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Stormwater Report Revised 10-29-20 Stormwater Management Plan Christian Brothers Automotive Chanhassen, MN City of Chanhassen Riley Purgatory Bluff Creek Watershed District Prepared for: Christian Brothers Automotive Corporation 17725 Katy Freeway Houston, TX 77094 Contact: Jonathan Wakefield Prepared by: Kimley-Horn 767 Eustis Street, Suite 100 St. Paul, MN 55114 Contact: Christian Jones, Project Manager. Brandon Elegert, P.E. Prepared On: September 18, 2020 Revised On: October 29, 2020 Christian Brothers Automotive - Stormwater Report Page 2 Chanhassen, MN Stormwater Management Report for Christian Brothers Automotive – Chanhassen, MN Prepared for: Christian Brothers Automotive Corporation October 29, 2020 Prepared By: Kimley-Horn and Associates, Inc. 767 Eustis Street, Suite 100 St. Paul, MN 55114 . I hereby certify that this plan, specification, or report was prepared by me or under my direct supervision and that I am a duly Registered Professional Engineer under the laws of the State of Minnesota. _______________________________________ Brandon R. Elegert, P.E. Date: October 29, 2020 Registration No. 50387 Christian Brothers Automotive - Stormwater Report Page 3 Chanhassen, MN Table of Contents 1.0 Introduction ............................................................................................... 4 2.0 Pre-development Conditions ..................................................................... 4 3.0 Post-development Conditions .................................................................... 4 4.0 Rate Attenuation Summary ....................................................................... 5 5.0 Volume Reduction Summary ...................................................................... 6 6.0 Water Quality Summary ............................................................................ 6 Exhibits ............................................................................................................... 8 Exhibit 1. Existing Drainage Exhibit ....................................................................................................... 9 Exhibit 2. Proposed Drainage Exhibit .................................................................................................. 10 Appendices ....................................................................................................... 11 Appendix 1. Pre-Development HydroCAD Model Analysis (TP-40) .................................................... 12 Appendix 2. Pre-Development HydroCAD Model Analysis (Atlas-14) ................................................ 13 Appendix 3. Post-Development HydroCAD Model Analysis (TP-40) ................................................... 14 Appendix 4. Post-Development HydroCAD Model Analysis (Atlas-14) ............................................... 15 Appendix 5. Water Quality Calculations (MIDS) ................................................................................. 16 Appendix 6. Operations and Maintenance Plan ................................................................................. 17 Christian Brothers Automotive - Stormwater Report Page 4 Chanhassen, MN 1.0 Introduction The proposed development consists of a new ±5,100 square foot automotive repair building, parking lot, associated utilities, and an underground and surface stormwater management BMPs. The 0.80- acre site is located at 8941 Crossroads Boulevard in Chanhassen, MN, and is part of the Crossroads of Chanhassen planned unit development. The Site is subject to the requirements of the Riley-Purgatory- Bluff Creek Watershed District (furthermore referred to as RPBCWD). This report is to provide information for the pre-development drainage conditions, the post-development drainage conditions, and the stormwater management system(s) designed to meet the RPBCWD storm water requirements for the proposed development. Kimley-Horn has analyzed the drainage conditions of the site and provides computations for applicable RPBCWD stormwater requirements in this report. The analysis of the pre-development and post- development drainage models was completed using HydroCAD, Version 10.00, a computer aided design system for modeling the hydrology and hydraulics of stormwater runoff. These calculations are largely based on the hydrology techniques developed by the Soil Conservation Service (SCS/NRCS), combined with other hydrology and hydraulics calculations. All calculations, hydrographs, and drainage area maps are provided in the appendix of this report. 2.0 Pre-development Conditions The existing site consists of a vacant grass area, with slopes of 1% to 4% encompassing much of the Site. Although a Geotechnical report has not been completed for this site, soil conditions referenced from the USDA NRCS Web Soil Survey outline a large majority of the site being encompassed by sandy loam and loamy sand from the surface to a depth of at least 6’ below finished grade. Based on this data, an infiltration rate of 0.80 in/hr is assumed for design calculations. In the existing conditions, stormwater from the northeastern portion of the site (V-DA-2) flows to an existing inlet to the north of the site along an internal road for the overall development and is conveyed to the public storm sewer system. The western and northwestern portion of the Site (V-DA-1 and V- DA-3) flows west to Crossroads Boulevard, a paved public street. Stormwater from the eastern and southern portion of the site (V-DA-4) flows to an existing area drain inlet on the south portion of the site and connects to the existing public underground stormwater system offsite. A summary of the pervious and impervious coverage for existing conditions is included below: • Drainage Area = 0.80 acres o Existing Pervious Area = 0.79 acres (99%) o Existing Impervious Area = 0.01 acres (1%) o Weighted Curve Number (CN) = 61 3.0 Post-development Conditions The proposed development consists of an approximately 5,100 sf commercial building, concrete parking lot, utilities, underground and above-ground stormwater management areas, and landscaping. Site improvements will maintain existing drainage patterns. Christian Brothers Automotive - Stormwater Report Page 5 Chanhassen, MN Stormwater runoff from a portion of the roof and majority of the paved parking surface will discharge to a proposed underground stormwater infiltration system, BMP #2. The underground stormwater infiltration system is proposed to be perforated 36” pipe. Overflow from this BMP is routed to the existing underground storm sewer network. Stormwater runoff from the western portion of the roof will discharge to an infiltration basin (BMP #1) on the west side of the proposed building. Overflow from this BMP is routed to an existing catch basin within Crossroads Boulevard. A summary of the pervious and impervious coverage for proposed conditions is included below. • Drainage Area = 0.80 acres o Proposed Pervious Area = 0.25 acres (31%) o Proposed Impervious Area = 0.55 acres (69%) o Weighted Curve Number (CN) = 87 4.0 Rate Attenuation Summary The Riley-Purgatory-Bluff Creek Watershed District requires that sites limit peak flow rates from the site in the 2-, 10-, and 100-year, 24-hour nested rainfall events and the 100-year, 10-day snowmelt event using Atlas 14 precipitation depths and storm distributions. In addition to City requirements, the site must maintain existing drainage patterns including volume and rate of existing runoff. The proposed development achieves this requirement as outlined in the table below: Table 1: Rate Attenuation – Atlas 14 Table 2: Rate Attenuation – TP-40 2 Year (2.84 in.) 10 Year (4.20 in.) 100 Year (7.18 in.) 100 Year, 10-day Snow Melt Event (7.30 in.) Rate Attenuation Summary – Total Site Pre-Development Rate (CFS) 0.23 1.04 3.69 1.08 Post-Development Rate (CFS) 0.13 0.33 2.41 0.22 Rate Attenuation Summary – Existing Onsite Inlet Pre-Development Rate (CFS) 0.09 0.41 1.40 0.36 Post-Development Rate (CFS) 0.02 0.08 0.26 0.06 2 Year (2.75 in.) 10 Year (4.20 in.) 100 Year (5.95 in.) 100 Year, 10-day Snow Melt Event (5.95 in.) Rate Attenuation Summary – Total Site Pre-Development Rate (CFS) 0.20 1.07 2.51 0.88 Post-Development Rate (CFS) 0.12 0.34 0.65 0.18 Rate Attenuation Summary – Existing Onsite Inlet Pre-Development Rate (CFS) 0.08 0.41 0.95 0.30 Post-Development Rate (CFS) 0.01 0.08 0.18 0.05 Christian Brothers Automotive - Stormwater Report Page 6 Chanhassen, MN Stormwater drainage from the proposed development flows via public storm sewer system to an existing MNDOT facility downstream within the MNDOT right-of-way at the corner of Crossroads Blvd. and MN 101. It is our understanding the existing MnDOT drainage facility was originally designed utilizing Technical Paper-40 rainfall data administered by the National Oceanic and Atmospheric Administration. The pre-development runoff rate utilizing TP-40 rainfall intensity data, as shown in Table 2 above, shows the existing runoff rate from the site is 2.51 CFS. The post- development condition is assessed using the Atlas-14 distribution, where the 100-year rainfall event for the total site is 2.41 CFS. The proposed post-development runoff rate utilizing the TP-40 rainfall intensity data yields a runoff rate of 0.65 CFS, which is lower than the existing MNDOT drainage facility was designed for. The proposed runoff rate utilizing the Atlas-14 analysis, as well as the TP- 40, is lower than the existing conditions TP-40 runoff rates, as shown above. 5.0 Volume Reduction Summary The Riley-Purgatory-Bluff Creek Watershed District requires applicants provide onsite retention of 1.1 inches over the proposed impervious surface of the Site. Based on the proposed plans the required onsite retention is met based on the following: Table 3: Volume Reduction Proposed Impervious Area (Reconstructed and New) 0.55 AC Treatment Depth Required 1.1 Inches Required Infiltration Volume 2,196 CF Provided Infiltration Volume BMP #1: 2,470 CF BMP #2: 5,669 CF 8,139 CF TOTAL 6.0 Water Quality Summary The Riley-Purgatory-Bluff Creek Watershed District requires removal of 60% of the total phosphorus (TP) and 90% of the total suspended solids (TSS). Watershed requirements will be achieved through the use of infiltration in BMP #1 and BMP #2. All BMPs systems are required to provide water quality volume below the lowest flow outlet and provide draw down within 48 hours. An infiltration rate of 0.8 in/hr was used per the USDA Web Soil Survey information and Minnesota Stormwater Manual recommendations. Based on this infiltration rate, the maximum allowable infiltration for these systems is based on a ponding depth of 3.2 feet above the bottom of the system. BMP #1 proposes a ponding depth of 1.70 feet, which is within the required limit. BMP #2 proposed a ponding depth of 2.60 feet, which is within the required limit. In addition to Results of the Minimal Impact Design Standards (MIDS) analysis for the site is shown in the Summary below. These results show that BMP #1 and BMP#2 increase the site’s removal efficiency of TP and TSS when compared to existing conditions, which is consistent with requirements of the RPBC Watershed District. A full analysis is provided in Appendix 3. Water Quality Calculations. Christian Brothers Automotive - Stormwater Report Page 7 Chanhassen, MN Minimal Impact Design Standards (MIDS) Summary: Christian Brothers Automotive - Stormwater Report Page 8 Chanhassen, MN Exhibits Christian Brothers Automotive - Stormwater Report Page 9 Chanhassen, MN Exhibit 1. Existing Drainage Exhibit 9 2 3 924922922922 923924922921 921921922 922 922 922 923 922V-DA-3 3.19% 3.99% 1.89 % 1.8 0 % 2 . 1 9%3.49%1.44%2.64%1.34%2 .99%3.28%2.35 %1.17%0.9 5 %CROSSROADS BOULEVARDV-DA-4 V-DA-2 V-DA-1 WATER FROM THE SITE DRAINS VIA SURFACE SHEET FLOW TO THE EXISTING PUBLIC STORM SEWER SYSTEM, WHICH FLOWS NORTH AND EAST TO PUBLIC STORM SEWER SYSTEM AT THE INTERSECTION OF MN-101 AND CROSSROADS BOULEVARD AND EVENTUALLY TO LAKE RILEY SOUTHEAST OF THE SITE This document, together with the concepts and designs presented herein, as an instrument of service, is intended only for the specific purpose and client for which it was prepared. Reuse of and improper reliance on this document without written authorization and adaptation by Kimley-Horn and Associates, Inc. shall be without liability to Kimley-Horn and Associates, Inc.SHEET NUMBER 2020 KIMLEY-HORN AND ASSOCIATES, INC.767 EUSTIS STREET, SUITE 100, ST. PAUL, MN 55114PHONE: 651-645-4197WWW.KIMLEY-HORN.COMK:\TWC_LDEV\CHRISTIAN BROTHERS AUTOMOTIVE\Chanhassen, MN\3 Design\Drainage\CAD\2020-0804 - Existing Drainage Exhibit.dwg October 26, 2020 - 8:11pm©BYREVISIONSNo.DATE1CITY COMMENTS10/16/2020CJJPRELIMINARY - NOT FOR CONSTRUCTIONDATECHECKED BYSCALEDESIGNED BYDRAWN BYKHA PROJECT16068400510/16/2020AS SHOWNCJJKAMBRENORTH PROPERTY LINE EXISTING CONTOUR LEGEND 0.0%EXISTING DRAINAGE DIRECTION PREPARED FOREXISTINGDRAINAGE AREASEXHIBITEX-18941 CROSSROADSBLVDCHRISTIAN BROTHERSAUTOMOTIVECHANHASSENMNEXISTING DRAINAGE AREA DELINEATION Christian Brothers Automotive - Stormwater Report Page 10 Chanhassen, MN Exhibit 2. Proposed Drainage Exhibit CROSSROADS BOULEVARDCROSSROADS BOULEVARD9 2 3 924922922922 923924922 921 921921 922 922 922 922 923 9222.1 0 % 1.87 % 2. 7 1 % 1.90%2.05%1.03% 1.78 % 1.86% 2. 5 9 %3.02%7.99%10.22%3.15%1.44 %4.34%1.19%6.38%C-DA-3 C-DA-1C-DA-2 C-DA-4 C-DA-5 C-DA-6 923 923 921 922922922 923923922 920921922922D BP-1: STORMWATER INFILTRATION BASIN BOTTOM OF BASIN: 919.50 TOP OF BASIN: 921.50 100-YR HWL: 920.78 TOTAL STORAGE VOLUME: 3,159 CF TREATMENT VOLUME: 2,470 CF BMP 2: UNDERGROUND INFILTRATION SYSTEM ADS 36" N-12 PERFORATED HDPE PIPE OR APPROVED EQUAL TOTAL STORAGE VOLUME: 6,420 CF TREATMENT VOLUME: 5,669 CF TOP OF PIPE: 918.90 PIPE INV.: 915.90 BOTTOM OF STONE: 915.40 100-YR HWL: 918.80 8.86% WATER FROM THE SITE DRAINS VIA SURFACE SHEET FLOW TO THE EXISTING PUBLIC STORM SEWER SYSTEM, WHICH FLOWS NORTH AND EAST TO PUBLIC STORM SEWER SYSTEM AT THE INTERSECTION OF MN-101 AND CROSSROADS BOULEVARD AND EVENTUALLY TO LAKE RILEY SOUTHEAST OF THE SITE EXISTING STORM SEWER This document, together with the concepts and designs presented herein, as an instrument of service, is intended only for the specific purpose and client for which it was prepared. Reuse of and improper reliance on this document without written authorization and adaptation by Kimley-Horn and Associates, Inc. shall be without liability to Kimley-Horn and Associates, Inc.SHEET NUMBER 2020 KIMLEY-HORN AND ASSOCIATES, INC.767 EUSTIS STREET, SUITE 100, ST. PAUL, MN 55114PHONE: 651-645-4197WWW.KIMLEY-HORN.COMK:\TWC_LDEV\CHRISTIAN BROTHERS AUTOMOTIVE\Chanhassen, MN\3 Design\Drainage\CAD\2020-0804 - Proposed Drainage Exhibit.dwg October 26, 2020 - 9:15pm©BYREVISIONSNo.DATE1CITY COMMENTS10/16/2020CJJPRELIMINARY - NOT FOR CONSTRUCTIONNORTH PROPERTY LINE LEGEND PROPOSED MANHOLE PROPOSED CATCH BASIN PROPOSED STORM SEWER EXISTING CONTOUR PROPOSED CONTOUR925 EXISTING MANHOLE EXISTING STORM SEWER EXISTING CATCH BASIN DRAINAGE AREA DELINEATION PROPOSED HEAVY DUTY CONCRETE PAVEMENT PROPOSED STORMWATER MANAGEMENT AREA PROPOSED CONCRETE SIDEWALK PROPOSED STANDARD DUTY CONCRETE PAVEMENT PREPARED FORPROPOSEDDRAINAGE AREASEXHIBITEX-28941 CROSSROADSBLVDCHRISTIAN BROTHERSAUTOMOTIVECHANHASSENMNDATECHECKED BYSCALEDESIGNED BYDRAWN BYKHA PROJECT16068400510/16/2020AS SHOWNCJJKAMBRE0.0%PROPOSED DRAINAGE DIRECTION Christian Brothers Automotive - Stormwater Report Page 11 Chanhassen, MN Appendices Christian Brothers Automotive - Stormwater Report Page 12 Chanhassen, MN Appendix 1. Pre-Development HydroCAD Model Analysis (TP-40) 1S V-DA-1 2S V-DA-3 3S V-DA-4 6S V-DA-2 4R TOTAL SITE 9R EX ONSITE INLET Routing Diagram for CBA Chanhassen Ex Cond_TP-40_Rainfall Prepared by Kimley-Horn and Associates, Printed 10/25/2020 HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Subcat Reach Pond Link CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 2HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.889 61 >75% Grass cover, Good, HSG B (1S, 2S, 3S, 6S) 0.889 61 TOTAL AREA CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 3HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 0.889 HSG B 1S, 2S, 3S, 6S 0.000 HSG C 0.000 HSG D 0.000 Other 0.889 TOTAL AREA CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 4HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.889 0.000 0.000 0.000 0.889 >75% Grass cover, Good 1S, 2S, 3S, 6S 0.000 0.889 0.000 0.000 0.000 0.889 TOTAL AREA Type II 24-hr 2-Year Rainfall=2.75"CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 5HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Time span=1.00-72.00 hrs, dt=0.05 hrs, 1421 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=0.097 ac 0.00% Impervious Runoff Depth=0.28"Subcatchment 1S: V-DA-1 Flow Length=70' Slope=0.0200 '/' Tc=7.8 min CN=61 Runoff=0.03 cfs 0.002 af Runoff Area=0.326 ac 0.00% Impervious Runoff Depth=0.28"Subcatchment 2S: V-DA-3 Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=61 Runoff=0.06 cfs 0.007 af Runoff Area=0.297 ac 0.00% Impervious Runoff Depth=0.28"Subcatchment 3S: V-DA-4 Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 Runoff=0.08 cfs 0.007 af Runoff Area=0.169 ac 0.00% Impervious Runoff Depth=0.28"Subcatchment 6S: V-DA-2 Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 Runoff=0.04 cfs 0.004 af Inflow=0.20 cfs 0.020 afReach 4R: TOTAL SITE Outflow=0.20 cfs 0.020 af Inflow=0.08 cfs 0.007 afReach 9R: EX ONSITE INLET Outflow=0.08 cfs 0.007 af Total Runoff Area = 0.889 ac Runoff Volume = 0.020 af Average Runoff Depth = 0.28" 100.00% Pervious = 0.889 ac 0.00% Impervious = 0.000 ac Type II 24-hr 2-Year Rainfall=2.75"CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 6HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: V-DA-1 Runoff = 0.03 cfs @ 12.04 hrs, Volume= 0.002 af, Depth= 0.28" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 2-Year Rainfall=2.75" Area (ac) CN Description 0.097 61 >75% Grass cover, Good, HSG B 0.097 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.8 70 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 1S: V-DA-1 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.028 0.026 0.024 0.022 0.02 0.018 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0 Type II 24-hr 2-Year Rainfall=2.75" Runoff Area=0.097 ac Runoff Volume=0.002 af Runoff Depth=0.28" Flow Length=70' Slope=0.0200 '/' Tc=7.8 min CN=61 0.03 cfs Type II 24-hr 2-Year Rainfall=2.75"CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 7HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: V-DA-3 Runoff = 0.06 cfs @ 12.11 hrs, Volume= 0.007 af, Depth= 0.28" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 2-Year Rainfall=2.75" Area (ac) CN Description 0.326 61 >75% Grass cover, Good, HSG B 0.326 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.6 140 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 2S: V-DA-3 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Type II 24-hr 2-Year Rainfall=2.75" Runoff Area=0.326 ac Runoff Volume=0.007 af Runoff Depth=0.28" Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=61 0.06 cfs Type II 24-hr 2-Year Rainfall=2.75"CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 8HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: V-DA-4 Runoff = 0.08 cfs @ 12.04 hrs, Volume= 0.007 af, Depth= 0.28" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 2-Year Rainfall=2.75" Area (ac) CN Description 0.297 61 >75% Grass cover, Good, HSG B 0.297 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.9 100 0.0400 0.21 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 3S: V-DA-4 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Type II 24-hr 2-Year Rainfall=2.75" Runoff Area=0.297 ac Runoff Volume=0.007 af Runoff Depth=0.28" Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 0.08 cfs Type II 24-hr 2-Year Rainfall=2.75"CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 9HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: V-DA-2 Runoff = 0.04 cfs @ 12.04 hrs, Volume= 0.004 af, Depth= 0.28" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 2-Year Rainfall=2.75" Area (ac) CN Description 0.169 61 >75% Grass cover, Good, HSG B 0.169 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.9 100 0.0400 0.21 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 6S: V-DA-2 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.048 0.046 0.044 0.042 0.04 0.038 0.036 0.034 0.032 0.03 0.028 0.026 0.024 0.022 0.02 0.018 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0 Type II 24-hr 2-Year Rainfall=2.75" Runoff Area=0.169 ac Runoff Volume=0.004 af Runoff Depth=0.28" Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 0.04 cfs Type II 24-hr 2-Year Rainfall=2.75"CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 10HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 4R: TOTAL SITE [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.889 ac, 0.00% Impervious, Inflow Depth = 0.28" for 2-Year event Inflow = 0.20 cfs @ 12.05 hrs, Volume= 0.020 af Outflow = 0.20 cfs @ 12.05 hrs, Volume= 0.020 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 4R: TOTAL SITE Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=0.889 ac 0.20 cfs 0.20 cfs Type II 24-hr 2-Year Rainfall=2.75"CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 11HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 9R: EX ONSITE INLET [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.297 ac, 0.00% Impervious, Inflow Depth = 0.28" for 2-Year event Inflow = 0.08 cfs @ 12.04 hrs, Volume= 0.007 af Outflow = 0.08 cfs @ 12.04 hrs, Volume= 0.007 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 9R: EX ONSITE INLET Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Inflow Area=0.297 ac 0.08 cfs 0.08 cfs Type II 24-hr 10-Year Rainfall=4.20"CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 12HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Time span=1.00-72.00 hrs, dt=0.05 hrs, 1421 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=0.097 ac 0.00% Impervious Runoff Depth=0.92"Subcatchment 1S: V-DA-1 Flow Length=70' Slope=0.0200 '/' Tc=7.8 min CN=61 Runoff=0.13 cfs 0.007 af Runoff Area=0.326 ac 0.00% Impervious Runoff Depth=0.92"Subcatchment 2S: V-DA-3 Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=61 Runoff=0.35 cfs 0.025 af Runoff Area=0.297 ac 0.00% Impervious Runoff Depth=0.92"Subcatchment 3S: V-DA-4 Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 Runoff=0.41 cfs 0.023 af Runoff Area=0.169 ac 0.00% Impervious Runoff Depth=0.92"Subcatchment 6S: V-DA-2 Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 Runoff=0.23 cfs 0.013 af Inflow=1.07 cfs 0.068 afReach 4R: TOTAL SITE Outflow=1.07 cfs 0.068 af Inflow=0.41 cfs 0.023 afReach 9R: EX ONSITE INLET Outflow=0.41 cfs 0.023 af Total Runoff Area = 0.889 ac Runoff Volume = 0.068 af Average Runoff Depth = 0.92" 100.00% Pervious = 0.889 ac 0.00% Impervious = 0.000 ac Type II 24-hr 10-Year Rainfall=4.20"CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 13HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: V-DA-1 Runoff = 0.13 cfs @ 12.01 hrs, Volume= 0.007 af, Depth= 0.92" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=4.20" Area (ac) CN Description 0.097 61 >75% Grass cover, Good, HSG B 0.097 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.8 70 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 1S: V-DA-1 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr 10-Year Rainfall=4.20" Runoff Area=0.097 ac Runoff Volume=0.007 af Runoff Depth=0.92" Flow Length=70' Slope=0.0200 '/' Tc=7.8 min CN=61 0.13 cfs Type II 24-hr 10-Year Rainfall=4.20"CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 14HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: V-DA-3 Runoff = 0.35 cfs @ 12.08 hrs, Volume= 0.025 af, Depth= 0.92" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=4.20" Area (ac) CN Description 0.326 61 >75% Grass cover, Good, HSG B 0.326 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.6 140 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 2S: V-DA-3 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr 10-Year Rainfall=4.20" Runoff Area=0.326 ac Runoff Volume=0.025 af Runoff Depth=0.92" Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=61 0.35 cfs Type II 24-hr 10-Year Rainfall=4.20"CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 15HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: V-DA-4 Runoff = 0.41 cfs @ 12.01 hrs, Volume= 0.023 af, Depth= 0.92" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=4.20" Area (ac) CN Description 0.297 61 >75% Grass cover, Good, HSG B 0.297 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.9 100 0.0400 0.21 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 3S: V-DA-4 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr 10-Year Rainfall=4.20" Runoff Area=0.297 ac Runoff Volume=0.023 af Runoff Depth=0.92" Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 0.41 cfs Type II 24-hr 10-Year Rainfall=4.20"CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 16HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: V-DA-2 Runoff = 0.23 cfs @ 12.01 hrs, Volume= 0.013 af, Depth= 0.92" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=4.20" Area (ac) CN Description 0.169 61 >75% Grass cover, Good, HSG B 0.169 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.9 100 0.0400 0.21 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 6S: V-DA-2 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.26 0.25 0.24 0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr 10-Year Rainfall=4.20" Runoff Area=0.169 ac Runoff Volume=0.013 af Runoff Depth=0.92" Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 0.23 cfs Type II 24-hr 10-Year Rainfall=4.20"CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 17HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 4R: TOTAL SITE [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.889 ac, 0.00% Impervious, Inflow Depth = 0.92" for 10-Year event Inflow = 1.07 cfs @ 12.02 hrs, Volume= 0.068 af Outflow = 1.07 cfs @ 12.02 hrs, Volume= 0.068 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 4R: TOTAL SITE Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)1 0 Inflow Area=0.889 ac 1.07 cfs 1.07 cfs Type II 24-hr 10-Year Rainfall=4.20"CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 18HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 9R: EX ONSITE INLET [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.297 ac, 0.00% Impervious, Inflow Depth = 0.92" for 10-Year event Inflow = 0.41 cfs @ 12.01 hrs, Volume= 0.023 af Outflow = 0.41 cfs @ 12.01 hrs, Volume= 0.023 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 9R: EX ONSITE INLET Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.297 ac 0.41 cfs 0.41 cfs Type II 24-hr 100-Year Rainfall=5.95"CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 19HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Time span=1.00-72.00 hrs, dt=0.05 hrs, 1421 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=0.097 ac 0.00% Impervious Runoff Depth=1.97"Subcatchment 1S: V-DA-1 Flow Length=70' Slope=0.0200 '/' Tc=7.8 min CN=61 Runoff=0.31 cfs 0.016 af Runoff Area=0.326 ac 0.00% Impervious Runoff Depth=1.97"Subcatchment 2S: V-DA-3 Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=61 Runoff=0.84 cfs 0.054 af Runoff Area=0.297 ac 0.00% Impervious Runoff Depth=1.97"Subcatchment 3S: V-DA-4 Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 Runoff=0.95 cfs 0.049 af Runoff Area=0.169 ac 0.00% Impervious Runoff Depth=1.97"Subcatchment 6S: V-DA-2 Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 Runoff=0.54 cfs 0.028 af Inflow=2.51 cfs 0.146 afReach 4R: TOTAL SITE Outflow=2.51 cfs 0.146 af Inflow=0.95 cfs 0.049 afReach 9R: EX ONSITE INLET Outflow=0.95 cfs 0.049 af Total Runoff Area = 0.889 ac Runoff Volume = 0.146 af Average Runoff Depth = 1.97" 100.00% Pervious = 0.889 ac 0.00% Impervious = 0.000 ac Type II 24-hr 100-Year Rainfall=5.95"CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 20HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: V-DA-1 Runoff = 0.31 cfs @ 12.00 hrs, Volume= 0.016 af, Depth= 1.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=5.95" Area (ac) CN Description 0.097 61 >75% Grass cover, Good, HSG B 0.097 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.8 70 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 1S: V-DA-1 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr 100-Year Rainfall=5.95" Runoff Area=0.097 ac Runoff Volume=0.016 af Runoff Depth=1.97" Flow Length=70' Slope=0.0200 '/' Tc=7.8 min CN=61 0.31 cfs Type II 24-hr 100-Year Rainfall=5.95"CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 21HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: V-DA-3 Runoff = 0.84 cfs @ 12.07 hrs, Volume= 0.054 af, Depth= 1.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=5.95" Area (ac) CN Description 0.326 61 >75% Grass cover, Good, HSG B 0.326 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.6 140 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 2S: V-DA-3 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 100-Year Rainfall=5.95" Runoff Area=0.326 ac Runoff Volume=0.054 af Runoff Depth=1.97" Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=61 0.84 cfs Type II 24-hr 100-Year Rainfall=5.95"CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 22HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: V-DA-4 Runoff = 0.95 cfs @ 12.00 hrs, Volume= 0.049 af, Depth= 1.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=5.95" Area (ac) CN Description 0.297 61 >75% Grass cover, Good, HSG B 0.297 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.9 100 0.0400 0.21 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 3S: V-DA-4 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)1 0 Type II 24-hr 100-Year Rainfall=5.95" Runoff Area=0.297 ac Runoff Volume=0.049 af Runoff Depth=1.97" Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 0.95 cfs Type II 24-hr 100-Year Rainfall=5.95"CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 23HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: V-DA-2 Runoff = 0.54 cfs @ 12.00 hrs, Volume= 0.028 af, Depth= 1.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=5.95" Area (ac) CN Description 0.169 61 >75% Grass cover, Good, HSG B 0.169 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.9 100 0.0400 0.21 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 6S: V-DA-2 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 100-Year Rainfall=5.95" Runoff Area=0.169 ac Runoff Volume=0.028 af Runoff Depth=1.97" Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 0.54 cfs Type II 24-hr 100-Year Rainfall=5.95"CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 24HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 4R: TOTAL SITE [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.889 ac, 0.00% Impervious, Inflow Depth = 1.97" for 100-Year event Inflow = 2.51 cfs @ 12.01 hrs, Volume= 0.146 af Outflow = 2.51 cfs @ 12.01 hrs, Volume= 0.146 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 4R: TOTAL SITE Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)2 1 0 Inflow Area=0.889 ac 2.51 cfs 2.51 cfs Type II 24-hr 100-Year Rainfall=5.95"CBA Chanhassen Ex Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 25HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 9R: EX ONSITE INLET [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.297 ac, 0.00% Impervious, Inflow Depth = 1.97" for 100-Year event Inflow = 0.95 cfs @ 12.00 hrs, Volume= 0.049 af Outflow = 0.95 cfs @ 12.00 hrs, Volume= 0.049 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 9R: EX ONSITE INLET Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)1 0 Inflow Area=0.297 ac 0.95 cfs 0.95 cfs 1S V-DA-1 2S V-DA-3 3S V-DA-4 6S V-DA-2 4R TOTAL SITE 9R EX ONSITE INLET Routing Diagram for CBA Chanhassen Ex Cond_TP-40_10 Day Snow Melt Prepared by Kimley-Horn and Associates, Printed 10/25/2020 HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Subcat Reach Pond Link CBA Chanhassen Ex Cond_TP-40_10 Day Snow Melt Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 2HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.889 100 >75% Grass cover, Good, HSG B (1S, 2S, 3S, 6S) 0.889 100 TOTAL AREA CBA Chanhassen Ex Cond_TP-40_10 Day Snow Melt Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 3HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 0.889 HSG B 1S, 2S, 3S, 6S 0.000 HSG C 0.000 HSG D 0.000 Other 0.889 TOTAL AREA CBA Chanhassen Ex Cond_TP-40_10 Day Snow Melt Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 4HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.889 0.000 0.000 0.000 0.889 >75% Grass cover, Good 1S, 2S, 3S, 6S 0.000 0.889 0.000 0.000 0.000 0.889 TOTAL AREA Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4CBA Chanhassen Ex Cond_TP-40_10 Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 5HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Time span=1.00-240.00 hrs, dt=0.01 hrs, 23901 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=0.097 ac 100.00% Impervious Runoff Depth>5.94"Subcatchment 1S: V-DA-1 Flow Length=70' Slope=0.0200 '/' Tc=7.8 min CN=100 Runoff=0.10 cfs 0.048 af Runoff Area=0.326 ac 100.00% Impervious Runoff Depth>5.94"Subcatchment 2S: V-DA-3 Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=100 Runoff=0.32 cfs 0.161 af Runoff Area=0.297 ac 100.00% Impervious Runoff Depth>5.94"Subcatchment 3S: V-DA-4 Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=100 Runoff=0.30 cfs 0.147 af Runoff Area=0.169 ac 100.00% Impervious Runoff Depth>5.94"Subcatchment 6S: V-DA-2 Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=100 Runoff=0.17 cfs 0.084 af Inflow=0.88 cfs 0.440 afReach 4R: TOTAL SITE Outflow=0.88 cfs 0.440 af Inflow=0.30 cfs 0.147 afReach 9R: EX ONSITE INLET Outflow=0.30 cfs 0.147 af Total Runoff Area = 0.889 ac Runoff Volume = 0.440 af Average Runoff Depth = 5.94" 0.00% Pervious = 0.000 ac 100.00% Impervious = 0.889 ac Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4CBA Chanhassen Ex Cond_TP-40_10 Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 6HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: V-DA-1 Runoff = 0.10 cfs @ 119.09 hrs, Volume= 0.048 af, Depth> 5.94" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4 Area (ac) CN Description * 0.097 100 >75% Grass cover, Good, HSG B 0.097 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.8 70 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 1S: V-DA-1 Runoff Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.105 0.1 0.095 0.09 0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Type II 24-hr 240.00 hrs Custom Rainfall=5.95" AMC=4 Runoff Area=0.097 ac Runoff Volume=0.048 af Runoff Depth>5.94" Flow Length=70' Slope=0.0200 '/' Tc=7.8 min CN=100 0.10 cfs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4CBA Chanhassen Ex Cond_TP-40_10 Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 7HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: V-DA-3 Runoff = 0.32 cfs @ 119.15 hrs, Volume= 0.161 af, Depth> 5.94" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4 Area (ac) CN Description * 0.326 100 >75% Grass cover, Good, HSG B 0.326 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.6 140 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 2S: V-DA-3 Runoff Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr 240.00 hrs Custom Rainfall=5.95" AMC=4 Runoff Area=0.326 ac Runoff Volume=0.161 af Runoff Depth>5.94" Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=100 0.32 cfs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4CBA Chanhassen Ex Cond_TP-40_10 Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 8HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: V-DA-4 Runoff = 0.30 cfs @ 119.09 hrs, Volume= 0.147 af, Depth> 5.94" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4 Area (ac) CN Description * 0.297 100 >75% Grass cover, Good, HSG B 0.297 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.9 100 0.0400 0.21 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 3S: V-DA-4 Runoff Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr 240.00 hrs Custom Rainfall=5.95" AMC=4 Runoff Area=0.297 ac Runoff Volume=0.147 af Runoff Depth>5.94" Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=100 0.30 cfs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4CBA Chanhassen Ex Cond_TP-40_10 Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 9HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: V-DA-2 Runoff = 0.17 cfs @ 119.09 hrs, Volume= 0.084 af, Depth> 5.94" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4 Area (ac) CN Description * 0.169 100 >75% Grass cover, Good, HSG B 0.169 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.9 100 0.0400 0.21 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 6S: V-DA-2 Runoff Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr 240.00 hrs Custom Rainfall=5.95" AMC=4 Runoff Area=0.169 ac Runoff Volume=0.084 af Runoff Depth>5.94" Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=100 0.17 cfs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4CBA Chanhassen Ex Cond_TP-40_10 Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 10HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 4R: TOTAL SITE [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.889 ac,100.00% Impervious, Inflow Depth > 5.94" for Custom event Inflow = 0.88 cfs @ 119.11 hrs, Volume= 0.440 af Outflow = 0.88 cfs @ 119.11 hrs, Volume= 0.440 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs Reach 4R: TOTAL SITE Inflow Outflow Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.95 0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.889 ac 0.88 cfs 0.88 cfs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4CBA Chanhassen Ex Cond_TP-40_10 Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 11HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 9R: EX ONSITE INLET [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.297 ac,100.00% Impervious, Inflow Depth > 5.94" for Custom event Inflow = 0.30 cfs @ 119.09 hrs, Volume= 0.147 af Outflow = 0.30 cfs @ 119.09 hrs, Volume= 0.147 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs Reach 9R: EX ONSITE INLET Inflow Outflow Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.297 ac 0.30 cfs 0.30 cfs Christian Brothers Automotive - Stormwater Report Page 13 Chanhassen, MN Appendix 2. Pre-Development HydroCAD Model Analysis (Atlas-14) 1S V-DA-1 2S V-DA-3 3S V-DA-4 6S V-DA-2 4R TOTAL SITE 9R EX ONSITE INLET Routing Diagram for CBA Chanhassen Ex Cond_Atlas 14_Rainfall Prepared by Kimley-Horn and Associates, Printed 10/25/2020 HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Subcat Reach Pond Link CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 2HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.889 61 >75% Grass cover, Good, HSG B (1S, 2S, 3S, 6S) 0.889 61 TOTAL AREA CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 3HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 0.889 HSG B 1S, 2S, 3S, 6S 0.000 HSG C 0.000 HSG D 0.000 Other 0.889 TOTAL AREA CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 4HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.889 0.000 0.000 0.000 0.889 >75% Grass cover, Good 1S, 2S, 3S, 6S 0.000 0.889 0.000 0.000 0.000 0.889 TOTAL AREA MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 5HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Time span=1.00-72.00 hrs, dt=0.05 hrs, 1421 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=0.097 ac 0.00% Impervious Runoff Depth=0.31"Subcatchment 1S: V-DA-1 Flow Length=70' Slope=0.0200 '/' Tc=7.8 min CN=61 Runoff=0.03 cfs 0.002 af Runoff Area=0.326 ac 0.00% Impervious Runoff Depth=0.31"Subcatchment 2S: V-DA-3 Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=61 Runoff=0.08 cfs 0.008 af Runoff Area=0.297 ac 0.00% Impervious Runoff Depth=0.31"Subcatchment 3S: V-DA-4 Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 Runoff=0.09 cfs 0.008 af Runoff Area=0.169 ac 0.00% Impervious Runoff Depth=0.31"Subcatchment 6S: V-DA-2 Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 Runoff=0.05 cfs 0.004 af Inflow=0.23 cfs 0.023 afReach 4R: TOTAL SITE Outflow=0.23 cfs 0.023 af Inflow=0.09 cfs 0.008 afReach 9R: EX ONSITE INLET Outflow=0.09 cfs 0.008 af Total Runoff Area = 0.889 ac Runoff Volume = 0.023 af Average Runoff Depth = 0.31" 100.00% Pervious = 0.889 ac 0.00% Impervious = 0.000 ac MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 6HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: V-DA-1 Runoff = 0.03 cfs @ 12.20 hrs, Volume= 0.002 af, Depth= 0.31" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 2-Year Rainfall=2.84" Area (ac) CN Description 0.097 61 >75% Grass cover, Good, HSG B 0.097 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.8 70 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 1S: V-DA-1 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.032 0.03 0.028 0.026 0.024 0.022 0.02 0.018 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0 MSE 24-hr 3 2-Year Rainfall=2.84" Runoff Area=0.097 ac Runoff Volume=0.002 af Runoff Depth=0.31" Flow Length=70' Slope=0.0200 '/' Tc=7.8 min CN=61 0.03 cfs MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 7HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: V-DA-3 Runoff = 0.08 cfs @ 12.29 hrs, Volume= 0.008 af, Depth= 0.31" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 2-Year Rainfall=2.84" Area (ac) CN Description 0.326 61 >75% Grass cover, Good, HSG B 0.326 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.6 140 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 2S: V-DA-3 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 MSE 24-hr 3 2-Year Rainfall=2.84" Runoff Area=0.326 ac Runoff Volume=0.008 af Runoff Depth=0.31" Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=61 0.08 cfs MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 8HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: V-DA-4 Runoff = 0.09 cfs @ 12.20 hrs, Volume= 0.008 af, Depth= 0.31" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 2-Year Rainfall=2.84" Area (ac) CN Description 0.297 61 >75% Grass cover, Good, HSG B 0.297 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.9 100 0.0400 0.21 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 3S: V-DA-4 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.1 0.095 0.09 0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 MSE 24-hr 3 2-Year Rainfall=2.84" Runoff Area=0.297 ac Runoff Volume=0.008 af Runoff Depth=0.31" Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 0.09 cfs MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 9HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: V-DA-2 Runoff = 0.05 cfs @ 12.20 hrs, Volume= 0.004 af, Depth= 0.31" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 2-Year Rainfall=2.84" Area (ac) CN Description 0.169 61 >75% Grass cover, Good, HSG B 0.169 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.9 100 0.0400 0.21 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 6S: V-DA-2 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 MSE 24-hr 3 2-Year Rainfall=2.84" Runoff Area=0.169 ac Runoff Volume=0.004 af Runoff Depth=0.31" Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 0.05 cfs MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 10HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 4R: TOTAL SITE [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.889 ac, 0.00% Impervious, Inflow Depth = 0.31" for 2-Year event Inflow = 0.23 cfs @ 12.22 hrs, Volume= 0.023 af Outflow = 0.23 cfs @ 12.22 hrs, Volume= 0.023 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 4R: TOTAL SITE Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.889 ac 0.23 cfs 0.23 cfs MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 11HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 9R: EX ONSITE INLET [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.297 ac, 0.00% Impervious, Inflow Depth = 0.31" for 2-Year event Inflow = 0.09 cfs @ 12.20 hrs, Volume= 0.008 af Outflow = 0.09 cfs @ 12.20 hrs, Volume= 0.008 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 9R: EX ONSITE INLET Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.1 0.095 0.09 0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Inflow Area=0.297 ac 0.09 cfs 0.09 cfs MSE 24-hr 3 10-Year Rainfall=4.20"CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 12HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Time span=1.00-72.00 hrs, dt=0.05 hrs, 1421 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=0.097 ac 0.00% Impervious Runoff Depth=0.92"Subcatchment 1S: V-DA-1 Flow Length=70' Slope=0.0200 '/' Tc=7.8 min CN=61 Runoff=0.13 cfs 0.007 af Runoff Area=0.326 ac 0.00% Impervious Runoff Depth=0.92"Subcatchment 2S: V-DA-3 Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=61 Runoff=0.35 cfs 0.025 af Runoff Area=0.297 ac 0.00% Impervious Runoff Depth=0.92"Subcatchment 3S: V-DA-4 Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 Runoff=0.41 cfs 0.023 af Runoff Area=0.169 ac 0.00% Impervious Runoff Depth=0.92"Subcatchment 6S: V-DA-2 Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 Runoff=0.23 cfs 0.013 af Inflow=1.04 cfs 0.068 afReach 4R: TOTAL SITE Outflow=1.04 cfs 0.068 af Inflow=0.41 cfs 0.023 afReach 9R: EX ONSITE INLET Outflow=0.41 cfs 0.023 af Total Runoff Area = 0.889 ac Runoff Volume = 0.068 af Average Runoff Depth = 0.92" 100.00% Pervious = 0.889 ac 0.00% Impervious = 0.000 ac MSE 24-hr 3 10-Year Rainfall=4.20"CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 13HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: V-DA-1 Runoff = 0.13 cfs @ 12.16 hrs, Volume= 0.007 af, Depth= 0.92" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 10-Year Rainfall=4.20" Area (ac) CN Description 0.097 61 >75% Grass cover, Good, HSG B 0.097 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.8 70 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 1S: V-DA-1 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 MSE 24-hr 3 10-Year Rainfall=4.20" Runoff Area=0.097 ac Runoff Volume=0.007 af Runoff Depth=0.92" Flow Length=70' Slope=0.0200 '/' Tc=7.8 min CN=61 0.13 cfs MSE 24-hr 3 10-Year Rainfall=4.20"CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 14HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: V-DA-3 Runoff = 0.35 cfs @ 12.25 hrs, Volume= 0.025 af, Depth= 0.92" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 10-Year Rainfall=4.20" Area (ac) CN Description 0.326 61 >75% Grass cover, Good, HSG B 0.326 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.6 140 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 2S: V-DA-3 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 MSE 24-hr 3 10-Year Rainfall=4.20" Runoff Area=0.326 ac Runoff Volume=0.025 af Runoff Depth=0.92" Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=61 0.35 cfs MSE 24-hr 3 10-Year Rainfall=4.20"CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 15HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: V-DA-4 Runoff = 0.41 cfs @ 12.17 hrs, Volume= 0.023 af, Depth= 0.92" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 10-Year Rainfall=4.20" Area (ac) CN Description 0.297 61 >75% Grass cover, Good, HSG B 0.297 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.9 100 0.0400 0.21 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 3S: V-DA-4 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 MSE 24-hr 3 10-Year Rainfall=4.20" Runoff Area=0.297 ac Runoff Volume=0.023 af Runoff Depth=0.92" Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 0.41 cfs MSE 24-hr 3 10-Year Rainfall=4.20"CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 16HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: V-DA-2 Runoff = 0.23 cfs @ 12.17 hrs, Volume= 0.013 af, Depth= 0.92" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 10-Year Rainfall=4.20" Area (ac) CN Description 0.169 61 >75% Grass cover, Good, HSG B 0.169 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.9 100 0.0400 0.21 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 6S: V-DA-2 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.26 0.25 0.24 0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 MSE 24-hr 3 10-Year Rainfall=4.20" Runoff Area=0.169 ac Runoff Volume=0.013 af Runoff Depth=0.92" Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 0.23 cfs MSE 24-hr 3 10-Year Rainfall=4.20"CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 17HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 4R: TOTAL SITE [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.889 ac, 0.00% Impervious, Inflow Depth = 0.92" for 10-Year event Inflow = 1.04 cfs @ 12.18 hrs, Volume= 0.068 af Outflow = 1.04 cfs @ 12.18 hrs, Volume= 0.068 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 4R: TOTAL SITE Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)1 0 Inflow Area=0.889 ac 1.04 cfs 1.04 cfs MSE 24-hr 3 10-Year Rainfall=4.20"CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 18HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 9R: EX ONSITE INLET [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.297 ac, 0.00% Impervious, Inflow Depth = 0.92" for 10-Year event Inflow = 0.41 cfs @ 12.17 hrs, Volume= 0.023 af Outflow = 0.41 cfs @ 12.17 hrs, Volume= 0.023 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 9R: EX ONSITE INLET Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.297 ac 0.41 cfs 0.41 cfs MSE 24-hr 3 100-Year Rainfall=7.18"CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 19HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Time span=1.00-72.00 hrs, dt=0.05 hrs, 1421 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=0.097 ac 0.00% Impervious Runoff Depth=2.83"Subcatchment 1S: V-DA-1 Flow Length=70' Slope=0.0200 '/' Tc=7.8 min CN=61 Runoff=0.46 cfs 0.023 af Runoff Area=0.326 ac 0.00% Impervious Runoff Depth=2.83"Subcatchment 2S: V-DA-3 Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=61 Runoff=1.22 cfs 0.077 af Runoff Area=0.297 ac 0.00% Impervious Runoff Depth=2.83"Subcatchment 3S: V-DA-4 Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 Runoff=1.40 cfs 0.070 af Runoff Area=0.169 ac 0.00% Impervious Runoff Depth=2.83"Subcatchment 6S: V-DA-2 Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 Runoff=0.80 cfs 0.040 af Inflow=3.69 cfs 0.210 afReach 4R: TOTAL SITE Outflow=3.69 cfs 0.210 af Inflow=1.40 cfs 0.070 afReach 9R: EX ONSITE INLET Outflow=1.40 cfs 0.070 af Total Runoff Area = 0.889 ac Runoff Volume = 0.210 af Average Runoff Depth = 2.83" 100.00% Pervious = 0.889 ac 0.00% Impervious = 0.000 ac MSE 24-hr 3 100-Year Rainfall=7.18"CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 20HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: V-DA-1 Runoff = 0.46 cfs @ 12.16 hrs, Volume= 0.023 af, Depth= 2.83" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 100-Year Rainfall=7.18" Area (ac) CN Description 0.097 61 >75% Grass cover, Good, HSG B 0.097 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.8 70 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 1S: V-DA-1 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.5 0.48 0.46 0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 MSE 24-hr 3 100-Year Rainfall=7.18" Runoff Area=0.097 ac Runoff Volume=0.023 af Runoff Depth=2.83" Flow Length=70' Slope=0.0200 '/' Tc=7.8 min CN=61 0.46 cfs MSE 24-hr 3 100-Year Rainfall=7.18"CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 21HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: V-DA-3 Runoff = 1.22 cfs @ 12.23 hrs, Volume= 0.077 af, Depth= 2.83" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 100-Year Rainfall=7.18" Area (ac) CN Description 0.326 61 >75% Grass cover, Good, HSG B 0.326 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.6 140 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 2S: V-DA-3 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)1 0 MSE 24-hr 3 100-Year Rainfall=7.18" Runoff Area=0.326 ac Runoff Volume=0.077 af Runoff Depth=2.83" Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=61 1.22 cfs MSE 24-hr 3 100-Year Rainfall=7.18"CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 22HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: V-DA-4 Runoff = 1.40 cfs @ 12.16 hrs, Volume= 0.070 af, Depth= 2.83" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 100-Year Rainfall=7.18" Area (ac) CN Description 0.297 61 >75% Grass cover, Good, HSG B 0.297 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.9 100 0.0400 0.21 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 3S: V-DA-4 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)1 0 MSE 24-hr 3 100-Year Rainfall=7.18" Runoff Area=0.297 ac Runoff Volume=0.070 af Runoff Depth=2.83" Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 1.40 cfs MSE 24-hr 3 100-Year Rainfall=7.18"CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 23HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: V-DA-2 Runoff = 0.80 cfs @ 12.16 hrs, Volume= 0.040 af, Depth= 2.83" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 100-Year Rainfall=7.18" Area (ac) CN Description 0.169 61 >75% Grass cover, Good, HSG B 0.169 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.9 100 0.0400 0.21 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 6S: V-DA-2 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 MSE 24-hr 3 100-Year Rainfall=7.18" Runoff Area=0.169 ac Runoff Volume=0.040 af Runoff Depth=2.83" Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 0.80 cfs MSE 24-hr 3 100-Year Rainfall=7.18"CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 24HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 4R: TOTAL SITE [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.889 ac, 0.00% Impervious, Inflow Depth = 2.83" for 100-Year event Inflow = 3.69 cfs @ 12.17 hrs, Volume= 0.210 af Outflow = 3.69 cfs @ 12.17 hrs, Volume= 0.210 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 4R: TOTAL SITE Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)4 3 2 1 0 Inflow Area=0.889 ac 3.69 cfs 3.69 cfs MSE 24-hr 3 100-Year Rainfall=7.18"CBA Chanhassen Ex Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 25HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 9R: EX ONSITE INLET [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.297 ac, 0.00% Impervious, Inflow Depth = 2.83" for 100-Year event Inflow = 1.40 cfs @ 12.16 hrs, Volume= 0.070 af Outflow = 1.40 cfs @ 12.16 hrs, Volume= 0.070 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 9R: EX ONSITE INLET Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)1 0 Inflow Area=0.297 ac 1.40 cfs 1.40 cfs 1S V-DA-1 2S V-DA-3 3S V-DA-4 6S V-DA-2 4R TOTAL SITE 9R EX ONSITE INLET Routing Diagram for CBA Chanhassen Ex Cond_Atlas 14_10 Day Snow Melt Prepared by Kimley-Horn and Associates, Printed 10/25/2020 HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Subcat Reach Pond Link CBA Chanhassen Ex Cond_Atlas 14_10 Day Snow Melt Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 2HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.889 100 >75% Grass cover, Good, HSG B (1S, 2S, 3S, 6S) 0.889 100 TOTAL AREA CBA Chanhassen Ex Cond_Atlas 14_10 Day Snow Melt Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 3HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 0.889 HSG B 1S, 2S, 3S, 6S 0.000 HSG C 0.000 HSG D 0.000 Other 0.889 TOTAL AREA CBA Chanhassen Ex Cond_Atlas 14_10 Day Snow Melt Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 4HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.889 0.000 0.000 0.000 0.889 >75% Grass cover, Good 1S, 2S, 3S, 6S 0.000 0.889 0.000 0.000 0.000 0.889 TOTAL AREA MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4CBA Chanhassen Ex Cond_Atlas 14_ Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 5HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Time span=1.00-240.00 hrs, dt=0.01 hrs, 23901 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=0.097 ac 100.00% Impervious Runoff Depth>7.30"Subcatchment 1S: V-DA-1 Flow Length=70' Slope=0.0200 '/' Tc=7.8 min CN=100 Runoff=0.12 cfs 0.059 af Runoff Area=0.326 ac 100.00% Impervious Runoff Depth>7.30"Subcatchment 2S: V-DA-3 Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=100 Runoff=0.40 cfs 0.198 af Runoff Area=0.297 ac 100.00% Impervious Runoff Depth>7.30"Subcatchment 3S: V-DA-4 Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=100 Runoff=0.36 cfs 0.181 af Runoff Area=0.169 ac 100.00% Impervious Runoff Depth>7.30"Subcatchment 6S: V-DA-2 Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=100 Runoff=0.20 cfs 0.103 af Inflow=1.08 cfs 0.541 afReach 4R: TOTAL SITE Outflow=1.08 cfs 0.541 af Inflow=0.36 cfs 0.181 afReach 9R: EX ONSITE INLET Outflow=0.36 cfs 0.181 af Total Runoff Area = 0.889 ac Runoff Volume = 0.541 af Average Runoff Depth = 7.30" 0.00% Pervious = 0.000 ac 100.00% Impervious = 0.889 ac MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4CBA Chanhassen Ex Cond_Atlas 14_ Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 6HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: V-DA-1 Runoff = 0.12 cfs @ 120.77 hrs, Volume= 0.059 af, Depth> 7.30" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4 Area (ac) CN Description * 0.097 100 >75% Grass cover, Good, HSG B 0.097 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.8 70 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 1S: V-DA-1 Runoff Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.13 0.125 0.12 0.115 0.11 0.105 0.1 0.095 0.09 0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30" AMC=4 Runoff Area=0.097 ac Runoff Volume=0.059 af Runoff Depth>7.30" Flow Length=70' Slope=0.0200 '/' Tc=7.8 min CN=100 0.12 cfs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4CBA Chanhassen Ex Cond_Atlas 14_ Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 7HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: V-DA-3 Runoff = 0.40 cfs @ 120.78 hrs, Volume= 0.198 af, Depth> 7.30" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4 Area (ac) CN Description * 0.326 100 >75% Grass cover, Good, HSG B 0.326 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.6 140 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 2S: V-DA-3 Runoff Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30" AMC=4 Runoff Area=0.326 ac Runoff Volume=0.198 af Runoff Depth>7.30" Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=100 0.40 cfs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4CBA Chanhassen Ex Cond_Atlas 14_ Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 8HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: V-DA-4 Runoff = 0.36 cfs @ 120.51 hrs, Volume= 0.181 af, Depth> 7.30" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4 Area (ac) CN Description * 0.297 100 >75% Grass cover, Good, HSG B 0.297 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.9 100 0.0400 0.21 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 3S: V-DA-4 Runoff Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30" AMC=4 Runoff Area=0.297 ac Runoff Volume=0.181 af Runoff Depth>7.30" Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=100 0.36 cfs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4CBA Chanhassen Ex Cond_Atlas 14_ Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 9HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: V-DA-2 Runoff = 0.20 cfs @ 120.51 hrs, Volume= 0.103 af, Depth> 7.30" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4 Area (ac) CN Description * 0.169 100 >75% Grass cover, Good, HSG B 0.169 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.9 100 0.0400 0.21 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 6S: V-DA-2 Runoff Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30" AMC=4 Runoff Area=0.169 ac Runoff Volume=0.103 af Runoff Depth>7.30" Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=100 0.20 cfs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4CBA Chanhassen Ex Cond_Atlas 14_ Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 10HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 4R: TOTAL SITE [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.889 ac,100.00% Impervious, Inflow Depth > 7.30" for Custom event Inflow = 1.08 cfs @ 120.81 hrs, Volume= 0.541 af Outflow = 1.08 cfs @ 120.81 hrs, Volume= 0.541 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs Reach 4R: TOTAL SITE Inflow Outflow Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)1 0 Inflow Area=0.889 ac 1.08 cfs 1.08 cfs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4CBA Chanhassen Ex Cond_Atlas 14_ Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 11HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 9R: EX ONSITE INLET [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.297 ac,100.00% Impervious, Inflow Depth > 7.30" for Custom event Inflow = 0.36 cfs @ 120.51 hrs, Volume= 0.181 af Outflow = 0.36 cfs @ 120.51 hrs, Volume= 0.181 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs Reach 9R: EX ONSITE INLET Inflow Outflow Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.297 ac 0.36 cfs 0.36 cfs Christian Brothers Automotive - Stormwater Report Page 14 Chanhassen, MN Appendix 3. Post-Development HydroCAD Model Analysis (TP-40) 1S C-DA-1 2S C-DA-2 3S C-DA-3 7S C-DA-4 8S C-DA-6 9S C-DA-5 8R EX ONSITE INLET 10R TOTAL SITE 6P U/G 36" INFILTRATION 7P INFILTRATION BASIN Routing Diagram for CBA Chanhassen Pr Cond_TP-40_Rainfall Prepared by Kimley-Horn and Associates, Printed 10/25/2020 HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Subcat Reach Pond Link CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 2HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.297 61 >75% Grass cover, Good, HSG B (1S, 2S, 3S, 7S, 8S, 9S) 0.501 98 Paved parking, HSG B (1S, 2S, 7S, 9S) 0.066 98 Roofs, HSG B (3S) 0.864 85 TOTAL AREA CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 3HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 0.864 HSG B 1S, 2S, 3S, 7S, 8S, 9S 0.000 HSG C 0.000 HSG D 0.000 Other 0.864 TOTAL AREA CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 4HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.297 0.000 0.000 0.000 0.297 >75% Grass cover, Good 1S, 2S, 3S, 7S, 8S, 9S 0.000 0.501 0.000 0.000 0.000 0.501 Paved parking 1S, 2S, 7S, 9S 0.000 0.066 0.000 0.000 0.000 0.066 Roofs 3S 0.000 0.864 0.000 0.000 0.000 0.864 TOTAL AREA CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 5HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pipe Listing (all nodes) Line# Node Number In-Invert (feet) Out-Invert (feet) Length (feet) Slope (ft/ft) n Diam/Width (inches) Height (inches) Inside-Fill (inches) 1 6P 915.40 915.05 50.0 0.0070 0.011 12.0 0.0 0.0 2 7P 918.00 917.50 25.0 0.0200 0.012 12.0 0.0 0.0 Type II 24-hr 2-Year Rainfall=2.75"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 6HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Time span=1.00-72.00 hrs, dt=0.05 hrs, 1421 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=0.035 ac 68.57% Impervious Runoff Depth=1.45"Subcatchment 1S: C-DA-1 Flow Length=145' Slope=0.0200 '/' Tc=14.0 min CN=86 Runoff=0.07 cfs 0.004 af Runoff Area=0.060 ac 1.67% Impervious Runoff Depth=0.30"Subcatchment 2S: C-DA-2 Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=62 Runoff=0.01 cfs 0.002 af Runoff Area=0.147 ac 44.90% Impervious Runoff Depth=0.95"Subcatchment 3S: C-DA-3 Tc=7.0 min CN=78 Runoff=0.24 cfs 0.012 af Runoff Area=0.538 ac 86.43% Impervious Runoff Depth=2.02"Subcatchment 7S: C-DA-4 Tc=7.0 min CN=93 Runoff=1.74 cfs 0.090 af Runoff Area=0.053 ac 0.00% Impervious Runoff Depth=0.28"Subcatchment 8S: C-DA-6 Tc=7.0 min CN=61 Runoff=0.01 cfs 0.001 af Runoff Area=0.031 ac 35.48% Impervious Runoff Depth=0.75"Subcatchment 9S: C-DA-5 Tc=7.0 min CN=74 Runoff=0.04 cfs 0.002 af Inflow=0.01 cfs 0.001 afReach 8R: EX ONSITE INLET Outflow=0.01 cfs 0.001 af Inflow=0.12 cfs 0.009 afReach 10R: TOTAL SITE Outflow=0.12 cfs 0.009 af Peak Elev=916.83' Storage=2,070 cf Inflow=1.74 cfs 0.090 afPond 6P: U/G 36" INFILTRATION Discarded=0.06 cfs 0.090 af Primary=0.00 cfs 0.000 af Outflow=0.06 cfs 0.090 af Peak Elev=919.74' Storage=207 cf Inflow=0.24 cfs 0.012 afPond 7P: INFILTRATION BASIN Discarded=0.02 cfs 0.012 af Primary=0.00 cfs 0.000 af Outflow=0.02 cfs 0.012 af Total Runoff Area = 0.864 ac Runoff Volume = 0.111 af Average Runoff Depth = 1.54" 34.37% Pervious = 0.297 ac 65.63% Impervious = 0.567 ac Type II 24-hr 2-Year Rainfall=2.75"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 7HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: C-DA-1 Runoff = 0.07 cfs @ 12.06 hrs, Volume= 0.004 af, Depth= 1.45" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 2-Year Rainfall=2.75" Area (ac) CN Description 0.011 61 >75% Grass cover, Good, HSG B 0.024 98 Paved parking, HSG B 0.035 86 Weighted Average 0.011 31.43% Pervious Area 0.024 68.57% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.0 145 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 1S: C-DA-1 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Type II 24-hr 2-Year Rainfall=2.75" Runoff Area=0.035 ac Runoff Volume=0.004 af Runoff Depth=1.45" Flow Length=145' Slope=0.0200 '/' Tc=14.0 min CN=86 0.07 cfs Type II 24-hr 2-Year Rainfall=2.75"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 8HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: C-DA-2 Runoff = 0.01 cfs @ 12.11 hrs, Volume= 0.002 af, Depth= 0.30" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 2-Year Rainfall=2.75" Area (ac) CN Description 0.059 61 >75% Grass cover, Good, HSG B 0.001 98 Paved parking, HSG B 0.060 62 Weighted Average 0.059 98.33% Pervious Area 0.001 1.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.6 140 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 2S: C-DA-2 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.016 0.015 0.014 0.013 0.012 0.011 0.01 0.009 0.008 0.007 0.006 0.005 0.004 0.003 0.002 0.001 0 Type II 24-hr 2-Year Rainfall=2.75" Runoff Area=0.060 ac Runoff Volume=0.002 af Runoff Depth=0.30" Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=62 0.01 cfs Type II 24-hr 2-Year Rainfall=2.75"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 9HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: C-DA-3 Runoff = 0.24 cfs @ 11.99 hrs, Volume= 0.012 af, Depth= 0.95" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 2-Year Rainfall=2.75" Area (ac) CN Description 0.081 61 >75% Grass cover, Good, HSG B 0.066 98 Roofs, HSG B 0.147 78 Weighted Average 0.081 55.10% Pervious Area 0.066 44.90% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 3S: C-DA-3 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.26 0.25 0.24 0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr 2-Year Rainfall=2.75" Runoff Area=0.147 ac Runoff Volume=0.012 af Runoff Depth=0.95" Tc=7.0 min CN=78 0.24 cfs Type II 24-hr 2-Year Rainfall=2.75"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 10HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 7S: C-DA-4 Runoff = 1.74 cfs @ 11.98 hrs, Volume= 0.090 af, Depth= 2.02" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 2-Year Rainfall=2.75" Area (ac) CN Description 0.073 61 >75% Grass cover, Good, HSG B 0.465 98 Paved parking, HSG B 0.538 93 Weighted Average 0.073 13.57% Pervious Area 0.465 86.43% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 7S: C-DA-4 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)1 0 Type II 24-hr 2-Year Rainfall=2.75" Runoff Area=0.538 ac Runoff Volume=0.090 af Runoff Depth=2.02" Tc=7.0 min CN=93 1.74 cfs Type II 24-hr 2-Year Rainfall=2.75"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 11HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 8S: C-DA-6 Runoff = 0.01 cfs @ 12.02 hrs, Volume= 0.001 af, Depth= 0.28" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 2-Year Rainfall=2.75" Area (ac) CN Description 0.053 61 >75% Grass cover, Good, HSG B 0.053 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 8S: C-DA-6 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.016 0.015 0.014 0.013 0.012 0.011 0.01 0.009 0.008 0.007 0.006 0.005 0.004 0.003 0.002 0.001 0 Type II 24-hr 2-Year Rainfall=2.75" Runoff Area=0.053 ac Runoff Volume=0.001 af Runoff Depth=0.28" Tc=7.0 min CN=61 0.01 cfs Type II 24-hr 2-Year Rainfall=2.75"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 12HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 9S: C-DA-5 Runoff = 0.04 cfs @ 11.99 hrs, Volume= 0.002 af, Depth= 0.75" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 2-Year Rainfall=2.75" Area (ac) CN Description 0.011 98 Paved parking, HSG B 0.020 61 >75% Grass cover, Good, HSG B 0.031 74 Weighted Average 0.020 64.52% Pervious Area 0.011 35.48% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 9S: C-DA-5 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.042 0.04 0.038 0.036 0.034 0.032 0.03 0.028 0.026 0.024 0.022 0.02 0.018 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0 Type II 24-hr 2-Year Rainfall=2.75" Runoff Area=0.031 ac Runoff Volume=0.002 af Runoff Depth=0.75" Tc=7.0 min CN=74 0.04 cfs Type II 24-hr 2-Year Rainfall=2.75"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 13HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 8R: EX ONSITE INLET [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.053 ac, 0.00% Impervious, Inflow Depth = 0.28" for 2-Year event Inflow = 0.01 cfs @ 12.02 hrs, Volume= 0.001 af Outflow = 0.01 cfs @ 12.02 hrs, Volume= 0.001 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 8R: EX ONSITE INLET Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.016 0.015 0.014 0.013 0.012 0.011 0.01 0.009 0.008 0.007 0.006 0.005 0.004 0.003 0.002 0.001 0 Inflow Area=0.053 ac 0.01 cfs 0.01 cfs Type II 24-hr 2-Year Rainfall=2.75"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 14HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 10R: TOTAL SITE [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.864 ac, 65.63% Impervious, Inflow Depth = 0.12" for 2-Year event Inflow = 0.12 cfs @ 12.03 hrs, Volume= 0.009 af Outflow = 0.12 cfs @ 12.03 hrs, Volume= 0.009 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 10R: TOTAL SITE Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=0.864 ac 0.12 cfs 0.12 cfs Type II 24-hr 2-Year Rainfall=2.75"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 15HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Pond 6P: U/G 36" INFILTRATION Inflow Area = 0.538 ac, 86.43% Impervious, Inflow Depth = 2.02" for 2-Year event Inflow = 1.74 cfs @ 11.98 hrs, Volume= 0.090 af Outflow = 0.06 cfs @ 11.15 hrs, Volume= 0.090 af, Atten= 97%, Lag= 0.0 min Discarded = 0.06 cfs @ 11.15 hrs, Volume= 0.090 af Primary = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 916.83' @ 13.85 hrs Surf.Area= 3,154 sf Storage= 2,070 cf Plug-Flow detention time= 334.2 min calculated for 0.090 af (100% of inflow) Center-of-Mass det. time= 334.2 min ( 1,130.0 - 795.8 ) Volume Invert Avail.Storage Storage Description #1A 915.40' 3,692 cf 38.00'W x 83.00'L x 4.50'H Field A 14,193 cf Overall - 4,962 cf Embedded = 9,231 cf x 40.0% Voids #2A 915.90' 3,976 cf ADS N-12 36" x 28 Inside #1 Inside= 36.1"W x 36.1"H => 7.10 sf x 20.00'L = 142.0 cf Outside= 42.0"W x 42.0"H => 8.86 sf x 20.00'L = 177.2 cf 7 Rows of 4 Chambers 7,668 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 915.40'0.800 in/hr Exfiltration over Surface area #2 Device 3 918.50'4.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 #3 Primary 915.40'12.0" Round Culvert L= 50.0' Ke= 0.100 Inlet / Outlet Invert= 915.40' / 915.05' S= 0.0070 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean, Flow Area= 0.79 sf Discarded OutFlow Max=0.06 cfs @ 11.15 hrs HW=915.45' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=0.00 cfs @ 1.00 hrs HW=915.40' (Free Discharge) 3=Culvert ( Controls 0.00 cfs) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type II 24-hr 2-Year Rainfall=2.75"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 16HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 6P: U/G 36" INFILTRATION - Chamber Wizard Field A Chamber Model = ADS N-12 36" (ADS N-12® Pipe) Inside= 36.1"W x 36.1"H => 7.10 sf x 20.00'L = 142.0 cf Outside= 42.0"W x 42.0"H => 8.86 sf x 20.00'L = 177.2 cf 42.0" Wide + 21.0" Spacing = 63.0" C-C Row Spacing 4 Chambers/Row x 20.00' Long = 80.00' Row Length +18.0" End Stone x 2 = 83.00' Base Length 7 Rows x 42.0" Wide + 21.0" Spacing x 6 + 18.0" Side Stone x 2 = 38.00' Base Width 6.0" Base + 42.0" Chamber Height + 6.0" Cover = 4.50' Field Height 28 Chambers x 142.0 cf = 3,976.0 cf Chamber Storage 28 Chambers x 177.2 cf = 4,962.2 cf Displacement 14,193.0 cf Field - 4,962.2 cf Chambers = 9,230.8 cf Stone x 40.0% Voids = 3,692.3 cf Stone Storage Chamber Storage + Stone Storage = 7,668.3 cf = 0.176 af Overall Storage Efficiency = 54.0% Overall System Size = 83.00' x 38.00' x 4.50' 28 Chambers 525.7 cy Field 341.9 cy Stone Type II 24-hr 2-Year Rainfall=2.75"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 17HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 6P: U/G 36" INFILTRATION Inflow Outflow Discarded Primary Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)1 0 Inflow Area=0.538 ac Peak Elev=916.83' Storage=2,070 cf 1.74 cfs 0.06 cfs 0.06 cfs 0.00 cfs Type II 24-hr 2-Year Rainfall=2.75"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 18HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Pond 7P: INFILTRATION BASIN Inflow Area = 0.147 ac, 44.90% Impervious, Inflow Depth = 0.95" for 2-Year event Inflow = 0.24 cfs @ 11.99 hrs, Volume= 0.012 af Outflow = 0.02 cfs @ 12.83 hrs, Volume= 0.012 af, Atten= 93%, Lag= 50.5 min Discarded = 0.02 cfs @ 12.83 hrs, Volume= 0.012 af Primary = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 919.74' @ 12.83 hrs Surf.Area= 954 sf Storage= 207 cf Plug-Flow detention time= 110.2 min calculated for 0.012 af (100% of inflow) Center-of-Mass det. time= 110.2 min ( 965.6 - 855.4 ) Volume Invert Avail.Storage Storage Description #1 919.50' 3,159 cf BASIN WEST (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 919.50 790 255.4 0 0 790 920.50 1,584 274.3 1,164 1,164 1,630 921.50 2,436 293.2 1,995 3,159 2,529 Device Routing Invert Outlet Devices #1 Discarded 919.50'0.800 in/hr Exfiltration over Surface area #2 Device 3 921.20'24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Primary 918.00'12.0" Round Culvert L= 25.0' Ke= 0.100 Inlet / Outlet Invert= 918.00' / 917.50' S= 0.0200 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Discarded OutFlow Max=0.02 cfs @ 12.83 hrs HW=919.74' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max=0.00 cfs @ 1.00 hrs HW=919.50' (Free Discharge) 3=Culvert (Passes 0.00 cfs of 4.74 cfs potential flow) 2=Orifice/Grate ( Controls 0.00 cfs) Type II 24-hr 2-Year Rainfall=2.75"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 19HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 7P: INFILTRATION BASIN Inflow Outflow Discarded Primary Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.147 ac Peak Elev=919.74' Storage=207 cf 0.24 cfs 0.02 cfs 0.02 cfs 0.00 cfs Type II 24-hr 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 20HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Time span=1.00-72.00 hrs, dt=0.05 hrs, 1421 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=0.035 ac 68.57% Impervious Runoff Depth=2.73"Subcatchment 1S: C-DA-1 Flow Length=145' Slope=0.0200 '/' Tc=14.0 min CN=86 Runoff=0.13 cfs 0.008 af Runoff Area=0.060 ac 1.67% Impervious Runoff Depth=0.97"Subcatchment 2S: C-DA-2 Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=62 Runoff=0.07 cfs 0.005 af Runoff Area=0.147 ac 44.90% Impervious Runoff Depth=2.05"Subcatchment 3S: C-DA-3 Tc=7.0 min CN=78 Runoff=0.51 cfs 0.025 af Runoff Area=0.538 ac 86.43% Impervious Runoff Depth=3.41"Subcatchment 7S: C-DA-4 Tc=7.0 min CN=93 Runoff=2.85 cfs 0.153 af Runoff Area=0.053 ac 0.00% Impervious Runoff Depth=0.92"Subcatchment 8S: C-DA-6 Tc=7.0 min CN=61 Runoff=0.08 cfs 0.004 af Runoff Area=0.031 ac 35.48% Impervious Runoff Depth=1.74"Subcatchment 9S: C-DA-5 Tc=7.0 min CN=74 Runoff=0.09 cfs 0.005 af Inflow=0.08 cfs 0.004 afReach 8R: EX ONSITE INLET Outflow=0.08 cfs 0.004 af Inflow=0.34 cfs 0.021 afReach 10R: TOTAL SITE Outflow=0.34 cfs 0.021 af Peak Elev=917.71' Storage=3,978 cf Inflow=2.85 cfs 0.153 afPond 6P: U/G 36" INFILTRATION Discarded=0.06 cfs 0.153 af Primary=0.00 cfs 0.000 af Outflow=0.06 cfs 0.153 af Peak Elev=920.06' Storage=550 cf Inflow=0.51 cfs 0.025 afPond 7P: INFILTRATION BASIN Discarded=0.02 cfs 0.025 af Primary=0.00 cfs 0.000 af Outflow=0.02 cfs 0.025 af Total Runoff Area = 0.864 ac Runoff Volume = 0.200 af Average Runoff Depth = 2.77" 34.37% Pervious = 0.297 ac 65.63% Impervious = 0.567 ac Type II 24-hr 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 21HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: C-DA-1 Runoff = 0.13 cfs @ 12.06 hrs, Volume= 0.008 af, Depth= 2.73" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=4.20" Area (ac) CN Description 0.011 61 >75% Grass cover, Good, HSG B 0.024 98 Paved parking, HSG B 0.035 86 Weighted Average 0.011 31.43% Pervious Area 0.024 68.57% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.0 145 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 1S: C-DA-1 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr 10-Year Rainfall=4.20" Runoff Area=0.035 ac Runoff Volume=0.008 af Runoff Depth=2.73" Flow Length=145' Slope=0.0200 '/' Tc=14.0 min CN=86 0.13 cfs Type II 24-hr 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 22HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: C-DA-2 Runoff = 0.07 cfs @ 12.07 hrs, Volume= 0.005 af, Depth= 0.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=4.20" Area (ac) CN Description 0.059 61 >75% Grass cover, Good, HSG B 0.001 98 Paved parking, HSG B 0.060 62 Weighted Average 0.059 98.33% Pervious Area 0.001 1.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.6 140 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 2S: C-DA-2 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Type II 24-hr 10-Year Rainfall=4.20" Runoff Area=0.060 ac Runoff Volume=0.005 af Runoff Depth=0.97" Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=62 0.07 cfs Type II 24-hr 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 23HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: C-DA-3 Runoff = 0.51 cfs @ 11.99 hrs, Volume= 0.025 af, Depth= 2.05" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=4.20" Area (ac) CN Description 0.081 61 >75% Grass cover, Good, HSG B 0.066 98 Roofs, HSG B 0.147 78 Weighted Average 0.081 55.10% Pervious Area 0.066 44.90% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 3S: C-DA-3 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 10-Year Rainfall=4.20" Runoff Area=0.147 ac Runoff Volume=0.025 af Runoff Depth=2.05" Tc=7.0 min CN=78 0.51 cfs Type II 24-hr 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 24HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 7S: C-DA-4 Runoff = 2.85 cfs @ 11.98 hrs, Volume= 0.153 af, Depth= 3.41" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=4.20" Area (ac) CN Description 0.073 61 >75% Grass cover, Good, HSG B 0.465 98 Paved parking, HSG B 0.538 93 Weighted Average 0.073 13.57% Pervious Area 0.465 86.43% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 7S: C-DA-4 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)3 2 1 0 Type II 24-hr 10-Year Rainfall=4.20" Runoff Area=0.538 ac Runoff Volume=0.153 af Runoff Depth=3.41" Tc=7.0 min CN=93 2.85 cfs Type II 24-hr 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 25HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 8S: C-DA-6 Runoff = 0.08 cfs @ 12.00 hrs, Volume= 0.004 af, Depth= 0.92" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=4.20" Area (ac) CN Description 0.053 61 >75% Grass cover, Good, HSG B 0.053 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 8S: C-DA-6 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Type II 24-hr 10-Year Rainfall=4.20" Runoff Area=0.053 ac Runoff Volume=0.004 af Runoff Depth=0.92" Tc=7.0 min CN=61 0.08 cfs Type II 24-hr 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 26HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 9S: C-DA-5 Runoff = 0.09 cfs @ 11.99 hrs, Volume= 0.005 af, Depth= 1.74" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=4.20" Area (ac) CN Description 0.011 98 Paved parking, HSG B 0.020 61 >75% Grass cover, Good, HSG B 0.031 74 Weighted Average 0.020 64.52% Pervious Area 0.011 35.48% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 9S: C-DA-5 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.1 0.095 0.09 0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Type II 24-hr 10-Year Rainfall=4.20" Runoff Area=0.031 ac Runoff Volume=0.005 af Runoff Depth=1.74" Tc=7.0 min CN=74 0.09 cfs Type II 24-hr 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 27HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 8R: EX ONSITE INLET [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.053 ac, 0.00% Impervious, Inflow Depth = 0.92" for 10-Year event Inflow = 0.08 cfs @ 12.00 hrs, Volume= 0.004 af Outflow = 0.08 cfs @ 12.00 hrs, Volume= 0.004 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 8R: EX ONSITE INLET Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Inflow Area=0.053 ac 0.08 cfs 0.08 cfs Type II 24-hr 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 28HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 10R: TOTAL SITE [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.864 ac, 65.63% Impervious, Inflow Depth = 0.30" for 10-Year event Inflow = 0.34 cfs @ 12.02 hrs, Volume= 0.021 af Outflow = 0.34 cfs @ 12.02 hrs, Volume= 0.021 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 10R: TOTAL SITE Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.864 ac 0.34 cfs 0.34 cfs Type II 24-hr 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 29HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Pond 6P: U/G 36" INFILTRATION Inflow Area = 0.538 ac, 86.43% Impervious, Inflow Depth = 3.41" for 10-Year event Inflow = 2.85 cfs @ 11.98 hrs, Volume= 0.153 af Outflow = 0.06 cfs @ 10.20 hrs, Volume= 0.153 af, Atten= 98%, Lag= 0.0 min Discarded = 0.06 cfs @ 10.20 hrs, Volume= 0.153 af Primary = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 917.71' @ 15.61 hrs Surf.Area= 3,154 sf Storage= 3,978 cf Plug-Flow detention time= 636.6 min calculated for 0.153 af (100% of inflow) Center-of-Mass det. time= 636.8 min ( 1,418.1 - 781.3 ) Volume Invert Avail.Storage Storage Description #1A 915.40' 3,692 cf 38.00'W x 83.00'L x 4.50'H Field A 14,193 cf Overall - 4,962 cf Embedded = 9,231 cf x 40.0% Voids #2A 915.90' 3,976 cf ADS N-12 36" x 28 Inside #1 Inside= 36.1"W x 36.1"H => 7.10 sf x 20.00'L = 142.0 cf Outside= 42.0"W x 42.0"H => 8.86 sf x 20.00'L = 177.2 cf 7 Rows of 4 Chambers 7,668 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 915.40'0.800 in/hr Exfiltration over Surface area #2 Device 3 918.50'4.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 #3 Primary 915.40'12.0" Round Culvert L= 50.0' Ke= 0.100 Inlet / Outlet Invert= 915.40' / 915.05' S= 0.0070 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean, Flow Area= 0.79 sf Discarded OutFlow Max=0.06 cfs @ 10.20 hrs HW=915.45' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=0.00 cfs @ 1.00 hrs HW=915.40' (Free Discharge) 3=Culvert ( Controls 0.00 cfs) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type II 24-hr 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 30HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 6P: U/G 36" INFILTRATION - Chamber Wizard Field A Chamber Model = ADS N-12 36" (ADS N-12® Pipe) Inside= 36.1"W x 36.1"H => 7.10 sf x 20.00'L = 142.0 cf Outside= 42.0"W x 42.0"H => 8.86 sf x 20.00'L = 177.2 cf 42.0" Wide + 21.0" Spacing = 63.0" C-C Row Spacing 4 Chambers/Row x 20.00' Long = 80.00' Row Length +18.0" End Stone x 2 = 83.00' Base Length 7 Rows x 42.0" Wide + 21.0" Spacing x 6 + 18.0" Side Stone x 2 = 38.00' Base Width 6.0" Base + 42.0" Chamber Height + 6.0" Cover = 4.50' Field Height 28 Chambers x 142.0 cf = 3,976.0 cf Chamber Storage 28 Chambers x 177.2 cf = 4,962.2 cf Displacement 14,193.0 cf Field - 4,962.2 cf Chambers = 9,230.8 cf Stone x 40.0% Voids = 3,692.3 cf Stone Storage Chamber Storage + Stone Storage = 7,668.3 cf = 0.176 af Overall Storage Efficiency = 54.0% Overall System Size = 83.00' x 38.00' x 4.50' 28 Chambers 525.7 cy Field 341.9 cy Stone Type II 24-hr 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 31HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 6P: U/G 36" INFILTRATION Inflow Outflow Discarded Primary Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)3 2 1 0 Inflow Area=0.538 ac Peak Elev=917.71' Storage=3,978 cf 2.85 cfs 0.06 cfs 0.06 cfs 0.00 cfs Type II 24-hr 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 32HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Pond 7P: INFILTRATION BASIN Inflow Area = 0.147 ac, 44.90% Impervious, Inflow Depth = 2.05" for 10-Year event Inflow = 0.51 cfs @ 11.99 hrs, Volume= 0.025 af Outflow = 0.02 cfs @ 13.59 hrs, Volume= 0.025 af, Atten= 96%, Lag= 96.0 min Discarded = 0.02 cfs @ 13.59 hrs, Volume= 0.025 af Primary = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 920.06' @ 13.59 hrs Surf.Area= 1,199 sf Storage= 550 cf Plug-Flow detention time= 273.8 min calculated for 0.025 af (100% of inflow) Center-of-Mass det. time= 273.7 min ( 1,106.6 - 832.9 ) Volume Invert Avail.Storage Storage Description #1 919.50' 3,159 cf BASIN WEST (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 919.50 790 255.4 0 0 790 920.50 1,584 274.3 1,164 1,164 1,630 921.50 2,436 293.2 1,995 3,159 2,529 Device Routing Invert Outlet Devices #1 Discarded 919.50'0.800 in/hr Exfiltration over Surface area #2 Device 3 921.20'24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Primary 918.00'12.0" Round Culvert L= 25.0' Ke= 0.100 Inlet / Outlet Invert= 918.00' / 917.50' S= 0.0200 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Discarded OutFlow Max=0.02 cfs @ 13.59 hrs HW=920.06' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max=0.00 cfs @ 1.00 hrs HW=919.50' (Free Discharge) 3=Culvert (Passes 0.00 cfs of 4.74 cfs potential flow) 2=Orifice/Grate ( Controls 0.00 cfs) Type II 24-hr 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 33HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 7P: INFILTRATION BASIN Inflow Outflow Discarded Primary Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.147 ac Peak Elev=920.06' Storage=550 cf 0.51 cfs 0.02 cfs 0.02 cfs 0.00 cfs Type II 24-hr 100-Year Rainfall=5.95"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 34HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Time span=1.00-72.00 hrs, dt=0.05 hrs, 1421 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=0.035 ac 68.57% Impervious Runoff Depth=4.36"Subcatchment 1S: C-DA-1 Flow Length=145' Slope=0.0200 '/' Tc=14.0 min CN=86 Runoff=0.20 cfs 0.013 af Runoff Area=0.060 ac 1.67% Impervious Runoff Depth=2.06"Subcatchment 2S: C-DA-2 Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=62 Runoff=0.16 cfs 0.010 af Runoff Area=0.147 ac 44.90% Impervious Runoff Depth=3.53"Subcatchment 3S: C-DA-3 Tc=7.0 min CN=78 Runoff=0.87 cfs 0.043 af Runoff Area=0.538 ac 86.43% Impervious Runoff Depth=5.13"Subcatchment 7S: C-DA-4 Tc=7.0 min CN=93 Runoff=4.18 cfs 0.230 af Runoff Area=0.053 ac 0.00% Impervious Runoff Depth=1.97"Subcatchment 8S: C-DA-6 Tc=7.0 min CN=61 Runoff=0.18 cfs 0.009 af Runoff Area=0.031 ac 35.48% Impervious Runoff Depth=3.14"Subcatchment 9S: C-DA-5 Tc=7.0 min CN=74 Runoff=0.16 cfs 0.008 af Inflow=0.18 cfs 0.009 afReach 8R: EX ONSITE INLET Outflow=0.18 cfs 0.009 af Inflow=0.65 cfs 0.061 afReach 10R: TOTAL SITE Outflow=0.65 cfs 0.061 af Peak Elev=918.56' Storage=5,780 cf Inflow=4.18 cfs 0.230 afPond 6P: U/G 36" INFILTRATION Discarded=0.06 cfs 0.209 af Primary=0.15 cfs 0.021 af Outflow=0.21 cfs 0.230 af Peak Elev=920.43' Storage=1,054 cf Inflow=0.87 cfs 0.043 afPond 7P: INFILTRATION BASIN Discarded=0.03 cfs 0.043 af Primary=0.00 cfs 0.000 af Outflow=0.03 cfs 0.043 af Total Runoff Area = 0.864 ac Runoff Volume = 0.313 af Average Runoff Depth = 4.35" 34.37% Pervious = 0.297 ac 65.63% Impervious = 0.567 ac Type II 24-hr 100-Year Rainfall=5.95"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 35HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: C-DA-1 Runoff = 0.20 cfs @ 12.05 hrs, Volume= 0.013 af, Depth= 4.36" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=5.95" Area (ac) CN Description 0.011 61 >75% Grass cover, Good, HSG B 0.024 98 Paved parking, HSG B 0.035 86 Weighted Average 0.011 31.43% Pervious Area 0.024 68.57% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.0 145 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 1S: C-DA-1 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr 100-Year Rainfall=5.95" Runoff Area=0.035 ac Runoff Volume=0.013 af Runoff Depth=4.36" Flow Length=145' Slope=0.0200 '/' Tc=14.0 min CN=86 0.20 cfs Type II 24-hr 100-Year Rainfall=5.95"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 36HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: C-DA-2 Runoff = 0.16 cfs @ 12.06 hrs, Volume= 0.010 af, Depth= 2.06" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=5.95" Area (ac) CN Description 0.059 61 >75% Grass cover, Good, HSG B 0.001 98 Paved parking, HSG B 0.060 62 Weighted Average 0.059 98.33% Pervious Area 0.001 1.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.6 140 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 2S: C-DA-2 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr 100-Year Rainfall=5.95" Runoff Area=0.060 ac Runoff Volume=0.010 af Runoff Depth=2.06" Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=62 0.16 cfs Type II 24-hr 100-Year Rainfall=5.95"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 37HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: C-DA-3 Runoff = 0.87 cfs @ 11.98 hrs, Volume= 0.043 af, Depth= 3.53" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=5.95" Area (ac) CN Description 0.081 61 >75% Grass cover, Good, HSG B 0.066 98 Roofs, HSG B 0.147 78 Weighted Average 0.081 55.10% Pervious Area 0.066 44.90% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 3S: C-DA-3 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.95 0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 100-Year Rainfall=5.95" Runoff Area=0.147 ac Runoff Volume=0.043 af Runoff Depth=3.53" Tc=7.0 min CN=78 0.87 cfs Type II 24-hr 100-Year Rainfall=5.95"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 38HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 7S: C-DA-4 Runoff = 4.18 cfs @ 11.98 hrs, Volume= 0.230 af, Depth= 5.13" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=5.95" Area (ac) CN Description 0.073 61 >75% Grass cover, Good, HSG B 0.465 98 Paved parking, HSG B 0.538 93 Weighted Average 0.073 13.57% Pervious Area 0.465 86.43% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 7S: C-DA-4 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)4 3 2 1 0 Type II 24-hr 100-Year Rainfall=5.95" Runoff Area=0.538 ac Runoff Volume=0.230 af Runoff Depth=5.13" Tc=7.0 min CN=93 4.18 cfs Type II 24-hr 100-Year Rainfall=5.95"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 39HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 8S: C-DA-6 Runoff = 0.18 cfs @ 11.99 hrs, Volume= 0.009 af, Depth= 1.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=5.95" Area (ac) CN Description 0.053 61 >75% Grass cover, Good, HSG B 0.053 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 8S: C-DA-6 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr 100-Year Rainfall=5.95" Runoff Area=0.053 ac Runoff Volume=0.009 af Runoff Depth=1.97" Tc=7.0 min CN=61 0.18 cfs Type II 24-hr 100-Year Rainfall=5.95"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 40HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 9S: C-DA-5 Runoff = 0.16 cfs @ 11.98 hrs, Volume= 0.008 af, Depth= 3.14" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=5.95" Area (ac) CN Description 0.011 98 Paved parking, HSG B 0.020 61 >75% Grass cover, Good, HSG B 0.031 74 Weighted Average 0.020 64.52% Pervious Area 0.011 35.48% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 9S: C-DA-5 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr 100-Year Rainfall=5.95" Runoff Area=0.031 ac Runoff Volume=0.008 af Runoff Depth=3.14" Tc=7.0 min CN=74 0.16 cfs Type II 24-hr 100-Year Rainfall=5.95"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 41HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 8R: EX ONSITE INLET [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.053 ac, 0.00% Impervious, Inflow Depth = 1.97" for 100-Year event Inflow = 0.18 cfs @ 11.99 hrs, Volume= 0.009 af Outflow = 0.18 cfs @ 11.99 hrs, Volume= 0.009 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 8R: EX ONSITE INLET Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=0.053 ac 0.18 cfs 0.18 cfs Type II 24-hr 100-Year Rainfall=5.95"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 42HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 10R: TOTAL SITE [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.864 ac, 65.63% Impervious, Inflow Depth = 0.85" for 100-Year event Inflow = 0.65 cfs @ 12.01 hrs, Volume= 0.061 af Outflow = 0.65 cfs @ 12.01 hrs, Volume= 0.061 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 10R: TOTAL SITE Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.864 ac 0.65 cfs 0.65 cfs Type II 24-hr 100-Year Rainfall=5.95"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 43HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Pond 6P: U/G 36" INFILTRATION Inflow Area = 0.538 ac, 86.43% Impervious, Inflow Depth = 5.13" for 100-Year event Inflow = 4.18 cfs @ 11.98 hrs, Volume= 0.230 af Outflow = 0.21 cfs @ 13.03 hrs, Volume= 0.230 af, Atten= 95%, Lag= 63.1 min Discarded = 0.06 cfs @ 8.75 hrs, Volume= 0.209 af Primary = 0.15 cfs @ 13.03 hrs, Volume= 0.021 af Routing by Stor-Ind method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 918.56' @ 13.03 hrs Surf.Area= 3,154 sf Storage= 5,780 cf Plug-Flow detention time= 816.9 min calculated for 0.230 af (100% of inflow) Center-of-Mass det. time= 817.4 min ( 1,588.0 - 770.6 ) Volume Invert Avail.Storage Storage Description #1A 915.40' 3,692 cf 38.00'W x 83.00'L x 4.50'H Field A 14,193 cf Overall - 4,962 cf Embedded = 9,231 cf x 40.0% Voids #2A 915.90' 3,976 cf ADS N-12 36" x 28 Inside #1 Inside= 36.1"W x 36.1"H => 7.10 sf x 20.00'L = 142.0 cf Outside= 42.0"W x 42.0"H => 8.86 sf x 20.00'L = 177.2 cf 7 Rows of 4 Chambers 7,668 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 915.40'0.800 in/hr Exfiltration over Surface area #2 Device 3 918.50'4.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 #3 Primary 915.40'12.0" Round Culvert L= 50.0' Ke= 0.100 Inlet / Outlet Invert= 915.40' / 915.05' S= 0.0070 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean, Flow Area= 0.79 sf Discarded OutFlow Max=0.06 cfs @ 8.75 hrs HW=915.45' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=0.15 cfs @ 13.03 hrs HW=918.56' (Free Discharge) 3=Culvert (Passes 0.15 cfs of 6.69 cfs potential flow) 2=Broad-Crested Rectangular Weir (Weir Controls 0.15 cfs @ 0.66 fps) Type II 24-hr 100-Year Rainfall=5.95"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 44HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 6P: U/G 36" INFILTRATION - Chamber Wizard Field A Chamber Model = ADS N-12 36" (ADS N-12® Pipe) Inside= 36.1"W x 36.1"H => 7.10 sf x 20.00'L = 142.0 cf Outside= 42.0"W x 42.0"H => 8.86 sf x 20.00'L = 177.2 cf 42.0" Wide + 21.0" Spacing = 63.0" C-C Row Spacing 4 Chambers/Row x 20.00' Long = 80.00' Row Length +18.0" End Stone x 2 = 83.00' Base Length 7 Rows x 42.0" Wide + 21.0" Spacing x 6 + 18.0" Side Stone x 2 = 38.00' Base Width 6.0" Base + 42.0" Chamber Height + 6.0" Cover = 4.50' Field Height 28 Chambers x 142.0 cf = 3,976.0 cf Chamber Storage 28 Chambers x 177.2 cf = 4,962.2 cf Displacement 14,193.0 cf Field - 4,962.2 cf Chambers = 9,230.8 cf Stone x 40.0% Voids = 3,692.3 cf Stone Storage Chamber Storage + Stone Storage = 7,668.3 cf = 0.176 af Overall Storage Efficiency = 54.0% Overall System Size = 83.00' x 38.00' x 4.50' 28 Chambers 525.7 cy Field 341.9 cy Stone Type II 24-hr 100-Year Rainfall=5.95"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 45HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 6P: U/G 36" INFILTRATION Inflow Outflow Discarded Primary Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)4 3 2 1 0 Inflow Area=0.538 ac Peak Elev=918.56' Storage=5,780 cf 4.18 cfs 0.21 cfs 0.06 cfs 0.15 cfs Type II 24-hr 100-Year Rainfall=5.95"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 46HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Pond 7P: INFILTRATION BASIN Inflow Area = 0.147 ac, 44.90% Impervious, Inflow Depth = 3.53" for 100-Year event Inflow = 0.87 cfs @ 11.98 hrs, Volume= 0.043 af Outflow = 0.03 cfs @ 14.07 hrs, Volume= 0.043 af, Atten= 97%, Lag= 125.4 min Discarded = 0.03 cfs @ 14.07 hrs, Volume= 0.043 af Primary = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 920.43' @ 14.07 hrs Surf.Area= 1,519 sf Storage= 1,054 cf Plug-Flow detention time= 428.7 min calculated for 0.043 af (100% of inflow) Center-of-Mass det. time= 428.8 min ( 1,246.2 - 817.3 ) Volume Invert Avail.Storage Storage Description #1 919.50' 3,159 cf BASIN WEST (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 919.50 790 255.4 0 0 790 920.50 1,584 274.3 1,164 1,164 1,630 921.50 2,436 293.2 1,995 3,159 2,529 Device Routing Invert Outlet Devices #1 Discarded 919.50'0.800 in/hr Exfiltration over Surface area #2 Device 3 921.20'24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Primary 918.00'12.0" Round Culvert L= 25.0' Ke= 0.100 Inlet / Outlet Invert= 918.00' / 917.50' S= 0.0200 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Discarded OutFlow Max=0.03 cfs @ 14.07 hrs HW=920.43' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.03 cfs) Primary OutFlow Max=0.00 cfs @ 1.00 hrs HW=919.50' (Free Discharge) 3=Culvert (Passes 0.00 cfs of 4.74 cfs potential flow) 2=Orifice/Grate ( Controls 0.00 cfs) Type II 24-hr 100-Year Rainfall=5.95"CBA Chanhassen Pr Cond_TP-40_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 47HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 7P: INFILTRATION BASIN Inflow Outflow Discarded Primary Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.95 0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.147 ac Peak Elev=920.43' Storage=1,054 cf 0.87 cfs 0.03 cfs 0.03 cfs 0.00 cfs 1S C-DA-1 2S C-DA-2 3S C-DA-3 7S C-DA-4 8S C-DA-6 9S C-DA-5 8R EX ONSITE INLET 10R TOTAL SITE 6P U/G 36" INFILTRATION 7P INFILTRATION BASIN Routing Diagram for CBA Chanhassen Pr Cond_TP-40_10 Day Snow Melt Prepared by Kimley-Horn and Associates, Printed 10/25/2020 HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Subcat Reach Pond Link CBA Chanhassen Pr Cond_TP-40_10 Day Snow Melt Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 2HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.297 100 >75% Grass cover, Good, HSG B (1S, 2S, 3S, 7S, 8S, 9S) 0.501 98 Paved parking, HSG B (1S, 2S, 7S, 9S) 0.066 98 Roofs, HSG B (3S) 0.864 99 TOTAL AREA CBA Chanhassen Pr Cond_TP-40_10 Day Snow Melt Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 3HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 0.864 HSG B 1S, 2S, 3S, 7S, 8S, 9S 0.000 HSG C 0.000 HSG D 0.000 Other 0.864 TOTAL AREA CBA Chanhassen Pr Cond_TP-40_10 Day Snow Melt Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 4HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.297 0.000 0.000 0.000 0.297 >75% Grass cover, Good 1S, 2S, 3S, 7S, 8S, 9S 0.000 0.501 0.000 0.000 0.000 0.501 Paved parking 1S, 2S, 7S, 9S 0.000 0.066 0.000 0.000 0.000 0.066 Roofs 3S 0.000 0.864 0.000 0.000 0.000 0.864 TOTAL AREA CBA Chanhassen Pr Cond_TP-40_10 Day Snow Melt Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 5HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pipe Listing (all nodes) Line# Node Number In-Invert (feet) Out-Invert (feet) Length (feet) Slope (ft/ft) n Diam/Width (inches) Height (inches) Inside-Fill (inches) 1 6P 915.40 915.05 50.0 0.0070 0.011 12.0 0.0 0.0 2 7P 918.00 917.50 25.0 0.0200 0.012 12.0 0.0 0.0 Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4CBA Chanhassen Pr Cond_TP-40_10 Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 6HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Time span=1.00-240.00 hrs, dt=0.01 hrs, 23901 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=0.035 ac 100.00% Impervious Runoff Depth>5.83"Subcatchment 1S: C-DA-1 Flow Length=145' Slope=0.0200 '/' Tc=14.0 min CN=99 Runoff=0.03 cfs 0.017 af Runoff Area=0.060 ac 100.00% Impervious Runoff Depth>5.94"Subcatchment 2S: C-DA-2 Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=100 Runoff=0.06 cfs 0.030 af Runoff Area=0.147 ac 100.00% Impervious Runoff Depth>5.83"Subcatchment 3S: C-DA-3 Tc=7.0 min CN=99 Runoff=0.15 cfs 0.071 af Runoff Area=0.538 ac 100.00% Impervious Runoff Depth>5.71"Subcatchment 7S: C-DA-4 Tc=7.0 min CN=98 Runoff=0.54 cfs 0.256 af Runoff Area=0.053 ac 100.00% Impervious Runoff Depth>5.94"Subcatchment 8S: C-DA-6 Tc=7.0 min CN=100 Runoff=0.05 cfs 0.026 af Runoff Area=0.031 ac 100.00% Impervious Runoff Depth>5.83"Subcatchment 9S: C-DA-5 Tc=7.0 min CN=99 Runoff=0.03 cfs 0.015 af Inflow=0.05 cfs 0.026 afReach 8R: EX ONSITE INLET Outflow=0.05 cfs 0.026 af Inflow=0.18 cfs 0.088 afReach 10R: TOTAL SITE Outflow=0.18 cfs 0.088 af Peak Elev=917.46' Storage=3,409 cf Inflow=0.54 cfs 0.256 afPond 6P: U/G 36" INFILTRATION Discarded=0.06 cfs 0.256 af Primary=0.00 cfs 0.000 af Outflow=0.06 cfs 0.256 af Peak Elev=920.31' Storage=878 cf Inflow=0.15 cfs 0.071 afPond 7P: INFILTRATION BASIN Discarded=0.03 cfs 0.071 af Primary=0.00 cfs 0.000 af Outflow=0.03 cfs 0.071 af Total Runoff Area = 0.864 ac Runoff Volume = 0.416 af Average Runoff Depth = 5.77" 0.00% Pervious = 0.000 ac 100.00% Impervious = 0.864 ac Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4CBA Chanhassen Pr Cond_TP-40_10 Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 7HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: C-DA-1 Runoff = 0.03 cfs @ 119.17 hrs, Volume= 0.017 af, Depth> 5.83" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4 Area (ac) CN Description * 0.011 100 >75% Grass cover, Good, HSG B 0.024 98 Paved parking, HSG B 0.035 99 Weighted Average 0.035 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.0 145 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 1S: C-DA-1 Runoff Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.038 0.036 0.034 0.032 0.03 0.028 0.026 0.024 0.022 0.02 0.018 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0 Type II 24-hr 240.00 hrs Custom Rainfall=5.95" AMC=4 Runoff Area=0.035 ac Runoff Volume=0.017 af Runoff Depth>5.83" Flow Length=145' Slope=0.0200 '/' Tc=14.0 min CN=99 0.03 cfs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4CBA Chanhassen Pr Cond_TP-40_10 Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 8HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: C-DA-2 Runoff = 0.06 cfs @ 119.15 hrs, Volume= 0.030 af, Depth> 5.94" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4 Area (ac) CN Description * 0.059 100 >75% Grass cover, Good, HSG B 0.001 98 Paved parking, HSG B 0.060 100 Weighted Average 0.060 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.6 140 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 2S: C-DA-2 Runoff Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Type II 24-hr 240.00 hrs Custom Rainfall=5.95" AMC=4 Runoff Area=0.060 ac Runoff Volume=0.030 af Runoff Depth>5.94" Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=100 0.06 cfs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4CBA Chanhassen Pr Cond_TP-40_10 Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 9HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: C-DA-3 Runoff = 0.15 cfs @ 119.09 hrs, Volume= 0.071 af, Depth> 5.83" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4 Area (ac) CN Description * 0.081 100 >75% Grass cover, Good, HSG B 0.066 98 Roofs, HSG B 0.147 99 Weighted Average 0.147 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 3S: C-DA-3 Runoff Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr 240.00 hrs Custom Rainfall=5.95" AMC=4 Runoff Area=0.147 ac Runoff Volume=0.071 af Runoff Depth>5.83" Tc=7.0 min CN=99 0.15 cfs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4CBA Chanhassen Pr Cond_TP-40_10 Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 10HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 7S: C-DA-4 Runoff = 0.54 cfs @ 119.09 hrs, Volume= 0.256 af, Depth> 5.71" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4 Area (ac) CN Description * 0.073 100 >75% Grass cover, Good, HSG B 0.465 98 Paved parking, HSG B 0.538 98 Weighted Average 0.538 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 7S: C-DA-4 Runoff Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 240.00 hrs Custom Rainfall=5.95" AMC=4 Runoff Area=0.538 ac Runoff Volume=0.256 af Runoff Depth>5.71" Tc=7.0 min CN=98 0.54 cfs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4CBA Chanhassen Pr Cond_TP-40_10 Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 11HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 8S: C-DA-6 Runoff = 0.05 cfs @ 119.09 hrs, Volume= 0.026 af, Depth> 5.94" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4 Area (ac) CN Description * 0.053 100 >75% Grass cover, Good, HSG B 0.053 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 8S: C-DA-6 Runoff Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Type II 24-hr 240.00 hrs Custom Rainfall=5.95" AMC=4 Runoff Area=0.053 ac Runoff Volume=0.026 af Runoff Depth>5.94" Tc=7.0 min CN=100 0.05 cfs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4CBA Chanhassen Pr Cond_TP-40_10 Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 12HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 9S: C-DA-5 Runoff = 0.03 cfs @ 119.09 hrs, Volume= 0.015 af, Depth> 5.83" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4 Area (ac) CN Description 0.011 98 Paved parking, HSG B * 0.020 100 >75% Grass cover, Good, HSG B 0.031 99 Weighted Average 0.031 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 9S: C-DA-5 Runoff Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.034 0.032 0.03 0.028 0.026 0.024 0.022 0.02 0.018 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0 Type II 24-hr 240.00 hrs Custom Rainfall=5.95" AMC=4 Runoff Area=0.031 ac Runoff Volume=0.015 af Runoff Depth>5.83" Tc=7.0 min CN=99 0.03 cfs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4CBA Chanhassen Pr Cond_TP-40_10 Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 13HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 8R: EX ONSITE INLET [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.053 ac,100.00% Impervious, Inflow Depth > 5.94" for Custom event Inflow = 0.05 cfs @ 119.09 hrs, Volume= 0.026 af Outflow = 0.05 cfs @ 119.09 hrs, Volume= 0.026 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs Reach 8R: EX ONSITE INLET Inflow Outflow Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Inflow Area=0.053 ac 0.05 cfs 0.05 cfs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4CBA Chanhassen Pr Cond_TP-40_10 Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 14HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 10R: TOTAL SITE [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.864 ac,100.00% Impervious, Inflow Depth > 1.22" for Custom event Inflow = 0.18 cfs @ 119.10 hrs, Volume= 0.088 af Outflow = 0.18 cfs @ 119.10 hrs, Volume= 0.088 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs Reach 10R: TOTAL SITE Inflow Outflow Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=0.864 ac 0.18 cfs 0.18 cfs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4CBA Chanhassen Pr Cond_TP-40_10 Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 15HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Pond 6P: U/G 36" INFILTRATION Inflow Area = 0.538 ac,100.00% Impervious, Inflow Depth > 5.71" for Custom event Inflow = 0.54 cfs @ 119.09 hrs, Volume= 0.256 af Outflow = 0.06 cfs @ 115.61 hrs, Volume= 0.256 af, Atten= 89%, Lag= 0.0 min Discarded = 0.06 cfs @ 115.61 hrs, Volume= 0.256 af Primary = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs Peak Elev= 917.46' @ 120.97 hrs Surf.Area= 3,154 sf Storage= 3,409 cf Plug-Flow detention time= 320.2 min calculated for 0.256 af (100% of inflow) Center-of-Mass det. time= 318.0 min ( 7,679.2 - 7,361.2 ) Volume Invert Avail.Storage Storage Description #1A 915.40' 3,692 cf 38.00'W x 83.00'L x 4.50'H Field A 14,193 cf Overall - 4,962 cf Embedded = 9,231 cf x 40.0% Voids #2A 915.90' 3,976 cf ADS N-12 36" x 28 Inside #1 Inside= 36.1"W x 36.1"H => 7.10 sf x 20.00'L = 142.0 cf Outside= 42.0"W x 42.0"H => 8.86 sf x 20.00'L = 177.2 cf 7 Rows of 4 Chambers 7,668 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 915.40'0.800 in/hr Exfiltration over Surface area #2 Device 3 918.50'4.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 #3 Primary 915.40'12.0" Round Culvert L= 50.0' Ke= 0.100 Inlet / Outlet Invert= 915.40' / 915.05' S= 0.0070 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean, Flow Area= 0.79 sf Discarded OutFlow Max=0.06 cfs @ 115.61 hrs HW=915.45' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=0.00 cfs @ 1.00 hrs HW=915.40' (Free Discharge) 3=Culvert ( Controls 0.00 cfs) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4CBA Chanhassen Pr Cond_TP-40_10 Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 16HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 6P: U/G 36" INFILTRATION - Chamber Wizard Field A Chamber Model = ADS N-12 36" (ADS N-12® Pipe) Inside= 36.1"W x 36.1"H => 7.10 sf x 20.00'L = 142.0 cf Outside= 42.0"W x 42.0"H => 8.86 sf x 20.00'L = 177.2 cf 42.0" Wide + 21.0" Spacing = 63.0" C-C Row Spacing 4 Chambers/Row x 20.00' Long = 80.00' Row Length +18.0" End Stone x 2 = 83.00' Base Length 7 Rows x 42.0" Wide + 21.0" Spacing x 6 + 18.0" Side Stone x 2 = 38.00' Base Width 6.0" Base + 42.0" Chamber Height + 6.0" Cover = 4.50' Field Height 28 Chambers x 142.0 cf = 3,976.0 cf Chamber Storage 28 Chambers x 177.2 cf = 4,962.2 cf Displacement 14,193.0 cf Field - 4,962.2 cf Chambers = 9,230.8 cf Stone x 40.0% Voids = 3,692.3 cf Stone Storage Chamber Storage + Stone Storage = 7,668.3 cf = 0.176 af Overall Storage Efficiency = 54.0% Overall System Size = 83.00' x 38.00' x 4.50' 28 Chambers 525.7 cy Field 341.9 cy Stone Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4CBA Chanhassen Pr Cond_TP-40_10 Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 17HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 6P: U/G 36" INFILTRATION Inflow Outflow Discarded Primary Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.538 ac Peak Elev=917.46' Storage=3,409 cf 0.54 cfs 0.06 cfs 0.06 cfs 0.00 cfs Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4CBA Chanhassen Pr Cond_TP-40_10 Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 18HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Pond 7P: INFILTRATION BASIN Inflow Area = 0.147 ac,100.00% Impervious, Inflow Depth > 5.83" for Custom event Inflow = 0.15 cfs @ 119.09 hrs, Volume= 0.071 af Outflow = 0.03 cfs @ 120.05 hrs, Volume= 0.071 af, Atten= 82%, Lag= 57.6 min Discarded = 0.03 cfs @ 120.05 hrs, Volume= 0.071 af Primary = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs Peak Elev= 920.31' @ 120.05 hrs Surf.Area= 1,411 sf Storage= 878 cf Plug-Flow detention time= 193.1 min calculated for 0.071 af (100% of inflow) Center-of-Mass det. time= 190.7 min ( 7,465.4 - 7,274.8 ) Volume Invert Avail.Storage Storage Description #1 919.50' 3,159 cf BASIN WEST (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 919.50 790 255.4 0 0 790 920.50 1,584 274.3 1,164 1,164 1,630 921.50 2,436 293.2 1,995 3,159 2,529 Device Routing Invert Outlet Devices #1 Discarded 919.50'0.800 in/hr Exfiltration over Surface area #2 Device 3 921.20'24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Primary 918.00'12.0" Round Culvert L= 25.0' Ke= 0.100 Inlet / Outlet Invert= 918.00' / 917.50' S= 0.0200 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Discarded OutFlow Max=0.03 cfs @ 120.05 hrs HW=920.31' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.03 cfs) Primary OutFlow Max=0.00 cfs @ 1.00 hrs HW=919.50' (Free Discharge) 3=Culvert (Passes 0.00 cfs of 4.74 cfs potential flow) 2=Orifice/Grate ( Controls 0.00 cfs) Type II 24-hr 240.00 hrs Custom Rainfall=5.95", AMC=4CBA Chanhassen Pr Cond_TP-40_10 Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 19HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 7P: INFILTRATION BASIN Inflow Outflow Discarded Primary Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=0.147 ac Peak Elev=920.31' Storage=878 cf 0.15 cfs 0.03 cfs 0.03 cfs 0.00 cfs Christian Brothers Automotive - Stormwater Report Page 15 Chanhassen, MN Appendix 4. Post-Development HydroCAD Model Analysis (Atlas-14) 1S C-DA-1 2S C-DA-2 3S C-DA-3 7S C-DA-4 8S C-DA-6 9S C-DA-5 8R EX ONSITE INLET 10R TOTAL SITE 6P U/G 36" INFILTRATION 7P INFILTRATION BASIN Routing Diagram for CBA Chanhassen Pr Cond_Atlas 14_Rainfall Prepared by Kimley-Horn and Associates, Printed 10/25/2020 HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Subcat Reach Pond Link CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 2HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.297 61 >75% Grass cover, Good, HSG B (1S, 2S, 3S, 7S, 8S, 9S) 0.501 98 Paved parking, HSG B (1S, 2S, 7S, 9S) 0.066 98 Roofs, HSG B (3S) 0.864 85 TOTAL AREA CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 3HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 0.864 HSG B 1S, 2S, 3S, 7S, 8S, 9S 0.000 HSG C 0.000 HSG D 0.000 Other 0.864 TOTAL AREA CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 4HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.297 0.000 0.000 0.000 0.297 >75% Grass cover, Good 1S, 2S, 3S, 7S, 8S, 9S 0.000 0.501 0.000 0.000 0.000 0.501 Paved parking 1S, 2S, 7S, 9S 0.000 0.066 0.000 0.000 0.000 0.066 Roofs 3S 0.000 0.864 0.000 0.000 0.000 0.864 TOTAL AREA CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 5HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pipe Listing (all nodes) Line# Node Number In-Invert (feet) Out-Invert (feet) Length (feet) Slope (ft/ft) n Diam/Width (inches) Height (inches) Inside-Fill (inches) 1 6P 915.40 915.05 50.0 0.0070 0.011 12.0 0.0 0.0 2 7P 918.00 917.50 25.0 0.0200 0.012 12.0 0.0 0.0 MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 6HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Time span=1.00-72.00 hrs, dt=0.05 hrs, 1421 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=0.035 ac 68.57% Impervious Runoff Depth=1.53"Subcatchment 1S: C-DA-1 Flow Length=145' Slope=0.0200 '/' Tc=14.0 min CN=86 Runoff=0.07 cfs 0.004 af Runoff Area=0.060 ac 1.67% Impervious Runoff Depth=0.34"Subcatchment 2S: C-DA-2 Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=62 Runoff=0.02 cfs 0.002 af Runoff Area=0.147 ac 44.90% Impervious Runoff Depth=1.02"Subcatchment 3S: C-DA-3 Tc=7.0 min CN=78 Runoff=0.26 cfs 0.012 af Runoff Area=0.538 ac 86.43% Impervious Runoff Depth=2.10"Subcatchment 7S: C-DA-4 Tc=7.0 min CN=93 Runoff=1.87 cfs 0.094 af Runoff Area=0.053 ac 0.00% Impervious Runoff Depth=0.31"Subcatchment 8S: C-DA-6 Tc=7.0 min CN=61 Runoff=0.02 cfs 0.001 af Runoff Area=0.031 ac 35.48% Impervious Runoff Depth=0.81"Subcatchment 9S: C-DA-5 Tc=7.0 min CN=74 Runoff=0.04 cfs 0.002 af Inflow=0.02 cfs 0.001 afReach 8R: EX ONSITE INLET Outflow=0.02 cfs 0.001 af Inflow=0.13 cfs 0.010 afReach 10R: TOTAL SITE Outflow=0.13 cfs 0.010 af Peak Elev=917.06' Storage=2,547 cf Inflow=1.87 cfs 0.094 afPond 6P: U/G 36" INFILTRATION Discarded=0.06 cfs 0.094 af Primary=0.00 cfs 0.000 af Outflow=0.06 cfs 0.094 af Peak Elev=919.80' Storage=269 cf Inflow=0.26 cfs 0.012 afPond 7P: INFILTRATION BASIN Discarded=0.02 cfs 0.012 af Primary=0.00 cfs 0.000 af Outflow=0.02 cfs 0.012 af Total Runoff Area = 0.864 ac Runoff Volume = 0.116 af Average Runoff Depth = 1.61" 34.37% Pervious = 0.297 ac 65.63% Impervious = 0.567 ac MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 7HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: C-DA-1 Runoff = 0.07 cfs @ 12.22 hrs, Volume= 0.004 af, Depth= 1.53" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 2-Year Rainfall=2.84" Area (ac) CN Description 0.011 61 >75% Grass cover, Good, HSG B 0.024 98 Paved parking, HSG B 0.035 86 Weighted Average 0.011 31.43% Pervious Area 0.024 68.57% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.0 145 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 1S: C-DA-1 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 MSE 24-hr 3 2-Year Rainfall=2.84" Runoff Area=0.035 ac Runoff Volume=0.004 af Runoff Depth=1.53" Flow Length=145' Slope=0.0200 '/' Tc=14.0 min CN=86 0.07 cfs MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 8HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: C-DA-2 Runoff = 0.02 cfs @ 12.28 hrs, Volume= 0.002 af, Depth= 0.34" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 2-Year Rainfall=2.84" Area (ac) CN Description 0.059 61 >75% Grass cover, Good, HSG B 0.001 98 Paved parking, HSG B 0.060 62 Weighted Average 0.059 98.33% Pervious Area 0.001 1.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.6 140 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 2S: C-DA-2 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.018 0.017 0.016 0.015 0.014 0.013 0.012 0.011 0.01 0.009 0.008 0.007 0.006 0.005 0.004 0.003 0.002 0.001 0 MSE 24-hr 3 2-Year Rainfall=2.84" Runoff Area=0.060 ac Runoff Volume=0.002 af Runoff Depth=0.34" Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=62 0.02 cfs MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 9HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: C-DA-3 Runoff = 0.26 cfs @ 12.15 hrs, Volume= 0.012 af, Depth= 1.02" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 2-Year Rainfall=2.84" Area (ac) CN Description 0.081 61 >75% Grass cover, Good, HSG B 0.066 98 Roofs, HSG B 0.147 78 Weighted Average 0.081 55.10% Pervious Area 0.066 44.90% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 3S: C-DA-3 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 MSE 24-hr 3 2-Year Rainfall=2.84" Runoff Area=0.147 ac Runoff Volume=0.012 af Runoff Depth=1.02" Tc=7.0 min CN=78 0.26 cfs MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 10HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 7S: C-DA-4 Runoff = 1.87 cfs @ 12.14 hrs, Volume= 0.094 af, Depth= 2.10" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 2-Year Rainfall=2.84" Area (ac) CN Description 0.073 61 >75% Grass cover, Good, HSG B 0.465 98 Paved parking, HSG B 0.538 93 Weighted Average 0.073 13.57% Pervious Area 0.465 86.43% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 7S: C-DA-4 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)2 1 0 MSE 24-hr 3 2-Year Rainfall=2.84" Runoff Area=0.538 ac Runoff Volume=0.094 af Runoff Depth=2.10" Tc=7.0 min CN=93 1.87 cfs MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 11HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 8S: C-DA-6 Runoff = 0.02 cfs @ 12.18 hrs, Volume= 0.001 af, Depth= 0.31" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 2-Year Rainfall=2.84" Area (ac) CN Description 0.053 61 >75% Grass cover, Good, HSG B 0.053 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 8S: C-DA-6 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.018 0.017 0.016 0.015 0.014 0.013 0.012 0.011 0.01 0.009 0.008 0.007 0.006 0.005 0.004 0.003 0.002 0.001 0 MSE 24-hr 3 2-Year Rainfall=2.84" Runoff Area=0.053 ac Runoff Volume=0.001 af Runoff Depth=0.31" Tc=7.0 min CN=61 0.02 cfs MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 12HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 9S: C-DA-5 Runoff = 0.04 cfs @ 12.15 hrs, Volume= 0.002 af, Depth= 0.81" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 2-Year Rainfall=2.84" Area (ac) CN Description 0.011 98 Paved parking, HSG B 0.020 61 >75% Grass cover, Good, HSG B 0.031 74 Weighted Average 0.020 64.52% Pervious Area 0.011 35.48% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 9S: C-DA-5 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.046 0.044 0.042 0.04 0.038 0.036 0.034 0.032 0.03 0.028 0.026 0.024 0.022 0.02 0.018 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0 MSE 24-hr 3 2-Year Rainfall=2.84" Runoff Area=0.031 ac Runoff Volume=0.002 af Runoff Depth=0.81" Tc=7.0 min CN=74 0.04 cfs MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 13HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 8R: EX ONSITE INLET [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.053 ac, 0.00% Impervious, Inflow Depth = 0.31" for 2-Year event Inflow = 0.02 cfs @ 12.18 hrs, Volume= 0.001 af Outflow = 0.02 cfs @ 12.18 hrs, Volume= 0.001 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 8R: EX ONSITE INLET Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.018 0.017 0.016 0.015 0.014 0.013 0.012 0.011 0.01 0.009 0.008 0.007 0.006 0.005 0.004 0.003 0.002 0.001 0 Inflow Area=0.053 ac 0.02 cfs 0.02 cfs MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 14HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 10R: TOTAL SITE [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.864 ac, 65.63% Impervious, Inflow Depth = 0.13" for 2-Year event Inflow = 0.13 cfs @ 12.20 hrs, Volume= 0.010 af Outflow = 0.13 cfs @ 12.20 hrs, Volume= 0.010 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 10R: TOTAL SITE Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=0.864 ac 0.13 cfs 0.13 cfs MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 15HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Pond 6P: U/G 36" INFILTRATION Inflow Area = 0.538 ac, 86.43% Impervious, Inflow Depth = 2.10" for 2-Year event Inflow = 1.87 cfs @ 12.14 hrs, Volume= 0.094 af Outflow = 0.06 cfs @ 11.10 hrs, Volume= 0.094 af, Atten= 97%, Lag= 0.0 min Discarded = 0.06 cfs @ 11.10 hrs, Volume= 0.094 af Primary = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 917.06' @ 13.69 hrs Surf.Area= 3,154 sf Storage= 2,547 cf Plug-Flow detention time= 407.3 min calculated for 0.094 af (100% of inflow) Center-of-Mass det. time= 407.3 min ( 1,190.2 - 782.9 ) Volume Invert Avail.Storage Storage Description #1A 915.40' 3,692 cf 38.00'W x 83.00'L x 4.50'H Field A 14,193 cf Overall - 4,962 cf Embedded = 9,231 cf x 40.0% Voids #2A 915.90' 3,976 cf ADS N-12 36" x 28 Inside #1 Inside= 36.1"W x 36.1"H => 7.10 sf x 20.00'L = 142.0 cf Outside= 42.0"W x 42.0"H => 8.86 sf x 20.00'L = 177.2 cf 7 Rows of 4 Chambers 7,668 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 915.40'0.800 in/hr Exfiltration over Surface area #2 Device 3 918.50'4.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 #3 Primary 915.40'12.0" Round Culvert L= 50.0' Ke= 0.100 Inlet / Outlet Invert= 915.40' / 915.05' S= 0.0070 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean, Flow Area= 0.79 sf Discarded OutFlow Max=0.06 cfs @ 11.10 hrs HW=915.45' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=0.00 cfs @ 1.00 hrs HW=915.40' (Free Discharge) 3=Culvert ( Controls 0.00 cfs) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 16HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 6P: U/G 36" INFILTRATION - Chamber Wizard Field A Chamber Model = ADS N-12 36" (ADS N-12® Pipe) Inside= 36.1"W x 36.1"H => 7.10 sf x 20.00'L = 142.0 cf Outside= 42.0"W x 42.0"H => 8.86 sf x 20.00'L = 177.2 cf 42.0" Wide + 21.0" Spacing = 63.0" C-C Row Spacing 4 Chambers/Row x 20.00' Long = 80.00' Row Length +18.0" End Stone x 2 = 83.00' Base Length 7 Rows x 42.0" Wide + 21.0" Spacing x 6 + 18.0" Side Stone x 2 = 38.00' Base Width 6.0" Base + 42.0" Chamber Height + 6.0" Cover = 4.50' Field Height 28 Chambers x 142.0 cf = 3,976.0 cf Chamber Storage 28 Chambers x 177.2 cf = 4,962.2 cf Displacement 14,193.0 cf Field - 4,962.2 cf Chambers = 9,230.8 cf Stone x 40.0% Voids = 3,692.3 cf Stone Storage Chamber Storage + Stone Storage = 7,668.3 cf = 0.176 af Overall Storage Efficiency = 54.0% Overall System Size = 83.00' x 38.00' x 4.50' 28 Chambers 525.7 cy Field 341.9 cy Stone MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 17HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 6P: U/G 36" INFILTRATION Inflow Outflow Discarded Primary Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)2 1 0 Inflow Area=0.538 ac Peak Elev=917.06' Storage=2,547 cf 1.87 cfs 0.06 cfs 0.06 cfs 0.00 cfs MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 18HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Pond 7P: INFILTRATION BASIN Inflow Area = 0.147 ac, 44.90% Impervious, Inflow Depth = 1.02" for 2-Year event Inflow = 0.26 cfs @ 12.15 hrs, Volume= 0.012 af Outflow = 0.02 cfs @ 13.39 hrs, Volume= 0.012 af, Atten= 93%, Lag= 74.5 min Discarded = 0.02 cfs @ 13.39 hrs, Volume= 0.012 af Primary = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 919.80' @ 13.39 hrs Surf.Area= 1,001 sf Storage= 269 cf Plug-Flow detention time= 145.7 min calculated for 0.012 af (100% of inflow) Center-of-Mass det. time= 145.6 min ( 970.4 - 824.8 ) Volume Invert Avail.Storage Storage Description #1 919.50' 3,159 cf BASIN WEST (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 919.50 790 255.4 0 0 790 920.50 1,584 274.3 1,164 1,164 1,630 921.50 2,436 293.2 1,995 3,159 2,529 Device Routing Invert Outlet Devices #1 Discarded 919.50'0.800 in/hr Exfiltration over Surface area #2 Device 3 921.20'24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Primary 918.00'12.0" Round Culvert L= 25.0' Ke= 0.100 Inlet / Outlet Invert= 918.00' / 917.50' S= 0.0200 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Discarded OutFlow Max=0.02 cfs @ 13.39 hrs HW=919.80' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max=0.00 cfs @ 1.00 hrs HW=919.50' (Free Discharge) 3=Culvert (Passes 0.00 cfs of 4.74 cfs potential flow) 2=Orifice/Grate ( Controls 0.00 cfs) MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 19HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 7P: INFILTRATION BASIN Inflow Outflow Discarded Primary Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.147 ac Peak Elev=919.80' Storage=269 cf 0.26 cfs 0.02 cfs 0.02 cfs 0.00 cfs MSE 24-hr 3 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 20HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Time span=1.00-72.00 hrs, dt=0.05 hrs, 1421 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=0.035 ac 68.57% Impervious Runoff Depth=2.73"Subcatchment 1S: C-DA-1 Flow Length=145' Slope=0.0200 '/' Tc=14.0 min CN=86 Runoff=0.13 cfs 0.008 af Runoff Area=0.060 ac 1.67% Impervious Runoff Depth=0.97"Subcatchment 2S: C-DA-2 Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=62 Runoff=0.07 cfs 0.005 af Runoff Area=0.147 ac 44.90% Impervious Runoff Depth=2.05"Subcatchment 3S: C-DA-3 Tc=7.0 min CN=78 Runoff=0.52 cfs 0.025 af Runoff Area=0.538 ac 86.43% Impervious Runoff Depth=3.41"Subcatchment 7S: C-DA-4 Tc=7.0 min CN=93 Runoff=2.95 cfs 0.153 af Runoff Area=0.053 ac 0.00% Impervious Runoff Depth=0.92"Subcatchment 8S: C-DA-6 Tc=7.0 min CN=61 Runoff=0.08 cfs 0.004 af Runoff Area=0.031 ac 35.48% Impervious Runoff Depth=1.74"Subcatchment 9S: C-DA-5 Tc=7.0 min CN=74 Runoff=0.09 cfs 0.005 af Inflow=0.08 cfs 0.004 afReach 8R: EX ONSITE INLET Outflow=0.08 cfs 0.004 af Inflow=0.33 cfs 0.021 afReach 10R: TOTAL SITE Outflow=0.33 cfs 0.021 af Peak Elev=917.97' Storage=4,552 cf Inflow=2.95 cfs 0.153 afPond 6P: U/G 36" INFILTRATION Discarded=0.06 cfs 0.153 af Primary=0.00 cfs 0.000 af Outflow=0.06 cfs 0.153 af Peak Elev=920.13' Storage=645 cf Inflow=0.52 cfs 0.025 afPond 7P: INFILTRATION BASIN Discarded=0.02 cfs 0.025 af Primary=0.00 cfs 0.000 af Outflow=0.02 cfs 0.025 af Total Runoff Area = 0.864 ac Runoff Volume = 0.200 af Average Runoff Depth = 2.77" 34.37% Pervious = 0.297 ac 65.63% Impervious = 0.567 ac MSE 24-hr 3 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 21HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: C-DA-1 Runoff = 0.13 cfs @ 12.22 hrs, Volume= 0.008 af, Depth= 2.73" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 10-Year Rainfall=4.20" Area (ac) CN Description 0.011 61 >75% Grass cover, Good, HSG B 0.024 98 Paved parking, HSG B 0.035 86 Weighted Average 0.011 31.43% Pervious Area 0.024 68.57% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.0 145 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 1S: C-DA-1 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 MSE 24-hr 3 10-Year Rainfall=4.20" Runoff Area=0.035 ac Runoff Volume=0.008 af Runoff Depth=2.73" Flow Length=145' Slope=0.0200 '/' Tc=14.0 min CN=86 0.13 cfs MSE 24-hr 3 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 22HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: C-DA-2 Runoff = 0.07 cfs @ 12.24 hrs, Volume= 0.005 af, Depth= 0.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 10-Year Rainfall=4.20" Area (ac) CN Description 0.059 61 >75% Grass cover, Good, HSG B 0.001 98 Paved parking, HSG B 0.060 62 Weighted Average 0.059 98.33% Pervious Area 0.001 1.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.6 140 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 2S: C-DA-2 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 MSE 24-hr 3 10-Year Rainfall=4.20" Runoff Area=0.060 ac Runoff Volume=0.005 af Runoff Depth=0.97" Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=62 0.07 cfs MSE 24-hr 3 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 23HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: C-DA-3 Runoff = 0.52 cfs @ 12.15 hrs, Volume= 0.025 af, Depth= 2.05" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 10-Year Rainfall=4.20" Area (ac) CN Description 0.081 61 >75% Grass cover, Good, HSG B 0.066 98 Roofs, HSG B 0.147 78 Weighted Average 0.081 55.10% Pervious Area 0.066 44.90% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 3S: C-DA-3 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 MSE 24-hr 3 10-Year Rainfall=4.20" Runoff Area=0.147 ac Runoff Volume=0.025 af Runoff Depth=2.05" Tc=7.0 min CN=78 0.52 cfs MSE 24-hr 3 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 24HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 7S: C-DA-4 Runoff = 2.95 cfs @ 12.14 hrs, Volume= 0.153 af, Depth= 3.41" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 10-Year Rainfall=4.20" Area (ac) CN Description 0.073 61 >75% Grass cover, Good, HSG B 0.465 98 Paved parking, HSG B 0.538 93 Weighted Average 0.073 13.57% Pervious Area 0.465 86.43% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 7S: C-DA-4 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)3 2 1 0 MSE 24-hr 3 10-Year Rainfall=4.20" Runoff Area=0.538 ac Runoff Volume=0.153 af Runoff Depth=3.41" Tc=7.0 min CN=93 2.95 cfs MSE 24-hr 3 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 25HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 8S: C-DA-6 Runoff = 0.08 cfs @ 12.16 hrs, Volume= 0.004 af, Depth= 0.92" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 10-Year Rainfall=4.20" Area (ac) CN Description 0.053 61 >75% Grass cover, Good, HSG B 0.053 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 8S: C-DA-6 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 MSE 24-hr 3 10-Year Rainfall=4.20" Runoff Area=0.053 ac Runoff Volume=0.004 af Runoff Depth=0.92" Tc=7.0 min CN=61 0.08 cfs MSE 24-hr 3 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 26HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 9S: C-DA-5 Runoff = 0.09 cfs @ 12.15 hrs, Volume= 0.005 af, Depth= 1.74" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 10-Year Rainfall=4.20" Area (ac) CN Description 0.011 98 Paved parking, HSG B 0.020 61 >75% Grass cover, Good, HSG B 0.031 74 Weighted Average 0.020 64.52% Pervious Area 0.011 35.48% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 9S: C-DA-5 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.105 0.1 0.095 0.09 0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 MSE 24-hr 3 10-Year Rainfall=4.20" Runoff Area=0.031 ac Runoff Volume=0.005 af Runoff Depth=1.74" Tc=7.0 min CN=74 0.09 cfs MSE 24-hr 3 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 27HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 8R: EX ONSITE INLET [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.053 ac, 0.00% Impervious, Inflow Depth = 0.92" for 10-Year event Inflow = 0.08 cfs @ 12.16 hrs, Volume= 0.004 af Outflow = 0.08 cfs @ 12.16 hrs, Volume= 0.004 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 8R: EX ONSITE INLET Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Inflow Area=0.053 ac 0.08 cfs 0.08 cfs MSE 24-hr 3 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 28HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 10R: TOTAL SITE [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.864 ac, 65.63% Impervious, Inflow Depth = 0.30" for 10-Year event Inflow = 0.33 cfs @ 12.18 hrs, Volume= 0.021 af Outflow = 0.33 cfs @ 12.18 hrs, Volume= 0.021 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 10R: TOTAL SITE Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.864 ac 0.33 cfs 0.33 cfs MSE 24-hr 3 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 29HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Pond 6P: U/G 36" INFILTRATION Inflow Area = 0.538 ac, 86.43% Impervious, Inflow Depth = 3.41" for 10-Year event Inflow = 2.95 cfs @ 12.14 hrs, Volume= 0.153 af Outflow = 0.06 cfs @ 10.70 hrs, Volume= 0.153 af, Atten= 98%, Lag= 0.0 min Discarded = 0.06 cfs @ 10.70 hrs, Volume= 0.153 af Primary = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 917.97' @ 15.10 hrs Surf.Area= 3,154 sf Storage= 4,552 cf Plug-Flow detention time= 713.8 min calculated for 0.153 af (100% of inflow) Center-of-Mass det. time= 714.0 min ( 1,487.4 - 773.3 ) Volume Invert Avail.Storage Storage Description #1A 915.40' 3,692 cf 38.00'W x 83.00'L x 4.50'H Field A 14,193 cf Overall - 4,962 cf Embedded = 9,231 cf x 40.0% Voids #2A 915.90' 3,976 cf ADS N-12 36" x 28 Inside #1 Inside= 36.1"W x 36.1"H => 7.10 sf x 20.00'L = 142.0 cf Outside= 42.0"W x 42.0"H => 8.86 sf x 20.00'L = 177.2 cf 7 Rows of 4 Chambers 7,668 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 915.40'0.800 in/hr Exfiltration over Surface area #2 Device 3 918.50'4.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 #3 Primary 915.40'12.0" Round Culvert L= 50.0' Ke= 0.100 Inlet / Outlet Invert= 915.40' / 915.05' S= 0.0070 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean, Flow Area= 0.79 sf Discarded OutFlow Max=0.06 cfs @ 10.70 hrs HW=915.45' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=0.00 cfs @ 1.00 hrs HW=915.40' (Free Discharge) 3=Culvert ( Controls 0.00 cfs) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) MSE 24-hr 3 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 30HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 6P: U/G 36" INFILTRATION - Chamber Wizard Field A Chamber Model = ADS N-12 36" (ADS N-12® Pipe) Inside= 36.1"W x 36.1"H => 7.10 sf x 20.00'L = 142.0 cf Outside= 42.0"W x 42.0"H => 8.86 sf x 20.00'L = 177.2 cf 42.0" Wide + 21.0" Spacing = 63.0" C-C Row Spacing 4 Chambers/Row x 20.00' Long = 80.00' Row Length +18.0" End Stone x 2 = 83.00' Base Length 7 Rows x 42.0" Wide + 21.0" Spacing x 6 + 18.0" Side Stone x 2 = 38.00' Base Width 6.0" Base + 42.0" Chamber Height + 6.0" Cover = 4.50' Field Height 28 Chambers x 142.0 cf = 3,976.0 cf Chamber Storage 28 Chambers x 177.2 cf = 4,962.2 cf Displacement 14,193.0 cf Field - 4,962.2 cf Chambers = 9,230.8 cf Stone x 40.0% Voids = 3,692.3 cf Stone Storage Chamber Storage + Stone Storage = 7,668.3 cf = 0.176 af Overall Storage Efficiency = 54.0% Overall System Size = 83.00' x 38.00' x 4.50' 28 Chambers 525.7 cy Field 341.9 cy Stone MSE 24-hr 3 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 31HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 6P: U/G 36" INFILTRATION Inflow Outflow Discarded Primary Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)3 2 1 0 Inflow Area=0.538 ac Peak Elev=917.97' Storage=4,552 cf 2.95 cfs 0.06 cfs 0.06 cfs 0.00 cfs MSE 24-hr 3 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 32HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Pond 7P: INFILTRATION BASIN Inflow Area = 0.147 ac, 44.90% Impervious, Inflow Depth = 2.05" for 10-Year event Inflow = 0.52 cfs @ 12.15 hrs, Volume= 0.025 af Outflow = 0.02 cfs @ 13.60 hrs, Volume= 0.025 af, Atten= 96%, Lag= 87.3 min Discarded = 0.02 cfs @ 13.60 hrs, Volume= 0.025 af Primary = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 920.13' @ 13.60 hrs Surf.Area= 1,262 sf Storage= 645 cf Plug-Flow detention time= 302.2 min calculated for 0.025 af (100% of inflow) Center-of-Mass det. time= 302.1 min ( 1,112.0 - 809.9 ) Volume Invert Avail.Storage Storage Description #1 919.50' 3,159 cf BASIN WEST (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 919.50 790 255.4 0 0 790 920.50 1,584 274.3 1,164 1,164 1,630 921.50 2,436 293.2 1,995 3,159 2,529 Device Routing Invert Outlet Devices #1 Discarded 919.50'0.800 in/hr Exfiltration over Surface area #2 Device 3 921.20'24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Primary 918.00'12.0" Round Culvert L= 25.0' Ke= 0.100 Inlet / Outlet Invert= 918.00' / 917.50' S= 0.0200 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Discarded OutFlow Max=0.02 cfs @ 13.60 hrs HW=920.13' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max=0.00 cfs @ 1.00 hrs HW=919.50' (Free Discharge) 3=Culvert (Passes 0.00 cfs of 4.74 cfs potential flow) 2=Orifice/Grate ( Controls 0.00 cfs) MSE 24-hr 3 10-Year Rainfall=4.20"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 33HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 7P: INFILTRATION BASIN Inflow Outflow Discarded Primary Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.147 ac Peak Elev=920.13' Storage=645 cf 0.52 cfs 0.02 cfs 0.02 cfs 0.00 cfs MSE 24-hr 3 100-Year Rainfall=7.18"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 34HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Time span=1.00-72.00 hrs, dt=0.05 hrs, 1421 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=0.035 ac 68.57% Impervious Runoff Depth=5.54"Subcatchment 1S: C-DA-1 Flow Length=145' Slope=0.0200 '/' Tc=14.0 min CN=86 Runoff=0.25 cfs 0.016 af Runoff Area=0.060 ac 1.67% Impervious Runoff Depth=2.93"Subcatchment 2S: C-DA-2 Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=62 Runoff=0.23 cfs 0.015 af Runoff Area=0.147 ac 44.90% Impervious Runoff Depth=4.64"Subcatchment 3S: C-DA-3 Tc=7.0 min CN=78 Runoff=1.16 cfs 0.057 af Runoff Area=0.538 ac 86.43% Impervious Runoff Depth=6.35"Subcatchment 7S: C-DA-4 Tc=7.0 min CN=93 Runoff=5.28 cfs 0.285 af Runoff Area=0.053 ac 0.00% Impervious Runoff Depth=2.83"Subcatchment 8S: C-DA-6 Tc=7.0 min CN=61 Runoff=0.26 cfs 0.013 af Runoff Area=0.031 ac 35.48% Impervious Runoff Depth=4.20"Subcatchment 9S: C-DA-5 Tc=7.0 min CN=74 Runoff=0.22 cfs 0.011 af Inflow=0.26 cfs 0.013 afReach 8R: EX ONSITE INLET Outflow=0.26 cfs 0.013 af Inflow=2.41 cfs 0.139 afReach 10R: TOTAL SITE Outflow=2.41 cfs 0.139 af Peak Elev=918.80' Storage=6,238 cf Inflow=5.28 cfs 0.285 afPond 6P: U/G 36" INFILTRATION Discarded=0.06 cfs 0.200 af Primary=1.84 cfs 0.084 af Outflow=1.90 cfs 0.285 af Peak Elev=920.78' Storage=1,645 cf Inflow=1.16 cfs 0.057 afPond 7P: INFILTRATION BASIN Discarded=0.03 cfs 0.057 af Primary=0.00 cfs 0.000 af Outflow=0.03 cfs 0.057 af Total Runoff Area = 0.864 ac Runoff Volume = 0.396 af Average Runoff Depth = 5.50" 34.37% Pervious = 0.297 ac 65.63% Impervious = 0.567 ac MSE 24-hr 3 100-Year Rainfall=7.18"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 35HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: C-DA-1 Runoff = 0.25 cfs @ 12.22 hrs, Volume= 0.016 af, Depth= 5.54" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 100-Year Rainfall=7.18" Area (ac) CN Description 0.011 61 >75% Grass cover, Good, HSG B 0.024 98 Paved parking, HSG B 0.035 86 Weighted Average 0.011 31.43% Pervious Area 0.024 68.57% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.0 145 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 1S: C-DA-1 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 MSE 24-hr 3 100-Year Rainfall=7.18" Runoff Area=0.035 ac Runoff Volume=0.016 af Runoff Depth=5.54" Flow Length=145' Slope=0.0200 '/' Tc=14.0 min CN=86 0.25 cfs MSE 24-hr 3 100-Year Rainfall=7.18"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 36HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: C-DA-2 Runoff = 0.23 cfs @ 12.23 hrs, Volume= 0.015 af, Depth= 2.93" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 100-Year Rainfall=7.18" Area (ac) CN Description 0.059 61 >75% Grass cover, Good, HSG B 0.001 98 Paved parking, HSG B 0.060 62 Weighted Average 0.059 98.33% Pervious Area 0.001 1.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.6 140 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 2S: C-DA-2 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.26 0.25 0.24 0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 MSE 24-hr 3 100-Year Rainfall=7.18" Runoff Area=0.060 ac Runoff Volume=0.015 af Runoff Depth=2.93" Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=62 0.23 cfs MSE 24-hr 3 100-Year Rainfall=7.18"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 37HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: C-DA-3 Runoff = 1.16 cfs @ 12.14 hrs, Volume= 0.057 af, Depth= 4.64" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 100-Year Rainfall=7.18" Area (ac) CN Description 0.081 61 >75% Grass cover, Good, HSG B 0.066 98 Roofs, HSG B 0.147 78 Weighted Average 0.081 55.10% Pervious Area 0.066 44.90% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 3S: C-DA-3 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)1 0 MSE 24-hr 3 100-Year Rainfall=7.18" Runoff Area=0.147 ac Runoff Volume=0.057 af Runoff Depth=4.64" Tc=7.0 min CN=78 1.16 cfs MSE 24-hr 3 100-Year Rainfall=7.18"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 38HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 7S: C-DA-4 Runoff = 5.28 cfs @ 12.14 hrs, Volume= 0.285 af, Depth= 6.35" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 100-Year Rainfall=7.18" Area (ac) CN Description 0.073 61 >75% Grass cover, Good, HSG B 0.465 98 Paved parking, HSG B 0.538 93 Weighted Average 0.073 13.57% Pervious Area 0.465 86.43% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 7S: C-DA-4 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)5 4 3 2 1 0 MSE 24-hr 3 100-Year Rainfall=7.18" Runoff Area=0.538 ac Runoff Volume=0.285 af Runoff Depth=6.35" Tc=7.0 min CN=93 5.28 cfs MSE 24-hr 3 100-Year Rainfall=7.18"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 39HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 8S: C-DA-6 Runoff = 0.26 cfs @ 12.15 hrs, Volume= 0.013 af, Depth= 2.83" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 100-Year Rainfall=7.18" Area (ac) CN Description 0.053 61 >75% Grass cover, Good, HSG B 0.053 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 8S: C-DA-6 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 MSE 24-hr 3 100-Year Rainfall=7.18" Runoff Area=0.053 ac Runoff Volume=0.013 af Runoff Depth=2.83" Tc=7.0 min CN=61 0.26 cfs MSE 24-hr 3 100-Year Rainfall=7.18"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 40HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 9S: C-DA-5 Runoff = 0.22 cfs @ 12.14 hrs, Volume= 0.011 af, Depth= 4.20" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs MSE 24-hr 3 100-Year Rainfall=7.18" Area (ac) CN Description 0.011 98 Paved parking, HSG B 0.020 61 >75% Grass cover, Good, HSG B 0.031 74 Weighted Average 0.020 64.52% Pervious Area 0.011 35.48% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 9S: C-DA-5 Runoff Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.25 0.24 0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 MSE 24-hr 3 100-Year Rainfall=7.18" Runoff Area=0.031 ac Runoff Volume=0.011 af Runoff Depth=4.20" Tc=7.0 min CN=74 0.22 cfs MSE 24-hr 3 100-Year Rainfall=7.18"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 41HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 8R: EX ONSITE INLET [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.053 ac, 0.00% Impervious, Inflow Depth = 2.83" for 100-Year event Inflow = 0.26 cfs @ 12.15 hrs, Volume= 0.013 af Outflow = 0.26 cfs @ 12.15 hrs, Volume= 0.013 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 8R: EX ONSITE INLET Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.053 ac 0.26 cfs 0.26 cfs MSE 24-hr 3 100-Year Rainfall=7.18"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 42HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 10R: TOTAL SITE [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.864 ac, 65.63% Impervious, Inflow Depth = 1.92" for 100-Year event Inflow = 2.41 cfs @ 12.30 hrs, Volume= 0.139 af Outflow = 2.41 cfs @ 12.30 hrs, Volume= 0.139 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Reach 10R: TOTAL SITE Inflow Outflow Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)2 1 0 Inflow Area=0.864 ac 2.41 cfs 2.41 cfs MSE 24-hr 3 100-Year Rainfall=7.18"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 43HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Pond 6P: U/G 36" INFILTRATION Inflow Area = 0.538 ac, 86.43% Impervious, Inflow Depth = 6.35" for 100-Year event Inflow = 5.28 cfs @ 12.14 hrs, Volume= 0.285 af Outflow = 1.90 cfs @ 12.31 hrs, Volume= 0.285 af, Atten= 64%, Lag= 10.4 min Discarded = 0.06 cfs @ 9.20 hrs, Volume= 0.200 af Primary = 1.84 cfs @ 12.31 hrs, Volume= 0.084 af Routing by Stor-Ind method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 918.80' @ 12.31 hrs Surf.Area= 3,154 sf Storage= 6,238 cf Plug-Flow detention time= 637.5 min calculated for 0.285 af (100% of inflow) Center-of-Mass det. time= 637.3 min ( 1,399.2 - 761.8 ) Volume Invert Avail.Storage Storage Description #1A 915.40' 3,692 cf 38.00'W x 83.00'L x 4.50'H Field A 14,193 cf Overall - 4,962 cf Embedded = 9,231 cf x 40.0% Voids #2A 915.90' 3,976 cf ADS N-12 36" x 28 Inside #1 Inside= 36.1"W x 36.1"H => 7.10 sf x 20.00'L = 142.0 cf Outside= 42.0"W x 42.0"H => 8.86 sf x 20.00'L = 177.2 cf 7 Rows of 4 Chambers 7,668 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 915.40'0.800 in/hr Exfiltration over Surface area #2 Device 3 918.50'4.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 #3 Primary 915.40'12.0" Round Culvert L= 50.0' Ke= 0.100 Inlet / Outlet Invert= 915.40' / 915.05' S= 0.0070 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean, Flow Area= 0.79 sf Discarded OutFlow Max=0.06 cfs @ 9.20 hrs HW=915.45' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=1.78 cfs @ 12.31 hrs HW=918.79' (Free Discharge) 3=Culvert (Passes 1.78 cfs of 7.00 cfs potential flow) 2=Broad-Crested Rectangular Weir (Weir Controls 1.78 cfs @ 1.54 fps) MSE 24-hr 3 100-Year Rainfall=7.18"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 44HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 6P: U/G 36" INFILTRATION - Chamber Wizard Field A Chamber Model = ADS N-12 36" (ADS N-12® Pipe) Inside= 36.1"W x 36.1"H => 7.10 sf x 20.00'L = 142.0 cf Outside= 42.0"W x 42.0"H => 8.86 sf x 20.00'L = 177.2 cf 42.0" Wide + 21.0" Spacing = 63.0" C-C Row Spacing 4 Chambers/Row x 20.00' Long = 80.00' Row Length +18.0" End Stone x 2 = 83.00' Base Length 7 Rows x 42.0" Wide + 21.0" Spacing x 6 + 18.0" Side Stone x 2 = 38.00' Base Width 6.0" Base + 42.0" Chamber Height + 6.0" Cover = 4.50' Field Height 28 Chambers x 142.0 cf = 3,976.0 cf Chamber Storage 28 Chambers x 177.2 cf = 4,962.2 cf Displacement 14,193.0 cf Field - 4,962.2 cf Chambers = 9,230.8 cf Stone x 40.0% Voids = 3,692.3 cf Stone Storage Chamber Storage + Stone Storage = 7,668.3 cf = 0.176 af Overall Storage Efficiency = 54.0% Overall System Size = 83.00' x 38.00' x 4.50' 28 Chambers 525.7 cy Field 341.9 cy Stone MSE 24-hr 3 100-Year Rainfall=7.18"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 45HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 6P: U/G 36" INFILTRATION Inflow Outflow Discarded Primary Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)5 4 3 2 1 0 Inflow Area=0.538 ac Peak Elev=918.80' Storage=6,238 cf 5.28 cfs 1.90 cfs 0.06 cfs 1.84 cfs MSE 24-hr 3 100-Year Rainfall=7.18"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 46HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Pond 7P: INFILTRATION BASIN Inflow Area = 0.147 ac, 44.90% Impervious, Inflow Depth = 4.64" for 100-Year event Inflow = 1.16 cfs @ 12.14 hrs, Volume= 0.057 af Outflow = 0.03 cfs @ 14.40 hrs, Volume= 0.057 af, Atten= 97%, Lag= 135.8 min Discarded = 0.03 cfs @ 14.40 hrs, Volume= 0.057 af Primary = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 920.78' @ 14.40 hrs Surf.Area= 1,807 sf Storage= 1,645 cf Plug-Flow detention time= 556.0 min calculated for 0.057 af (100% of inflow) Center-of-Mass det. time= 556.2 min ( 1,349.6 - 793.4 ) Volume Invert Avail.Storage Storage Description #1 919.50' 3,159 cf BASIN WEST (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 919.50 790 255.4 0 0 790 920.50 1,584 274.3 1,164 1,164 1,630 921.50 2,436 293.2 1,995 3,159 2,529 Device Routing Invert Outlet Devices #1 Discarded 919.50'0.800 in/hr Exfiltration over Surface area #2 Device 3 921.20'24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Primary 918.00'12.0" Round Culvert L= 25.0' Ke= 0.100 Inlet / Outlet Invert= 918.00' / 917.50' S= 0.0200 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Discarded OutFlow Max=0.03 cfs @ 14.40 hrs HW=920.78' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.03 cfs) Primary OutFlow Max=0.00 cfs @ 1.00 hrs HW=919.50' (Free Discharge) 3=Culvert (Passes 0.00 cfs of 4.74 cfs potential flow) 2=Orifice/Grate ( Controls 0.00 cfs) MSE 24-hr 3 100-Year Rainfall=7.18"CBA Chanhassen Pr Cond_Atlas 14_Rainfall Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 47HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 7P: INFILTRATION BASIN Inflow Outflow Discarded Primary Hydrograph Time (hours) 72706866646260585654525048464442403836343230282624222018161412108642Flow (cfs)1 0 Inflow Area=0.147 ac Peak Elev=920.78' Storage=1,645 cf 1.16 cfs 0.03 cfs 0.03 cfs 0.00 cfs 1S C-DA-1 2S C-DA-2 3S C-DA-3 7S C-DA-4 8S C-DA-6 9S C-DA-5 8R EX ONSITE INLET 10R TOTAL SITE 6P U/G 36" INFILTRATION 7P INFILTRATION BASIN Routing Diagram for CBA Chanhassen Pr Cond_Atlas 14_10 Day Snow Melt Prepared by Kimley-Horn and Associates, Printed 10/25/2020 HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Subcat Reach Pond Link CBA Chanhassen Pr Cond_Atlas 14_10 Day Snow Melt Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 2HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.297 100 >75% Grass cover, Good, HSG B (1S, 2S, 3S, 7S, 8S, 9S) 0.501 98 Paved parking, HSG B (1S, 2S, 7S, 9S) 0.066 98 Roofs, HSG B (3S) 0.864 99 TOTAL AREA CBA Chanhassen Pr Cond_Atlas 14_10 Day Snow Melt Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 3HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 0.864 HSG B 1S, 2S, 3S, 7S, 8S, 9S 0.000 HSG C 0.000 HSG D 0.000 Other 0.864 TOTAL AREA CBA Chanhassen Pr Cond_Atlas 14_10 Day Snow Melt Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 4HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.297 0.000 0.000 0.000 0.297 >75% Grass cover, Good 1S, 2S, 3S, 7S, 8S, 9S 0.000 0.501 0.000 0.000 0.000 0.501 Paved parking 1S, 2S, 7S, 9S 0.000 0.066 0.000 0.000 0.000 0.066 Roofs 3S 0.000 0.864 0.000 0.000 0.000 0.864 TOTAL AREA CBA Chanhassen Pr Cond_Atlas 14_10 Day Snow Melt Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 5HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pipe Listing (all nodes) Line# Node Number In-Invert (feet) Out-Invert (feet) Length (feet) Slope (ft/ft) n Diam/Width (inches) Height (inches) Inside-Fill (inches) 1 6P 915.40 915.05 50.0 0.0070 0.011 12.0 0.0 0.0 2 7P 918.00 917.50 25.0 0.0200 0.012 12.0 0.0 0.0 MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4CBA Chanhassen Pr Cond_Atlas 14_ Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 6HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Time span=1.00-240.00 hrs, dt=0.01 hrs, 23901 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=0.035 ac 100.00% Impervious Runoff Depth>7.18"Subcatchment 1S: C-DA-1 Flow Length=145' Slope=0.0200 '/' Tc=14.0 min CN=99 Runoff=0.04 cfs 0.021 af Runoff Area=0.060 ac 100.00% Impervious Runoff Depth>7.30"Subcatchment 2S: C-DA-2 Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=100 Runoff=0.07 cfs 0.036 af Runoff Area=0.147 ac 100.00% Impervious Runoff Depth>7.18"Subcatchment 3S: C-DA-3 Tc=7.0 min CN=99 Runoff=0.18 cfs 0.088 af Runoff Area=0.538 ac 100.00% Impervious Runoff Depth>7.06"Subcatchment 7S: C-DA-4 Tc=7.0 min CN=98 Runoff=0.65 cfs 0.317 af Runoff Area=0.053 ac 100.00% Impervious Runoff Depth>7.30"Subcatchment 8S: C-DA-6 Tc=7.0 min CN=100 Runoff=0.06 cfs 0.032 af Runoff Area=0.031 ac 100.00% Impervious Runoff Depth>7.18"Subcatchment 9S: C-DA-5 Tc=7.0 min CN=99 Runoff=0.04 cfs 0.019 af Inflow=0.06 cfs 0.032 afReach 8R: EX ONSITE INLET Outflow=0.06 cfs 0.032 af Inflow=0.22 cfs 0.108 afReach 10R: TOTAL SITE Outflow=0.22 cfs 0.108 af Peak Elev=918.23' Storage=5,104 cf Inflow=0.65 cfs 0.317 afPond 6P: U/G 36" INFILTRATION Discarded=0.06 cfs 0.317 af Primary=0.00 cfs 0.000 af Outflow=0.06 cfs 0.317 af Peak Elev=920.52' Storage=1,202 cf Inflow=0.18 cfs 0.088 afPond 7P: INFILTRATION BASIN Discarded=0.03 cfs 0.088 af Primary=0.00 cfs 0.000 af Outflow=0.03 cfs 0.088 af Total Runoff Area = 0.864 ac Runoff Volume = 0.513 af Average Runoff Depth = 7.12" 0.00% Pervious = 0.000 ac 100.00% Impervious = 0.864 ac MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4CBA Chanhassen Pr Cond_Atlas 14_ Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 7HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: C-DA-1 Runoff = 0.04 cfs @ 120.82 hrs, Volume= 0.021 af, Depth> 7.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4 Area (ac) CN Description * 0.011 100 >75% Grass cover, Good, HSG B 0.024 98 Paved parking, HSG B 0.035 99 Weighted Average 0.035 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.0 145 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 1S: C-DA-1 Runoff Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.046 0.044 0.042 0.04 0.038 0.036 0.034 0.032 0.03 0.028 0.026 0.024 0.022 0.02 0.018 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0 MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30" AMC=4 Runoff Area=0.035 ac Runoff Volume=0.021 af Runoff Depth>7.18" Flow Length=145' Slope=0.0200 '/' Tc=14.0 min CN=99 0.04 cfs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4CBA Chanhassen Pr Cond_Atlas 14_ Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 8HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: C-DA-2 Runoff = 0.07 cfs @ 120.78 hrs, Volume= 0.036 af, Depth> 7.30" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4 Area (ac) CN Description * 0.059 100 >75% Grass cover, Good, HSG B 0.001 98 Paved parking, HSG B 0.060 100 Weighted Average 0.060 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.6 140 0.0200 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 2.84" Subcatchment 2S: C-DA-2 Runoff Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30" AMC=4 Runoff Area=0.060 ac Runoff Volume=0.036 af Runoff Depth>7.30" Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=100 0.07 cfs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4CBA Chanhassen Pr Cond_Atlas 14_ Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 9HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: C-DA-3 Runoff = 0.18 cfs @ 121.00 hrs, Volume= 0.088 af, Depth> 7.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4 Area (ac) CN Description * 0.081 100 >75% Grass cover, Good, HSG B 0.066 98 Roofs, HSG B 0.147 99 Weighted Average 0.147 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 3S: C-DA-3 Runoff Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30" AMC=4 Runoff Area=0.147 ac Runoff Volume=0.088 af Runoff Depth>7.18" Tc=7.0 min CN=99 0.18 cfs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4CBA Chanhassen Pr Cond_Atlas 14_ Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 10HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 7S: C-DA-4 Runoff = 0.65 cfs @ 121.00 hrs, Volume= 0.317 af, Depth> 7.06" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4 Area (ac) CN Description * 0.073 100 >75% Grass cover, Good, HSG B 0.465 98 Paved parking, HSG B 0.538 98 Weighted Average 0.538 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 7S: C-DA-4 Runoff Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30" AMC=4 Runoff Area=0.538 ac Runoff Volume=0.317 af Runoff Depth>7.06" Tc=7.0 min CN=98 0.65 cfs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4CBA Chanhassen Pr Cond_Atlas 14_ Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 11HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 8S: C-DA-6 Runoff = 0.06 cfs @ 120.75 hrs, Volume= 0.032 af, Depth> 7.30" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4 Area (ac) CN Description * 0.053 100 >75% Grass cover, Good, HSG B 0.053 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 8S: C-DA-6 Runoff Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30" AMC=4 Runoff Area=0.053 ac Runoff Volume=0.032 af Runoff Depth>7.30" Tc=7.0 min CN=100 0.06 cfs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4CBA Chanhassen Pr Cond_Atlas 14_ Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 12HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Subcatchment 9S: C-DA-5 Runoff = 0.04 cfs @ 121.00 hrs, Volume= 0.019 af, Depth> 7.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4 Area (ac) CN Description 0.011 98 Paved parking, HSG B * 0.020 100 >75% Grass cover, Good, HSG B 0.031 99 Weighted Average 0.031 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 9S: C-DA-5 Runoff Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.042 0.04 0.038 0.036 0.034 0.032 0.03 0.028 0.026 0.024 0.022 0.02 0.018 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0 MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30" AMC=4 Runoff Area=0.031 ac Runoff Volume=0.019 af Runoff Depth>7.18" Tc=7.0 min CN=99 0.04 cfs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4CBA Chanhassen Pr Cond_Atlas 14_ Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 13HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 8R: EX ONSITE INLET [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.053 ac,100.00% Impervious, Inflow Depth > 7.30" for Custom event Inflow = 0.06 cfs @ 120.75 hrs, Volume= 0.032 af Outflow = 0.06 cfs @ 120.75 hrs, Volume= 0.032 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs Reach 8R: EX ONSITE INLET Inflow Outflow Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Inflow Area=0.053 ac 0.06 cfs 0.06 cfs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4CBA Chanhassen Pr Cond_Atlas 14_ Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 14HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Reach 10R: TOTAL SITE [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.864 ac,100.00% Impervious, Inflow Depth > 1.50" for Custom event Inflow = 0.22 cfs @ 121.00 hrs, Volume= 0.108 af Outflow = 0.22 cfs @ 121.00 hrs, Volume= 0.108 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs Reach 10R: TOTAL SITE Inflow Outflow Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.24 0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=0.864 ac 0.22 cfs 0.22 cfs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4CBA Chanhassen Pr Cond_Atlas 14_ Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 15HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Pond 6P: U/G 36" INFILTRATION Inflow Area = 0.538 ac,100.00% Impervious, Inflow Depth > 7.06" for Custom event Inflow = 0.65 cfs @ 121.00 hrs, Volume= 0.317 af Outflow = 0.06 cfs @ 115.26 hrs, Volume= 0.317 af, Atten= 91%, Lag= 0.0 min Discarded = 0.06 cfs @ 115.26 hrs, Volume= 0.317 af Primary = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs Peak Elev= 918.23' @ 125.11 hrs Surf.Area= 3,154 sf Storage= 5,104 cf Plug-Flow detention time= 570.9 min calculated for 0.317 af (100% of inflow) Center-of-Mass det. time= 570.4 min ( 7,926.9 - 7,356.5 ) Volume Invert Avail.Storage Storage Description #1A 915.40' 3,692 cf 38.00'W x 83.00'L x 4.50'H Field A 14,193 cf Overall - 4,962 cf Embedded = 9,231 cf x 40.0% Voids #2A 915.90' 3,976 cf ADS N-12 36" x 28 Inside #1 Inside= 36.1"W x 36.1"H => 7.10 sf x 20.00'L = 142.0 cf Outside= 42.0"W x 42.0"H => 8.86 sf x 20.00'L = 177.2 cf 7 Rows of 4 Chambers 7,668 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 915.40'0.800 in/hr Exfiltration over Surface area #2 Device 3 918.50'4.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 #3 Primary 915.40'12.0" Round Culvert L= 50.0' Ke= 0.100 Inlet / Outlet Invert= 915.40' / 915.05' S= 0.0070 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean, Flow Area= 0.79 sf Discarded OutFlow Max=0.06 cfs @ 115.26 hrs HW=915.45' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=0.00 cfs @ 1.00 hrs HW=915.40' (Free Discharge) 3=Culvert ( Controls 0.00 cfs) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4CBA Chanhassen Pr Cond_Atlas 14_ Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 16HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 6P: U/G 36" INFILTRATION - Chamber Wizard Field A Chamber Model = ADS N-12 36" (ADS N-12® Pipe) Inside= 36.1"W x 36.1"H => 7.10 sf x 20.00'L = 142.0 cf Outside= 42.0"W x 42.0"H => 8.86 sf x 20.00'L = 177.2 cf 42.0" Wide + 21.0" Spacing = 63.0" C-C Row Spacing 4 Chambers/Row x 20.00' Long = 80.00' Row Length +18.0" End Stone x 2 = 83.00' Base Length 7 Rows x 42.0" Wide + 21.0" Spacing x 6 + 18.0" Side Stone x 2 = 38.00' Base Width 6.0" Base + 42.0" Chamber Height + 6.0" Cover = 4.50' Field Height 28 Chambers x 142.0 cf = 3,976.0 cf Chamber Storage 28 Chambers x 177.2 cf = 4,962.2 cf Displacement 14,193.0 cf Field - 4,962.2 cf Chambers = 9,230.8 cf Stone x 40.0% Voids = 3,692.3 cf Stone Storage Chamber Storage + Stone Storage = 7,668.3 cf = 0.176 af Overall Storage Efficiency = 54.0% Overall System Size = 83.00' x 38.00' x 4.50' 28 Chambers 525.7 cy Field 341.9 cy Stone MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4CBA Chanhassen Pr Cond_Atlas 14_ Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 17HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 6P: U/G 36" INFILTRATION Inflow Outflow Discarded Primary Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.538 ac Peak Elev=918.23' Storage=5,104 cf 0.65 cfs 0.06 cfs 0.06 cfs 0.00 cfs MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4CBA Chanhassen Pr Cond_Atlas 14_ Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 18HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Summary for Pond 7P: INFILTRATION BASIN Inflow Area = 0.147 ac,100.00% Impervious, Inflow Depth > 7.18" for Custom event Inflow = 0.18 cfs @ 121.00 hrs, Volume= 0.088 af Outflow = 0.03 cfs @ 123.12 hrs, Volume= 0.088 af, Atten= 83%, Lag= 127.2 min Discarded = 0.03 cfs @ 123.12 hrs, Volume= 0.088 af Primary = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 1.00-240.00 hrs, dt= 0.01 hrs Peak Elev= 920.52' @ 123.12 hrs Surf.Area= 1,602 sf Storage= 1,202 cf Plug-Flow detention time= 287.4 min calculated for 0.088 af (100% of inflow) Center-of-Mass det. time= 286.8 min ( 7,581.1 - 7,294.3 ) Volume Invert Avail.Storage Storage Description #1 919.50' 3,159 cf BASIN WEST (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 919.50 790 255.4 0 0 790 920.50 1,584 274.3 1,164 1,164 1,630 921.50 2,436 293.2 1,995 3,159 2,529 Device Routing Invert Outlet Devices #1 Discarded 919.50'0.800 in/hr Exfiltration over Surface area #2 Device 3 921.20'24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Primary 918.00'12.0" Round Culvert L= 25.0' Ke= 0.100 Inlet / Outlet Invert= 918.00' / 917.50' S= 0.0200 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Discarded OutFlow Max=0.03 cfs @ 123.12 hrs HW=920.52' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.03 cfs) Primary OutFlow Max=0.00 cfs @ 1.00 hrs HW=919.50' (Free Discharge) 3=Culvert (Passes 0.00 cfs of 4.74 cfs potential flow) 2=Orifice/Grate ( Controls 0.00 cfs) MSE 24-hr 3 240.00 hrs Custom Rainfall=7.30", AMC=4CBA Chanhassen Pr Cond_Atlas 14_ Printed 10/25/2020Prepared by Kimley-Horn and Associates Page 19HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Pond 7P: INFILTRATION BASIN Inflow Outflow Discarded Primary Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=0.147 ac Peak Elev=920.52' Storage=1,202 cf 0.18 cfs 0.03 cfs 0.03 cfs 0.00 cfs Christian Brothers Automotive - Stormwater Report Page 16 Chanhassen, MN Appendix 5. Water Quality Calculations (MIDS) Project Information Calculator Version:Version 3: January 2017 Project Name:CBA -Chanhassen, MN User Name / Company Name:Kimley-Horn & Associates, Inc. Date:09/17/2020 Project Description: Construction Permit?:Yes Site Information Retention Requirement (inches):1.1 Site's Zip Code:55317 Annual Rainfall (inches):29.9 Phosphorus EMC (mg/l):0.3 TSS EMC (mg/l):54.5 Total Site Area Land Cover A Soils (acres) B Soils (acres) C Soils (acres) D Soils (acres) Total (acres) Forest/Open Space -Undisturbed, protected forest/open space or reforested land 0 Managed Turf -disturbed, graded for yards or other turf to be mowed/managed .25 0.25 Impervious Area (acres).55 Total Area (acres)0.8 Site Areas Routed to BMPs Land Cover A Soils (acres) B Soils (acres) C Soils (acres) D Soils (acres) Total (acres) Forest/Open Space -Undisturbed, protected forest/open space or reforested land 0 Managed Turf -disturbed, graded for yards or other turf to be mowed/managed 0.154 0.154 Impervious Area (acres)0.531 Total Area (acres)0.685 Summary Information Performance Goal Requirement Performance goal volume retention requirement:2196 ft3 Volume removed by BMPs towards performance goal:2120 ft3 Percent volume removed towards performance goal 97 % Annual Volume and Pollutant Load Reductions Post development annual runoff volume 1.2838 acre-ft Annual runoff volume removed by BMPs:1.2003 acre-ft Percent annual runoff volume removed:93 % Post development annual particulate P load:0.576 lbs Annual particulate P removed by BMPs:0.539 lbs Post development annual dissolved P load:0.471 lbs Annual dissolved P removed by BMPs:0.441 lbs Percent annual total phosphorus removed:93 % Post development annual TSS load:190.3 lbs Annual TSS removed by BMPs:177.9 lbs Percent annual TSS removed:93 % BMP Summary Performance Goal Summary BMP Name BMP Volume Capacity (ft3) Volume Recieved (ft3) Volume Retained (ft3) Volume Outflow (ft3) Percent Retained (%) 1 -Infiltration basin/Infiltration trench (aboveground)2519 264 264 0 100 1 -Underground infiltration 6300 1857 1857 0 100 Annual Volume Summary BMP Name Volume From Direct Watershed (acre-ft) Volume From Upstream BMPs (acre-ft) Volume Retained (acre-ft) Volume outflow (acre-ft) Percent Retained (%) 1 -Infiltration basin/Infiltration trench (aboveground)0.1769 0 0.1769 0 100 1 -Underground infiltration 1.0234 0 1.0234 0 100 Particulate Phosphorus Summary BMP Name Load From Direct Watershed (lbs) Load From Upstream BMPs (lbs) Load Retained (lbs) Outflow Load (lbs) Percent Retained (%) 1 -Infiltration basin/Infiltration trench (aboveground)0.0794 0 0.0794 0 100 1 -Underground infiltration 0.4593 0 0.4593 0 100 Dissolved Phosphorus Summary BMP Name Load From Direct Watershed (lbs) Load From Upstream BMPs (lbs) Load Retained (lbs) Outflow Load (lbs) Percent Retained (%) 1 -Infiltration basin/Infiltration trench (aboveground)0.065 0 0.065 0 100 1 -Underground infiltration 0.3758 0 0.3758 0 100 TSS Summary BMP Name Load From Direct Watershed (lbs) Load From Upstream BMPs (lbs) Load Retained (lbs) Outflow Load (lbs) Percent Retained (%) 1 -Infiltration basin/Infiltration trench (aboveground)26.23 0 26.23 0 100 1 -Underground infiltration 151.7 0 151.7 0 100 BMP Schematic Christian Brothers Automotive - Stormwater Report Page 17 Chanhassen, MN Appendix 6. Operations and Maintenance Plan Christian Brothers Automotive Chanhassen, MN STORMWATER MANAGEMENT OPERATION & MAINTENANCE PLAN - 1 OPERATIONS AND MAINTENANCE PLAN 8941 Crossroads Blvd. Chanhassen, MN Prepared for: Christian Brothers Automotive September 18, 2020 Prepared By: Kimley-Horn and Associates, Inc. 767 Eustis Street, Suite 100 St. Paul, MN 55114 (651) 645-4197 I hereby certify that this plan, specification, or report was prepared by me or under my direct supervision, and that I am a duly Registered Professional Engineer under the laws of the State of Minnesota. _________________________________ Brandon R. Elegert, P.E. Date: 09/18/2020 Registration No. 50387 Christian Brothers Automotive Chanhassen, MN STORMWATER MANAGEMENT OPERATION & MAINTENANCE PLAN - 2 CHRISTIAN BROTHERS AUTOMOTIVE CHANHASSEN STORMWATER MANAGEMENT OPERATION & MAINTENANCE PLAN Activity Frequency Water plants As necessary during first growing season Water plants during dry periods As needed after first growing season Re-mulch void areas As needed Treat diseased trees and shrubs As needed Inspect soil and repair eroded areas Monthly Inspect integrity of storm sewer castings and remove accumulated debris from grates As needed Remove litter and debris Monthly Add additional mulch Once per year Sumped Manholes Once per year or as needed SAFL Baffle Once per year or as needed Access Sufficient access shall be provided to the facility to allow all necessary inspection and maintenance activities to be completed. Maintenance of access areas shall include removal of tree seedlings and woody vegetation, repair of eroded areas and removal of litter and debris. Erosion The soil and mulch in the facility and in areas draining to the facility shall be inspected for eroded areas. Eroded areas shall be filled with soil or mulch and vegetated. Outlet Structure Maintenance The Owner will be responsible for outlet structure maintenance. Periodically, the low flow orifice may clog with debris. Debris should be removed and disposed of outside of the facility limits. Debris & Litter Debris and litter should be removed on a monthly basis to maintain appearance and functionality of the facility. Christian Brothers Automotive Chanhassen, MN STORMWATER MANAGEMENT OPERATION & MAINTENANCE PLAN - 3 Plant Maintenance The vegetation type and amount are important to ensure that the facility operates correctly. Proper vegetation maintenance includes watering plants during dry periods, re-mulching void areas, treating diseased trees and shrubs and mowing turf areas. MAINTENANCE OF UNDERGROUND ADS INFILTRATION SYSTEM Regular inspection and maintenance are critical to the effective operation of the underground filtration systems. It is the responsibility of the property owner to maintain all stormwater BMPs in accordance with the minimum design standards and other guidance provided in this manual. See Appendix A for ADS Stormtech guidelines for additional operation and maintenance procedures. Inspection Schedule One inspection form shall be completed for the underground detention system on a monthly or annual basis as specified on the checklist. Erosion The soil and mulch on the property shall be inspected for eroded areas. Eroded areas shall be filled with soil or mulch and vegetated. In the event that erosion persists in a particular area, compacted aggregate shall be used to further stabilize the slope and to mitigate future erosion. Sediment Accumulation & Clogging Sediment accumulation within the facility may reduce the infiltration capacity and impair proper performance of the facility. The facility shall be inspected for accumulation of sediment as part of the inspection. Excessive sediment accumulation shall be removed. Outlet Structure Maintenance The Owner will be responsible for outlet structure maintenance. Periodically, the outlet pipe may clog with debris. Debris should be removed and appropriately disposed of off- site. Standing Water/Pipe Inspection Visual inspection of the pipe chamber system shall occur once per year until a cleaning schedule can be established based on the amount of sediment that is left within the system. Prior to entry into the underground system, the user shall follow all applicable OSHA and local safety regulations. Inspections should occur at least 2-3 days after the most recent rainfall event. The system should be visually inspected at all manhole locations. Utilizing a sediment pole, measure and document the amount of silt at each manhole locations. Inspect each pipe opening to ensure that the silt level or any foreign objects are not blocking the pipes. The sediment level should be measured and recorded during the inspection process. Christian Brothers Automotive Chanhassen, MN STORMWATER MANAGEMENT OPERATION & MAINTENANCE PLAN - 4 The system should be cleaned once the available depth of sediment is 6” above the bottom of the chambers. Cleaning of the system can be done by a vacuum truck every 3-5 years based on actual sediment accumulation or as needed to remain below maximum sediment volume per manufacturer’s recommendations. If the facility has standing water more than 48 hours after a rain event, the system shall be cleaned. To clean, remove the manhole cover at the top of the system and lower a vacuum hose into one of the rows of the pipe system. Open the manhole at the opposite end of the system and use sewer jetting equipment to force water in the same row from one end of the pipe system row to the opposite side. Place the vacuum hose and the sewer jetting equipment in the next row and repeat the process. Inspection and Maintenance (per manufacturer recommendations) Inspect isolator row for sediment. If sediment is at or above 3”, clean out isolator row using the Jetvac process, vacuum structure sump as required. Replace all covers, grates, filters, and lids; record observations and actions. Inspect and clean basins and manholes upstream of the Stormtech system. Refer to manufacturer for complete inspection and maintenance requirements and recommendations. Inspect every 6 months during the first year of operation. Adjust the inspection interval based on previous observations of sediment accumulation and high-water elevations. Conduct jetting and vactoring annually or when inspection shows that maintenance is necessary. MAINTENANCE OF SUMPED PRETREATMENT MANHOLE Remove sediment from the manhole and pretreatment device by using a vacuum truck. Visual inspection to ensure no pipe blockage should occur at the time of cleaning. Prior to entry into the storm sewer manhole, the user shall follow all applicable OSHA and local safety regulations. The pretreatment manholes shall be inspected at least three times during the first two years to inspect the amount accumulated sediment and screen/baffle clogging over the first two years following installation. From the frequent inspections a structure specific maintenance program can be developed. Sediment shall be cleaned once one foot of sediment has accumulated in the manhole sumps. At a minimum the structures containing pretreatment device shall be fully cleaned once a year. Christian Brothers Automotive Chanhassen, MN STORMWATER MANAGEMENT OPERATION & MAINTENANCE PLAN - 5 INSPECTION FORM BMP #1 Underground Infiltration System (Perf. 36” HDPE System) Date: Time: Weather: Inspector: Maintenance Item Comments on Condition Actions to be Taken As Needed Remove Trash and debris Stabilize tributary drainage area when erosion is evident Inflow and outflow at inlet and outlet structures are clean Catch Basins are functioning properly and free of litter and debris Semi Annually (Or After several storm events/extreme storm events) Inspect inflow/outflow and pre- treatment systems for clogging (off- line systems) and remove any sediment Annually in Fall Inspect and remove any sediment and debris build up in pretreatment areas Inspect inflow points and surface for buildup of road sand associated with spring melt, remove as needed Note signs of pollution, such as oil sheens, discolored water, or unpleasant odors. Comments and Actions Required: Christian Brothers Automotive Chanhassen, MN STORMWATER MANAGEMENT OPERATION & MAINTENANCE PLAN - 6 Appendix A Retention/Detention System Maintenance 1 TECHNICAL NOTE 4640 TRUEMAN BLVD. HILLIARD, OH 43026. (800) 821-6710 – www.ads-pipe.com ATN601 ©ADS 2007 TN 6.01 February 2007 This document is provided for informational purposes only and is meant only to be a guide. Individuals using this information should make their own decisions as to suitability of this guideline for their individual projects and adjust accordingly. Introduction A retention/detention system is comprised of a series of pipes and fittings that form an underground storage area, which retains or detains storm water runoff from a given area. As sediment and debris settle out of the detained stormwater, build up occurs that requires the system to be regularly inspected and cleaned in order for the system to perform as originally designed. The following provides the available fittings and guidelines for inspection and maintenance of an HDPE underground storage system. System Accessories and Fittings Concentric Reducers Concentric Reducers are fittings that transition between two pipes, either in line with one another or at perpendicular angles. The centerlines of the two pipes are at the same elevation. When a concentric reducer is used to connect the manifold pipe to the lateral pipes, most debris will be trapped in the manifold pipe. SIDE VIEW SECTION VIEWSIDE VIEW SECTION VIEW Eccentric Reducers Eccentric Reducers are fittings that transition between two pipes, either in line with one another or at perpendicular angles. The inverts of the two pipes are at the same elevations. When an eccentric reducer is used to connect the manifold pipe to the lateral pipes, most debris will follow the flow of the storm water into the lateral pipes. SIDE VIEW SECTION VIEW SIDE VIEW SECTION VIEW 2 4640 TRUEMAN BLVD. HILLIARD, OH 43026. (800) 821-6710 – www.ads-pipe.com Riser Each retention/detention system typically has risers strategically placed for maintenance and inspection of the system. These risers are typically 24” in diameter or larger and are placed on the manifold fittings. Cleanouts Cleanout ports are usually 4-, 6-, or 8-in diameter pipe and are placed on the manifold fittings. They are used for entrance of a pipe from a vacuum truck or a water-jetting device. For a complete listing of available fittings and components please refer to the ADS Fittings Manual. Maintenance Overview of a Retention/Detention System Maintaining a clean and obstruction-free retention/detention system helps to ensure the system performs the intended function of the primary design. Build up of debris may obstruct flow through the laterals in a retention system or block the entranceway of the outlet pipe in a detention system. This may result in ineffective operation or complete failure of the system . Additionally, surrounding areas may potentially run the risk of damage due to flooding or other similar issues. Inspection/Maintenance Frequency All retention/detention systems must be cleaned and maintained. Underground systems may be maintained more cost effectively if these simple guidelines are followed. Inspection should be performed at a minimum of once per year. Cleaning should be done at the discretion of individuals responsible to maintain proper storage and flow. While maintenance can generally be performed year round, it should be scheduled during a relatively dry season. Pre-Inspection A post-installation inspection should be performed to allow the owner to measure the invert prior to accumulation of sediment. This survey will allow the monitoring of sediment build-up without requiring access to the retention/detention system. The following is the recommended procedure for pre-inspections: 1) Locate the riser section or cleanouts of the retention/detention system. The riser will typically be 24” in diameter or larger and the cleanouts are usually 4”, 6” or 8” in diameter. 2) Remove the lid of the riser or clean outs. 3) Insert a measuring device into the opening and make note to a point of reference on the stick or string. (This is done so that sediment build up can be determined in the future without having to enter the system.) RISER CROSS-SECTION VIEW CLEANOUT CROSS-SECTION VIEW 3 4640 TRUEMAN BLVD. HILLIARD, OH 43026. (800) 821-6710 – www.ads-pipe.com Inspection/Maintenance A retention/detention system should be inspected at a minimum of one time a year or after major rain events if necessary. The following is the recommended procedure to inspect system in service: 1) Locate the riser section of the retention/detention system. The riser will typically be 24” in diameter or larger. 2) Remove the lid from the riser. 3) Measure the sediment buildup at each riser and cleanout location. Only certified confined space entry personnel having appropriate equipment should be permitted to enter the retention/detention System. 4) Inspect each manifold, all laterals, and outlet pipes for sediment build up, obstructions, or other problems. Obstructions should be removed at this time. 5) If measured sediment build up is between 5% - 20% of the pipe diameter, cleaning should be considered; if sediment build up exceeds 20%, cleaning should be performed at the earliest opportunity. A thorough cleaning of the system (manifolds and laterals) shall be performed by either manual methods or by a vacuum truck.