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Drainage Report
STORM WATER MANAGEMENT TECHNICAL REPORT Our Lady of Mount Carmel 14598 Oak Ridge Road, Carmel, Indiana 46032 July 2021 PREPARED FOR OUR LADY OF MOUNT CARMEL 14598 OAK RIDGE ROAD CARMEL, IN 46032 8365 Keystone Crossing, Suite 201 Indianapolis, Indiana 46240 Phone: (317) 202-0864 Fax: (317)202-0908 OUR LADY OF MOUNT CARMEL TABLE OF CONTENTS NARRATIVE EXISTING CONDITIONS Appendix A EXISTING DRAINAGE MAP PROPOSED CONDITIONS Appendix B PROPOSED DRAINAGE MAP STORM SEWER CALCULATIONS Appendix C HYDRAULIC GRADE LINE CALCULATIONS INLET CAPACITY CALCULATIONS WATER QUALITY Appendix D WATER BMP MAP TABLE 701.1 WQ CURVE # CALCULATIONS HYDROCAD MODEL FOR WATER QUALITY DESIGN WATER QUALITY DETAILS CARMEL ELEMENTARY SCHOOL 1 | Page ABSTRACT This Technical Brief pertaining to storm water drainage has been prepared for the purposes of demonstrating governmental compliance. This compliance is with the current technical rules, regulations and requirements of the governing authorities, in particular elements applicable to storm water management including detention, water quality treatment and / or best management practices (BMPs). The City of Carmel is the primary governing jurisdictional body. The total area of the site is 16.09 acres. The existing site is already in-use as a church and elementary school and owned by Our Lady of Mount Carmel (OLMC). OLMC proposes to improve this land with a building addition and re-working of parking and sidewalks. The net effect of the project will not increase net impervious area and therefore will not require new detention for this phase of development. There will be new utilities to serve the building addition and infrastructure re-working. This shall include storm water inlets and pipes. Proposed disturbed area is 1.52 acres, which is above 1.0 acres, therefore triggering the water quality threshold requirement. The new building addition and some of the yard and sidewalk is proposed to be water quality treated in a hydrodynamic swirl filter. There is proposed to be an “area swap” of one proposed area (PR-1 + PR-2 + PR-3 in Proposed Drainage Area Map)(See Appendices) for an existing area (X2 in drainage area map). The proposed area had previously drained to an underground BMP (hydrodynamic swirl filter) and an underground detention. The proposed area will now not be able to be directed to those facilities, but instead is proposed to go to a proposed BMP (hydrodynamic swirl filter) and bypass the underground detention. The existing area X2 will be intercepted and redirected to the existing BMP and detention basin. That is the proposed area swap. Storm water topics which shall be addressed and predominately demonstrated in compliance include drainage area delineation, hydraulic grade line calculations, water quality calculations, and inlet calculations. There are some existing storm water pipes which are at too flat of a slope and all we can do is work with them the best we can. These proposed pipes which are a retrofit or reroute of existing ones will not be shown to be in conformance but instead we are asking for an exception to be made to allow these grandfather-clause type of conditions to be modified as needed. Primarily this is needed in order to not have a new building get built on top of the existing storm sewer pipe system. CARMEL ELEMENTARY SCHOOL 2 | Page ZONING The project is in the S-2 Low Density Single family residential zoning district, as shown in the below map, taken from the Carmel GIS Viewer. City of Carmel Zoning Map CARMEL ELEMENTARY SCHOOL 3 | Page FLOOD MAP ZONE The FIRM Map Panel No. 18057C0207G dated November 19, 2014 indicates that this watershed falls entirely within Flood Zones X. Flood Hazard zone X includes areas that are determined to be outside the 0.2% annual chance of flood. FEMA FIRM Map 18057C0207G CARMEL ELEMENTARY SCHOOL 4 | Page WATER SHEDS OF HAMILTON COUNTY The following exhibit shows watersheds of Hamilton County per GIS: There is a Cool Creek Shed (Watershed) to the north of the property. There is an Overman Harvey Drain to the west and / or southwest of the property. CARMEL ELEMENTARY SCHOOL 5 | Page SOILS The existing soils include two primary classifications: Brookston Silty Clay Loam (0 to 2 percent slopes) and Crosby Silt Loam, Fine-Loamy subsoil (2 to 6 percent slopes). The two soils account for 100% of the site area, with Crosby Silt Loam dominating (60%). CARMEL ELEMENTARY SCHOOL 6 | Page The hydrologic soil group designation is our interest here. We have C /D and C soils, with B/D being 65% or more of this development. The standard engineering protocol is to downgrade to the lowest possible class if there is a choice to make, and the lowest is hydrologic soil group D. For simplicity and to be conservative, Class / type D soil causes the most runoff and is therefore accepted as being the most conservative class / type to select for engineering studies / calculations such as these. Detailed Descriptions of the primary site soil types are as follows: CARMEL ELEMENTARY SCHOOL 7 | Page YbvA Brookston silt loam, 0 to 2 percent slopes This is a somewhat poorly drained soil with a seasonal high water table at 0 to 2.0 ft. This soil is located on rises on till plains; slopes are 0 to 2 percent. The native vegetation is hardwood forest. The surface layer is Brookstone silt loam and has moderately low to moderate organic matter content (1.0 to 3.0 percent). Permeability is very slow (<0.06 in/hr) in the most restrictive layer above 60 inches. Available water capacity is moderate (8.9 inches in the upper 60 inches). The pH of the surface layer in non-limed areas is 5.1 to 6.5. Droughtiness and wetness are concerns for crops production. This soil responds well to tile drainage; it is designated potentially highly erodible (class 2) in the Highly Erodible Land (HEL) classification system. YClA or CrA Crosby silt loam, o to 2 to 6 percent slopes This is a somewhat poorly drained soil and has a seasonal high water table at 0.5 to 2.0 ft. and is on rises on uplands. Slopes are 0 to 2 percent. The native vegetation is hardwoods. The surface layer is silt loam and has moderately low or moderate organic matter content (1.0 to 3.0 percent). Permeability is very slow (< 0.06 in/hr) in the most restrictive layer above 60 inches. Available water capacity is moderate (6.2 inches in the upper 60 inches).The pH of the surface layer in non---limed areas is 5.1 to 6.0. Droughtiness and wetness are management concerns for crop production. This soil responds well to tile drainage. STORM WATER SEWERS AND INLETS Storm water sewer inlet calculations and hydraulic grade line calculations have been prepared which demonstrate that the proposed storm water sewer system (inlets and pipes) has been properly designed to both intercept and convey the rational method 10-year storm event and therefore is compliant per City of Carmel standards to the maximum extent practicable given the constraints of working with and connecting with, as necessary, an existing system at occasionally insufficient pipe slopes. CARMEL ELEMENTARY SCHOOL 8 | Page DOWNSTREAM RECEIVING STORM WATER SYSTEMS The drainage watersheds shown on USGS maps for this property appears to be split. There are 2 USGS maps pertinent: Westfield and Carmel. Putting these 2 maps together, the drainage that leaves headed north appears to go to Cool Creek, and the drainage that leaves to the southeast appears to go to Hiway Run. The site is in yellow. USGS Map: CARMEL & WESTFIELD CARMEL ELEMENTARY SCHOOL 9 | Page WATER QUALITY The storm water runoff for the proposed building addition and associated area is proposed to be treated by a BMP: a hydrodynamic swirl filter or hydrodynamic separator. The XC-3 XCelerator until has been chosen, which will treat a maximum of 1.13 cfs water quality flow. We are well below that threshold. DETENTION INCLUDING MODELING, RELEASE AND SEDIMENT VOLUME Detention is not being provided due to no net increase in runoff, due to no net increase in impervious area. The following spreadsheet details this. SUMMARY All inlets, pipes, and water quality improvements have been designed in accordance with the most current Carmel requirements to the maximum extent practicable in retrofitting to a pre- developed site. As mentioned in the Abstract section at the start of the Report, there is an area swap in effect: the 3 areas PR-1 + PR-2 + PR-3 are being swapped for area X2. Project:OLMC Date:7/20/2021 Location:Carmel, IN Engineer:A&F Engineering Project No.:19052L Existing Roof Imperv's Pervious Surface Surface Area Comp.Tc ID:0.90 0.85 0.15 0.00 0.00 Total C min SW 0.44 0.04 0.00 0.00 0.00 0.48 0.90 5.00 X2 0.27 0.26 0.53 0.53 5.00 N 0.30 0.00 0.13 0.00 0.00 0.43 0.67 6.60 SE 0.91 0.00 0.20 0.00 0.00 1.11 0.76 11.30 P1 2.77 0.00 1.16 0.00 0.00 3.93 0.68 5.00 DA 7 0.25 0.10 0.15 0.50 0.67 7.00 TOTALS 4.94 0.14 1.90 0.00 0.00 6.98 0.69 11.30 Proposed Roof Imperv's Pervious Surface Surface Area Comp.Tc ID:0.90 0.85 0.15 0.00 0.00 Total C min SW 0.44 0.04 0.00 0.00 0.00 0.48 0.90 5.00 P-N 0.28 0.00 0.05 0.00 0.00 0.33 0.79 10.30 P-SE 0.85 0.00 0.11 0.00 0.00 0.96 0.81 11.30 PR-3 0.15 0.00 0.00 0.00 0.00 0.15 0.90 5.00 PR-2 0.18 0.00 0.24 0.00 0.00 0.42 0.47 11.00 PR-1 0.35 0.00 0.00 0.00 0.00 0.35 0.90 5.00 P1 2.28 0.00 1.10 0.00 0.00 3.38 0.66 5.00 X2 0.27 0.26 0.53 0.53 5.00 DA 7 0.13 0.10 0.15 0.38 0.59 5.00 TOTALS 4.93 0.14 1.91 0.00 0.00 6.98 0.69 11.30 Basin Rational Surface Coefficient - C / Areas - ac. Basin Rational Surface Coefficient - C / Areas - ac. i Q = cia i Q = cia i Q = cia i Q = cia 6.99 3.01 8.08 3.47 8.83 3.80 9.70 4.17 6.99 1.97 8.08 2.28 8.83 2.49 9.70 2.74 6.41 1.86 7.45 2.16 8.17 2.37 8.97 2.60 5.20 4.41 6.08 5.16 6.74 5.72 7.40 6.28 6.99 18.64 8.08 21.55 8.83 23.55 9.70 25.87 6.29 2.09 7.30 2.43 8.02 2.67 8.81 2.93 31.98 37.05 40.59 44.59 i Q = cia i Q = cia i Q = cia i Q = cia 6.99 3.01 8.08 3.47 8.83 3.80 9.70 4.17 5.42 1.41 6.33 1.64 7.00 1.82 7.68 1.99 5.20 4.06 6.08 4.75 6.74 5.27 7.40 5.78 6.99 0.92 8.08 1.07 8.83 1.17 9.70 1.28 5.26 1.04 6.15 1.22 6.81 1.35 7.48 1.48 6.99 2.20 8.08 2.55 8.83 2.78 9.70 3.06 6.99 15.50 8.08 17.91 8.83 19.58 9.70 21.50 6.99 1.97 8.08 2.28 8.83 2.49 9.70 2.74 6.99 1.57 8.08 1.81 8.83 1.98 9.70 2.18 31.68 36.71 40.23 44.18 Rational Design Frequency - Intensity and Runoff 10-year 25-year 50-year 100-year Rational Design Frequency - Intensity and Runoff 10-year 25-year 50-year 100-year Appendix A OHUOHUOHUOHUW W W W W WOHUWW WWWWWOHU WW FDC WWWWSSSSFRENCH DRAIN FOR HOLY WATERP1SWDA4-6NA=1.11Apervious =0.20acA=3.93 AC.Aper=1.16A=0.48Apervious =0SEEXDADA1-3A=0.53Apervious =0.26acDA 7A=0.50Apervious=0.15DA 8O1X2A=0.43Apervious=0.13SHEET No.SCALE:Date:PROJECT:TITLE:Job No.8365 Keystone Crossing, Suite 201 Indianapolis, IN. 46240 (317) 202-0864 EXISTING BASIN EXHIBITE11"= 80'OUR LADY OF MOUNT CARMEL Appendix B OHUOHUOHUOHUW W W WOHUWW WWWWWOHU WW FDC WWWWSSSSFRENCH DRAIN FOR HOLY WATEREX0inv=877.7EX10EX14EX12EX3INV=878.5SE EINV IN=878.74INV OUT=878.64INV IN=877.67STPTCCCCCCCCINV= 876.83" SAN ITARY SEWER FORCE MA IN LATERALTOTAL = 0.45 ACP = 0.32 ACTOTAL = 0.17 ACP = 0.14 ACTOTAL = 0.18 ACP = 0.15 ACTOTAL = 0.15 ACP = 0.14 ACTOTAL = 0.08 ACP = 0.01 ACTOTAL = 0.18 ACP = 0.05 ACTOTAL = 0.03 ACP = 0.00 ACTOTAL = 0.05 ACP = 0.003 ACTOTAL = 0.11 ACP = 0.01 ACTOTAL = 0.16 ACP = 0.14 ACTOTAL = 0.14 ACP = 0.04 ACTOTAL = 0.33 ACP = 0.31 ACTOTAL = 0.90 ACTOTAL = 0.19 ACP = 0.16 ACTOTAL = 0.14 ACP = 0.13 ACTOTAL = 0.09 ACP = 0.09 ACTOTAL = 0.28 ACP = 0.27 ACTOTAL = 0.62 ACP = 0.53 ACTOTAL = 0.10 ACP = 0.01 ACTOTAL = 0.58 ACP = 0.56 ACTOTAL = 0.07 ACP = 0.07 ACTOTAL = 0.26 ACP = 0.26 ACTOTAL = 0.55 ACP = 0.55 ACTOTAL = 0.04 ACP = 0.03 ACTOTAL = 0.15 ACP = 0.07 ACTOTAL = 0.14 ACP = 0.11 ACPR-2PR-1A=0.33ACAper = 0.05P-NPR-3A= 0.96 ACAper = 0.11A= 0.35 ACA= 0.15 ACA= 0.42 ACAper = 0.24 acP-P1A=3.38 AC.P-SESWA=0.48Apervious =0acAper=1.1 AC.X2A=0.53Apervious =0.26acDA 7A= 0.38 ACSHEET No.SCALE:Date:PROJECT:TITLE:Job No.8365 Keystone Crossing, Suite 201 Indianapolis, IN. 46240 (317) 202-0864 PROPOSED BASIN EXHIBITP11"= 80'OUR LADY OF MOUNT CARMEL Appendix C Inlet calculations & areas summed to BMP #1: hydrodynamic separator Project 21014L Our Lady of Mount Carmel by Mark Kilgore, P.E. & Divyat Agarwal, E.I.T. 10-yr x 1.9= 10-yr surface 10-yr 10-yr 100-yr 100-yr 100-yr available total flow flow flow flow flow flow flow ponding to inlet to inlet into inlet past inlet to inlet into inlet past inlet (ft/ft)(ft)imperv pervious Area I (cfs)(cfs)(cfs)(cfs)(cfs)(cfs)(cfs) program #C3D #slope depth acres acres x C (in/hr)Q= CIA Q= CIA intaken bypass Q= CIA intaken bypass inlet chosen 701 to ex 701 0.50 0.00 0.09 0.02 7.20 0.13 0.13 0.13 0.00 0.25 0.25 0.00 GI R-4215 702 to 701 702 0.10 0.01 0.27 0.06 7.20 0.45 0.45 0.45 0.00 0.86 0.86 0.00 GI R-4215 703 to ex 703 0.70 0.10 0.04 0.10 7.20 0.71 0.20 0.20 0.00 0.38 0.38 0.00 GI R-4215 704 to 703 704 0.30 0.09 0.01 0.08 7.20 0.60 0.20 0.20 0.00 0.38 0.38 0.00 GI R-4215 705 to 704 705 0.30 0.02 0.56 0.13 7.20 0.94 0.94 0.94 0.00 1.78 1.78 0.00 GI R-4215 706 to ex 706 0.30 0.01 0.14 0.04 7.20 0.27 1.70 1.70 0.00 3.23 3.23 0.00 GI R-4215 707 to 706 707 0.60 0.03 0.15 0.06 7.20 0.41 1.70 1.70 0.00 3.23 3.23 0.00 GI R-4215 708 to 707 708 0.30 0.03 0.14 0.06 7.20 0.40 1.00 1.00 0.00 1.90 1.90 0.00 GI R-4215 709 to 708 709 0.10 0.13 0.32 0.18 7.20 1.30 1.30 1.30 0.00 2.48 2.48 0.00 GI R-4215 711 to ex 711 n/a 0.00 0.00 0.00 7.20 0.00 0.00 0.00 0.00 0.01 0.01 0.00 MH 712 to 711 712 0.30 0.10 0.01 0.09 7.20 0.66 0.66 0.66 0.00 1.26 1.26 0.00 GI R-4215 713 to ex 713 0.20 0.08 0.00 0.07 7.20 0.52 0.52 0.52 0.00 0.98 0.98 0.00 GI R-4215 721 to ex 721 0.22 0.01 0.13 0.04 7.20 0.25 0.25 0.25 0.00 0.48 0.48 0.00 CI R-3010 722 to 721 722 n/a 0.00 0.00 0.00 7.20 0.00 0.00 0.00 0.00 0.00 0.00 0.00 MH 723 to 722 723 n/a 0.00 0.00 0.00 7.20 0.00 0.00 0.00 0.00 0.00 0.00 0.00 BMP XC-3 724 to 722 724 n/a 0.00 0.00 0.00 7.20 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Div MH 710 to 725 710 0.25 0.01 0.03 0.02 7.20 0.11 1.00 1.00 0.00 1.90 1.90 0.00 GI R-4215 725 to 724 725 0.50 0.09 0.53 0.19 7.20 1.35 1.35 1.35 0.00 2.56 2.56 0.00 GI R-4215 726 to 725 726 0.20 0.13 0.05 0.13 7.20 0.91 0.91 0.91 0.00 1.74 1.74 0.00 GI R-4215 727 to 726 727 1.85 0.07 0.01 0.07 7.20 0.47 0.47 0.47 0.00 0.89 0.89 0.00 GI R-4215 0.30 0.62 to BMP ac imp ac perv Appendix D OHUOHUOHUOHUW W W WOHUWW WWWWWOHU WW FDC WWWWSSSSFRENCH DRAIN FOR HOLY WATERSHEET No.SCALE:Date:PROJECT:TITLE:Job No.8365 Keystone Crossing, Suite 201 Indianapolis, IN. 46240 (317) 202-0864 BMP LOCATION MAPWQ11"= 80'OUR LOADY OF MOUNT CARMEL to BMP to BMP Routing Diagram for WQ-21014L Prepared by {enter your company name here}, Printed 7/20/2021 HydroCAD® 10.00-26 s/n 07656 © 2020 HydroCAD Software Solutions LLC Subcat Reach Pond Link WQ-21014L Printed 7/20/2021Prepared by {enter your company name here} Page 2HydroCAD® 10.00-26 s/n 07656 © 2020 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.960 91 WQ Exhibit 701.1 (to BMP) 0.960 91 TOTAL AREA WQ-21014L Printed 7/20/2021Prepared by {enter your company name here} Page 3HydroCAD® 10.00-26 s/n 07656 © 2020 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 0.000 HSG B 0.000 HSG C 0.000 HSG D 0.960 Other to BMP 0.960 TOTAL AREA WQ-21014L Printed 7/20/2021Prepared by {enter your company name here} Page 4HydroCAD® 10.00-26 s/n 07656 © 2020 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 0.000 0.000 0.000 0.960 0.960 WQ Exhibit 701.1 to BMP 0.000 0.000 0.000 0.000 0.960 0.960 TOTAL AREA Type II 24-hr 10-Year Rainfall=3.83"WQ-21014L Printed 7/20/2021Prepared by {enter your company name here} Page 5HydroCAD® 10.00-26 s/n 07656 © 2020 HydroCAD Software Solutions LLC Time span=0.00-30.00 hrs, dt=0.05 hrs, 601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Runoff Area=0.960 ac 0.00% Impervious Runoff Depth=2.85"Subcatchment to BMP: to BMP Flow Length=89' Tc=6.6 min CN=91 Runoff=4.38 cfs 0.228 af Total Runoff Area = 0.960 ac Runoff Volume = 0.228 af Average Runoff Depth = 2.85" 100.00% Pervious = 0.960 ac 0.00% Impervious = 0.000 ac Type II 24-hr 10-Year Rainfall=3.83"WQ-21014L Printed 7/20/2021Prepared by {enter your company name here} Page 6HydroCAD® 10.00-26 s/n 07656 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment to BMP: to BMP Runoff = 4.38 cfs @ 11.97 hrs, Volume= 0.228 af, Depth= 2.85" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=3.83" Area (ac) CN Description * 0.960 91 WQ Exhibit 701.1 0.960 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.3 25 0.0120 0.07 Sheet Flow, SF Grass: Dense n= 0.240 P2= 2.66" 0.1 16 0.0120 2.22 Shallow Concentrated Flow, SCF Paved Kv= 20.3 fps 0.2 48 0.0125 3.27 3.27 Channel Flow, CF Area= 1.0 sf Perim= 2.2' r= 0.45' n= 0.030 6.6 89 Total Subcatchment to BMP: to BMP Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)4 3 2 1 0 Type II 24-hr 10-Year Rainfall=3.83" Runoff Area=0.960 ac Runoff Volume=0.228 af Runoff Depth=2.85" Flow Length=89' Tc=6.6 min CN=91 4.38 cfs Type II 24-hr 100-Year Rainfall=6.46"WQ-21014L Printed 7/20/2021Prepared by {enter your company name here} Page 7HydroCAD® 10.00-26 s/n 07656 © 2020 HydroCAD Software Solutions LLC Time span=0.00-30.00 hrs, dt=0.05 hrs, 601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Runoff Area=0.960 ac 0.00% Impervious Runoff Depth=5.41"Subcatchment to BMP: to BMP Flow Length=89' Tc=6.6 min CN=91 Runoff=7.97 cfs 0.433 af Total Runoff Area = 0.960 ac Runoff Volume = 0.433 af Average Runoff Depth = 5.41" 100.00% Pervious = 0.960 ac 0.00% Impervious = 0.000 ac Type II 24-hr 100-Year Rainfall=6.46"WQ-21014L Printed 7/20/2021Prepared by {enter your company name here} Page 8HydroCAD® 10.00-26 s/n 07656 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment to BMP: to BMP Runoff = 7.97 cfs @ 11.97 hrs, Volume= 0.433 af, Depth= 5.41" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=6.46" Area (ac) CN Description * 0.960 91 WQ Exhibit 701.1 0.960 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.3 25 0.0120 0.07 Sheet Flow, SF Grass: Dense n= 0.240 P2= 2.66" 0.1 16 0.0120 2.22 Shallow Concentrated Flow, SCF Paved Kv= 20.3 fps 0.2 48 0.0125 3.27 3.27 Channel Flow, CF Area= 1.0 sf Perim= 2.2' r= 0.45' n= 0.030 6.6 89 Total Subcatchment to BMP: to BMP Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)8 7 6 5 4 3 2 1 0 Type II 24-hr 100-Year Rainfall=6.46" Runoff Area=0.960 ac Runoff Volume=0.433 af Runoff Depth=5.41" Flow Length=89' Tc=6.6 min CN=91 7.97 cfs Type II 24-hr WQ_24 Rainfall=1.00"WQ-21014L Printed 7/20/2021Prepared by {enter your company name here} Page 9HydroCAD® 10.00-26 s/n 07656 © 2020 HydroCAD Software Solutions LLC Time span=0.00-30.00 hrs, dt=0.05 hrs, 601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Runoff Area=0.960 ac 0.00% Impervious Runoff Depth=0.36"Subcatchment to BMP: to BMP Flow Length=89' Tc=6.6 min CN=91 Runoff=0.59 cfs 0.029 af Total Runoff Area = 0.960 ac Runoff Volume = 0.029 af Average Runoff Depth = 0.36" 100.00% Pervious = 0.960 ac 0.00% Impervious = 0.000 ac Type II 24-hr WQ_24 Rainfall=1.00"WQ-21014L Printed 7/20/2021Prepared by {enter your company name here} Page 10HydroCAD® 10.00-26 s/n 07656 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment to BMP: to BMP Runoff = 0.59 cfs @ 11.99 hrs, Volume= 0.029 af, Depth= 0.36" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr WQ_24 Rainfall=1.00" Area (ac) CN Description * 0.960 91 WQ Exhibit 701.1 0.960 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.3 25 0.0120 0.07 Sheet Flow, SF Grass: Dense n= 0.240 P2= 2.66" 0.1 16 0.0120 2.22 Shallow Concentrated Flow, SCF Paved Kv= 20.3 fps 0.2 48 0.0125 3.27 3.27 Channel Flow, CF Area= 1.0 sf Perim= 2.2' r= 0.45' n= 0.030 6.6 89 Total Subcatchment to BMP: to BMP Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr WQ_24 Rainfall=1.00" Runoff Area=0.960 ac Runoff Volume=0.029 af Runoff Depth=0.36" Flow Length=89' Tc=6.6 min CN=91 0.59 cfs City of Indianapolis Stormwater Quality Unit (SQU) Selection Guide Pg. 1 08/26/2020 Version 18.0 (Check : https://www.indy.gov/activity/public-works-specifications-and-manuals for current Selection Guide) Performance Matrix for Manufactured SQUs that are approved for use as post-construction water quality units in the City of Indianapolis and in compliance with the Stormwater Design and Construction Specifications Manual PLEASE NOTE: All SQUs shall be configured as off-line units unless approved for on-line use. On-line units must document the peak 10-year flow (per the Stormwater Design and Construction Specification Manual) is less than the approved maximum10-yr flow rate. Rate Based SQUs - Table 1 Manufactured SQU SQU System Model Max Treatment Flow (cfs) Max 10-yr On-Line Flow Rate (cfs) Cleanout Depth (Inches) SciClone1 SC-3 0.39 N/A 9 SC-4 0.70 N/A 9 SC-5 1.09 N/A 9 SC-6 1.57 N/A 9 SC-7 2.14 N/A 9 SC-8 2.80 N/A 9 SC-9 3.54 N/A 9 SC-10 4.37 N/A 9 SC-11 5.29 N/A 9 SC-12 6.30 N/A 9 CDS Technologies1 CDS-3 0.52 1.04 9 CDS-4 0.93 1.86 9 CDS-5 1.5 3.00 9 CDS-6 2.1 4.2 9 CDS-7 2.8 5.60 9 CDS-8 3.7 7.4 9 CDS-10 5.8 11.6 9 CDS-12 8.4 16.8 9 DVS1 DVS-36C 0.56 1.12 9 DVS-48C 1.00 2.00 9 DVS-60C 1.56 3.12 9 DVS-72C 2.25 4.50 9 DVS-84C 3.06 6.12 9 DVS-96C 4.00 8.00 9 DVS-120C 6.25 12.50 9 DVS-144C 9.00 18.00 9 City of Indianapolis Stormwater Quality Unit (SQU) Selection Guide Pg. 2 08/26/2020 Version 18.0 Manufactured SQU SQU System Model Max Treatment Flow (cfs) Max 10-yr On-Line Flow Rate (cfs) Cleanout Depth (Inches) Hydro International Downstream Defender1 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 12 ft 10.08 26.51 21 Hydro International First Defense High Capacity1 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 8-ft 6.00 12.96 9 HydroStorm by Hydroworks, LLC1 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 HS-12 7.91 15.82 6 AquaShield Aqua-Swirl Xcelerator1 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 XC-13 15.53 31.60 6 Contech Cascade Separator CS-3 1.02 2.27 9 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 CS-12 16.2 36.3 9 City of Indianapolis Stormwater Quality Unit (SQU) Selection Guide Pg. 3 08/26/2020 Version 18.0 Manufactured SQU SQU System Model Max Treatment Flow (cfs) Max 10-yr On-Line Flow Rate (cfs) Cleanout Depth (Inches) Oldcastle NSBB-HVT 2-4 0.62 2.57 6 3-6 1.4 5.80 6 3-8 1.87 7.75 6 4-8 2.49 10.31 6 5-10 3.89 16.11 6 6-12 5.6 23.19 6 6-13.75 6.42 26.59 6 7-14 7.62 31.56 6 7-15 8.17 33.84 6 8-14 8.71 36.08 6 8-16 9.96 41.25 6 9-18 12.6 52.19 6 10-17 13.22 54.76 6 10-20 15.56 64.45 6 12-21 19.6 81.18 6 12-24 22.4 92.78 6 AquaShield Aqua Swirl Concentrator AS-2 0.36 0.73 7 AS-3 0.71 1.44 7 AS-4 1.18 2.39 7 AS-5 1.46 2.96 7 AS-6 2.11 4.28 7 AS-7 2.87 5.82 7 AS-8 3.74 7.59 7 AS-9 4.73 9.59 7 AS-10 5.84 11.84 7 AS-11 7.07 14.34 7 AS-12 8.42 17.08 7 AS-13 9.87 20.02 7 ADS Barracuda S3 0.70 1.40 10 S4 1.25 2.50 10 S5 1.95 3.90 10 S6 2.80 5.60 10 S8 5.00 10.00 10 S10 7.80 15.60 10 1 Installed in the configuration as reviewed by NJCAT only City of Indianapolis Stormwater Quality Unit (SQU) Selection Guide Pg. 4 08/26/2020 Version 18.0 Appendix I Design Treatment Flow Rate Determination For Table 1 SQUs Stormwater Quality Flow Rate Determination – Table 1 SQUs The design flow rate for manufactured stormwater quality units (SQUs) shall be determined using the SCS runoff methodology as outlined below. 1. Delineate the watershed basin(s) to be served by the proposed SQU(s). Tabulate the total impervious and pervious areas. Please note impervious and pervious area runoff rates MUST be calculated as separate basins. The sizing calculation assumes the impervious area is connected directly to the SQU and the Tc calculation must be adjusted for this assumption (i.e. no flow over grass) for the impervious basin. This can be accomplished by creating two basins, one with an area equivalent to the total impervious area and the other with an area equivalent to the total pervious area of the delineated watershed to be served by the SQU. 2. Determine the time-of-concentration (Tc) using the TR-55 methodology (Worksheet 3, Chapter 200 Appendix of the City of Indianapolis Stormwater Specifications Manual) for each basin. A minimum 5-minute Tc may be assumed for the impervious basin. 3. Calculate the curve numbers (CN) for each basin, using CN=98 for the impervious basin. 4. Determine the peak discharge from the 0.3-inch storm using the appropriate Huff, 50% rainfall distribution (Storm duration 0 up to and including 6 hrs – 1st Quartile, 6.1 to 12 hrs – 2nd Quartile, 12.1 to 24 hrs – 3rd Quartile. See Table below for Huff ordinates.). A single hydrograph for each basin should be determined and all basin hydrographs added to determine the peak flow. Storm durations of 15-, 30- and 45 minutes as well as 1-, 2-, 3- 6- 12- and 24- hours should be checked to determine the peak SQU flow. City of Indianapolis Stormwater Quality Unit (SQU) Selection Guide Pg. 5 08/26/2020 Version 18.0 Huff Ordinates Table IA % Storm Time Indianapolis Huff Quartile 1st Quartile 2nd Quartile 3rd Quartile 4th Quartile 0 0.00 0.00 0.00 0.00 10 20.00 6.50 5.26 6.67 20 40.80 18.13 11.55 14.25 30 54.95 35.85 17.06 20.00 40 62.50 52.94 24.24 26.09 50 68.75 67.86 37.78 33.33 60 76.67 76.52 58.33 40.00 70 83.05 83.81 78.03 50.00 80 89.70 90.67 88.68 68.57 90 95.00 95.89 95.29 88.37 100 100.00 100.00 100.00 100.00 City of Indianapolis Stormwater Quality Unit (SQU) Selection Guide Pg. 6 08/26/2020 Version 18.0 Appendix II O&M Manual Checklist In addition to the requirements listed in Section 102.06 of the Stormwater Specifications Manual, the following notes / maintenance items should be included in the Operations and Maintenance Manual (O & M Manual): _____ 1. Owner name, address, business phone number, home phone number, email address, cellular phone number. _____ 2. Site drawings (8½” by 11” or 11” by 17”), showing both plan and cross-section views, showing the infrastructure and applicable features, including dimensions, easements, outlet works, forebays, all water quality and quantity features, inspection and maintenance features (ports, access drives, etc.), signage, etc., as well as an overall site map of the development showing all structures. _____ 3. A stormwater management easement is required for each facility. The easement must include the BMP, all outlet structures and access to the BMP. _____ 4. Requirement of owner to perform periodic inspections and maintenance, annually at minimum and as necessary to confirm the system is functioning as designed and permitted; _____ 5. Frequency of required inspection and maintenance for each BMP; _____ 6. Requirement of owner to keep records of inspections and maintenance activities; _____ 7. Requirement of owner to self-certify when requested by the City that inspections and maintenance was performed according to the O&M Manual; _____ 8. Requirement of the owner to remove and replace filter media as need, determined by infiltration rate, drain down time, percolation test, etc. _____ 9. The maximum sediment depth should be clearly specified, e.g. 8” based on the table above. _____ 10. Graphical and written description of sediment measuring procedure. This should include the use of a dipstick tube equipped with a ball valve (e.g. Sludge Judge). _____ 11. Oil and other floatable materials removal procedure during routine cleanout. _____ 12. The O & M Manual should specify if entry into the SQU should be considered an OSHA confined space and guidelines followed. City of Indianapolis Stormwater Quality Unit (SQU) Selection Guide Pg. 7 08/26/2020 Version 18.0 _____ 13. A minimum inspection and maintenance frequency of annually should be specified in the narrative and the tabular inspection schedule. _____ 14. Off-line configurations must include inspection and maintenance of connecting manhole and diversion weir. _____ 15. Detail drawing of proposed SQU, including floating debris capture device where applicable, should be included. _____ 16. Note in the manual to clean unit immediately if there is a hydrocarbon spill (e.g. gasoline or oil). _____ 17. The use of adsorbents should be addressed as appropriate. _____ 18. A note should be provided indicating disposal of all sediment must be in accordance with all federal, state and local requirements and should NOT be dumped into the storm sewer or a sanitary sewer. _____ 19. Other specific requirements per the manufacturer’s recommendations. Plan Checklist The following items should be specified on all plans referencing a SQU submitted for approval by the City of Indianapolis: _____ 1. The minimum cover requirement as specified by the Stormwater Specifications Manual should be shown on the details for all connecting pipes. _____ 2. A minimum 6” stone base should be shown on the detail. _____ 3. The backfill should be specified as required by the manufacturer. _____ 4. Detail drawing of each SQU model, including floating debris capture device as applicable, per the manufacturer should be included on plans. _____ 5. Detail of connecting structures and diversion for off-line configurations should be included. _____ 6. A minimum 24” access opening must be shown. _____ 7. All construction plans shall show the SQUs installed with one inlet and one outlet pipe approximately 180 degrees apart unless the design report includes documentation the unit was tested by NJCAT and certified by NJDEP for the proposed layout. The inclusion of surface inlets must also include the testing and certification documentation. City of Indianapolis Stormwater Quality Unit (SQU) Selection Guide Pg. 8 08/26/2020 Version 18.0 Drainage Report Checklist The following requirements should be addressed in drainage design reports: _____ 1. The design storm must not create a hydraulic tailwater condition on the SQU. A first flush hydraulic gradeline evaluation should be included in the report. _____ 2. The design storm should be the peak runoff for a 0.3-inch rainfall depth using the appropriate Huff, 50% rainfall distribution. The contributing watershed should be modeled with the pervious and impervious areas inputted as separate areas (i.e. not combined using a single curve number.) _____ 3. The 10-yr pipe capacity up- and downstream of all water quality structures should be documented with calculations to demonstrate the water surface for the 10-yr storm is below the crown of the pipe as required by the Stormwater Specifications Manual. _____ 4. Diversion structure design should be documented with calculations as appropriate. _____ 5. Buoyancy shall be addressed in the report. _____ 6. Traffic loading requirements should be addressed in the report. 2DIVERSION MANHOLE STRUCTURE 724NOT TO SCALE7' Ø MANHOLE