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Drainage Report
-i- Ardalan Plaza October 2024 Project: ARDALAN PLAZA 331 W. Main Street Carmel, IN 46032 Prepared For: STUDIO M ARCHITECT 275 Veterans Wy, Suite 200 Carmel, IN 46033 Prepared By: CIVIL & ENVIRONMENTAL CONSULTANTS, INC. Indianapolis, Indiana Civil Engineer: Nicholas Justice, P.E. CEC Project 344-583 OCTOBER 2024 Drainage Report -ii- Ardalan Plaza October 2024 TABLE OF CONTENTS 1.0 REPORT OVERVIEW .....................................................................................................1 2.0 PROJECT BACKGROUND.............................................................................................1 2.1 Existing conditions.................................................................................................. 1 2.1.1 FEMA Map ..................................................................................................1 2.1.2 Watershed Description .................................................................................1 2.1.3 Soils Map .....................................................................................................2 3.0 STORMWATER DESIGN ...............................................................................................2 3.1 Proposed CONDITIONS ........................................................................................ 2 3.2 Stormwater Management ........................................................................................ 2 3.2.1 Hydraulic Performance ................................................................................2 3.2.2 Outlet Control Structure ...............................................................................3 3.2.3 Runoff Curve Number (CN) Determination ................................................3 3.2.4 Water Quality Treatment ..........................................................................3 4.0 CONCLUSION ..................................................................................................................4 5.0 REFERENCES ...................................................................................................................4 -iii- Ardalan Plaza October 2024 APPENDICES Appendix A – FEMA Firm Map Appendix B – Soils Map Appendix C – Existing & Proposed Watershed Maps Appendix D – Existing HydroCAD Output Appendix E – Proposed HydroCAD Output Appendix F – Water Quality Calculations Appendix G – Storm Sewer Sizing Calculations -1- Ardalan Plaza October 2024 1.0 REPORT OVERVIEW This report establishes the stormwater quantity and quality requirements for the Ardalan Plaza project located at 331 W. Main Street, Carmel, IN 46032. The existing site is made up of three separates, developed, residential-use parcels. The improvements to the site include an apartment building, parking garage, and underground detention. Through a system of storm sewer and permeable pavers, stormwater will be routed into an underground detention system. The proposed improvements will provide stormwater detention and water quality treatment. 2.0 PROJECT BACKGROUND 2.1 EXISTING CONDITIONS The project site is located to the southeast of the intersection between W Main Street and 4th Avenue. This site consists of three occupied buildings, three separated garages, and other landscaping items. The existing condition consists of one large parcel, Basin Pre-A. The site overall drains poorly, there are many pooling spots, however on overall runoff will drain west to east and leave the site as direct discharge. The existing drainage basin map Figure B-1 in Appendix C delineates the drainage area used to calculate detention release rates. The existing discharge rates are summarized as below in Table 1. Detailed HydroCAD calculation results can be found in Appendix D. Table 1: Existing Peak Runoff Rates To Public Storm/Combined System (cfs) Condition Area (Ac) CN 2-Year (cfs) 10-Year (cfs) 100-Year (cfs) Basin Pre-A 0.66 77 0.99 2.01 4.56 Total 0.66 77 0.99 2.01 4.56 2.1.1 FEMA Map The project site is located within the FEMA Community Panel Map #18057C0207G dated November 19, 2014 which indicates the site is located within the Flood Designation ‘Zone X, Area of Minimal Flood Hazard.” The FEMA Map with determined Base Flood Elevations (BFE) is included in Appendix A. 2.1.2 Watershed Description The project site drains to the Cool Creek watershed as provided on the IndianaMap GIS system and identified with a 12-digit Hydrologic Unit Code (HUC) of #051202011001. -2- Ardalan Plaza October 2024 2.1.3 Soils Map The approximate limits of each soil type are depicted in the Soils Map provided in Appendix B. 3.0 STORMWATER DESIGN 3.1 PROPOSED CONDITIONS The proposed combined property is approximately ±0.662 acres and the proposed improvements will include an apartment building, connecting sidewalks, an underground stormwater detention system, water quality treatment unit, and utility infrastructure. The impervious area of the site will increase by approximately ±15,353 ft2 (0.35 acres). The parcel is considered one large watershed named Post-A. Basin Post-A’s runoff will be routed into the proposed underground detention system through a series of stormsewer and permeable pavers, pass through an Aqua-Swirl water quality treatment unit, before being discharged into the stormsewer system located along 3rd Avenue. Refer to the proposed drainage maps Figures C-1 in Appendix C. Calculations for detention sizing and detailed HydroCAD calculations can be found in Appendix E. Per the City of Indianapolis Stormwater “Additional Approved Product” list dated 06/30/2022, the Belgard Interlocking Concrete Paver System is proposed to be used as alternative stormwater conveyance system. Per the manual, the minimum surface area must be designed at ten (10) times the surface area needed for the flow rate directed into the system. The required permeable paving area is calculated as below: A = 1.33 (Qx10) / I = 1.33 (6.08 x 10) / 1.1 = 73.5 yd2 = 662 ft2 o A = Area of paver system in square-yards o Q = Design runoff rate (100-yr storm, obtained from HydroCAD results) in cfs o I = pavement infiltration rate as established in manual = 1.1 in/s Provided permeable pavement area = 3,824 ft2 3.2 STORMWATER MANAGEMENT 3.2.1 Hydraulic Performance The maximum allowable peak runoff rate is constrained to meet the criteria outlined in section 302.03 of the City of Carmel Stormwater Manual. An outlet control structure will reduce runoff from the site to the allowable release rates. However, meeting the allowable discharge rates requires a 10-yr control orifice smaller than 2.0” in the outlet control structure of both detention vault. An actual proposed discharge is also calculated utilizing the minimum required 2” orifice size. Both theoretical and actual results are presented below in Table 2. -3- Ardalan Plaza October 2024 Table 2: Proposed Discharge Rates To Public Storm/Combined System (cfs) Condition Area (Ac) CN 2-Year (cfs) 10-Year (cfs) 100-Year (cfs) Allowable* 0.66 - 0.07 0.07 0.20 Theoretical (Post-A) 95 0.05 0.07 0.20 Actual (Post-A) 0.10 0.13 0.27 * Q2-yr,10-yr post = 0.1 cfs/ac | Q100-yr, post = 0.3 cfs/ac * Q2-yr,10-yr post = 0.1 x 0.662 = 0.07 cfs | Q100-yr, post = 0.1 x 0.662 = 0.20 cfs 3.2.2 Outlet Control Structure As mentioned prior in Section 3.2.1, a theoretical and actual design outlet orifice will be provided to show that detention are designed to the City of Carmel’s standards, the actual orifice sizes to detain the runoff from the basins summarized as below: 2.0” @ 825.25 2.0” @ 826.80 3.2.3 Runoff Curve Number (CN) Determination For impervious areas such as buildings and pavement, a CN value of 98 was used. Areas with exposed subgrade and grass cover were modeled using a CN of 61 for soil group “B”, CN of 74 for soil group “C” and CN of 80 for soil group “D” classification highlighted in Appendix B. The HydroCAD reports in Appendix D and Appendix E show the calculated CN values as well as time of concentration for each site basin. Rainfall depths in the City of Indianapolis Technical Standards Manual were used to develop the basin hydrographs. 3.2.4 Water Quality Treatment A water quality treatment unit will be provided to treat the runoff before discharging into the sewer system. The project site will be serviced by an Aqua-swirl XC-4 unit to be used on-line. The water quality map and calculations can be found in Appendix F. 3.2.5 Pipe Sizing The storm sewer pipes are sized for a 10-year rainfall event. The time of concentration is assumed to be a minimum allowable of 5 minutes. Storm sewer sizing calculations from Hydraflow and inlet capacity calculations can be found in Appendix G. -4- Ardalan Plaza October 2024 4.0 CONCLUSION The proposed Ardalan Plaza project will be served with adequate detention and water quality facilities in accordance with the City of Carmel Stormwater Specification Manual. No adverse impacts are expected for upstream or downstream property owners. 5.0 REFERENCES 1. USDA NRCS Web Soil Survey 2. U.S. Geological Survey, IndianaMap website 3. FEMA Flood Insurance Rate Maps, FEMA website 4. City of Carmel Stormwater Technical Standards Manual APPENDIX A FEMA FIRM National Flood Hazard Layer FIRMette 0 500 1,000 1,500 2,000250 Feet Ü SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOOD HAZARD AREAS Without Base Flood Elevation (BFE) Zone A, V, A99 With BFE or DepthZone AE, AO, AH, VE, AR Regulatory Floodway 0.2% Annual Chance Flood Hazard, Areas of 1% annual chance flood with average depth less than one foot or with drainage areas of less than one square mileZone X Future Conditions 1% Annual Chance Flood HazardZone X Area with Reduced Flood Risk due to Levee. See Notes.Zone X Area with Flood Risk due to LeveeZone D NO SCREEN Area of Minimal Flood Hazard Zone X Area of Undetermined Flood HazardZone D Channel, Culvert, or Storm Sewer Levee, Dike, or Floodwall Cross Sections with 1% Annual Chance 17.5 Water Surface Elevation Coastal Transect Coastal Transect Baseline Profile Baseline Hydrographic Feature Base Flood Elevation Line (BFE) Effective LOMRs Limit of Study Jurisdiction Boundary Digital Data Available No Digital Data Available Unmapped This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from the authoritative NFHL web services provided by FEMA. This map was exported on 9/9/2024 at 3:54 PM and does not reflect changes or amendments subsequent to this date and time. The NFHL and effective information may change or become superseded by new data over time. This map image is void if the one or more of the following map elements do not appear: basemap imagery, flood zone labels, legend, scale bar, map creation date, community identifiers, FIRM panel number, and FIRM effective date. Map images for unmapped and unmodernized areas cannot be used for regulatory purposes. Legend OTHER AREAS OF FLOOD HAZARD OTHER AREAS GENERAL STRUCTURES OTHER FEATURES MAP PANELS 8 B 20.2 The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. 1:6,000 86°8'13"W 39°58'55"N 86°7'35"W 39°58'27"N Basemap Imagery Source: USGS National Map 2023 APPENDIX B SOILS MAP Soil Map—Hamilton County, Indiana (344583) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 9/9/2024 Page 1 of 3 44 2 5 6 1 0 44 2 5 6 2 0 44 2 5 6 3 0 44 2 5 6 4 0 44 2 5 6 5 0 44 2 5 6 6 0 44 2 5 6 7 0 44 2 5 6 8 0 44 2 5 6 9 0 44 2 5 7 0 0 44 2 5 7 1 0 44 2 5 6 1 0 44 2 5 6 2 0 44 2 5 6 3 0 44 2 5 6 4 0 44 2 5 6 5 0 44 2 5 6 6 0 44 2 5 6 7 0 44 2 5 6 8 0 44 2 5 6 9 0 44 2 5 7 0 0 44 2 5 7 1 0 574130 574140 574150 574160 574170 574180 574190 574200 574210 574130 574140 574150 574160 574170 574180 574190 574200 574210 39° 58' 42'' N 86 ° 7 ' 5 4 ' ' W 39° 58' 42'' N 86 ° 7 ' 5 1 ' ' W 39° 58' 38'' N 86 ° 7 ' 5 4 ' ' W 39° 58' 38'' N 86 ° 7 ' 5 1 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 16N WGS84 0 25 50 100 150 Feet 0 5 10 20 30 Meters Map Scale: 1:542 if printed on A portrait (8.5" x 11") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:15,800. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Hamilton County, Indiana Survey Area Data: Version 24, Sep 1, 2023 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jun 15, 2022—Jun 21, 2022 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Soil Map—Hamilton County, Indiana (344583) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 9/9/2024 Page 2 of 3 Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI Or Orthents 0.8 51.0% YmsB2 Miami silt loam-Urban land complex, 2 to 6 percent slopes, eroded 0.7 49.0% Totals for Area of Interest 1.5 100.0% Soil Map—Hamilton County, Indiana 344583 Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 9/9/2024 Page 3 of 3 Hamilton County, Indiana Or—Orthents Map Unit Setting National map unit symbol: 5dbc Elevation: 720 to 980 feet Mean annual precipitation: 36 to 42 inches Mean annual air temperature: 49 to 52 degrees F Frost-free period: 175 to 185 days Farmland classification: Not prime farmland Map Unit Composition Orthents and similar soils:98 percent Minor components:2 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Orthents Setting Landform:Terraces, till plains Properties and qualities Slope:6 to 12 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 8 Other vegetative classification: Trees/Timber (Woody Vegetation) Hydric soil rating: Unranked Minor Components Water Percent of map unit:2 percent Hydric soil rating: No Data Source Information Soil Survey Area: Hamilton County, Indiana Survey Area Data: Version 24, Sep 1, 2023 Map Unit Description: Orthents---Hamilton County, Indiana 344583 Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 9/9/2024 Page 1 of 1 Hamilton County, Indiana YmsB2—Miami silt loam-Urban land complex, 2 to 6 percent slopes, eroded Map Unit Setting National map unit symbol: 2w586 Elevation: 180 to 1,040 feet Mean annual precipitation: 37 to 46 inches Mean annual air temperature: 48 to 55 degrees F Frost-free period: 145 to 180 days Farmland classification: Not prime farmland Map Unit Composition Miami, eroded, and similar soils:50 percent Urban land:35 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Miami, Eroded Setting Landform:Till plains Landform position (two-dimensional):Backslope, shoulder, footslope Landform position (three-dimensional):Side slope Down-slope shape:Convex Across-slope shape:Linear Parent material:Loess over loamy till Typical profile Ap - 0 to 8 inches: silt loam Bt - 8 to 13 inches: silty clay loam 2Bt - 13 to 31 inches: clay loam 2BCt - 31 to 36 inches: loam 2Cd - 36 to 79 inches: loam Properties and qualities Slope:2 to 6 percent Depth to restrictive feature:24 to 40 inches to densic material Drainage class:Moderately well drained Runoff class: High Capacity of the most limiting layer to transmit water (Ksat):Low to moderately high (0.01 to 0.20 in/hr) Depth to water table:About 24 to 36 inches Frequency of flooding:None Frequency of ponding:None Calcium carbonate, maximum content:45 percent Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water supply, 0 to 60 inches: Low (about 5.8 inches) Map Unit Description: Miami silt loam-Urban land complex, 2 to 6 percent slopes, eroded--- Hamilton County, Indiana 344583 Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 9/9/2024 Page 1 of 2 Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2e Hydrologic Soil Group: C Ecological site: F111XA009IN - Till Ridge Other vegetative classification: Trees/Timber (Woody Vegetation) Hydric soil rating: No Minor Components Williamstown Percent of map unit:5 percent Landform:Till plains Landform position (two-dimensional):Backslope, shoulder Landform position (three-dimensional):Side slope Down-slope shape:Convex Across-slope shape:Linear Ecological site:F111XA009IN - Till Ridge Other vegetative classification:Trees/Timber (Woody Vegetation) Hydric soil rating: No Treaty Percent of map unit:5 percent Landform:Till plains Landform position (two-dimensional):Toeslope Landform position (three-dimensional):Dip Down-slope shape:Concave Across-slope shape:Concave Ecological site:F111XA007IN - Till Depression Flatwood Other vegetative classification:Mixed/Transitional (Mixed Native Vegetation) Hydric soil rating: Yes Crosby Percent of map unit:5 percent Landform:Till plains Landform position (two-dimensional):Summit Landform position (three-dimensional):Interfluve Down-slope shape:Linear Across-slope shape:Convex Ecological site:F111XA008IN - Wet Till Ridge Other vegetative classification:Trees/Timber (Woody Vegetation) Hydric soil rating: No Data Source Information Soil Survey Area: Hamilton County, Indiana Survey Area Data: Version 24, Sep 1, 2023 Map Unit Description: Miami silt loam-Urban land complex, 2 to 6 percent slopes, eroded--- Hamilton County, Indiana 344583 Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 9/9/2024 Page 2 of 2 APPENDIX C EXISTING & PROPOSED WATERSHED MAPS MAP LEGEND: DATE:DWG SCALE: DRAWN BY:CHECKED BY:APPROVED BY: PROJECT NO: FIGURE NO.: EXISTING BASIN MAP 344-5831"=30'OCTOBER. 2024 HYC DRAFT DRAFT B-1 STUDIO M ARCHITECT ARDALAN PLAZA 331 W. MAIN STREET CARMEL, IN 46032 NORTH Civil & Environmental Consultants, Inc.www.cecinc.com 530 E. Ohio Street Ph: 317.655.7777 Indianapolis, IN 46204 Suite G PROPOSED BUILDING F.F.E. = 831.50 MAP LEGEND: NORTH Civil & Environmental Consultants, Inc.www.cecinc.com 530 E. Ohio Street Ph: 317.655.7777 Indianapolis, IN 46204 Suite G DATE:DWG SCALE: DRAWN BY:CHECKED BY:APPROVED BY: PROJECT NO: FIGURE NO.: PROPOSED BASIN MAP 344-5831"=30'OCTOBER. 2024 HYC DRAFT DRAFT C-1 STUDIO M ARCHITECT ARDALAN PLAZA 331 W. MAIN STREET CARMEL, IN 46032 PROPOSED BUILDING F.F.E. = 831.50 MAP LEGEND: NORTH Civil & Environmental Consultants, Inc.www.cecinc.com 530 E. Ohio Street Ph: 317.655.7777 Indianapolis, IN 46204 Suite G DATE:DWG SCALE: DRAWN BY:CHECKED BY:APPROVED BY: PROJECT NO: FIGURE NO.: INLET BASIN MAP 344-5831"=30'OCTOBER. 2024 HYC DRAFT DRAFT D-1 STUDIO M ARCHITECT ARDALAN PLAZA 331 W. MAIN STREET CARMEL, IN 46032 APPENDIX D EXISTING HYDROCAD OUTPUT Existing Conditions Pre-A Basin A Routing Diagram for 344583-CV01-Existing Conditions Prepared by CEC Inc, Printed 10/7/2024 HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Subcat Reach Pond Link 344583-CV01-Existing Conditions Printed 10/7/2024Prepared by CEC Inc Page 2HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Area Listing (selected nodes) Area (acres) CN Description (subcatchment-numbers) 0.286 61 >75% Grass cover, Good, HSG B (Pre-A) 0.146 74 >75% Grass cover, Good, HSG C (Pre-A) 0.012 96 Gravel surface, HSG B (Pre-A) 0.078 98 Impervious (Pre-A) 0.140 98 Roofs, HSG B (Pre-A) 0.662 77 TOTAL AREA Type II 24-hr 2 YR Rainfall=2.66"344583-CV01-Existing Conditions Printed 10/7/2024Prepared by CEC Inc Page 3HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Summary for Subcatchment Pre-A: Basin A Runoff = 0.99 cfs @ 11.97 hrs, Volume= 0.046 af, Depth= 0.84" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 2 YR Rainfall=2.66" Area (sf) CN Description * 3,397 98 Impervious 12,464 61 >75% Grass cover, Good, HSG B 6,347 74 >75% Grass cover, Good, HSG C 6,111 98 Roofs, HSG B 531 96 Gravel surface, HSG B 28,850 77 Weighted Average 19,342 67.04% Pervious Area 9,508 32.96% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment Pre-A: Basin A Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420 Fl o w ( c f s ) 1 0 Type II 24-hr 2 YR Rainfall=2.66" Runoff Area=28,850 sf Runoff Volume=0.046 af Runoff Depth=0.84" Tc=5.0 min CN=77 0.99 cfs Type II 24-hr 10 YR Rainfall=3.83"344583-CV01-Existing Conditions Printed 10/7/2024Prepared by CEC Inc Page 4HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Summary for Subcatchment Pre-A: Basin A Runoff = 2.01 cfs @ 11.96 hrs, Volume= 0.093 af, Depth= 1.68" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 10 YR Rainfall=3.83" Area (sf) CN Description * 3,397 98 Impervious 12,464 61 >75% Grass cover, Good, HSG B 6,347 74 >75% Grass cover, Good, HSG C 6,111 98 Roofs, HSG B 531 96 Gravel surface, HSG B 28,850 77 Weighted Average 19,342 67.04% Pervious Area 9,508 32.96% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment Pre-A: Basin A Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420 Fl o w ( c f s ) 2 1 0 Type II 24-hr 10 YR Rainfall=3.83" Runoff Area=28,850 sf Runoff Volume=0.093 af Runoff Depth=1.68" Tc=5.0 min CN=77 2.01 cfs Type II 24-hr 100 YR Rainfall=6.46"344583-CV01-Existing Conditions Printed 10/7/2024Prepared by CEC Inc Page 5HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Summary for Subcatchment Pre-A: Basin A Runoff = 4.56 cfs @ 11.96 hrs, Volume= 0.214 af, Depth= 3.88" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 100 YR Rainfall=6.46" Area (sf) CN Description * 3,397 98 Impervious 12,464 61 >75% Grass cover, Good, HSG B 6,347 74 >75% Grass cover, Good, HSG C 6,111 98 Roofs, HSG B 531 96 Gravel surface, HSG B 28,850 77 Weighted Average 19,342 67.04% Pervious Area 9,508 32.96% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment Pre-A: Basin A Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420 Fl o w ( c f s ) 5 4 3 2 1 0 Type II 24-hr 100 YR Rainfall=6.46" Runoff Area=28,850 sf Runoff Volume=0.214 af Runoff Depth=3.88" Tc=5.0 min CN=77 4.56 cfs Multi-Event Tables344583-CV01-Existing Conditions Printed 10/7/2024Prepared by CEC Inc Page 6HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Events for Subcatchment Pre-A: Basin A Event Rainfall (inches) Runoff (cfs) Volume (acre-feet) Depth (inches) 2 YR 2.66 0.99 0.046 0.84 10 YR 3.83 2.01 0.093 1.68 100 YR 6.46 4.56 0.214 3.88 APPENDIX E PROPOSED HYDROCAD OUTPUT Proposed Conditions Post-A Basin A P-D(T) Contech Composite Detention System (Theoretical) Routing Diagram for 344583-CV01-Proposed Conditions Prepared by CEC Inc, Printed 10/7/2024 HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Subcat Reach Pond Link 344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 2HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Area Listing (selected nodes) Area (acres) CN Description (subcatchment-numbers) 0.039 74 >75% Grass cover, Good, HSG C (Post-A) 0.053 80 >75% Grass cover, Good, HSG D (Post-A) 0.571 98 Impervious (Post-A) 0.663 95 TOTAL AREA Type II 24-hr 2 YR Rainfall=2.66"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 3HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Summary for Subcatchment Post-A: Basin A Runoff = 2.34 cfs @ 11.95 hrs, Volume= 0.117 af, Depth= 2.12" Routed to Pond P-D(T) : Contech Composite Detention System (Theoretical) Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 2 YR Rainfall=2.66" Area (ac) CN Description * 0.571 98 Impervious 0.039 74 >75% Grass cover, Good, HSG C 0.053 80 >75% Grass cover, Good, HSG D 0.663 95 Weighted Average 0.092 13.88% Pervious Area 0.571 86.12% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment Post-A: Basin A Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420 Fl o w ( c f s ) 2 1 0 Type II 24-hr 2 YR Rainfall=2.66" Runoff Area=0.663 ac Runoff Volume=0.117 af Runoff Depth=2.12" Tc=5.0 min CN=95 2.34 cfs Type II 24-hr 2 YR Rainfall=2.66"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 4HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Summary for Pond P-D(T): Contech Composite Detention System (Theoretical) Inflow Area = 0.663 ac, 86.12% Impervious, Inflow Depth = 2.12" for 2 YR event Inflow = 2.34 cfs @ 11.95 hrs, Volume= 0.117 af Outflow = 0.05 cfs @ 14.83 hrs, Volume= 0.114 af, Atten= 98%, Lag= 172.9 min Primary = 0.05 cfs @ 14.83 hrs, Volume= 0.114 af Routing by Dyn-Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 826.42' @ 14.83 hrs Surf.Area= 4,144 sf Storage= 3,361 cf Plug-Flow detention time= 737.8 min calculated for 0.114 af (97% of inflow) Center-of-Mass det. time= 721.5 min ( 1,504.1 - 782.6 ) Volume Invert Avail.Storage Storage Description #1 825.25' 413 cf Stone Chamber (48" Pipe) (Prismatic) Listed below (Recalc) 2,112 cf Overall - 1,081 cf Embedded = 1,031 cf x 40.0% Voids #2 825.25' 1,081 cf 48.0" Round 48" CMP Pipe Inside #1 L= 86.0' #3 825.25' 882 cf Stone Chamber (42" Pipe) (Prismatic) Listed below (Recalc) 5,495 cf Overall - 3,290 cf Embedded = 2,205 cf x 40.0% Voids #4 825.25' 3,271 cf 42.0" Round 42" CMP Pipe x 4 Inside #3 L= 85.0' #5 825.25' 19 cf 42.0" Round 42" CMP Pipe Manifold Inside #3 L= 2.0' #6 825.25' 1,169 cf Stone Chamber (36" Pipe) (Prismatic) Listed below (Recalc) 6,138 cf Overall - 3,216 cf Embedded = 2,922 cf x 40.0% Voids #7 825.25' 2,262 cf 36.0" Round 36" CMP Pipe (Long) x 4 Inside #6 L= 80.0' #8 825.25' 884 cf 36.0" Round 36" CMP Pipe (Short) x 5 Inside #6 L= 25.0' #9 825.25' 71 cf 36.0" Round 36" CMP Pipe Manifold Inside #6 L= 10.0' 10,050 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 825.25 528 0 0 829.25 528 2,112 2,112 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 825.25 1,570 0 0 828.75 1,570 5,495 5,495 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 825.25 2,046 0 0 828.25 2,046 6,138 6,138 Type II 24-hr 2 YR Rainfall=2.66"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 5HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Device Routing Invert Outlet Devices #1 Primary 825.25'1.4" Vert. 10-yr Orifice C= 0.600 Limited to weir flow at low heads #2 Primary 827.05'2.0" Vert. 100-yr Orifice C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.05 cfs @ 14.83 hrs HW=826.42' (Free Discharge) 1=10-yr Orifice (Orifice Controls 0.05 cfs @ 5.07 fps) 2=100-yr Orifice ( Controls 0.00 cfs) Pond P-D(T): Contech Composite Detention System (Theoretical) Inflow Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420 Fl o w ( c f s ) 2 1 0 Inflow Area=0.663 ac Peak Elev=826.42' Storage=3,361 cf 2.34 cfs 0.05 cfs Type II 24-hr 2 YR Rainfall=2.66"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 6HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Pond P-D(T): Contech Composite Detention System (Theoretical) Primary Stage-Discharge Discharge (cfs) 0.240.220.20.180.160.140.120.10.080.060.040.020 El e v a t i o n ( f e e t ) 829 828 827 826 10-yr Orifice 100-yr Orifice Type II 24-hr 10 YR Rainfall=3.83"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 7HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Summary for Subcatchment Post-A: Basin A Runoff = 3.50 cfs @ 11.95 hrs, Volume= 0.180 af, Depth= 3.26" Routed to Pond P-D(T) : Contech Composite Detention System (Theoretical) Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 10 YR Rainfall=3.83" Area (ac) CN Description * 0.571 98 Impervious 0.039 74 >75% Grass cover, Good, HSG C 0.053 80 >75% Grass cover, Good, HSG D 0.663 95 Weighted Average 0.092 13.88% Pervious Area 0.571 86.12% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment Post-A: Basin A Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420 Fl o w ( c f s ) 3 2 1 0 Type II 24-hr 10 YR Rainfall=3.83" Runoff Area=0.663 ac Runoff Volume=0.180 af Runoff Depth=3.26" Tc=5.0 min CN=95 3.50 cfs Type II 24-hr 10 YR Rainfall=3.83"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 8HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Summary for Pond P-D(T): Contech Composite Detention System (Theoretical) Inflow Area = 0.663 ac, 86.12% Impervious, Inflow Depth = 3.26" for 10 YR event Inflow = 3.50 cfs @ 11.95 hrs, Volume= 0.180 af Outflow = 0.07 cfs @ 15.53 hrs, Volume= 0.164 af, Atten= 98%, Lag= 214.8 min Primary = 0.07 cfs @ 15.53 hrs, Volume= 0.164 af Routing by Dyn-Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 827.02' @ 15.53 hrs Surf.Area= 4,144 sf Storage= 5,392 cf Plug-Flow detention time= 862.8 min calculated for 0.164 af (91% of inflow) Center-of-Mass det. time= 814.4 min ( 1,585.5 - 771.2 ) Volume Invert Avail.Storage Storage Description #1 825.25' 413 cf Stone Chamber (48" Pipe) (Prismatic) Listed below (Recalc) 2,112 cf Overall - 1,081 cf Embedded = 1,031 cf x 40.0% Voids #2 825.25' 1,081 cf 48.0" Round 48" CMP Pipe Inside #1 L= 86.0' #3 825.25' 882 cf Stone Chamber (42" Pipe) (Prismatic) Listed below (Recalc) 5,495 cf Overall - 3,290 cf Embedded = 2,205 cf x 40.0% Voids #4 825.25' 3,271 cf 42.0" Round 42" CMP Pipe x 4 Inside #3 L= 85.0' #5 825.25' 19 cf 42.0" Round 42" CMP Pipe Manifold Inside #3 L= 2.0' #6 825.25' 1,169 cf Stone Chamber (36" Pipe) (Prismatic) Listed below (Recalc) 6,138 cf Overall - 3,216 cf Embedded = 2,922 cf x 40.0% Voids #7 825.25' 2,262 cf 36.0" Round 36" CMP Pipe (Long) x 4 Inside #6 L= 80.0' #8 825.25' 884 cf 36.0" Round 36" CMP Pipe (Short) x 5 Inside #6 L= 25.0' #9 825.25' 71 cf 36.0" Round 36" CMP Pipe Manifold Inside #6 L= 10.0' 10,050 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 825.25 528 0 0 829.25 528 2,112 2,112 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 825.25 1,570 0 0 828.75 1,570 5,495 5,495 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 825.25 2,046 0 0 828.25 2,046 6,138 6,138 Type II 24-hr 10 YR Rainfall=3.83"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 9HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Device Routing Invert Outlet Devices #1 Primary 825.25'1.4" Vert. 10-yr Orifice C= 0.600 Limited to weir flow at low heads #2 Primary 827.05'2.0" Vert. 100-yr Orifice C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.07 cfs @ 15.53 hrs HW=827.02' (Free Discharge) 1=10-yr Orifice (Orifice Controls 0.07 cfs @ 6.30 fps) 2=100-yr Orifice ( Controls 0.00 cfs) Pond P-D(T): Contech Composite Detention System (Theoretical) Inflow Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420 Fl o w ( c f s ) 3 2 1 0 Inflow Area=0.663 ac Peak Elev=827.02' Storage=5,392 cf 3.50 cfs 0.07 cfs Type II 24-hr 10 YR Rainfall=3.83"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 10HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Pond P-D(T): Contech Composite Detention System (Theoretical) Primary Stage-Discharge Discharge (cfs) 0.240.220.20.180.160.140.120.10.080.060.040.020 El e v a t i o n ( f e e t ) 829 828 827 826 10-yr Orifice 100-yr Orifice Type II 24-hr 100 YR Rainfall=6.46"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 11HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Summary for Subcatchment Post-A: Basin A Runoff = 6.08 cfs @ 11.95 hrs, Volume= 0.324 af, Depth= 5.87" Routed to Pond P-D(T) : Contech Composite Detention System (Theoretical) Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 100 YR Rainfall=6.46" Area (ac) CN Description * 0.571 98 Impervious 0.039 74 >75% Grass cover, Good, HSG C 0.053 80 >75% Grass cover, Good, HSG D 0.663 95 Weighted Average 0.092 13.88% Pervious Area 0.571 86.12% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment Post-A: Basin A Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420 Fl o w ( c f s ) 6 5 4 3 2 1 0 Type II 24-hr 100 YR Rainfall=6.46" Runoff Area=0.663 ac Runoff Volume=0.324 af Runoff Depth=5.87" Tc=5.0 min CN=95 6.08 cfs Type II 24-hr 100 YR Rainfall=6.46"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 12HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Summary for Pond P-D(T): Contech Composite Detention System (Theoretical) Inflow Area = 0.663 ac, 86.12% Impervious, Inflow Depth = 5.87" for 100 YR event Inflow = 6.08 cfs @ 11.95 hrs, Volume= 0.324 af Outflow = 0.20 cfs @ 13.62 hrs, Volume= 0.292 af, Atten= 97%, Lag= 100.0 min Primary = 0.20 cfs @ 13.62 hrs, Volume= 0.292 af Routing by Dyn-Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 828.23' @ 13.62 hrs Surf.Area= 4,144 sf Storage= 9,178 cf Plug-Flow detention time= 698.7 min calculated for 0.291 af (90% of inflow) Center-of-Mass det. time= 647.6 min ( 1,404.8 - 757.2 ) Volume Invert Avail.Storage Storage Description #1 825.25' 413 cf Stone Chamber (48" Pipe) (Prismatic) Listed below (Recalc) 2,112 cf Overall - 1,081 cf Embedded = 1,031 cf x 40.0% Voids #2 825.25' 1,081 cf 48.0" Round 48" CMP Pipe Inside #1 L= 86.0' #3 825.25' 882 cf Stone Chamber (42" Pipe) (Prismatic) Listed below (Recalc) 5,495 cf Overall - 3,290 cf Embedded = 2,205 cf x 40.0% Voids #4 825.25' 3,271 cf 42.0" Round 42" CMP Pipe x 4 Inside #3 L= 85.0' #5 825.25' 19 cf 42.0" Round 42" CMP Pipe Manifold Inside #3 L= 2.0' #6 825.25' 1,169 cf Stone Chamber (36" Pipe) (Prismatic) Listed below (Recalc) 6,138 cf Overall - 3,216 cf Embedded = 2,922 cf x 40.0% Voids #7 825.25' 2,262 cf 36.0" Round 36" CMP Pipe (Long) x 4 Inside #6 L= 80.0' #8 825.25' 884 cf 36.0" Round 36" CMP Pipe (Short) x 5 Inside #6 L= 25.0' #9 825.25' 71 cf 36.0" Round 36" CMP Pipe Manifold Inside #6 L= 10.0' 10,050 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 825.25 528 0 0 829.25 528 2,112 2,112 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 825.25 1,570 0 0 828.75 1,570 5,495 5,495 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 825.25 2,046 0 0 828.25 2,046 6,138 6,138 Type II 24-hr 100 YR Rainfall=6.46"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 13HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Device Routing Invert Outlet Devices #1 Primary 825.25'1.4" Vert. 10-yr Orifice C= 0.600 Limited to weir flow at low heads #2 Primary 827.05'2.0" Vert. 100-yr Orifice C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.20 cfs @ 13.62 hrs HW=828.23' (Free Discharge) 1=10-yr Orifice (Orifice Controls 0.09 cfs @ 8.23 fps) 2=100-yr Orifice (Orifice Controls 0.11 cfs @ 5.04 fps) Pond P-D(T): Contech Composite Detention System (Theoretical) Inflow Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420 Fl o w ( c f s ) 6 5 4 3 2 1 0 Inflow Area=0.663 ac Peak Elev=828.23' Storage=9,178 cf 6.08 cfs 0.20 cfs Type II 24-hr 100 YR Rainfall=6.46"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 14HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Pond P-D(T): Contech Composite Detention System (Theoretical) Primary Stage-Discharge Discharge (cfs) 0.240.220.20.180.160.140.120.10.080.060.040.020 El e v a t i o n ( f e e t ) 829 828 827 826 10-yr Orifice 100-yr Orifice Multi-Event Tables344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 15HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Events for Subcatchment Post-A: Basin A Event Rainfall (inches) Runoff (cfs) Volume (acre-feet) Depth (inches) 2 YR 2.66 2.34 0.117 2.12 10 YR 3.83 3.50 0.180 3.26 100 YR 6.46 6.08 0.324 5.87 Multi-Event Tables344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 16HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Events for Pond P-D(T): Contech Composite Detention System (Theoretical) Event Inflow (cfs) Primary (cfs) Elevation (feet) Storage (cubic-feet) 2 YR 2.34 0.05 826.42 3,361 10 YR 3.50 0.07 827.02 5,392 100 YR 6.08 0.20 828.23 9,178 Proposed Conditions Post-A Basin A P-D(A) Contech Composite Detention System (Actual) Routing Diagram for 344583-CV01-Proposed Conditions Prepared by CEC Inc, Printed 10/7/2024 HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Subcat Reach Pond Link 344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 2HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Area Listing (selected nodes) Area (acres) CN Description (subcatchment-numbers) 0.039 74 >75% Grass cover, Good, HSG C (Post-A) 0.053 80 >75% Grass cover, Good, HSG D (Post-A) 0.571 98 Impervious (Post-A) 0.663 95 TOTAL AREA Type II 24-hr 2 YR Rainfall=2.66"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 3HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Summary for Subcatchment Post-A: Basin A Runoff = 2.34 cfs @ 11.95 hrs, Volume= 0.117 af, Depth= 2.12" Routed to Pond P-D(A) : Contech Composite Detention System (Actual) Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 2 YR Rainfall=2.66" Area (ac) CN Description * 0.571 98 Impervious 0.039 74 >75% Grass cover, Good, HSG C 0.053 80 >75% Grass cover, Good, HSG D 0.663 95 Weighted Average 0.092 13.88% Pervious Area 0.571 86.12% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment Post-A: Basin A Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420 Fl o w ( c f s ) 2 1 0 Type II 24-hr 2 YR Rainfall=2.66" Runoff Area=0.663 ac Runoff Volume=0.117 af Runoff Depth=2.12" Tc=5.0 min CN=95 2.34 cfs Type II 24-hr 2 YR Rainfall=2.66"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 4HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Summary for Pond P-D(A): Contech Composite Detention System (Actual) Inflow Area = 0.663 ac, 86.12% Impervious, Inflow Depth = 2.12" for 2 YR event Inflow = 2.34 cfs @ 11.95 hrs, Volume= 0.117 af Outflow = 0.10 cfs @ 13.11 hrs, Volume= 0.116 af, Atten= 96%, Lag= 69.5 min Primary = 0.10 cfs @ 13.11 hrs, Volume= 0.116 af Routing by Dyn-Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 826.28' @ 13.11 hrs Surf.Area= 4,144 sf Storage= 2,925 cf Plug-Flow detention time= 357.2 min calculated for 0.116 af (99% of inflow) Center-of-Mass det. time= 354.8 min ( 1,137.4 - 782.6 ) Volume Invert Avail.Storage Storage Description #1 825.25' 413 cf Stone Chamber (48" Pipe) (Prismatic) Listed below (Recalc) 2,112 cf Overall - 1,081 cf Embedded = 1,031 cf x 40.0% Voids #2 825.25' 1,081 cf 48.0" Round 48" CMP Pipe Inside #1 L= 86.0' #3 825.25' 882 cf Stone Chamber (42" Pipe) (Prismatic) Listed below (Recalc) 5,495 cf Overall - 3,290 cf Embedded = 2,205 cf x 40.0% Voids #4 825.25' 3,271 cf 42.0" Round 42" CMP Pipe x 4 Inside #3 L= 85.0' #5 825.25' 19 cf 42.0" Round 42" CMP Pipe Manifold Inside #3 L= 2.0' #6 825.25' 1,169 cf Stone Chamber (36" Pipe) (Prismatic) Listed below (Recalc) 6,138 cf Overall - 3,216 cf Embedded = 2,922 cf x 40.0% Voids #7 825.25' 2,262 cf 36.0" Round 36" CMP Pipe (Long) x 4 Inside #6 L= 80.0' #8 825.25' 884 cf 36.0" Round 36" CMP Pipe (Short) x 5 Inside #6 L= 25.0' #9 825.25' 71 cf 36.0" Round 36" CMP Pipe Manifold Inside #6 L= 10.0' 10,050 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 825.25 528 0 0 829.25 528 2,112 2,112 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 825.25 1,570 0 0 828.75 1,570 5,495 5,495 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 825.25 2,046 0 0 828.25 2,046 6,138 6,138 Type II 24-hr 2 YR Rainfall=2.66"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 5HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Device Routing Invert Outlet Devices #1 Primary 825.25'2.0" Vert. 10-yr Orifice C= 0.600 Limited to weir flow at low heads #2 Primary 826.80'2.0" Vert. 100-yr Orifice C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.10 cfs @ 13.11 hrs HW=826.28' (Free Discharge) 1=10-yr Orifice (Orifice Controls 0.10 cfs @ 4.70 fps) 2=100-yr Orifice ( Controls 0.00 cfs) Pond P-D(A): Contech Composite Detention System (Actual) Inflow Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420 Fl o w ( c f s ) 2 1 0 Inflow Area=0.663 ac Peak Elev=826.28' Storage=2,925 cf 2.34 cfs 0.10 cfs Type II 24-hr 2 YR Rainfall=2.66"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 6HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Pond P-D(A): Contech Composite Detention System (Actual) Primary Stage-Discharge Discharge (cfs) 0.360.340.320.30.280.260.240.220.20.180.160.140.120.10.080.060.040.020 El e v a t i o n ( f e e t ) 829 828 827 826 10-yr Orifice 100-yr Orifice Type II 24-hr 10 YR Rainfall=3.83"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 7HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Summary for Subcatchment Post-A: Basin A Runoff = 3.50 cfs @ 11.95 hrs, Volume= 0.180 af, Depth= 3.26" Routed to Pond P-D(A) : Contech Composite Detention System (Actual) Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 10 YR Rainfall=3.83" Area (ac) CN Description * 0.571 98 Impervious 0.039 74 >75% Grass cover, Good, HSG C 0.053 80 >75% Grass cover, Good, HSG D 0.663 95 Weighted Average 0.092 13.88% Pervious Area 0.571 86.12% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment Post-A: Basin A Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420 Fl o w ( c f s ) 3 2 1 0 Type II 24-hr 10 YR Rainfall=3.83" Runoff Area=0.663 ac Runoff Volume=0.180 af Runoff Depth=3.26" Tc=5.0 min CN=95 3.50 cfs Type II 24-hr 10 YR Rainfall=3.83"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 8HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Summary for Pond P-D(A): Contech Composite Detention System (Actual) Inflow Area = 0.663 ac, 86.12% Impervious, Inflow Depth = 3.26" for 10 YR event Inflow = 3.50 cfs @ 11.95 hrs, Volume= 0.180 af Outflow = 0.13 cfs @ 13.44 hrs, Volume= 0.179 af, Atten= 96%, Lag= 89.2 min Primary = 0.13 cfs @ 13.44 hrs, Volume= 0.179 af Routing by Dyn-Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 826.80' @ 13.44 hrs Surf.Area= 4,144 sf Storage= 4,658 cf Plug-Flow detention time= 443.3 min calculated for 0.179 af (99% of inflow) Center-of-Mass det. time= 441.3 min ( 1,212.5 - 771.2 ) Volume Invert Avail.Storage Storage Description #1 825.25' 413 cf Stone Chamber (48" Pipe) (Prismatic) Listed below (Recalc) 2,112 cf Overall - 1,081 cf Embedded = 1,031 cf x 40.0% Voids #2 825.25' 1,081 cf 48.0" Round 48" CMP Pipe Inside #1 L= 86.0' #3 825.25' 882 cf Stone Chamber (42" Pipe) (Prismatic) Listed below (Recalc) 5,495 cf Overall - 3,290 cf Embedded = 2,205 cf x 40.0% Voids #4 825.25' 3,271 cf 42.0" Round 42" CMP Pipe x 4 Inside #3 L= 85.0' #5 825.25' 19 cf 42.0" Round 42" CMP Pipe Manifold Inside #3 L= 2.0' #6 825.25' 1,169 cf Stone Chamber (36" Pipe) (Prismatic) Listed below (Recalc) 6,138 cf Overall - 3,216 cf Embedded = 2,922 cf x 40.0% Voids #7 825.25' 2,262 cf 36.0" Round 36" CMP Pipe (Long) x 4 Inside #6 L= 80.0' #8 825.25' 884 cf 36.0" Round 36" CMP Pipe (Short) x 5 Inside #6 L= 25.0' #9 825.25' 71 cf 36.0" Round 36" CMP Pipe Manifold Inside #6 L= 10.0' 10,050 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 825.25 528 0 0 829.25 528 2,112 2,112 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 825.25 1,570 0 0 828.75 1,570 5,495 5,495 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 825.25 2,046 0 0 828.25 2,046 6,138 6,138 Type II 24-hr 10 YR Rainfall=3.83"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 9HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Device Routing Invert Outlet Devices #1 Primary 825.25'2.0" Vert. 10-yr Orifice C= 0.600 Limited to weir flow at low heads #2 Primary 826.80'2.0" Vert. 100-yr Orifice C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.13 cfs @ 13.44 hrs HW=826.80' (Free Discharge) 1=10-yr Orifice (Orifice Controls 0.13 cfs @ 5.84 fps) 2=100-yr Orifice (Orifice Controls 0.00 cfs @ 0.16 fps) Pond P-D(A): Contech Composite Detention System (Actual) Inflow Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420 Fl o w ( c f s ) 3 2 1 0 Inflow Area=0.663 ac Peak Elev=826.80' Storage=4,658 cf 3.50 cfs 0.13 cfs Type II 24-hr 10 YR Rainfall=3.83"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 10HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Pond P-D(A): Contech Composite Detention System (Actual) Primary Stage-Discharge Discharge (cfs) 0.360.340.320.30.280.260.240.220.20.180.160.140.120.10.080.060.040.020 El e v a t i o n ( f e e t ) 829 828 827 826 10-yr Orifice 100-yr Orifice Type II 24-hr 100 YR Rainfall=6.46"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 11HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Summary for Subcatchment Post-A: Basin A Runoff = 6.08 cfs @ 11.95 hrs, Volume= 0.324 af, Depth= 5.87" Routed to Pond P-D(A) : Contech Composite Detention System (Actual) Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 100 YR Rainfall=6.46" Area (ac) CN Description * 0.571 98 Impervious 0.039 74 >75% Grass cover, Good, HSG C 0.053 80 >75% Grass cover, Good, HSG D 0.663 95 Weighted Average 0.092 13.88% Pervious Area 0.571 86.12% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment Post-A: Basin A Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420 Fl o w ( c f s ) 6 5 4 3 2 1 0 Type II 24-hr 100 YR Rainfall=6.46" Runoff Area=0.663 ac Runoff Volume=0.324 af Runoff Depth=5.87" Tc=5.0 min CN=95 6.08 cfs Type II 24-hr 100 YR Rainfall=6.46"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 12HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Summary for Pond P-D(A): Contech Composite Detention System (Actual) Inflow Area = 0.663 ac, 86.12% Impervious, Inflow Depth = 5.87" for 100 YR event Inflow = 6.08 cfs @ 11.95 hrs, Volume= 0.324 af Outflow = 0.27 cfs @ 13.02 hrs, Volume= 0.323 af, Atten= 95%, Lag= 63.9 min Primary = 0.27 cfs @ 13.02 hrs, Volume= 0.323 af Routing by Dyn-Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 827.91' @ 13.02 hrs Surf.Area= 4,144 sf Storage= 8,274 cf Plug-Flow detention time= 455.0 min calculated for 0.323 af (100% of inflow) Center-of-Mass det. time= 452.4 min ( 1,209.6 - 757.2 ) Volume Invert Avail.Storage Storage Description #1 825.25' 413 cf Stone Chamber (48" Pipe) (Prismatic) Listed below (Recalc) 2,112 cf Overall - 1,081 cf Embedded = 1,031 cf x 40.0% Voids #2 825.25' 1,081 cf 48.0" Round 48" CMP Pipe Inside #1 L= 86.0' #3 825.25' 882 cf Stone Chamber (42" Pipe) (Prismatic) Listed below (Recalc) 5,495 cf Overall - 3,290 cf Embedded = 2,205 cf x 40.0% Voids #4 825.25' 3,271 cf 42.0" Round 42" CMP Pipe x 4 Inside #3 L= 85.0' #5 825.25' 19 cf 42.0" Round 42" CMP Pipe Manifold Inside #3 L= 2.0' #6 825.25' 1,169 cf Stone Chamber (36" Pipe) (Prismatic) Listed below (Recalc) 6,138 cf Overall - 3,216 cf Embedded = 2,922 cf x 40.0% Voids #7 825.25' 2,262 cf 36.0" Round 36" CMP Pipe (Long) x 4 Inside #6 L= 80.0' #8 825.25' 884 cf 36.0" Round 36" CMP Pipe (Short) x 5 Inside #6 L= 25.0' #9 825.25' 71 cf 36.0" Round 36" CMP Pipe Manifold Inside #6 L= 10.0' 10,050 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 825.25 528 0 0 829.25 528 2,112 2,112 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 825.25 1,570 0 0 828.75 1,570 5,495 5,495 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 825.25 2,046 0 0 828.25 2,046 6,138 6,138 Type II 24-hr 100 YR Rainfall=6.46"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 13HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Device Routing Invert Outlet Devices #1 Primary 825.25'2.0" Vert. 10-yr Orifice C= 0.600 Limited to weir flow at low heads #2 Primary 826.80'2.0" Vert. 100-yr Orifice C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.27 cfs @ 13.02 hrs HW=827.91' (Free Discharge) 1=10-yr Orifice (Orifice Controls 0.17 cfs @ 7.72 fps) 2=100-yr Orifice (Orifice Controls 0.11 cfs @ 4.87 fps) Pond P-D(A): Contech Composite Detention System (Actual) Inflow Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420 Fl o w ( c f s ) 6 5 4 3 2 1 0 Inflow Area=0.663 ac Peak Elev=827.91' Storage=8,274 cf 6.08 cfs 0.27 cfs Type II 24-hr 100 YR Rainfall=6.46"344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 14HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Pond P-D(A): Contech Composite Detention System (Actual) Primary Stage-Discharge Discharge (cfs) 0.360.340.320.30.280.260.240.220.20.180.160.140.120.10.080.060.040.020 El e v a t i o n ( f e e t ) 829 828 827 826 10-yr Orifice 100-yr Orifice Multi-Event Tables344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 15HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Events for Subcatchment Post-A: Basin A Event Rainfall (inches) Runoff (cfs) Volume (acre-feet) Depth (inches) 2 YR 2.66 2.34 0.117 2.12 10 YR 3.83 3.50 0.180 3.26 100 YR 6.46 6.08 0.324 5.87 Multi-Event Tables344583-CV01-Proposed Conditions Printed 10/7/2024Prepared by CEC Inc Page 16HydroCAD® 10.20-2g s/n 01006 © 2022 HydroCAD Software Solutions LLC Events for Pond P-D(A): Contech Composite Detention System (Actual) Event Inflow (cfs) Primary (cfs) Elevation (feet) Storage (cubic-feet) 2 YR 2.34 0.10 826.28 2,925 10 YR 3.50 0.13 826.80 4,658 100 YR 6.08 0.27 827.91 8,274 APPENDIX F WATER QUALITY CALCULATIONS CIVIL & ENVIRONMENTAL CONSULTANTS, INC. CEC Project No.: 344-583 By: HYC Project Name: Ardalan Plaza Date 10/09/24 Description:WQ - Rational Runoff Method Rational Runoff Method, Q = CiA C = composite C i = rainfall intesity, inches per hour A = area, acres Q = runoff peak flow rate, cubic feet per second 2-Year 0.90 5.0 4.63 0.662 2.76 10-Year 0.90 5.0 6.12 0.662 3.65 100-Year 0.90 5.0 9.12 0.662 5.43 WQ Rainfall Event Composite C Peak Runoff Rate Time of Concentration Rainfall Intensity Area P:\340-000\344-583\-Calculations\Drainage\Water Quality\B-4, Rational Runoff Method.xlsx City of Indianapolis Stormwater Quality Unit (SQU) Selection Guide Pg. 2 02/11/2020 Version 17.0 Manufactured SQU SQU System Model Max Treatment Flow (cfs) Max 10-yr On-Line Flow Rate (cfs) Cleanout Depth (Inches) 4-ft 1.12 2.95 9 6-ft 2.52 6.63 12 8-ft 4.49 11.81 15 10-ft 7.00 18.40 18 Hydro International Downstream Defender1 12 ft 10.08 26.51 21 3-ft 0.85 1.84 9 4-ft 1.5 3.24 9 5-ft 2.35 5.08 9 6-ft 3.38 7.30 9 7-ft 4.60 9.94 9 Hydro International First Defense High Capacity1 8-ft 6.00 12.96 9 HS-3 0.50 1.00 6 HS-4 0.88 1.76 6 HS-5 1.37 2.74 6 HS-6 1.98 3.96 6 HS-7 2.69 5.38 6 HS-8 3.52 7.04 6 HS-9 4.45 8.9 6 HS-10 5.49 10.98 6 HS-11 6.65 13.3 6 HydroStorm by Hydroworks, LLC1 HS-12 7.91 15.82 6 XC-2 0.57 1.16 6 XC-3 1.13 2.30 6 XC-4 1.86 3.79 6 XC-5 2.78 5.66 6 XC-6 3.88 7.90 6 XC-7 5.17 10.52 6 XC-8 6.64 13.51 6 XC-9 8.29 16.87 6 XC-10 10.13 20.62 6 XC-11 12.15 24.73 6 XC-12 14.35 29.20 6 AquaShield Aqua-Swirl Xcelerator1 XC-13 15.53 31.60 6 CS-4 1.80 4.03 9 CS-5 2.81 6.29 9 CS-6 4.05 9.07 9 CS-8 7.20 16.1 9 CS-10 11.3 25.3 9 Contech Cascade Separator CS-12 16.2 36.3 9 APPENDIX G STORM SEWER SIZING CALCULATIONS CIVIL & ENVIRONMENTAL CONSULTANTS, INC. CEC Project No.: 344-583 By: HYC Project Name: Ardalan Plaza Date 10/09/24 Description:Inlet Conditions - Composite C Computation Rational Method runoff coefficients All watertight roof surfaces ………. 0.90 Pavement ………. 0.85 Gravel ………. 0.85 Slightly perivous soil (with turf) ………. 0.20 (ft2) (ft 2) (ft 2) (ft 2) (ft 2)(acres)(ft2) 0 0 0 271 271 0.006 0.20 (ft2) (ft 2) (ft 2) (ft 2) (ft 2)(acres)(ft2) 0 779 0 891 1,670 0.038 0.50 (ft2) (ft 2) (ft 2) (ft 2) (ft 2)(acres)(ft2) 0 453 0 472 925 0.021 0.52 (ft2) (ft 2) (ft 2) (ft 2) (ft 2)(acres)(ft2) 0 921 0 0 921 0.021 0.85 (ft2) (ft 2) (ft 2) (ft 2) (ft 2)(acres)(ft2) 14,511 900 0 0 15,411 0.354 0.90 Total Total Composite C RD-1 All watertight surfaces Pavement Gravel Pervious soil / turf Total Total Composite C TD-1 All watertight surfaces Pavement Gravel Pervious soil / turf Total Total Composite C Basin 107 All watertight surfaces Pavement Gravel Pervious soil / turf Total Total Composite C Basin 105 All watertight surfaces Pavement Gravel Pervious soil / turf Basin 113 All watertight surfaces Pavement Composite CGravel Total Total Pervious soil / turf P:\340-000\344-583\-Calculations\Drainage\Inlet\D-3, Composite C Worksheet.xlsx 3130 Verona Avenue • Buford, GA 30518 (866) 888-8479 / (770) 932-2443 • Fax: (770) 932-2490 © Nyloplast Inlet Capacity Charts June 2012 0.00 0.25 0.50 0.75 1.00 1.25 1.50 1.75 2.00 2.25 2.50 2.75 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.00 1.05 1.10 Ca p a c i t y ( c f s ) Head (ft) Nyloplast 12" Dome Grate Inlet Capacity Chart