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Storm Drainage CalculationsPage 2 of 2 << File: SD005677.pdf>> Joe, Attached is the previously approved drainage calcs that include all 22.4 ac of southern drainage area of which 3.08 is the Superdog site. This is based on a composite CN of 84 and NURP based on 80% impervious directly connected. Our combined new site will be somewhere under 60% impervious as well as a composite CN of under 84. Let me know as soon as you can if you do not agree with this. Otherwise, I will assume that the ponding, both quality and quantity, is taken care of with the regional pond system. Thanks. Kurt Kurt D. Quamtance, PE Vice President James R. Mill, Inc. 2500 West County Road 42, # 120 Burnsville, MN 55337 Ph. 052- 890 -6044 (ext.1 17) Fax. 952 - 890 -6244 Cell (61 2) 508 -8890 kguainta nce (a? irh i nc. com li c CITY RECEIVED SSEN JUL 2 0 7012 $- CHANHASSEN PLANNING DEPT 4/9/2012 Page 1 of 1 Kurt Quaintance From: Kurt Quaintance [kquaintance @jrhinc.com] Sent: Thursday, March 20, 2008 3:17 PM To: 'JSHAMLA @CI.CHANHASSEN.MN.US' Subject: ARBORETUM BUSINESS PARK DRAINAGE/SUPERDOG JOE, ATTACHED ARE DRAINAGE CALCULATIONS /MAPS FOR THE SOUTHERN REGIONAL POND OF THE ARBORETUM BUSINESS PARK (22.4 ACS DRAINAGE AREA). I HAVE INCLUDED A JRH HYDROCAD VERSION OF THE SCHOELL & MADSON DRAINAGE CALCS THAT I HAD RECEIVED FROM ALYSON, AS WELL AS SCHOELL & MADSON COMPS THAT ILLUSTRATE WHERE I PULLED SOME OF THE BASE NUMBERS. ONE OF THE HYDROCAD RUNS IS THE 100YR AND THE OTHER IS THE NPDES WATER QUALITY (0.5 IN RUNOFF -5.66 CFS /SURF AC). I HAVE ALSO INCLUDED A WALKER NURP CALC WITH THE REQUIRED MPCA PERMANENT VOLUME. IT LOOKS TO ME THAT THE CURRENT REGIONAL POND AS SHOWN AND DESIGNED PER THE DOCUMENTS PROVIDED BY SCHOELL & MADSON MEETS WATER QUANTITY AND QUALITY REQUIREMENTS FOR THE ENTIRE 22.4 ACS, WHICH INCLUDES THE 3.08 AC KENNEL SITE EAST OF THE HOLIDAY STATION STORE ON 82ND STREET. PLEASE LET ME KNOW WHAT YOU THINK. IF YOU HAVE ANY QUESTIONS, PLEASE GIVE ME A CALL. THANKS KURT Kurt D. Quaintance, PE 7�1 �, /i Z 1�- ►Ls � � Vice Pre51dent James R. Hill, Inc. 2500 West County Road 42, # 120 BurnWIIC, MN 55337 Ph. 952- 890 -6044 fax. 952-890-G244 k�juaintance(d,) J rh i n c. com CITY OF CHANHASSEN RECEIVED JUL 2 U CHANHASSEN PLANNING DEPT 3/20/2008 77 7 1 r S: (new Subc (new Pond) Subcat Reach on Link superdog proposed 3 -20-08 Type 11 24-hr 100yr Rainfall = 5.90" Prepared by {enter your company name here} Page 2 HydroCADO 7.00 s/n 000744 ©1986 -2003 Applied Microcomputer Systems 3/20/2008 Time span =0.00- 100.00 hrs, dt =0.10 hrs, 1001 points Runoff by SCS TR -20 method, UH =SCS Reach routing by Sim -Route method - Pond routing by Sim -Route method Subcatchment 1S: (new Subcat) RunoffArea= 22.400 ac Runoff Depth= 4.10" Tc =30.0 min CN =84 Runoff- cfs 7.659 of Pond 2P: (new Pond) Peak Elev= 966.19' Storage =4.271 of Inflow =78.56 cfs 7.659 of Outflow =10.00 cfs 7.614 of Total Runoff Area = 22.400 ac Runoff Volume = 7.659 of Average Runoff Depth = 4.10" superdog proposed 3 -20 -08 Type 1124 -hr 100yr Rainfall = 5.90" Prepared by {enter your company name here} Page 3 HydroCADO 7.00 s/n 000744 01986 -2003 Applied Microcomputer Systems 3/20/2008 Subcatchment 1S: (new Subcat) Runoff = 78.56 cfs @ 12.24 hrs, Volume= 7.659 af, Depth= 4.10" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00- 100.00 hrs, dt= 0.10 hrs Type II 24-hr 100yr Rainfall= 5.90" Area (ac) CN Description 22.400 84 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 30.0 Direct Entry, Pond 2P: (new Pond) Inflow Area = 22.400 ac, Inflow Depth = 4.10" for 100yr event Inflow = 78.56 cfs @ 12.24 hrs, Volume= 7.659 of Outflow = 10.00 cfs @ 13.27 hrs, Volume= 7.614 af, Atten= 87 %, Lag= 62.2 min Primary = 10.00 cfs @ 13.27 hrs, Volume= 7.614 of Routing by Sim -Route method, Time Span= 0.00- 100.00 hrs, dt= 0.10 hrs Peak Elev= 966.19'@ 13.27 hrs Surf.Area= 1.034 ac Storage= 4.271 of Flood Elev= 970.00' Surf.Area= 1.330 ac Storage= 8.160 of Plug -Flow detention time= 363.4 min calculated for 7.614 of (99% of inflow) Center -of -Mass det. time= 359.7 min ( 1,182.9 - 823.3) # Invert Avail.Storage Storage Description 1 962.00' 8.160 of Custom Stage Data (Prismatic) Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (acres) (acre -feet) (acre -feet) 962.00 0.710 0.000 0.000 970.00 1.330 8.160 8.160 P er fan # Routing Invert Outlet Devices RAvr-�,1 Primary 962.00' 24.0" x 65.0' long Culvert Ke= 0.500 Outlet Invert= 961.55' S= 0.0069'/' n=0.013 Cc= 0.900 2 Device 1 962.00' 9.0" Vert. Orifice /Grate C= 0.600 3 Device 1 963.30' 12.0" Vert. Orifice /Grate C= 0.600 Primary OutFlow Max =9.99 cfs @ 13.27 hrs HW= 966.19' (Free Discharge) L1= Culvert (Passes 9.99 cfs of 26.93 cfs potential flow) L (Orifice Controls 4.15 cfs @ 9.4 fps) 3= Orifice/Grate (Orifice Controls 5.84 cfs @ 7.4 fps) 1 (new Subc (new Pond) Subcat Reach on Lltlk superdog proposed water quality3 -20-08 Type 11 24 -hr water quality Rainfall= 0.70" Prepared by {enter your company name here} Page 2 HydroCAD® 7.00 s/n 000744 01986 -2003 Applied Microcomputer Systems 3/20/2008 Time span =0.00- 100.00 hrs, dt =0.10 hrs, 1001 points Runoff by SCS TR -20 method, UH =SCS Reach routing by Sim -Route method - Pond routing by Sim -Route method Subcatchment 1S: (new Subcat) RunoffArea= 22.400 ac Runoff Depth = 0.50" Tc =1.0 min CN =98 Runoff =20.00 cfs 0.940 of Pond 2P: (new Pond) Peak Elev= 962.57' Storage =0.578 of Inflow =20.00 cfs 0.940 of Outflow =0.92 cfs 0.901 of Total Runoff Area = 22.400 ac Runoff Volume = 0.940 of Average Runoff Depth = 0.50" superdog proposed water quality3 -20-08 Type // 24 -hr water quality Rainfall = 0.70" Prepared by {enter your company name here} Page 3 HydroCADO 7.00 s/n 000744 ©1986 -2003 Applied Microcomputer Systems 3/20/2008 Subcatchment IS: (new Subcat) [49] Hint: Tc <2dt may require smaller dt Runoff = 20.00 cfs @ 11.89 hrs, Volume= 0.940 af, Depth= 0.50" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.0 100.00 hrs, dt= 0.10 hrs Type II 24 -hr water quality Rainfall = 0.70" Area (ac) CN Description 22.400 98 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Pond 2P: (new Pond) Inflow Area = 22.400 ac, Inflow Depth = 0.50" for water quality event Inflow = 20.00 cfs @ 11.89 hrs, Volume= 0.940 of Outflow = 0.92 cfs @ 13.02 hrs, Volume= 0.901 af, Atten= 95 %, Lag= 68.0 min Primary = 0.92 cfs @ 13.02 hrs, Volume= 0.901 of Routing by Sim -Route method, Time Span= 0.00 - 100.00 hrs, dt= 0.10 hrs Peak Elev= 962.57'@ 13.02 hrs Surf.Area= 0.754 ac Storage= 0.578 f 3 �.5/ Flood Elev= 970.00' Surf.Area= 1.330 ac Storage= 8.160 of _ AL Plug -Flow detention time= 652.4 min calculated for 0.900 of (96% of inflo ) Center -of -Mass det. time= 632.4 min ( 1,424.9 - 792.5 ) # Invert Avail.Storage Storage Description 1 962.00' 8.160 of Custom Stage Data (Prismatic) Listed below Elevation Surf.Area Inc.Store Cum.Store feet acres acre -feet acre -feet 962.00 0.710 0.000 0.000 970.00 1.330 8.160 8.160 # Routing Invert Outlet Devices 1 Primary 962.00' 24.0" x 65.0' long Culvert Ke= 0.500 Outlet Invert= 961.55' S= 0.0069T n= 0.013 Cc= 0.900 2 Device 1 962.00' 9.0" Vert. Orifice /Grate C= 0.600 3 Device 1 963.30' 12.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max =0.92 cfs @ 13.02 hrs HW= 962.57' (Free Discharge) t1= Culvert (Passes 0.92 cfs of 1.61 cfs potential flow) L 2= Orifice /Grate (Orifice Controls 0.92 cfs @ 2.6 fps) 3=Orifice/Grate ( Controls 0.00 cfs) NURP DESIGN - POND PROJECT: ARBORETUM BUSINESS PARK PROJ. NO.: CLIENT: PLAN DATE: 3 -20 -08 LOCATION: CHANHASSEN, MINNESOTA COMP. DATE:3 -20 -08 NURP POND DESIGN INPUT DATA TOTAL WATERSHED AREA (ACRES): 22.4 TOTAL IMPERVIOUS AREA DIRECTLY CONNECTED TO STORM SEWER: 17.92 0% AREA WEIGHTED MEAN SCS CURVE NUMBER: 61 20% DESIGN STORM SIZE (INCHES): 2.5 NURP POND DESIGN OUTPUT PARAMETERS IMPERVIOUS FRACTION: 80.00% MAXIMUM SOIL RETENTION (INCHES) 6.39 DESIGN STORM RUNOFF (INCHES): 2.04 MIN. REQUIRED WET VOLUME STORAGE (NURP) VOLUME (ac -ft): 3.81 DESIGNED WET VOLUME STORAGE (NURP)- VOLUME (ac -ft): 4.04 PER PLAN REQUIRED MPCA PERMANENT VOLUME (1800FT ^3 /AC) (ac -ft): 0.93 Method of calculation is taken from "DESIGN CALCULATIONS FOR WET DETENTION PONDS" by William W. Walker, October, 1987. l Quick TR -55 Version: 5.46 S IN: Page 1 TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr. Duration Storm) Executed: 04 -04 -1997 09:31 :44 Watershed file: - -> C: \DATA \61809 \004 \PR \5100 WSD Hydrograph file: - -> C: \DATA \61809 \004 \PR \51000 .HYD GATEWAY CHANHASSEN 3/22/97 JK STORMWATER MANAGEMENT PLAN PROPOSED CONDITIONS NURP BASIN DESIGN SOUTH BASIN (BC -P2.7) 100 YEAR DESIGN STORM >>>> Input Parameters Used to Compute Hydrograph <<<< -------- - - - Subarea ------------------------------------------------------------- AREA CN•I_ Tc * Tt Precip. R unoff Ia /p , escription (acres) 4 6 1 � (hrs) (hrs) (in) I (in) input /used ----------------------------------------------------------------------------- PROPOSED 22.40 84.0 0.50 0.00 5.90 1 4.10 .06 .10 ----------------------------------------------------------------------- Travel time from subarea outfall to composite watershed outfall point. Total area = 22.40 acres or 0.03500 sq.mi Peak discharge = 76 cfs >>>> Computer Modifications of Input Parameters <<<<< ----------------------------------------------------------------------------- Input Values Rounded Values Ia /p Subarea a scription Tc * Tt Tc * Tt interpolated Ia /p (hr) (hr) (hr) (hr) (Yes /No) Messages --------------------------------------------------------------------------- ROPOSED 0.62 0.00 0.50 0.00 No Computed Ia /p < .1 - --------------------------------------------------------------- Travel t ime f rom subarea outfall to composite watershed outfall point. 1 L� e k ,Pv e �� . POND -2 Version: 5.17 SIN: XECUTED: 04 -04 -1997 09:39:51 Page 7 * * * * * * * * * * * * * * * * ** SUMMARY OF ROUTING COMPUTATIONS * * * * * * * * * * * * * * * * ** Pond File: C: \DP_TA \61809 \004 \PR \SPND .PND Inflow Hydrograph: C: \DATA \61809 \004 \PR \S1000 HYD Outflow Hydrograph: C: \DATA \61809 \004 \PR \OUT HYD Starting Pond W.S. Elevation = 962.00 ft * * * ** Summary of Approximate Peak Storage * * * ** Initial Storage = 4.04 ac - QL&A- A,-o Ck -M Peak Storage From Storm = ---- Total Total Storage in Pond = 7.70 ac -ft Warning: Inflow hydrograph truncated on left side. -0, J/ r * * * ** Summary of Peak Outflow and Peak Elevation * * * ** Peak Inflow = 76.00 cfs Peak Outflow = Peak Elevation = 11.29 966.26 cfs ft * * * ** Summary of Approximate Peak Storage * * * ** Initial Storage = 4.04 ac - QL&A- A,-o Ck -M Peak Storage From Storm = ---- Total Total Storage in Pond = 7.70 ac -ft Warning: Inflow hydrograph truncated on left side. -0, J/ r 1� POND -2 Version: 5.17 S/N: I I GATEWAY CHANHASSEN 4/3/97 JK STORMWATER MANAGEMENT PLAN PROPOSED NURP BASIN DESIGN SOUTH BASIN STORAGE VOLUMES CALCULATED 04 -04 -1997 10:08 :32 DISK FILE: C: \DATA \.61809 \004 \PR \SVOL .VOL Planimeter scale: 1 inch = 100 ft. i� LL Volume = (1/3) * (EL2 -ELI) * (Areal + Area2 + sq.rt.(Areal *Area2)) Incremental volume computed by the Conic Method for Reservoir Volumes. where: ELI, EL2 = Lower and upper elevations of the increment Areal,Area2 = Areas computed for ELI, EL2, respectively Volume = Incremental volume between ELI and EL2 t � * Elevation Planimeter Area Al +A2 +sgr(P_1 *A2) Volume Volume Sum (ft) (sq.in.) (acres) (acres) (acre -ft) (acre -ft) 952.00 1.00 0.23 0.00 0.00 0.00 9 00 2.40 0.5 1.14 3.41 3.41 3.10 1.89 0.63 4.04 970.00 5.80 1.33 3.02 8.04 12.08 i� LL Volume = (1/3) * (EL2 -ELI) * (Areal + Area2 + sq.rt.(Areal *Area2)) Incremental volume computed by the Conic Method for Reservoir Volumes. where: ELI, EL2 = Lower and upper elevations of the increment Areal,Area2 = Areas computed for ELI, EL2, respectively Volume = Incremental volume between ELI and EL2 t � Outlet Structure File: SSTR: STR POND -2 Version: 5.17 SIN: Date Executed: Time Executed: GATEWAY CHANHASSEN 4/3/97 JK STORMWATER MANAGEMENT PLAN PROPOSED NUTRIENT TRAP SOUTH BASIN (BC -P2.7) >>>>>> Structure NO. 1 <<<<<< (Input Data) ORIFICE Orifice - Based on Area and Datum Elevation E1 elev. (ft) ? 962. 0* E2 elev.(ft)? 970.0 Orifice coeff.? .62 Invert elev. (ft) ? 962.0 Datum elev. (ft) ? 962,0 Orifice area (sq ft) ? .4416 O� Outlet Structure File: SSTR STR POND -2 Version: 5.17 SIN: Date Executed: Time Executed: GATEWAY CHANHASSEN 4/3/97 JK STORMWATER MANAGEMENT PLAN PROPOSED NUTRIENT TRAP SOUTH BASIN (BC -P2.7) >>>>>> Structure No. 2 <<<<<< ( Input Data) ORIFICE Orifice - Based on Area and Datum Elevation El elev. (ft) ? E2 el ev. (ft) ? Orifice coeff.? Invert elev.. (ft) ? Datum elev. (ft) ? Orifice area ( sq ft)? 963 .3,* 970 .62 963.3 tl 963.3 `f .785