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CBA Chanhassen_Stormwater Report_FINAL 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 Christian Brothers Automotive - Stormwater Report Page 2 Chanhassen, MN Stormwater Management Report for Christian Brothers Automotive – Chanhassen, MN Prepared for: Christian Brothers Automotive Corporation September 18, 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: September 18, 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 ................................................................. 12 Appendix 2. Post-Development HydroCAD Model Analysis ............................................................... 13 Appendix 3. Water Quality Calculations (MIDS) ................................................................................. 14 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. Prior to the proposed development, 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 underground stormwater system. 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 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 0.54 Post-Development Rate (CFS) 0.13 0.33 2.41 0.14 Rate Attenuation Summary – Existing Onsite Inlet Pre-Development Rate (CFS) 0.03 0.41 1.40 0.18 Post-Development Rate (CFS) 0.02 0.08 0.26 0.03 Christian Brothers Automotive - Stormwater Report Page 6 Chanhassen, MN 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 2: 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 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 September 18, 2020 - 2:57pm©BYREVISIONSNo.DATEPRELIMINARY - NOT FOR CONSTRUCTIONDATECHECKED BYSCALEDESIGNED BYDRAWN BYKHA PROJECT1606840059/18/2020AS SHOWNCJJKAMBRENORTH PROPERTY LINE EXISTING CONTOUR PROPOSED CONTOUR925 LEGEND 0.0%PROPOSED 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 BOULEVARDCROSSROADS BOULEVARD9 2 3 924922922922 923924922 921 921921 922 922 922 922 923 9222.1 0 % 1.65 % 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 %7.55%2. 1 9 %6.52%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 STORAGE VOLUME: 1,645 SF TREATMENT VOLUME: 2,470 CF BMP 2: UNDERGROUND INFILTRATION SYSTEM ADS 36" N-12 PERFORATED HDPE PIPE OR APPROVED EQUAL TOTAL STORAGE VOLUME: 6,238 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%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 September 18, 2020 - 2:56pm©BYREVISIONSNo.DATEPRELIMINARY - 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 PROJECT1606840059/18/2020AS SHOWNCJJKAMBRE 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 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 Existing Conditions Prepared by Kimley-Horn and Associates, Printed 9/18/2020 HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Subcat Reach Pond Link CBA Chanhassen Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions Printed 9/18/2020Prepared 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 Existing Conditions_10 Day Snow Melt Prepared by Kimley-Horn and Associates, Printed 9/18/2020 HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Subcat Reach Pond Link CBA Chanhassen Existing Conditions_10 Day Snow Melt Printed 9/18/2020Prepared 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 Existing Conditions_10 Day Snow Melt Printed 9/18/2020Prepared 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 Existing Conditions_10 Day Snow Melt Printed 9/18/2020Prepared 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 100-YR 10-Day Snow Melt Rainfall=7.30"CBA Chanhassen Existing C Printed 9/18/2020Prepared 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=0.50 hrs, 479 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>2.92"Subcatchment 1S: V-DA-1 Flow Length=70' Slope=0.0200 '/' Tc=7.8 min CN=61 Runoff=0.06 cfs 0.024 af Runoff Area=0.326 ac 0.00% Impervious Runoff Depth>2.92"Subcatchment 2S: V-DA-3 Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=61 Runoff=0.21 cfs 0.079 af Runoff Area=0.297 ac 0.00% Impervious Runoff Depth>2.92"Subcatchment 3S: V-DA-4 Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 Runoff=0.18 cfs 0.072 af Runoff Area=0.169 ac 0.00% Impervious Runoff Depth>2.92"Subcatchment 6S: V-DA-2 Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 Runoff=0.10 cfs 0.041 af Inflow=0.54 cfs 0.216 afReach 4R: TOTAL SITE Outflow=0.54 cfs 0.216 af Inflow=0.18 cfs 0.072 afReach 9R: EX ONSITE INLET Outflow=0.18 cfs 0.072 af Total Runoff Area = 0.889 ac Runoff Volume = 0.216 af Average Runoff Depth = 2.92" 100.00% Pervious = 0.889 ac 0.00% Impervious = 0.000 ac MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30"CBA Chanhassen Existing C Printed 9/18/2020Prepared 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 [49] Hint: Tc<2dt may require smaller dt Runoff = 0.06 cfs @ 120.66 hrs, Volume= 0.024 af, Depth> 2.92" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.50 hrs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30" 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) 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 MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30" Runoff Area=0.097 ac Runoff Volume=0.024 af Runoff Depth>2.92" Flow Length=70' Slope=0.0200 '/' Tc=7.8 min CN=61 0.06 cfs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30"CBA Chanhassen Existing C Printed 9/18/2020Prepared 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 [49] Hint: Tc<2dt may require smaller dt Runoff = 0.21 cfs @ 120.78 hrs, Volume= 0.079 af, Depth> 2.92" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.50 hrs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30" 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) 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 100-YR 10-Day Snow Melt Rainfall=7.30" Runoff Area=0.326 ac Runoff Volume=0.079 af Runoff Depth>2.92" Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=61 0.21 cfs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30"CBA Chanhassen Existing C Printed 9/18/2020Prepared 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 [49] Hint: Tc<2dt may require smaller dt Runoff = 0.18 cfs @ 120.66 hrs, Volume= 0.072 af, Depth> 2.92" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.50 hrs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30" 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) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)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 100-YR 10-Day Snow Melt Rainfall=7.30" Runoff Area=0.297 ac Runoff Volume=0.072 af Runoff Depth>2.92" Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 0.18 cfs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30"CBA Chanhassen Existing C Printed 9/18/2020Prepared 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 [49] Hint: Tc<2dt may require smaller dt Runoff = 0.10 cfs @ 120.66 hrs, Volume= 0.041 af, Depth> 2.92" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.50 hrs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30" 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) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)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 100-YR 10-Day Snow Melt Rainfall=7.30" Runoff Area=0.169 ac Runoff Volume=0.041 af Runoff Depth>2.92" Flow Length=100' Slope=0.0400 '/' Tc=7.9 min CN=61 0.10 cfs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30"CBA Chanhassen Existing C Printed 9/18/2020Prepared 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 > 2.92" for 100-YR 10-Day Snow Melt event Inflow = 0.54 cfs @ 120.71 hrs, Volume= 0.216 af Outflow = 0.54 cfs @ 120.71 hrs, Volume= 0.216 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-240.00 hrs, dt= 0.50 hrs Reach 4R: TOTAL SITE Inflow Outflow 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=0.889 ac 0.54 cfs 0.54 cfs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30"CBA Chanhassen Existing C Printed 9/18/2020Prepared 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 > 2.92" for 100-YR 10-Day Snow Melt event Inflow = 0.18 cfs @ 120.66 hrs, Volume= 0.072 af Outflow = 0.18 cfs @ 120.66 hrs, Volume= 0.072 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-240.00 hrs, dt= 0.50 hrs Reach 9R: EX ONSITE INLET Inflow Outflow Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)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=0.297 ac 0.18 cfs 0.18 cfs Christian Brothers Automotive - Stormwater Report Page 13 Chanhassen, MN Appendix 2. Post-Development HydroCAD Model Analysis 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 Proposed Conditions_Rainfall Prepared by Kimley-Horn and Associates, Printed 9/18/2020 HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Subcat Reach Pond Link CBA Chanhassen Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Primary 921.20'24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads 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) 2=Orifice/Grate ( Controls 0.00 cfs) MSE 24-hr 3 2-Year Rainfall=2.84"CBA Chanhassen Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Primary 921.20'24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads 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) 2=Orifice/Grate ( Controls 0.00 cfs) MSE 24-hr 3 10-Year Rainfall=4.20"CBA Chanhassen Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Primary 921.20'24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads 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) 2=Orifice/Grate ( Controls 0.00 cfs) MSE 24-hr 3 100-Year Rainfall=7.18"CBA Chanhassen Proposed Conditions_Rainfall Printed 9/18/2020Prepared 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 Proposed Conditions_10 Day Snow Melt Prepared by Kimley-Horn and Associates, Printed 9/18/2020 HydroCAD® 10.00-22 s/n 09843 © 2018 HydroCAD Software Solutions LLC Subcat Reach Pond Link CBA Chanhassen Proposed Conditions_10 Day Snow Melt Printed 9/18/2020Prepared 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 Proposed Conditions_10 Day Snow Melt Printed 9/18/2020Prepared 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 Proposed Conditions_10 Day Snow Melt Printed 9/18/2020Prepared 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 Proposed Conditions_10 Day Snow Melt Printed 9/18/2020Prepared 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 MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30"CBA Chanhassen Proposed Printed 9/18/2020Prepared 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=0.50 hrs, 479 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>5.65"Subcatchment 1S: C-DA-1 Flow Length=145' Slope=0.0200 '/' Tc=14.0 min CN=86 Runoff=0.04 cfs 0.016 af Runoff Area=0.060 ac 1.67% Impervious Runoff Depth>3.02"Subcatchment 2S: C-DA-2 Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=62 Runoff=0.04 cfs 0.015 af Runoff Area=0.147 ac 44.90% Impervious Runoff Depth>4.75"Subcatchment 3S: C-DA-3 Tc=7.0 min CN=78 Runoff=0.14 cfs 0.058 af Runoff Area=0.538 ac 86.43% Impervious Runoff Depth>6.47"Subcatchment 7S: C-DA-4 Tc=7.0 min CN=93 Runoff=0.64 cfs 0.290 af Runoff Area=0.053 ac 0.00% Impervious Runoff Depth>2.92"Subcatchment 8S: C-DA-6 Tc=7.0 min CN=61 Runoff=0.03 cfs 0.013 af Runoff Area=0.031 ac 35.48% Impervious Runoff Depth>4.30"Subcatchment 9S: C-DA-5 Tc=7.0 min CN=74 Runoff=0.03 cfs 0.011 af Inflow=0.03 cfs 0.013 afReach 8R: EX ONSITE INLET Outflow=0.03 cfs 0.013 af Inflow=0.14 cfs 0.056 afReach 10R: TOTAL SITE Outflow=0.14 cfs 0.056 af Peak Elev=918.11' Storage=4,843 cf Inflow=0.64 cfs 0.290 afPond 6P: U/G 36" INFILTRATION Discarded=0.06 cfs 0.290 af Primary=0.00 cfs 0.000 af Outflow=0.06 cfs 0.290 af Peak Elev=920.26' Storage=813 cf Inflow=0.14 cfs 0.058 afPond 7P: INFILTRATION BASIN Discarded=0.03 cfs 0.058 af Primary=0.00 cfs 0.000 af Outflow=0.03 cfs 0.058 af Total Runoff Area = 0.864 ac Runoff Volume = 0.404 af Average Runoff Depth = 5.61" 34.37% Pervious = 0.297 ac 65.63% Impervious = 0.567 ac MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30"CBA Chanhassen Proposed Printed 9/18/2020Prepared 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 [49] Hint: Tc<2dt may require smaller dt Runoff = 0.04 cfs @ 120.70 hrs, Volume= 0.016 af, Depth> 5.65" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.50 hrs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30" 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) 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 100-YR 10-Day Snow Melt Rainfall=7.30" Runoff Area=0.035 ac Runoff Volume=0.016 af Runoff Depth>5.65" Flow Length=145' Slope=0.0200 '/' Tc=14.0 min CN=86 0.04 cfs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30"CBA Chanhassen Proposed Printed 9/18/2020Prepared 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 [49] Hint: Tc<2dt may require smaller dt Runoff = 0.04 cfs @ 120.78 hrs, Volume= 0.015 af, Depth> 3.02" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.50 hrs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30" 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) 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 100-YR 10-Day Snow Melt Rainfall=7.30" Runoff Area=0.060 ac Runoff Volume=0.015 af Runoff Depth>3.02" Flow Length=140' Slope=0.0200 '/' Tc=13.6 min CN=62 0.04 cfs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30"CBA Chanhassen Proposed Printed 9/18/2020Prepared 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 [49] Hint: Tc<2dt may require smaller dt Runoff = 0.14 cfs @ 120.59 hrs, Volume= 0.058 af, Depth> 4.75" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.50 hrs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30" 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) 240230220210200190180170160150140130120110100908070605040302010Flow (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 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30" Runoff Area=0.147 ac Runoff Volume=0.058 af Runoff Depth>4.75" Tc=7.0 min CN=78 0.14 cfs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30"CBA Chanhassen Proposed Printed 9/18/2020Prepared 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 [49] Hint: Tc<2dt may require smaller dt Runoff = 0.64 cfs @ 120.56 hrs, Volume= 0.290 af, Depth> 6.47" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.50 hrs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30" 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) 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 100-YR 10-Day Snow Melt Rainfall=7.30" Runoff Area=0.538 ac Runoff Volume=0.290 af Runoff Depth>6.47" Tc=7.0 min CN=93 0.64 cfs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30"CBA Chanhassen Proposed Printed 9/18/2020Prepared 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 [49] Hint: Tc<2dt may require smaller dt Runoff = 0.03 cfs @ 120.64 hrs, Volume= 0.013 af, Depth> 2.92" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.50 hrs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30" 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) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)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 100-YR 10-Day Snow Melt Rainfall=7.30" Runoff Area=0.053 ac Runoff Volume=0.013 af Runoff Depth>2.92" Tc=7.0 min CN=61 0.03 cfs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30"CBA Chanhassen Proposed Printed 9/18/2020Prepared 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 [49] Hint: Tc<2dt may require smaller dt Runoff = 0.03 cfs @ 120.60 hrs, Volume= 0.011 af, Depth> 4.30" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-240.00 hrs, dt= 0.50 hrs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30" 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) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)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 100-YR 10-Day Snow Melt Rainfall=7.30" Runoff Area=0.031 ac Runoff Volume=0.011 af Runoff Depth>4.30" Tc=7.0 min CN=74 0.03 cfs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30"CBA Chanhassen Proposed Printed 9/18/2020Prepared 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 > 2.92" for 100-YR 10-Day Snow Melt event Inflow = 0.03 cfs @ 120.64 hrs, Volume= 0.013 af Outflow = 0.03 cfs @ 120.64 hrs, Volume= 0.013 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-240.00 hrs, dt= 0.50 hrs Reach 8R: EX ONSITE INLET Inflow Outflow Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (cfs)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 Inflow Area=0.053 ac 0.03 cfs 0.03 cfs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30"CBA Chanhassen Proposed Printed 9/18/2020Prepared 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 > 0.77" for 100-YR 10-Day Snow Melt event Inflow = 0.14 cfs @ 120.69 hrs, Volume= 0.056 af Outflow = 0.14 cfs @ 120.69 hrs, Volume= 0.056 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 1.00-240.00 hrs, dt= 0.50 hrs Reach 10R: TOTAL SITE Inflow Outflow Hydrograph Time (hours) 240230220210200190180170160150140130120110100908070605040302010Flow (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 Inflow Area=0.864 ac 0.14 cfs 0.14 cfs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30"CBA Chanhassen Proposed Printed 9/18/2020Prepared 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 > 6.47" for 100-YR 10-Day Snow Melt event Inflow = 0.64 cfs @ 120.56 hrs, Volume= 0.290 af Outflow = 0.06 cfs @ 116.00 hrs, Volume= 0.290 af, Atten= 91%, Lag= 0.0 min Discarded = 0.06 cfs @ 116.00 hrs, Volume= 0.290 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= 0.50 hrs Peak Elev= 918.11' @ 125.19 hrs Surf.Area= 3,154 sf Storage= 4,843 cf Plug-Flow detention time= 569.9 min calculated for 0.290 af (100% of inflow) Center-of-Mass det. time= 569.5 min ( 8,125.9 - 7,556.3 ) 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 @ 116.00 hrs HW=915.46' (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 100-YR 10-Day Snow Melt Rainfall=7.30"CBA Chanhassen Proposed Printed 9/18/2020Prepared 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 100-YR 10-Day Snow Melt Rainfall=7.30"CBA Chanhassen Proposed Printed 9/18/2020Prepared 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=918.11' Storage=4,843 cf 0.64 cfs 0.06 cfs 0.06 cfs 0.00 cfs MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30"CBA Chanhassen Proposed Printed 9/18/2020Prepared 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 > 4.75" for 100-YR 10-Day Snow Melt event Inflow = 0.14 cfs @ 120.59 hrs, Volume= 0.058 af Outflow = 0.03 cfs @ 123.29 hrs, Volume= 0.058 af, Atten= 82%, Lag= 162.2 min Discarded = 0.03 cfs @ 123.29 hrs, Volume= 0.058 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= 0.50 hrs Peak Elev= 920.26' @ 123.29 hrs Surf.Area= 1,370 sf Storage= 813 cf Plug-Flow detention time= 248.6 min calculated for 0.058 af (100% of inflow) Center-of-Mass det. time= 248.1 min ( 8,119.1 - 7,871.0 ) 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 Primary 921.20'24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.03 cfs @ 123.29 hrs HW=920.26' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.03 cfs) Primary OutFlow Max=0.00 cfs @ 1.00 hrs HW=919.50' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) MSE 24-hr 3 240.00 hrs 100-YR 10-Day Snow Melt Rainfall=7.30"CBA Chanhassen Proposed Printed 9/18/2020Prepared 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)0.15 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=920.26' Storage=813 cf 0.14 cfs 0.03 cfs 0.03 cfs 0.00 cfs Christian Brothers Automotive - Stormwater Report Page 14 Chanhassen, MN Appendix 3. 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