open area / total area Overflow Grate Open Area with Debris = ft2 Debris Clogging % = % User Input: Outlet Pipe w/ Flow Restriction Plate (Circular Orifice, Restrictor Plate, or Rectangular Orifice) Calculated Parameters for Outlet Pipe w/ Flow Restriction Plate Not Selected Not Selected Not Selected Not Selected Depth to Invert of Outlet Pipe = ft (distance below bottom of basin at Stage = 0 ft) Outlet Orifice Area = ft2 Circular Orifice Diameter = inches Outlet Orifice Centroid = feet Half‐Central Angle of Restrictor Plate on Pipe = N/A N/A radians User Input: Emergency Spillway (Rectangular or Trapezoidal) Calculated Parameters for Spillway Spillway Invert Stage= 2.17 ft (relative to bottom of basin at Stage = 0 ft) Spillway Design Flow Depth= 0.13 feet Spillway Crest Length = 12.00 feet Stage at Top of Freeboard = 2.30 feet Spillway End Slopes = 3.00 H:V Basin Area at Top of Freeboard = 0.05acres Freeboard above Spillway = feet Routed Hydrograph Results Design Storm Return Period = WQCV EURV 2 Year 5 Year 10 Year 25 Year 50 Year 100 Year 500 Year One-Hour Rainfall Depth (in) = 0.53 1.07 0.82 1.34 1.64 2.02 2.32 2.83 3.29 Calculated Runoff Volume (acre-ft) = 0.008 0.030 0.021 0.037 0.048 0.064 0.075 0.095 0.115 OPTIONAL Override Runoff Volume (acre-ft) = Inflow Hydrograph Volume (acre-ft) = 0.008 0.029 0.020 0.037 0.048 0.063 0.075 0.095 0.115 Predevelopment Unit Peak Flow, q (cfs/acre) = 0.00 0.00 0.01 0.28 0.48 0.90 1.14 1.43 2.00 Predevelopment Peak Q (cfs) = 0.0 0.0 0.0 0.1 0.2 0.4 0.5 0.6 0.9 Peak Inflow Q (cfs) = 0.2 0.6 0.4 0.7 0.9 1.3 1.5 1.9 2.3 Peak Outflow Q (cfs) = 0.0 0.1 0.1 0.1 0.2 0.2 0.2 0.2 0.2 Ratio Peak Outflow to Predevelopment Q = N/A N/A N/A 1.1 0.8 0.5 0.4 0.4 0.3 Structure Controlling Flow = Filtration Media Vertical Orifice 1 Vertical Orifice 1 Vertical Orifice 1 Vertical Orifice 1 Vertical Orifice 1 Vertical Orifice 1 Vertical Orifice 1 Vertical Orifice 1 Max Velocity through Grate 1 (fps) = N/A N/A N/A N/A N/A N/A N/A N/A N/A Max Velocity through Grate 2 (fps) = N/A N/A N/A N/A N/A N/A N/A N/A N/A COUNTA for Basin Tab = 1AoDia WQ Plate Type Vert Orifice 1 Vert Orifice 2 Count_Underdrain = 10.11 meter = 3/8 inch) 1 2 1 Count_WQPlate = 00.14 eter = 7/16 inch) Count_VertOrifice1 = 10.18 meter = 1/2 inch) Outlet Plate 1 Outlet Plate 2 Drain Time Message Boolean Count_VertOrifice2 = 00.24 eter = 9/16 inch) 1 1 5yr, <72hr 0 Count_Weir1 = 00.29 meter = 5/8 inch) >5yr, <120hr 0 Count_Weir2 = 00.36 er = 11/16 inch) Max Depth Row Count_OutletPipe1 = 00.42 meter = 3/4 inch) WQCV 52 Watershed Constraint Check Count_OutletPipe2 = 00.50 er = 13/16 inch) 2 Year 90 Slope 0.010 COUNTA_2 (Standard FSD Setup)= 00.58 meter = 7/8 inch) EURV 110 Shape 2.00 MaxPondDepth_Error? FALSE 0.67 er = 15/16 inch) 5 Year 127 Hidden Parameters & Calculations 0.76 ameter = 1 inch) 10 Year 148 Spillway Depth WQ Ao 1st Est = #VALUE! 0.86 = 1-1/16 inches) 25 Year 178 0.13 WQ Plate Flow at 100yr depth = 0.00 0.97 = 1-1/8 inches) 50 Year 198 CLOG #1= 0% 1.08 = 1-3/16 inches) 100 Year 229 1 Z1_Boolean Cdw #1 = 1.20 = 1-1/4 inches) 500 Year 256 1 Z2_Boolean Cdo #1 = 1.32 = 1-5/16 inches) Zone3_Pulldown Message 1 Z3_Boolean Overflow Weir #1 Angle = 1.45 = 1-3/8 inches) 1 Opening Message CLOG #2= 0% 1.59 = 1-7/16 inches) Draintime Running Cdw #2 = 1.73 = 1-1/2 inches) Outlet Boolean Outlet Rank Total (1 to 4) Cdo #2 = 1.88 = 1-9/16 inches) Vertical Orifice 1 111 Overflow Weir #2 Angle = 2.03 = 1-5/8 inches) Vertical Orifice 2 00 Boolean Underdrain Q at 100yr depth = 0.01 2.20 1-11/16 inches) Overflow Weir 1 00 0Max Depth VertOrifice1 Q at 100yr depth = 0.22 2.36 = 1-3/4 inches) Overflow Weir 2 00 0 500yr Depth VertOrifice2 Q at 100yr depth = 0.00 2.54 1-13/16 inches) Outlet Pipe 1 0 0 0 Freeboard EURV_draintime_user = 2.72 = 1-7/8 inches) Outlet Pipe 2 0 0 0 Spillway Count_User_Hydrographs 0 2.90 1-15/16 inches) CountA_3 (EURV & 100yr) = 03.09 eter = 2 inches) Button Visibility Boolean CountA_4 (100yr Only) = 0 3.29 gular openings) 1 Button_Trigger 1 Underdrain 0 WQCV Plate 0 EURV-WQCV Plate 0 EURV-WQCV VertOrifice 0 Outlet 90% Qpeak 0 Outlet Undetained Detention Basin Outlet Structure Design 0 0.5 1 1.5 2 2.5 0.1 1 10 FLOW [cfs] TIME [hr] 100YR IN 100YR OUT 50YR IN 50YR OUT 25YR IN 25YR OUT 10YR IN 10YR OUT 5YR IN 5YR OUT 2YR IN 2YR OUT EURV IN EURV OUT WQCV IN Outflow Hydrograph Workbook Filename: Storm Inflow Hydrographs The user can override the calculated inflow hydrographs from this workbook with inflow hydrographs developed in a separate program. SOURCE Time Interval TIME WQCV [cfs] EURV [cfs] 2 Year [cfs] 5 Year [cfs] 10 Year [cfs] 25 Year [cfs] 50 Year [cfs] 100 Year [cfs] 500 Year [cfs] 5.00 min 0:00:00 0:05:00 Hydrograph 0:10:00 Constant 0:15:00 0.882 0:20:00 0:25:00 0:30:00 0:35:00 0:40:00 0:45:00 0:50:00 0:55:00 1:00:00 1:05:00 1:10:00 1:15:00 1:20:00 1:25:00 1:30:00 1:35:00 1:40:00 1:45:00 1:50:00 1:55:00 2:00:00 2:05:00 2:10:00 2:15:00 2:20:00 2:25:00 2:30:00 2:35:00 2:40:00 2:45:00 2:50:00 2:55:00 3:00:00 3:05:00 3:10:00 3:15:00 3:20:00 3:25:00 3:30:00 3:35:00 3:40:00 3:45:00 3:50:00 3:55:00 4:00:00 4:05:00 4:10:00 4:15:00 4:20:00 4:25:00 4:30:00 Project: Basin ID: Depth Increment = 0.25 ft Required Volume Calculation Media Surface 0.00 63.1 4.2 265 0.006 Selected BMP Type = RG 0.25 64.5 5.6 364 0.008 75 0.002 Watershed Area = 0.30 acres 0.50 66.0 7.1 472 0.011 180 0.004 Watershed Length = 150 ft Zone 1 (WQCV) 0.56 66.4 7.6 502 0.012 214 0.005 Watershed Slope = 0.005 ft/ft 0.75 67.5 8.6 584 0.013 312 0.007 Watershed Imperviousness = 62.40% percent 1.00 69.0 10.1 700 0.016 472 0.011 Percentage Hydrologic Soil Group A = 0.0% percent 1.25 70.5 11.6 821 0.019 662 0.015 Percentage Hydrologic Soil Group B = 0.0% percent 1.50 72.0 13.1 946 0.022 883 0.020 Percentage Hydrologic Soil Groups C/D = 100.0% percent 1.75 73.5 14.6 1,076 0.025 1,136 0.026 Desired WQCV Drain Time = 12.0 hours 2.00 75.0 16.1 1,211 0.028 1,421 0.033 Location for 1-hr Rainfall Depths = UDFCD Default Zone 2 (100-year) 2.14 75.9 17.0 1,294 0.030 1,609 0.037 Water Quality Capture Volume (WQCV) = 0.005 acre-feet 2.25 76.6 17.7 1,356 0.031 1,755 0.040 Excess Urban Runoff Volume (EURV) = 0.018 acre-feet 2.50 78.1 19.2 1,499 0.034 2,112 0.048 2-yr Runoff Volume (P1 = 0.82 in.) = 0.012 acre-feet 0.82 inches 2.75 79.6 20.7 1,647 0.038 2,505 0.058 5-yr Runoff Volume (P1 = 1.34 in.) = 0.023 acre-feet inches 3.00 81.1 22.2 1,800 0.041 2,936 0.067 10-yr Runoff Volume (P1 = 1.64 in.) = 0.031 acre-feet inches 3.25 82.6 23.7 1,957 0.045 3,405 0.078 25-yr Runoff Volume (P1 = 2.02 in.) = 0.041 acre-feet inches 3.50 84.1 25.2 2,119 0.049 3,915 0.090 50-yr Runoff Volume (P1 = 2.32 in.) = 0.049 acre-feet inches 3.75 85.6 26.7 2,285 0.052 4,465 0.103 100-yr Runoff Volume (P1 = 2.83 in.) = 0.063 acre-feet 2.83 inches 4.00 87.1 28.2 2,456 0.056 5,058 0.116 500-yr Runoff Volume (P1 = 3.29 in.) = 0.076 acre-feet inches 4.25 88.6 29.7 2,631 0.060 5,693 0.131 Approximate 2-yr Detention Volume = 0.012 acre-feet 4.50 90.1 31.2 2,810 0.065 6,373 0.146 Approximate 5-yr Detention Volume = 0.020 acre-feet 4.75 91.6 32.7 2,995 0.069 7,099 0.163 Approximate 10-yr Detention Volume = 0.022 acre-feet 5.00 93.1 34.2 3,183 0.073 7,871 0.181 Approximate 25-yr Detention Volume = 0.025 acre-feet 5.25 94.6 35.7 3,376 0.078 8,691 0.200 Approximate 50-yr Detention Volume = 0.029 acre-feet 5.50 96.1 37.2 3,574 0.082 9,560 0.219 Approximate 100-yr Detention Volume = 0.037 acre-feet 5.75 97.6 38.7 3,776 0.087 10,478 0.241 6.00 99.1 40.2 3,983 0.091 11,448 0.263 Stage-Storage Calculation 6.25 100.6 41.7 4,194 0.096 12,470 0.286 Zone 1 Volume (WQCV) = 0.005 acre-feet 6.50 102.1 43.2 4,410 0.101 13,545 0.311 Zone 2 Volume (100-year - Zone 1) = 0.032 acre-feet 6.75 103.6 44.7 4,630 0.106 14,675 0.337 Select Zone 3 Storage Volume (Optional) = acre-feet 7.00 105.1 46.2 4,854 0.111 15,861 0.364 Total Detention Basin Volume = 0.037 acre-feet 7.25 106.6 47.7 5,084 0.117 17,103 0.393 Initial Surcharge Volume (ISV) = N/A ft^3 7.50 108.1 49.2 5,317 0.122 18,403 0.422 Initial Surcharge Depth (ISD) = N/A ft 7.75 109.6 50.7 5,555 0.128 19,762 0.454 Total Available Detention Depth (Htotal) = 2.20 ft 8.00 111.1 52.2 5,798 0.133 21,181 0.486 Depth of Trickle Channel (HTC) = N/A ft 8.25 112.6 53.7 6,045 0.139 22,661 0.520 Slope of Trickle Channel (STC) = N/A ft/ft 8.50 114.1 55.2 6,297 0.145 24,204 0.556 Slopes of Main Basin Sides (Smain) = 3 H:V 8.75 115.6 56.7 6,553 0.150 25,810 0.593 Basin Length-to-Width Ratio (RL/W) = 15 9.00 117.1 58.2 6,814 0.156 27,481 0.631 9.25 118.6 59.7 7,079 0.163 29,217 0.671 Initial Surcharge Area (AISV) = 0 ft^2 9.50 120.1 61.2 7,349 0.169 31,021 0.712 Surcharge Volume Length (LISV) = 0.0 ft 9.75 121.6 62.7 7,623 0.175 32,892 0.755 Surcharge Volume Width (WISV) = 0.0 ft 10.00 123.1 64.2 7,901 0.181 34,832 0.800 Depth of Basin Floor (HFLOOR) = 0.00 ft 10.25 124.6 65.7 8,184 0.188 36,843 0.846 Length of Basin Floor (LFLOOR) = 63.1 ft 10.50 126.1 67.2 8,472 0.194 38,925 0.894 Width of Basin Floor (WFLOOR) = 4.2 ft 10.75 127.6 68.7 8,764 0.201 41,079 0.943 Area of Basin Floor (AFLOOR) = 265 ft^2 11.00 129.1 70.2 9,061 0.208 43,307 0.994 Volume of Basin Floor (VFLOOR) = 0 ft^3 11.25 130.6 71.7 9,362 0.215 45,610 1.047 Depth of Main Basin (HMAIN) = 2.20 ft 11.50 132.1 73.2 9,668 0.222 47,989 1.102 Length of Main Basin (LMAIN) = 76.3 ft 11.75 133.6 74.7 9,978 0.229 50,445 1.158 Width of Main Basin (WMAIN) = 17.4 ft 12.00 135.1 76.2 10,293 0.236 52,978 1.216 Area of Main Basin (AMAIN) = 1,327 ft^2 12.25 136.6 77.7 10,612 0.244 55,591 1.276 Volume of Main Basin (VMAIN) = 1,603 ft^3 12.50 138.1 79.2 10,935 0.251 58,284 1.338 Calculated Total Basin Volume (Vtotal) = 0.037 acre-feet 12.75 139.6 80.7 11,264 0.259 61,059 1.402 0 User Defined Stage-Area Boolean for Message 0 Equal Stage-Area Inputs Watershed L:W 1 CountA 0Calc_S_TC H_FLOOR 63.0652 L_FLOOR_OTHER 0.00 ISV 0.00 ISV 0.00 Floor 0.00 Floor 0.56 Zone 1 (WQCV) 0.56 Zone 1 (WQCV) 2.14 Zone 2 (100-year 2.14 Zone 2 (100-year) 0.00 Zone 3 0.00 Zone 3 DETENTION BASIN STAGE‐STORAGE TABLE BUILDER 0.000 0.520 1.040 1.560 2.080 0.000 0.085 0.170 0.255 0.340 0.00 4.00 8.00 12.00 16.00 Volume (ac‐ft) Area (acres) Stage (ft.) Area (acres) Volume (ac‐ft) 0 3700 7400 11100 14800 0 40 80 120 160 0.00 4.00 8.00 12.00 16.00 Area (sq.ft.) Length, Width (ft.) Stage (ft) Length (ft) Width (ft) Area (sq.ft.) UD-Detention_v3 01 - Basin 2, Basin 3/14/2016, 12:18 PM Project: Basin ID: Stage (ft) Zone Volume (ac‐ft) Outlet Type Zone 1 (WQCV) 0.56 0.005 Filtration Media Zone 2 (100‐year) 2.14 0.032 Circular Orifice Zone 3 0.037 Total User Input: Orifice at Underdrain Outlet (typically used to drain WQCV in a Filtration BMP) Calculated Parameters for Underdrain Underdrain Orifice Invert Depth = 1.50 ft (distance below the filtration media surface) Underdrain Orifice Area = 0.0 ft2 Underdrain Orifice Diameter = 0.33 inches Underdrain Orifice Centroid = 0.01 feet User Input: Orifice Plate with one or more orifices or Elliptical Slot Weir (typically used to drain WQCV and/or EURV in a sedimentation BMP) Calculated Parameters for Plate Invert of Lowest Orifice = N/A ft (relative to bottom of basin at Stage = 0 ft) WQ Orifice Area per Row = N/A ft2 Depth at top of Zone using Orifice Plate = N/A ft (relative to bottom of basin at Stage = 0 ft) Elliptical Half‐Width = N/A feet Orifice Plate: Orifice Vertical Spacing = N/A inches Elliptical Slot Centroid = N/A feet Orifice Plate: Orifice Area per Row = N/A inches Elliptical Slot Area = N/A ft2 User Input: Stage and Total Area of Each Orifice Row (numbered from lowest to highest) Row 1 (optional) Row 2 (optional) Row 3 (optional) Row 4 (optional) Row 5 (optional) Row 6 (optional) Row 7 (optional) Row 8 (optional) Stage of Orifice Centroid (ft) N/A N/A N/A N/A N/A N/A N/A N/A Orifice Area (sq. inches) N/A N/A N/A N/A N/A N/A N/A N/A Row 9 (optional) Row 10 (optional) Row 11 (optional) Row 12 (optional) Row 13 (optional) Row 14 (optional) Row 15 (optional) Row 16 (optional) Stage of Orifice Centroid (ft) N/A N/A N/A N/A N/A N/A N/A N/A Orifice Area (sq. inches) N/A N/A N/A N/A N/A N/A N/A N/A User Input: Vertical Orifice (Circular or Rectangular) Calculated Parameters for Vertical Orifice Zone 2 Circular Not Selected Zone 2 Circular Not Selected Invert of Vertical Orifice = 0.56 ft (relative to bottom of basin at Stage = 0 ft) Vertical Orifice Area = 0.02 ft2 Depth at top of Zone using Vertical Orifice = 2.14 ft (relative to bottom of basin at Stage = 0 ft) Vertical Orifice Centroid = 0.08 feet Vertical Orifice Diameter = 2.00 inches User Input: Overflow Weir (Dropbox) and Grate (Flat or Sloped) Calculated Parameters for Overflow Weir Not Selected Not Selected Not Selected Not Selected Overflow Weir Front Edge Height, Ho = ft (relative to bottom of basin at Stage = 0 ft) Height of Grate Upper Edge, Ht = feet Overflow Weir Front Edge Length = feet Over Flow Weir Slope Length = feet Overflow Weir Slope = H:V (enter zero for flat grate) Grate Open Area / 100‐yr Orifice Area = should be > 4 Horiz. Length of Weir Sides = feet Overflow Grate Open Area w/o Debris = ft2 Overflow Grate Open Area % = %, grate open area / total area Overflow Grate Open Area with Debris = ft2 Debris Clogging % = % User Input: Outlet Pipe w/ Flow Restriction Plate (Circular Orifice, Restrictor Plate, or Rectangular Orifice) Calculated Parameters for Outlet Pipe w/ Flow Restriction Plate Not Selected Not Selected Not Selected Not Selected Depth to Invert of Outlet Pipe = ft (distance below bottom of basin at Stage = 0 ft) Outlet Orifice Area = ft2 Circular Orifice Diameter = inches Outlet Orifice Centroid = feet Half‐Central Angle of Restrictor Plate on Pipe = N/A N/A radians User Input: Emergency Spillway (Rectangular or Trapezoidal) Calculated Parameters for Spillway Spillway Invert Stage= 2.60 ft (relative to bottom of basin at Stage = 0 ft) Spillway Design Flow Depth= 0.10 feet Spillway Crest Length = 12.00 feet Stage at Top of Freeboard = 3.70 feet Spillway End Slopes = 3.00 H:V Basin Area at Top of Freeboard = 0.05acres Freeboard above Spillway = 1.00 feet Routed Hydrograph Results Design Storm Return Period = WQCV EURV 2 Year 5 Year 10 Year 25 Year 50 Year 100 Year 500 Year One-Hour Rainfall Depth (in) = 0.53 1.07 0.82 1.34 1.64 2.02 2.32 2.83 3.29 Calculated Runoff Volume (acre-ft) = 0.005 0.018 0.012 0.023 0.031 0.041 0.049 0.063 0.076 OPTIONAL Override Runoff Volume (acre-ft) = Inflow Hydrograph Volume (acre-ft) = 0.005 0.017 0.012 0.023 0.030 0.041 0.049 0.062 0.076 Predevelopment Unit Peak Flow, q (cfs/acre) = 0.00 0.00 0.01 0.28 0.48 0.90 1.14 1.43 2.00 Predevelopment Peak Q (cfs) = 0.0 0.0 0.0 0.1 0.1 0.3 0.3 0.4 0.6 Peak Inflow Q (cfs) = 0.1 0.3 0.2 0.5 0.6 0.8 0.9 1.2 1.5 Peak Outflow Q (cfs) = 0.0 0.1 0.0 0.1 0.1 0.1 0.1 0.1 0.4 Ratio Peak Outflow to Predevelopment Q = N/A N/A N/A 1.0 0.7 0.4 0.4 0.3 0.7 Structure Controlling Flow = Filtration Media Vertical Orifice 1 Vertical Orifice 1 Vertical Orifice 1 Vertical Orifice 1 Vertical Orifice 1 Vertical Orifice 1 Vertical Orifice 1 Spillway Max Velocity through Grate 1 (fps) = N/A N/A N/A N/A N/A N/A N/A N/A N/A Max Velocity through Grate 2 (fps) = N/A N/A N/A N/A N/A N/A N/A N/A N/A Time to Drain 97% of Inflow Volume (hours) = 16 21 21 22 22 23 24 25 25 COUNTA for Basin Tab = 1AoDia WQ Plate Type Vert Orifice 1 Vert Orifice 2 Count_Underdrain = 10.11 meter = 3/8 inch) 1 2 1 Count_WQPlate = 00.14 eter = 7/16 inch) Count_VertOrifice1 = 10.18 meter = 1/2 inch) Outlet Plate 1 Outlet Plate 2 Drain Time Message Boolean Count_VertOrifice2 = 00.24 eter = 9/16 inch) 1 1 5yr, <72hr 0 Count_Weir1 = 00.29 meter = 5/8 inch) >5yr, <120hr 0 Count_Weir2 = 00.36 er = 11/16 inch) Max Depth Row Count_OutletPipe1 = 00.42 meter = 3/4 inch) WQCV 48 Watershed Constraint Check Count_OutletPipe2 = 00.50 er = 13/16 inch) 2 Year 81 Slope 0.010 COUNTA_2 (Standard FSD Setup)= 00.58 meter = 7/8 inch) EURV 105 Shape 2.00 MaxPondDepth_Error? FALSE 0.67 er = 15/16 inch) 5 Year 127 Hidden Parameters & Calculations 0.76 ameter = 1 inch) 10 Year 152 Spillway Depth WQ Ao 1st Est = #VALUE! 0.86 = 1-1/16 inches) 25 Year 187 0.10 WQ Plate Flow at 100yr depth = 0.00 0.97 = 1-1/8 inches) 50 Year 210 CLOG #1= 0% 1.08 = 1-3/16 inches) 100 Year 246 1 Z1_Boolean Cdw #1 = 1.20 = 1-1/4 inches) 500 Year 265 1 Z2_Boolean Cdo #1 = 1.32 = 1-5/16 inches) Zone3_Pulldown Message 1 Z3_Boolean Overflow Weir #1 Angle = 1.45 = 1-3/8 inches) 1 Opening Message CLOG #2= 0% 1.59 = 1-7/16 inches) Draintime Running Cdw #2 = 1.73 = 1-1/2 inches) Outlet Boolean Outlet Rank Total (1 to 4) Cdo #2 = 1.88 = 1-9/16 inches) Vertical Orifice 1 111 Overflow Weir #2 Angle = 2.03 = 1-5/8 inches) Vertical Orifice 2 00 Boolean Underdrain Q at 100yr depth = 0.01 2.20 1-11/16 inches) Overflow Weir 1 00 0Max Depth VertOrifice1 Q at 100yr depth = 0.14 2.36 = 1-3/4 inches) Overflow Weir 2 00 0 500yr Depth VertOrifice2 Q at 100yr depth = 0.00 2.54 1-13/16 inches) Outlet Pipe 1 0 0 0 Freeboard EURV_draintime_user = 2.72 = 1-7/8 inches) Outlet Pipe 2 0 0 1 Spillway Count_User_Hydrographs 0 2.90 1-15/16 inches) CountA_3 (EURV & 100yr) = 03.09 eter = 2 inches) Button Visibility Boolean CountA_4 (100yr Only) = 0 3.29 gular openings) 1 Button_Trigger 1 Underdrain 0 WQCV Plate 0 EURV-WQCV Plate 0 EURV-WQCV VertOrifice 0 Outlet 90% Qpeak 0 Outlet Undetained Detention Basin Outlet Structure Design 0 0.2 0.4 0.6 0.8 1 1.2 1.4 0.1 1 10 FLOW [cfs] TIME [hr] 100YR IN 100YR OUT 50YR IN 50YR OUT 25YR IN 25YR OUT 10YR IN 10YR OUT 5YR IN 5YR OUT 2YR IN 2YR OUT EURV IN Outflow Hydrograph Workbook Filename: Storm Inflow Hydrographs The user can override the calculated inflow hydrographs from this workbook with inflow hydrographs developed in a separate program. SOURCE WORKBOOK WORKBOOK WORKBOOK WORKBOOK WORKBOOK WORKBOOK WORKBOOK WORKBOOK WORKBOOK Time Interval TIME WQCV [cfs] EURV [cfs] 2 Year [cfs] 5 Year [cfs] 10 Year [cfs] 25 Year [cfs] 50 Year [cfs] 100 Year [cfs] 500 Year [cfs] 5.79 min 0:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0:05:47 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hydrograph 0:11:35 0.01 0.02 0.02 0.03 0.04 0.05 0.06 0.07 0.09 Constant 0:17:22 0.02 0.05 0.04 0.06 0.08 0.11 0.13 0.17 0.21 0.863 0:23:10 0.04 0.13 0.09 0.18 0.23 0.31 0.37 0.47 0.57 0:28:57 0.09 0.34 0.22 0.45 0.58 0.78 0.93 1.18 1.44 0:34:45 0.09 0.34 0.22 0.45 0.59 0.79 0.95 1.21 1.48 0:40:32 0.08 0.28 0.19 0.37 0.48 0.66 0.78 1.01 1.23 0:46:20 0.06 0.22 0.15 0.29 0.38 0.52 0.62 0.80 0.97 0:52:07 0.05 0.18 0.12 0.24 0.31 0.42 0.50 0.64 0.78 0:57:55 0.04 0.13 0.09 0.18 0.24 0.32 0.38 0.49 0.61 1:03:42 0.03 0.10 0.07 0.14 0.18 0.25 0.30 0.39 0.48 1:09:30 0.02 0.09 0.06 0.12 0.16 0.21 0.26 0.33 0.40 1:15:17 0.02 0.06 0.04 0.08 0.11 0.15 0.18 0.23 0.28 1:21:05 0.01 0.05 0.03 0.06 0.08 0.11 0.14 0.17 0.21 1:26:52 0.01 0.03 0.02 0.04 0.06 0.08 0.09 0.12 0.14 1:32:40 0.01 0.02 0.02 0.03 0.04 0.06 0.07 0.09 0.11 1:38:27 0.01 0.02 0.01 0.02 0.03 0.04 0.05 0.07 0.08 1:44:15 0.00 0.02 0.01 0.02 0.03 0.04 0.04 0.06 0.07 1:50:02 0.00 0.01 0.01 0.02 0.02 0.03 0.04 0.05 0.06 1:55:50 0.00 0.01 0.01 0.02 0.02 0.03 0.04 0.05 0.06 2:01:37 0.00 0.01 0.01 0.02 0.02 0.03 0.04 0.05 0.06 2:07:25 0.00 0.01 0.01 0.02 0.02 0.03 0.04 0.05 0.06 2:13:12 0.00 0.01 0.01 0.02 0.02 0.03 0.04 0.05 0.06 2:19:00 0.00 0.01 0.01 0.01 0.01 0.02 0.02 0.03 0.04 2:24:47 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.02 0.02 2:30:35 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 2:36:22 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 2:42:09 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2:47:57 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2:53:44 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2:59:32 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:05:19 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:11:07 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:16:54 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:22:42 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:28:29 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:34:17 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:40:04 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:45:52 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:51:39 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:57:27 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:03:14 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:09:02 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:14:49 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:20:37 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:26:24 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:32:12 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:37:59 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:43:47 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:49:34 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:55:22 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:01:09 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:06:57 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:12:44 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:18:31 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:24:19 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:30:06 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:35:54 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:41:41 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:47:29 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:53:16 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:59:04 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6:04:51 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6:10:39 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6:16:26 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6:22:14 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6:28:01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6:33:49 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6:39:36 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6:45:24 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6:51:11 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6:56:59 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Detention Basin Outlet Structure Design EURV OUT WQCV IN WQCV OUT 0 0.5 1 1.5 2 2.5 3 0.1 1 10 100 PONDING DEPTH [ft] DRAIN TIME [hr] 100YR 50YR 25YR 10YR 5YR 2YR EURV WQCV 0.00 1,000.00 2,000.00 3,000.00 4,000.00 5,000.00 6,000.00 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 100000 0 5 10 15 20 25 OUTFLOW [cfs] AREA [ft^2], VOLUME [ft^3] PONDING DEPTH [ft] User Area [ft^2] Interpolated Area [ft^2] Volume [ft^3] Outflow [cfs] Time to Drain 99% of Inflow Volume (hours) = 16 21 21 22 23 24 24 25 26 Maximum Ponding Depth (ft) = 0.48 1.05 0.81 1.27 1.52 1.87 2.09 2.45 2.64 Area at Maximum Ponding Depth (acres) = 0.01 0.02 0.01 0.02 0.02 0.03 0.03 0.03 0.04 Maximum Volume Stored (acre-ft) = 0.004 0.012 0.008 0.016 0.021 0.029 0.035 0.047 0.053 Detention Basin Outlet Structure Design Lot 18 Basin 2 13.00 141.1 82.2 11,596 0.266 63,917 1.467 13.25 142.6 83.7 11,933 0.274 66,858 1.535 13.50 144.1 85.2 12,275 0.282 69,884 1.604 13.75 145.6 86.7 12,621 0.290 72,996 1.676 14.00 147.1 88.2 12,972 0.298 76,195 1.749 14.25 148.6 89.7 13,327 0.306 79,482 1.825 14.50 150.1 91.2 13,687 0.314 82,858 1.902 14.75 151.6 92.7 14,051 0.323 86,325 1.982 15.00 153.1 94.2 14,419 0.331 89,884 2.063 DETENTION BASIN STAGE‐STORAGE TABLE BUILDER Optional Override Area (ft^2) Length (ft) Optional Override Stage (ft) Stage (ft) Stage - Storage Description Area (ft^2) Width (ft) Lot 18 Basin 2 Volume (ft^3) Volume (ac-ft) Area (acre) Optional User Input 1-hr Precipitation Example Zone Configuration (Retention Pond) UD-Detention_v3 01 - Basin 2, Basin 3/14/2016, 12:18 PM 4:35:00 4:40:00 4:45:00 4:50:00 4:55:00 5:00:00 5:05:00 5:10:00 5:15:00 5:20:00 5:25:00 5:30:00 5:35:00 5:40:00 5:45:00 5:50:00 5:55:00 6:00:00 Detention Basin Outlet Structure Design WQCV OUT 0 0.5 1 1.5 2 2.5 0.1 1 10 100 PONDING DEPTH [ft] DRAIN TIME [hr] 100YR 50YR 25YR 10YR 5YR 2YR EURV WQCV 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0 20000 40000 60000 80000 100000 120000 140000 160000 180000 0 5 10 15 20 25 OUTFLOW [cfs] AREA [ft^2], VOLUME [ft^3] PONDING DEPTH [ft] User Area [ft^2] Interpolated Area [ft^2] Volume [ft^3] Outflow [cfs] Time to Drain 97% of Inflow Volume (hours) = 22 32 32 32 33 34 34 35 36 Time to Drain 99% of Inflow Volume (hours) = 23 32 32 33 33 34 34 35 36 Maximum Ponding Depth (ft) = 0.52 1.10 0.90 1.27 1.48 1.78 1.98 2.28 2.55 Area at Maximum Ponding Depth (acres) = 0.02 0.03 0.02 0.03 0.03 0.04 0.04 0.05 0.06 Maximum Volume Stored (acre-ft) = 0.006 0.018 0.013 0.023 0.030 0.041 0.049 0.063 0.078 Detention Basin Outlet Structure Design Lot 18 Basin 1 13.00 185.1 108.1 20,003 0.459 108,726 2.496 13.25 187.1 110.1 20,594 0.473 113,800 2.612 13.50 189.1 112.1 21,192 0.487 119,023 2.732 13.75 191.1 114.1 21,798 0.500 124,397 2.856 14.00 193.1 116.1 22,413 0.515 129,923 2.983 14.25 195.1 118.1 23,035 0.529 135,604 3.113 14.50 197.1 120.1 23,665 0.543 141,441 3.247 14.75 199.1 122.1 24,304 0.558 147,437 3.385 15.00 201.1 124.1 24,950 0.573 153,594 3.526 Optional User Input 1-hr Precipitation Volume (ft^3) Volume (ac-ft) Area (acre) DETENTION BASIN STAGE‐STORAGE TABLE BUILDER Optional Override Area (ft^2) Length (ft) Optional Override Stage (ft) Stage (ft) Stage - Storage Description Area (ft^2) Width (ft) Lot 18 Basin 1 Example Zone Configuration (Retention Pond) UD-Detention_v3 01 - Basin 1, Basin 3/14/2016, 12:36 PM 2600 0.05 837 0.50 0.02 3,290 -2,452 2600 0.16 4,716 0.50 0.02 3,290 1,426 2700 0.05 844 0.50 0.02 3,416 -2,571 2700 0.16 4,754 0.50 0.02 3,416 1,338 2800 0.04 851 0.50 0.02 3,542 -2,691 2800 0.15 4,791 0.50 0.02 3,542 1,249 2900 0.04 857 0.50 0.02 3,668 -2,810 2900 0.15 4,827 0.50 0.02 3,668 1,159 3000 0.04 863 0.50 0.02 3,794 -2,930 3000 0.15 4,862 0.50 0.02 3,794 1,068 3100 0.04 870 0.50 0.02 3,920 -3,050 3100 0.14 4,896 0.50 0.02 3,920 977 3200 0.04 875 0.50 0.02 4,046 -3,170 3200 0.14 4,930 0.50 0.02 4,046 884 3300 0.04 881 0.50 0.02 4,172 -3,291 3300 0.13 4,962 0.50 0.02 4,172 790 3400 0.04 887 0.50 0.02 4,298 -3,411 3400 0.13 4,994 0.50 0.02 4,298 696 3500 0.04 892 0.50 0.02 4,424 -3,531 3500 0.13 5,025 0.50 0.02 4,424 601 3600 0.04 898 0.50 0.02 4,550 -3,652 3600 0.13 5,055 0.50 0.02 4,550 505 3700 0.04 903 0.50 0.02 4,676 -3,773 3700 0.12 5,085 0.50 0.02 4,676 409 3800 0.03 908 0.50 0.02 4,802 -3,894 3800 0.12 5,114 0.50 0.02 4,802 312 3900 0.03 913 0.50 0.02 4,928 -4,015 3900 0.12 5,142 0.50 0.02 4,928 214 4000 0.03 918 0.50 0.02 5,054 -4,136 4000 0.12 5,170 0.50 0.02 5,054 116 4100 0.03 923 0.50 0.02 5,180 -4,257 4100 0.11 5,197 0.50 0.02 5,180 17 4200 0.03 928 0.50 0.02 5,306 -4,378 4200 0.11 5,224 0.50 0.02 5,306 -82 4300 0.03 932 0.50 0.02 5,432 -4,499 4300 0.11 5,250 0.50 0.02 5,432 -182 4400 0.03 937 0.50 0.02 5,558 -4,621 4400 0.11 5,276 0.50 0.02 5,558 -282 4500 0.03 941 0.50 0.02 5,684 -4,742 4500 0.11 5,301 0.50 0.02 5,684 -383 4600 0.03 946 0.50 0.02 5,810 -4,864 4600 0.10 5,326 0.50 0.02 5,810 -484 4700 0.03 950 0.50 0.02 5,936 -4,986 4700 0.10 5,350 0.50 0.02 5,936 -585 4800 0.03 954 0.50 0.02 6,062 -5,107 4800 0.10 5,374 0.50 0.02 6,062 -687 4900 0.03 959 0.50 0.02 6,188 -5,229 4900 0.10 5,398 0.50 0.02 6,188 -790 5000 0.03 963 0.50 0.02 6,314 -5,351 5000 0.10 5,421 0.50 0.02 6,314 -893 5100 0.03 967 0.50 0.02 6,440 -5,473 5100 0.10 5,444 0.50 0.02 6,440 -996 5200 0.03 971 0.50 0.02 6,566 -5,595 5200 0.09 5,467 0.50 0.02 6,566 -1,099 5300 0.03 975 0.50 0.02 6,692 -5,717 5300 0.09 5,489 0.50 0.02 6,692 -1,203 5400 0.03 979 0.50 0.02 6,818 -5,839 5400 0.09 5,511 0.50 0.02 6,818 -1,307 5500 0.03 982 0.50 0.02 6,944 -5,961 5500 0.09 5,532 0.50 0.02 6,944 -1,412 5600 0.03 986 0.50 0.02 7,070 -6,084 5600 0.09 5,553 0.50 0.02 7,070 -1,516 5700 0.03 990 0.50 0.02 7,196 -6,206 5700 0.09 5,574 0.50 0.02 7,196 -1,622 5800 0.03 994 0.50 0.02 7,322 -6,328 5800 0.09 5,595 0.50 0.02 7,322 -1,727 5900 0.02 997 0.50 0.02 7,448 -6,451 5900 0.09 5,615 0.50 0.02 7,448 -1,833 6000 0.02 1,001 0.50 0.02 7,574 -6,573 6000 0.08 5,635 0.50 0.02 7,574 -1,938 Mod. FAA Minor Storage Volume (cubic ft.) = 252 Mod. FAA Major Storage Volume (cubic ft.) = 2,657 Mod. FAA Minor Storage Volume (acre-ft.) = 0.0058 Mod. FAA Major Storage Volume (acre-ft.) = 0.0610 DETENTION VOLUME BY THE MODIFIED FAA METHOD (See USDCM Volume 2 Storage Chapter for description of method) Lot 18 Developed 100YR (Basin 2) - Reduced Imp 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 Storage Modified FAA Detention_Reduced Imp, Modified FAA 2/26/2016, 10:20 AM 2600 0.05 926 0.50 0.02 3,290 -2,364 2600 0.16 4,868 0.50 0.02 3,290 1,578 2700 0.05 933 0.50 0.02 3,416 -2,483 2700 0.16 4,907 0.50 0.02 3,416 1,491 2800 0.04 940 0.50 0.02 3,542 -2,601 2800 0.15 4,946 0.50 0.02 3,542 1,404 2900 0.04 947 0.50 0.02 3,668 -2,720 2900 0.15 4,983 0.50 0.02 3,668 1,315 3000 0.04 954 0.50 0.02 3,794 -2,839 3000 0.15 5,019 0.50 0.02 3,794 1,225 3100 0.04 961 0.50 0.02 3,920 -2,959 3100 0.14 5,054 0.50 0.02 3,920 1,135 3200 0.04 968 0.50 0.02 4,046 -3,078 3200 0.14 5,089 0.50 0.02 4,046 1,043 3300 0.04 974 0.50 0.02 4,172 -3,198 3300 0.13 5,122 0.50 0.02 4,172 950 3400 0.04 980 0.50 0.02 4,298 -3,318 3400 0.13 5,155 0.50 0.02 4,298 857 3500 0.04 986 0.50 0.02 4,424 -3,437 3500 0.13 5,187 0.50 0.02 4,424 763 3600 0.04 992 0.50 0.02 4,550 -3,558 3600 0.13 5,218 0.50 0.02 4,550 668 3700 0.04 998 0.50 0.02 4,676 -3,678 3700 0.12 5,249 0.50 0.02 4,676 573 3800 0.03 1,004 0.50 0.02 4,802 -3,798 3800 0.12 5,279 0.50 0.02 4,802 477 3900 0.03 1,009 0.50 0.02 4,928 -3,918 3900 0.12 5,308 0.50 0.02 4,928 380 4000 0.03 1,015 0.50 0.02 5,054 -4,039 4000 0.12 5,337 0.50 0.02 5,054 283 4100 0.03 1,020 0.50 0.02 5,180 -4,160 4100 0.11 5,365 0.50 0.02 5,180 185 4200 0.03 1,025 0.50 0.02 5,306 -4,280 4200 0.11 5,392 0.50 0.02 5,306 87 4300 0.03 1,030 0.50 0.02 5,432 -4,401 4300 0.11 5,419 0.50 0.02 5,432 -12 4400 0.03 1,036 0.50 0.02 5,558 -4,522 4400 0.11 5,446 0.50 0.02 5,558 -112 4500 0.03 1,041 0.50 0.02 5,684 -4,643 4500 0.11 5,472 0.50 0.02 5,684 -212 4600 0.03 1,045 0.50 0.02 5,810 -4,764 4600 0.10 5,498 0.50 0.02 5,810 -312 4700 0.03 1,050 0.50 0.02 5,936 -4,886 4700 0.10 5,523 0.50 0.02 5,936 -413 4800 0.03 1,055 0.50 0.02 6,062 -5,007 4800 0.10 5,548 0.50 0.02 6,062 -514 4900 0.03 1,060 0.50 0.02 6,188 -5,128 4900 0.10 5,572 0.50 0.02 6,188 -616 5000 0.03 1,064 0.50 0.02 6,314 -5,250 5000 0.10 5,596 0.50 0.02 6,314 -718 5100 0.03 1,069 0.50 0.02 6,440 -5,371 5100 0.10 5,620 0.50 0.02 6,440 -820 5200 0.03 1,073 0.50 0.02 6,566 -5,493 5200 0.09 5,643 0.50 0.02 6,566 -923 5300 0.03 1,077 0.50 0.02 6,692 -5,614 5300 0.09 5,666 0.50 0.02 6,692 -1,026 5400 0.03 1,082 0.50 0.02 6,818 -5,736 5400 0.09 5,688 0.50 0.02 6,818 -1,129 5500 0.03 1,086 0.50 0.02 6,944 -5,858 5500 0.09 5,711 0.50 0.02 6,944 -1,233 5600 0.03 1,090 0.50 0.02 7,070 -5,980 5600 0.09 5,732 0.50 0.02 7,070 -1,337 5700 0.03 1,094 0.50 0.02 7,196 -6,102 5700 0.09 5,754 0.50 0.02 7,196 -1,442 5800 0.03 1,098 0.50 0.02 7,322 -6,224 5800 0.09 5,775 0.50 0.02 7,322 -1,546 5900 0.02 1,102 0.50 0.02 7,448 -6,346 5900 0.09 5,796 0.50 0.02 7,448 -1,651 6000 0.02 1,106 0.50 0.02 7,574 -6,468 6000 0.08 5,817 0.50 0.02 7,574 -1,757 Mod. FAA Minor Storage Volume (cubic ft.) = 293 Mod. FAA Major Storage Volume (cubic ft.) = 2,767 Mod. FAA Minor Storage Volume (acre-ft.) = 0.0067 Mod. FAA Major Storage Volume (acre-ft.) = 0.0635 DETENTION VOLUME BY THE MODIFIED FAA METHOD (See USDCM Volume 2 Storage Chapter for description of method) Lot 18 Developed 100YR (Basin 2) 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 Storage Modified FAA Detention_Reduced Imp, Modified FAA 2/26/2016, 10:17 AM 2600 0.05 1,584 0.50 0.03 4,826 -3,242 2600 0.16 7,586 0.50 0.03 4,826 2,760 2700 0.05 1,597 0.50 0.03 5,010 -3,414 2700 0.16 7,647 0.50 0.03 5,010 2,637 2800 0.04 1,609 0.50 0.03 5,195 -3,586 2800 0.15 7,707 0.50 0.03 5,195 2,511 2900 0.04 1,621 0.50 0.03 5,380 -3,759 2900 0.15 7,765 0.50 0.03 5,380 2,385 3000 0.04 1,633 0.50 0.03 5,565 -3,932 3000 0.15 7,821 0.50 0.03 5,565 2,256 3100 0.04 1,644 0.50 0.03 5,750 -4,105 3100 0.14 7,876 0.50 0.03 5,750 2,127 3200 0.04 1,656 0.50 0.03 5,934 -4,279 3200 0.14 7,930 0.50 0.03 5,934 1,995 3300 0.04 1,667 0.50 0.03 6,119 -4,453 3300 0.13 7,982 0.50 0.03 6,119 1,863 3400 0.04 1,677 0.50 0.03 6,304 -4,627 3400 0.13 8,033 0.50 0.03 6,304 1,729 3500 0.04 1,688 0.50 0.03 6,489 -4,801 3500 0.13 8,083 0.50 0.03 6,489 1,594 3600 0.04 1,698 0.50 0.03 6,674 -4,976 3600 0.13 8,132 0.50 0.03 6,674 1,458 3700 0.04 1,708 0.50 0.03 6,858 -5,151 3700 0.12 8,179 0.50 0.03 6,858 1,321 3800 0.03 1,717 0.50 0.03 7,043 -5,326 3800 0.12 8,226 0.50 0.03 7,043 1,183 3900 0.03 1,727 0.50 0.03 7,228 -5,501 3900 0.12 8,271 0.50 0.03 7,228 1,043 4000 0.03 1,736 0.50 0.03 7,413 -5,677 4000 0.12 8,316 0.50 0.03 7,413 903 4100 0.03 1,746 0.50 0.03 7,598 -5,852 4100 0.11 8,360 0.50 0.03 7,598 762 4200 0.03 1,754 0.50 0.03 7,782 -6,028 4200 0.11 8,403 0.50 0.03 7,782 621 4300 0.03 1,763 0.50 0.03 7,967 -6,204 4300 0.11 8,445 0.50 0.03 7,967 478 4400 0.03 1,772 0.50 0.03 8,152 -6,380 4400 0.11 8,487 0.50 0.03 8,152 335 4500 0.03 1,780 0.50 0.03 8,337 -6,556 4500 0.11 8,527 0.50 0.03 8,337 190 4600 0.03 1,789 0.50 0.03 8,522 -6,733 4600 0.10 8,567 0.50 0.03 8,522 46 4700 0.03 1,797 0.50 0.03 8,706 -6,910 4700 0.10 8,607 0.50 0.03 8,706 -100 4800 0.03 1,805 0.50 0.03 8,891 -7,086 4800 0.10 8,645 0.50 0.03 8,891 -246 4900 0.03 1,813 0.50 0.03 9,076 -7,263 4900 0.10 8,683 0.50 0.03 9,076 -393 5000 0.03 1,821 0.50 0.03 9,261 -7,440 5000 0.10 8,721 0.50 0.03 9,261 -540 5100 0.03 1,828 0.50 0.03 9,446 -7,617 5100 0.10 8,757 0.50 0.03 9,446 -688 5200 0.03 1,836 0.50 0.03 9,630 -7,794 5200 0.09 8,794 0.50 0.03 9,630 -837 5300 0.03 1,843 0.50 0.03 9,815 -7,972 5300 0.09 8,829 0.50 0.03 9,815 -986 5400 0.03 1,851 0.50 0.03 10,000 -8,149 5400 0.09 8,864 0.50 0.03 10,000 -1,136 5500 0.03 1,858 0.50 0.03 10,185 -8,327 5500 0.09 8,899 0.50 0.03 10,185 -1,286 5600 0.03 1,865 0.50 0.03 10,370 -8,505 5600 0.09 8,933 0.50 0.03 10,370 -1,437 5700 0.03 1,872 0.50 0.03 10,554 -8,682 5700 0.09 8,967 0.50 0.03 10,554 -1,588 5800 0.03 1,879 0.50 0.03 10,739 -8,860 5800 0.09 9,000 0.50 0.03 10,739 -1,739 5900 0.02 1,886 0.50 0.03 10,924 -9,038 5900 0.09 9,033 0.50 0.03 10,924 -1,891 6000 0.02 1,893 0.50 0.03 11,109 -9,216 6000 0.08 9,065 0.50 0.03 11,109 -2,044 Mod. FAA Minor Storage Volume (cubic ft.) = 535 Mod. FAA Major Storage Volume (cubic ft.) = 4,390 Mod. FAA Minor Storage Volume (acre-ft.) = 0.0123 Mod. FAA Major Storage Volume (acre-ft.) = 0.1008 DETENTION VOLUME BY THE MODIFIED FAA METHOD (See USDCM Volume 2 Storage Chapter for description of method) Lot 18 Developed 100YR (Basin 1) Reduced Imp 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 Storage Modified FAA Detention_Reduced Imp, Modified FAA 2/26/2016, 10:19 AM 2600 0.05 1,713 0.50 0.03 4,826 -3,113 2600 0.16 7,809 0.50 0.03 4,826 2,983 2700 0.05 1,727 0.50 0.03 5,010 -3,283 2700 0.16 7,872 0.50 0.03 5,010 2,862 2800 0.04 1,740 0.50 0.03 5,195 -3,455 2800 0.15 7,933 0.50 0.03 5,195 2,738 2900 0.04 1,754 0.50 0.03 5,380 -3,627 2900 0.15 7,993 0.50 0.03 5,380 2,613 3000 0.04 1,766 0.50 0.03 5,565 -3,799 3000 0.15 8,051 0.50 0.03 5,565 2,486 3100 0.04 1,779 0.50 0.03 5,750 -3,971 3100 0.14 8,108 0.50 0.03 5,750 2,358 3200 0.04 1,791 0.50 0.03 5,934 -4,144 3200 0.14 8,163 0.50 0.03 5,934 2,229 3300 0.04 1,803 0.50 0.03 6,119 -4,317 3300 0.13 8,217 0.50 0.03 6,119 2,098 3400 0.04 1,814 0.50 0.03 6,304 -4,490 3400 0.13 8,269 0.50 0.03 6,304 1,965 3500 0.04 1,825 0.50 0.03 6,489 -4,663 3500 0.13 8,321 0.50 0.03 6,489 1,832 3600 0.04 1,836 0.50 0.03 6,674 -4,837 3600 0.13 8,371 0.50 0.03 6,674 1,697 3700 0.04 1,847 0.50 0.03 6,858 -5,011 3700 0.12 8,420 0.50 0.03 6,858 1,561 3800 0.03 1,858 0.50 0.03 7,043 -5,186 3800 0.12 8,468 0.50 0.03 7,043 1,424 3900 0.03 1,868 0.50 0.03 7,228 -5,360 3900 0.12 8,515 0.50 0.03 7,228 1,287 4000 0.03 1,878 0.50 0.03 7,413 -5,535 4000 0.12 8,561 0.50 0.03 7,413 1,148 4100 0.03 1,888 0.50 0.03 7,598 -5,710 4100 0.11 8,606 0.50 0.03 7,598 1,008 4200 0.03 1,898 0.50 0.03 7,782 -5,885 4200 0.11 8,650 0.50 0.03 7,782 868 4300 0.03 1,907 0.50 0.03 7,967 -6,060 4300 0.11 8,694 0.50 0.03 7,967 726 4400 0.03 1,917 0.50 0.03 8,152 -6,235 4400 0.11 8,736 0.50 0.03 8,152 584 4500 0.03 1,926 0.50 0.03 8,337 -6,411 4500 0.11 8,778 0.50 0.03 8,337 441 4600 0.03 1,935 0.50 0.03 8,522 -6,587 4600 0.10 8,819 0.50 0.03 8,522 298 4700 0.03 1,944 0.50 0.03 8,706 -6,763 4700 0.10 8,860 0.50 0.03 8,706 153 4800 0.03 1,952 0.50 0.03 8,891 -6,939 4800 0.10 8,899 0.50 0.03 8,891 8 4900 0.03 1,961 0.50 0.03 9,076 -7,115 4900 0.10 8,939 0.50 0.03 9,076 -138 5000 0.03 1,969 0.50 0.03 9,261 -7,291 5000 0.10 8,977 0.50 0.03 9,261 -284 5100 0.03 1,978 0.50 0.03 9,446 -7,468 5100 0.10 9,015 0.50 0.03 9,446 -431 5200 0.03 1,986 0.50 0.03 9,630 -7,645 5200 0.09 9,052 0.50 0.03 9,630 -578 5300 0.03 1,994 0.50 0.03 9,815 -7,821 5300 0.09 9,089 0.50 0.03 9,815 -726 5400 0.03 2,002 0.50 0.03 10,000 -7,998 5400 0.09 9,125 0.50 0.03 10,000 -875 5500 0.03 2,010 0.50 0.03 10,185 -8,175 5500 0.09 9,161 0.50 0.03 10,185 -1,024 5600 0.03 2,017 0.50 0.03 10,370 -8,352 5600 0.09 9,196 0.50 0.03 10,370 -1,174 5700 0.03 2,025 0.50 0.03 10,554 -8,529 5700 0.09 9,230 0.50 0.03 10,554 -1,324 5800 0.03 2,033 0.50 0.03 10,739 -8,707 5800 0.09 9,265 0.50 0.03 10,739 -1,475 5900 0.02 2,040 0.50 0.03 10,924 -8,884 5900 0.09 9,298 0.50 0.03 10,924 -1,626 6000 0.02 2,047 0.50 0.03 11,109 -9,062 6000 0.08 9,332 0.50 0.03 11,109 -1,777 Mod. FAA Minor Storage Volume (cubic ft.) = 596 Mod. FAA Major Storage Volume (cubic ft.) = 4,558 Mod. FAA Minor Storage Volume (acre-ft.) = 0.0137 Mod. FAA Major Storage Volume (acre-ft.) = 0.1046 DETENTION VOLUME BY THE MODIFIED FAA METHOD (See USDCM Volume 2 Storage Chapter for description of method) Lot 18 Developed 100-Year (Basin 1) 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 Storage Modified FAA Detention_Reduced Imp, Modified FAA 2/26/2016, 10:05 AM the version date(s) listed below. Soil Survey Area: Larimer County Area, Colorado Survey Area Data: Version 10, Sep 22, 2015 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Apr 22, 2011—Apr 28, 2011 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Soil Map—Larimer County Area, Colorado (Lot 18 - Midpoint Dr) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 2/29/2016 Page 2 of 3