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HomeMy WebLinkAboutDrainage LetterSeptember 11, 2006 Josh Norton, E.l.T. Graduate Engineer EMAIL: rm en gin eer @j u n o .com City of College Station 1101 Texas Avenue South College Station, TX 77842 RE: Drainage Letter for Westerheim Custom Homes -Office Building 240 Southwest Parkway, College Station, TX Lot SA, Block D -Ashford Square Subdivision, Brazos County RME No. 201-0289 Dear Josh, Please find the enclosed findings, calculations and attachments for the above referenced project's drainage facilities and improvements. This drainage letter and the supporting design methods were performed in accordance with the City of College Station's Drainage Design Policies and Standards. Information used for the design, and the resulting calculations, of these drainage improvements are as follows: •!• Exhibit #1 Carters Creek Watershed Map; •!• Exhibit #2 FEMA Map Panel; •!• Exhibit #3 Grading, Drainage, Erosion Control & Paving Plan (Sheet C 1.2) •!• Pre-Development Hydrology; •!• Post-Development Hydrology & Pond Routing; •!• Outlet Structure Routing; General The project site is a 0.1645 acre tract (Ashford Square Subdivision -Lot 8A, Block D) and is located within the Bee Creek drainage basin of the Carters Creek watershed. Runoff is conveyed overland and collects in the curb and gutter of a firelane located behind and north of the Lack's shopping center. Runoff, in general, travels in a southerly direction and eventually reaches the headworks of an unnamed tributary which drains into the Bee Creek (see Exhibit #1). Additionally, this project site is not located or adjacent to any FEMA mapped floodplain (see Exhibit #2). In general, undeveloped areas on this property are vacant, covered by native weeds and grasses, and have no tree coverage. Developed areas consist of the existing paved parking, and drives (see Exhibit #3). CD1-201-0289-L02 Page - 1 of3 Drainage Letter for Westerheim Custom Homes -Office Building 240 Southwest Parkway, College Station, TX Rabon Metcalf Engineering Lot SA, Block D -Ashford Square Subdivision, Brazos County September 11, 2006 Hydrology Using the SCS TR-20 method for hydrology modeling, runoff values were determined for each drainage condition (existing & proposed). Results from the 2, 5, 10, 25, 50 & 100-year rainfall events for these drainage basins are summarized below in Table #1 (see Hydrology sections). Proposed runoff rates are the resultants of routed all sub-drainage areas through the storm drain system using the hydrology/hydraulic program HydroCAD v7.0. TABLE#l-HYDROLOGYSUMMARY 1.-Year 5-Year D.A. (cfs) XI 0.62 Pl 0.68 XI -All of0.1645-acre tract; Pl -All of0.1645-acre tract; Hydraulics (cfs) 0.93 0.99 lU-Year 1.5-Year 50-Year (cfs) (cfs) (cfs) 1.15 1.40 1.59 1.21 1.46 1.64 Juu-Year (cfs) 1.80 1.86 With the proposed development, a detention facility will be provided that consists of a detention pond located at the rear of the Westerheim Office Building. At a maximum water surface elevation of 100.00' a storage of 254 ft3 will be available in the detention facility. Two 6" diameter drain pipes will be provided at the downstream end of the detention facility. Using the runoff hydrographs for proposed conditions, flows were routed through the detention system to determine expected runoff rates (see Routing sections). These stage-storage relationships, for the proposed conditions are summarized below in Table #2. TABLE #2 -ROUTING DATA Rainfall Peak Routed Event Storage Elevation Flow Pre-Dev. Diff. (yr) (cu.ft.) (ft) (cfs) Flow (cfs) (cfs) 2 12.0 98.96 0.68 0.62 0.06 5 29.0 99.18 0.98 0.93 0.05 10 54.0 99.36 1.16 1.15 0.01 25 100.0 99.57 1.35 1.40 -0.05 50 149.0 99.71 1.46 1.59 -0.13 100 223.0 99.86 1.57 1.80 -0.23 Discharge velocities from the to 6" drain lines are summarized below in Table #3. TABLE #3 -OUTFALL STRUCTURE Rainfall Event Flow Velocity (yr) (cfs) (fps) 2 0.68 1.8 5 0.98 2.0 10 1.16 2.1 25 1.35 2.2 50 1.46 2.3 100 1.57 2.2 CD1-201-0289-L02 Page - 2 of3 Drainage Letter for Westerheim Custom Homes -Office Building 240 Southwest Parkway, College Station, TX Lot SA, Block D -Ashford Square Subdivision, Brazos County Conclusions Rabon Metcalf Engineering September 11 , 2006 As shown, a maximum pond volume of 223 cubic feet occurs during the proposed conditions at a peak elevation of 99.86 feet with an outflow rate of 1.57 cfs discharged from the restrictor pipe. The outflow is greater than the existing runoff, during the 2-year through I 0-year rainfall events, but should be considered negligible. Larger rainfall events analyzed resulted with an outflow rate less than the pre-development condition. I hereby certify that this Drainage Report for the drainage design of the Westerheim Custom Homes Office No. 2 (240 Southwest Parkway, College Station, TX) was prepared by me, or under by supervision, in accordance with the provisions of the City of College Station - Drainage Policy and Design Standards for the owners thereof." Sincerely, rabon@rmengineer.com CD1-201-0289-L02 Page -3 of3 / / I I / ill I ;'t TEX ·-----_ _J / --PART1AL) ::i u.:' a: O' >-' ~ \_ a: t&l > . % , .... , .... liYEllBORN Ro. 0· , \ I , / DARTMOUTH I / @) '"'-,,.____ __ ~ @ ,..._ -~ City of College Station 480083 LIMIT OF STUDY"' APPROXIMATE SCALE 500 0 NA TIOllAL FLOOD lllSURAllCE PROGRAM FLOOD INSURANCE RATE MAP BRAZOS COUNTY, TEXAS AND INCORPORATED AREAS CIEE MAP INDEX flOR ,A.NELS NOT 'AINTIO) l!lll!HB ?Am 1!.'!l!! 480082 0144 COllEGl STATION. CITT' OF 480083 OIU •du tt Uttr. TIM MAI' NUMlfR lllowt hltw ...., M 11:M4 -1111<111t .., °'*n; doo COllMURllY RUMBIR •-...,_ ..W bt Wff 08 iHllMCt anlctlins IN .. "'itct ~· MAP NUMBER 48041C0144 C EFFECTIVE DATE: JULY 2, 1992 Federal Emergency Manqement Aaency This la an olliclal copy of a portion of the above referenced flood map. II was extracted using F-MIT Veralon 1.0. This map does not reflect changes or amendments which may have been mede subsequent to the date on the title bloci(. Futher Information about National Flood lnauranca Program flood hazard maps Is available at www.fema. vlmltllsd. PDF Creola Dote: !/1i1/2005 (crHted It -lo and type A) X1 P1 Drainage Area X1 Detention Facility Drainage Diagram for 0289T1 RA Prepared by {enter your company name here} 9/11/2006 HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC 0289T1RA Prepared by {enter your company name here} Westerheim Custom Homes Type II 24-hr 2 Year Rainfal/=4.50" Page 2 9/11/2006 HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Time span=0.00-20.00 hrs, dt=0.05 hrs, 401 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Star-Ind+ Trans method -Pond routing by Star-Ind method Subcatchment P1: Drainage Area P1 Subcatchment X1: Drainage Area X1 Pond 1 P: Detention Facility Runoff Area=?,167 sf Runoff Depth>3.18" Flow Length=90' Tc=15.5 min CN=90 Runoff=0.68 cfs 0.044 af Runoff Area=?, 167 sf Runoff Depth>2. 79" Flow Length=90' Tc=15.5 min CN=86 Runoff=0.62 cfs 0.038 af Peak Elev=98.96' Storage=12 cf lnflow=0.68 cfs 0.044 af 6.0" x 15.0' Culvert Outflow=0.68 cfs 0.044 af Total Runoff Area= 0.329 ac Runoff Volume= 0.082 af Average Runoff Depth= 2.99" 0289T1RA Prepared by {enter your company name here} Westerheim Custom Homes Type II 24-hr 2 Year Rainfal/=4.50" Page 2 9/11/2006 HydroCAD® 7.10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Time span=0.00-20.00 hrs, dt=0.05 hrs, 401 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-lnd+ Trans method -Pond routing by Star-Ind method Subcatchment P1: Drainage Area P1 Subcatchment X1: Drainage Area X1 _Pond 1 P: Detention Facility Runoff Area=?, 167 sf Runoff Depth>3.18" Flow Length=90' Tc=15.5 min CN=90 Runoff=0.68 cfs 0.044 af Runoff Area=?, 167 sf Runoff Depth>2. 79" Flow Length=90' Tc=15.5 min CN=86 Runoff=0.62 cfs 0.038 af Peak Elev=98.96' Storage=12 cf lnflow=0.68 cfs 0.044 af 6.0" x 15.0' Culvert Outflow=0.68 cfs 0.044 af Total Runoff Area = 0.329 ac Runoff Volume= 0.082 af Average Runoff Depth= 2.99" 0289T1RA Prepared by {enter your company name here} HydroCAD® 7 .1 0 sin 003394 © 2005 HydroCAD Software Solutions LLC Westerheim Custom Homes Type II 24-hr 2 Year Rainfal/=4. 50" Page 3 9/11/2006 Subcatchment P1 : Drainage Area P1 Runoff = 0.68 cfs@ 12.07 hrs, Volume= 0.044 af, Depth> 3.18" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 2 Year Rainfall=4.50" Area (sf) 2,264 4,903 7,167 CN Description 74 >75% Grass cover, Good , HSG C 98 Paved parking & roofs 90 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.5 90 0.0250 0.1 Sheet Flow, Overland Flow at Proposed Building Site Grass: Bermuda n= 0.410 P2= 4.50" 0.75 0.7 0.65 0.6 0.55 0.5 0.45 .!! ~ 0.4 ~ ..2 0.35: u. 0.3 0.25 0.2 0.15 0.1 0.05 Subcatchment P1 : Drainage Area P1 Hydrograph Type II 24-hr 2 Year Rai nfall=4.50 " Runoff Area=7, 167 sf Runoff Volume=0.044 af Runoff Depth>3.18" Flow Length=90' Tc=15.5 min CN =90 2 3 4 5 6 7 8 9 10 11 Time (hours) 0.68 cfs i 'I' ' ' 'I '' 12 13 14 15 16 17 18 19 20 I-Runoff I 0289T1RA Prepared by {enter your company name here} HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Westerheim Custom Homes Type II 24-hr 2 Year Rainfal/=4. 50" Page4 9/11/2006 Subcatchment X1: Drainage Area X1 Runoff = 0.62 cfs @ 12.07 hrs, Volume= 0.038 af, Depth> 2.79" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 2 Year Rainfall=4.50" · Area (sf) 2,504 4,663 7,167 CN Description 98 Paved parking & roofs 79 50-75% Grass cover, Fair HSG C 86 Weighted Average Tc Length Slope Velocity Capacity Description (min} (feet) (ft/ft) (ft/sec) (cfs} 15.5 90 0.0250 0.1 Sheet Flow, Overland Flow at Proposed Building Site Grass: Bermuda n= 0.410 P2= 4.50" 0.65~ 0.55 0.5 0.45- -0.4-.!! .., ; 0.35~ 0 ii: 0.3 0.25: 0.2 0.15 0.1- 0.05- 0- 0 Subcatchment X1: Drainage Area X1 Hydrograph 0.62 cfs Type 1124-hr 2 Year Rainfall=4.50" Runoff Area=7,167 sf Runoff Volume=0.038 af Runoff Depth>2. 79" Flow Length=90' Tc=15.5 min CN=86 ' 1 2 3 4 5 6 7 . 8 9 11 12 13 14 15 16 17 18 19 20 Time (hours) I-Runoff~ 0289T1RA Prepared by {enter your company name here} HydroCAD® 7 .10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Westerheim Custµm Homes Type II 24-hr 2 Year Rainfal/=4.50" Page4 9/11/2006 Subcatchment X1: Drainage Area X1 Runoff = 0.62 cfs@ 12.07 hrs, Volume= 0.038 af, Depth> 2. 79" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs , dt= 0.05 hrs Type II 24-hr 2 Year Rainfall=4.50" · Area (sf) 2,504 4,663 7,167 CN Description 98 Paved parking & roofs 79 50-75% Grass cover Fair, HSG C 86 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.5 90 0.0250 0.1 Sheet Flow, Overland Flow at Proposed Building Site Grass: Bermuda n= 0.41 O P2= 4.50" 0.65 0.6 0.55 0.5 0.45 ~ 0.4-.!! .!:!.. ii: 0.35~ 0 ii: 0.3- 0.25- 0.2 0.15 0.1 0.05 Subcatchment X1: Drainage Area X1 Hydrograph Type II 24-hr 2 Year Rainfall=4.50" Runoff Area=7, 167 sf Runoff Volume=0.038 af Runoff Depth>2. 79" Flow Length=90' Tc=15.5 min CN=86 I 0.62 cts I o.l...-.~ .......... ~ .. ......., ........ ~ ........... ~ ......... ,....,..~....,.~;:::;:;::;::;:;::;:::;:;;::::_.~,~.~ .. ~.-·....:.,.:.::;:,.:.:,;::;:;:; .. ~,~.;:;:::;:;:,~.~ .. ~.~.~. 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) I-Runoff~ 0289T1RA Prepared by {enter your company name here} Westerheim Custom Homes Type II 24-hr 2 Year Rainfal/=4.50" Page 5 9/11/2006 HydroCAD® 7 .1 O sin 003394 © 2005 HydroCAD Software Solutions LLC Inflow Area= Inflow = Outflow = Primary = Pond 1 P: Detention Facility 0.165 ac, Inflow Depth> 3.18" 0.68 cfs@ 12.07 hrs, Volume= 0.68 cfs@ 12.08 hrs, Volume= 0.68 cfs @ 12.08 hrs, Volume= for 2 Year event 0.044 af 0.044 af, Atten= 0%, Lag= 0.5 min 0.044 af Routing by Ster-Ind method, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 98.96'@ 12.08 hrs Surf.Area= 51 sf Storage= 12 cf Plug-Flow detention time= 0.2 min calculated for 0.044 af (100% of inflow) Center-of-Mass det. time= 0.2 min ( 764.1 -763.9 ) Volume Invert Avail.Storage Storage Description #1 98 .50' 314 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation (feet) Surf.Area (sq-ft) Inc.Store (cubic-feet) Cum .Store (cubic-feet) 98.50 99.00 99.50 100.00 Device Routing #1 Primary 0 56 215 715 0 14 68 233 0 14 82 314 Invert Outlet Devices 98.50' 6.0" x 15.0' long Culvert X 2.00 CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 98.35' S= 0.0100 '/' Cc= 0.900 n= 0.011 PVC, smooth interior Primary OutFlow Max=0.67 cfs@ 12.08 hrs HW=98.95' (Free Discharge) L1=Culvert (Inlet Controls 0.67 cfs@ 1.8 fps) 0289T1RA Prepared by {enter your company name here} HydroCAD® 7.10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Westerheim Custom Homes Type II 24-hr 2 Year Rainfal/=4. 50" Page 6 9/11/2006 Pond 1 P: Detention Facility Hydrograph 0.15-: 0.7 0.65: 0.6 0.55 0 5 0.45 J!! • ~ 0.4- ~ u: 0.35 0.3- 0.25- 0.2: 0.15 0.1 0.05- 0 .. 0 0 Inflow Area=0 .165 ac Peak Elev=98.96' Storage=12 cf 6.0" x 15.0' Culvert 2 3 4 5 6 7 8 9 10 11 Time (hours) 0.68 cfs 12 13 14 Pond 1 P: Detention Facility Stage-Area-Storage Surface/Horizontal/Wetted Area (sq-ft) 50 100 150 200 250 300 350 400 450 500 15 16 17 18 19 20 550 600 650 700 100 ................................. _... ____ ............... ______ ......... ____ ......_._._ ................................................................................................................ """"==~ l c 0 ~ iii 99 0 Ciistom S Data 20 40 60 80 100 ' .. 120 140 160 180 200 220 240 260 280 300 Storage (cubic-feet) -Inflow -Primary -Surface -Storage 0289T1RA Westerheim Custom Homes Type II 24-hr 2 Year Rainfal/=4. 50" Page 6 9/11/2006 Prepared by {enter your company name here} HydroCAD® 7.10 s/n 003394 © 2005 HydroCAD Software Solutions LLC ~ 0.75 0.7~ 0.65: 0.6- 0.55~ 0.5~ 0.45- ~ 0.4 ~ u: 0.35 0.3 0.25- 0.2 0.15 0.1 0 '. 0 Pond 1 P: Detention Facility Hydrograph I 0.68 cfs I Inflow Area=0.165 ac Peak Elev=98.96' Storage=12 cf 6.0" x 15.0' Culvert ... , . • ' I • 2 3 4 5 '•I• ••I ' ' • , •• , • • 1 •• 'I ' I ',, 'I ' 6 7 8 9 10 11 12 13 . 14 15 Time., (hours) Pond 1 P: Detention Facility Stage-Area-Storage Surface/Horizontal/Wetted Area (sq-ft) ' .. • ' • 1 • • 16 17 18 19 20 0 50 1 00 150 200 250 300 350 . 400 450 500 550 600 650 700 c 0 :;::; .. ~ ijj 100 ' .. 99 I ' ' ' I ' 'I 'I' 'I'''' I' I ' '' j • 'j ''''I ' ''''I '' 'l' 'I' 20 60 80 100 120 140 160 180 200 220 240 260 280 300 Storage (cubic-feet) -Inflow -Primary ;;,., Surface -Storage 0289T1RA Prepared by {enter your company name here} Westerheim Custom Homes Type II 24-hr 5 Year Rainfal/=6.20" Page 7 9/11/2006 HydroCAD® 7 .10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Time span=0.00-20.00 hrs, dt=0.05 hrs, 401 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Star-Ind+ Trans method -Pond routing by Star-Ind method Subcatchment P1: Drainage Area P1 Subcatchment X1: Drainage Area X1 Pond 1 P: Detention Facility Runoff Area=7,167 sf Runoff Depth>4.73" Flow Length=90' Tc=15.5 min CN=90 Runoff=0.99 cfs 0.065 af Runoff Area=?, 167 sf Runoff Depth>4.30" Flow Length=90' Tc=15.5 min CN=86 Runoff=0.93 cfs 0.059 af Peak Elev=99.18' Storage=29 cf lnflow=0.99 cfs 0.065 af 6.0" x 15.0' Culvert Outflow=0.98 cfs 0.065 af Total Runoff Area= 0.329 ac Runoff Volume= 0.124 af Average Runoff Depth= 4.52" 0289T1RA Prepared by {enter your company name here} HydroCAD® 7 .10 si n 003394 © 2005 HydroCAD Software Solutions LLC Westerheim Custom Homes Type II 24-hr 5 Year Rainfal/=6.20" Page 8 9/11/2006 Subcatchment P1: Drainage Area P1 Runoff = 0.99 cfs@ 12.07 hrs, Volume= 0.065 af, Depth> 4.73" Runoff by SGS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 5 Year Rainfall=6.20" Area (sf) 2,264 4,903 7,167 CN Description 74 >75% Grass cover, Good, HSG C 98 Paved parking & roofs 90 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.5 90 0.0250 0.1 Sheet Flow, Overland Flow at Proposed Building Site Grass: Bermuda n= 0.410 P2= 4.50" Subcatchment P1: Drainage Area P1 Type II 24-hr 5 Year Rainfall=6.20" Hydrograph Runoff Area=7, 167 sf Runoff Volume=0.065 af Runoff Depth>4.73" Flow Length=90' Tc=15.5 min CN=90 I 0.99 cfs I 0-·J.,.......,...-.......... ....,.. ........ ,...... ....... ~.~;;;;=;=;:;:;:;:;::;:;:;:::;::;:;:::;:;::::~~ ................ ....;:,:::;_,;;:;::;:;:;::;:;:;:;,::;::;:;::;:::;:;:::;:;:;:;~ 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) I-Runoff ~ 0289T1RA Westerheim Custom Homes Type II 24-hr 5 Year Rainfal/=6.20" Prepared by {enter your company name here} · Page 8 HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment Pf: Drainage Area P1 Runoff = 0.99 cfs@ 12.07 hrs, Volume= · 0.065 af, Depth> 4.73" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0."05 hrs Type II 24-hr 5 Year Rainfall=6.20" Area (sf) 2,264 4,903 7,167 CN Description 74 >75% Grass cover, Good, HSG C 98 Paved parking & roofs 90 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) . (ft/ft) (ft/sec) (cfs) 9/11/2006 15.5 90 0.0250 0.1 Sheet Flow, Overland Flow at Proposed Building Site Grass: Bermuda n= 0.410 P2= 4.50" 0 0 Subcatchment P1: Drainage Area P1 Hydrograph Type II 24-hr 5 Year Rainfall=6.20" Runoff Area=7, 167 sf Runoff Volume=0.065 af Runoff Depth>4.73" Flow Length=90' Tc=15.5 min CN=90 '. . , . ' . . ' . . . . ' . . . ' . . . . ' . . . 1 2 3 4 5 6 7 8 9 Time 10 11 (hours) I 0.99 cfs I .. ' . .. .. ., . .. 12 13 14 15 l -Runoff~ . , . ' 16 17 18 19 20 0289T1RA Prepared by {enter your company name here} HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Westerheim Custom Homes Type II 24-hr 5 Year Rainfa/1=6.20" Page 9 9/11/2006 Subcatchment X1: Drainage Area X1 Runoff = 0.93 cfs@ 12.07 hrs, Volume= 0.059 af, Depth> 4.30" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 5 Year Rainfall=6.20" Area (sf) 2,504 4,663 7,167 CN Description 98 Paved parking & roofs 79 50-75% Grass cover, Fair, HSG C 86 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (fUsec) (cfs) 15.5 90 0.0250 0.1 Sheet Flow, Overland Flow at Proposed Building Site Grass: Bermuda n= 0.41 O P2= 4.50" Subcatchment X1: Drainage Area X1 1- Type 1124-hr 5 Year Rainfall=6.20" Hydrograph Runoff Area=7,167 sf Runoff Volume=0.059 af Runoff Depth>4.30" Flow Length=90' Tc=15.5 min CN=86 I 0.93 cfs I o~ ............... ~.-..~ .......... ~.-·-·~·-· ~~~ .. ~. ~ .. ::;:;:; .. ~ .. --....,....""'"'"'"_;:::;:;::;:;:;:;:;:;;:;:;::;::;::;:::;:;:;;::;.~.~ 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) I-Runoff I 0289T1RA Prepared by {enter your company name here} Westerheim Custom Homes Type II 24-hr 5 Year Rainfal/=6.20" Page 10 9/11/2006 HydroCAD® 7 .10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Inflow Area= Inflow = Outflow = Primary = Pond 1 P: Detention Facility 0.165 ac, Inflow Depth > 4. 73" 0.99 cfs@ 12.07 hrs, Volume= 0.98 cfs@ 12.09 hrs, Volume= 0.98 cfs@ 12.09 hrs, Volume= for 5 Year event 0.065 af 0.065 af, Atten= 2%, Lag= 1.3 min 0.065 af Routing by Stor-lnd method, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 99.18' @ 12.09 hrs Surf.Area= 112 sf Storage= 29 cf Plug-Flow detention time= 0.3 min calculated for 0.065 af (100% of inflow) Center-of-Mass det. time= 0.2 min ( 754.6 -754.4 ) Volume Invert Avail.Storage Storage Description #1 98.50' 314 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation (feet) Surf.Area (sq-ft) Inc.Store (cubic-feet) Cum.Store (cubic-feet) 98.50 99.00 99.50 100.00 Device Routing #1 Primary 0 56 215 715 0 14 68 233 0 14 82 314 Invert Outlet Devices 98.50' 6.0" x 15.0' long Culvert X 2.00 CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 98.35' S= 0.0100 '!' Cc= 0.900 n= 0.011 PVC, smooth interior Primary OutFlow Max=0.97 cfs@ 12.09 hrs HW=99.17' (Free Discharge) L1=Culvert (Inlet Controls 0.97 cfs@ 2.5 fps) 0289T1RA Prepared by {enter your company name here} Westerheim Custom Homes Type II 24-hr 5 Year Rainfal/=6.20" Page 10 9/11/2006 HydroCAD® 7 .10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Inflow Area = Inflow = Outflow = Primary = Pond 1 P: Detention Facility 0.165 ac, Inflow Depth> 4.73" 0.99 cfs@ 12.07 hrs, Volume= 0.98 cfs@ 12.09 hrs, Volume= 0.98 cfs@ 12.09 hrs, Volume= for 5 Year event 0.065 af 0.065 af, Atten= 2%, Lag= 1.3 min 0.065 af Routing by Star-Ind method, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 99.18' @ 12.09 hrs Surf.Area= 112 sf Storage= 29 cf Plug-Flow detention time= 0.3 min calculated for 0.065 af (100% of inflow) Center-of-Mass det. time= 0.2 min ( 754.6 -754.4 ) Volume Invert Avail.Storage Storage Description #1 98.50' 314 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation (feet) Suri.Area (sq-ft) Inc.Store (cubic-feet) Cum.Store (cubic-feet) 98.50 99.00 99.50 100.00 Device Routing #1 Primary 0 56 215 715 0 14 68 233 0 14 82 314 Invert Outlet Devices 98.50' 6.0" x 15.0' long Culvert X 2.00 CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 98.35' S= 0.0100 '/' Cc= 0.900 n= 0.011 PVC, smooth interior Primary OutFlow Max=0.97 cfs@ 12.09 hrs HW=99.17' (Free Discharge) L1=Culvert (Inlet Controls 0.97 cfs@ 2.5 fps) 0289T1RA Prepared by {enter your company name here} HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Westerheim Custom Homes Type II 24-hr 5 Year Rainfal/=6.20" Page 11 9/11/2006 Pond 1 P: Detention Facility Hydrograph Inflow Area=0.165 ac Peak Elev=99.18' Storage=29 cf i 6.0" x 15.0' Culvert ~ ii: 0 0 2 3 4 5 6 7 8 9 10 11 Time (hours) 0.98 cfs 12 13 14 Pond 1 P: Detention Facility Stage-Area-Storage Surface/Horizontal/Wetted Area (sq-ft) 50 100 150 200 250 300 350 400 450 99 0 20 40 60 100 140 160 180 200 Storage (cubic-feet) -Inflow -Primary ., .. 15 16 17 18 19 20 550 600 650 700 -Surface -Storage 240 260 280 300 0289T1RA Westerheim Custom Homes Type II 24-hr 10 Year Rainfa/1=7.40" Prepared by {enter your company name here} Page 12 9/11/2006 HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Time span=0.00-20.00 hrs, dt=0.05 hrs, 401 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-lnd+ Trans method -Pond routing by Stor-lnd method Subcatchment P1: Drainage Area P1 Subcatchment X1 : Drainage Area X1 Pond 1 P: Detention Facility Runoff Area=?, 167 sf Runoff Depth>5.85" Flow Length=90' Tc=15.5 min CN=90 Runoff=1 .21 cfs 0.080 af Runoff Area=?, 167 sf Runoff Depth>5.39" Flow Length=90' Tc=15.5 min CN=86 Runoff=1 .15 cfs 0.074 af Peak Elev=99.36' Storage=54 cf lnflow=1 .21 cfs 0.080 af 6.0" x 15.0' Culvert Outflow=1.16 cfs 0.080 af Total Runoff Area= 0.329 ac Runoff Volume= 0.154 af Average Runoff Depth= 5.62" 0289T1RA Westerheim Custom Homes Type II 24-hr 10 Year Rainfal/=7.40" Prepared by {enter your company name here} Page 12 9/11/2006 HydroCAD® 7.10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Time span=0.00-20.00 hrs, dt=0.05 hrs, 401 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-lnd+ Trans method -Pond routing by Stor-lnd method Subcatchment P1: Drainage Area P1 Subcatchment X1: Drainage Area X1 Pond 1 P: Detention Facility Runoff Area=?, 167 sf Runoff Depth>5.85" Flow Length=90' Tc=15.5 min CN=90 Runoff=1 .21 cfs 0.080 af Runoff Area=?, 167 sf Runoff Depth>5.39" Flow Length=90' Tc=15.5 min CN=86 Runoff=1 .:1 5 cfs 0.074 af Peak Elev=99.36' Storage=54 cf lnflow=1 .21 cfs 0.080 af 6. O" x 15. O' Culvert Outflow= 1. 16 cfs 0. 080 af Total Runoff Area= 0.329 ac Runoff Volume= 0.154 af Average Runoff Depth= 5.62" 0289T1RA Westerheim Custom Homes Type II 24-hr 10 Year Rainfal/=7.40" Prepared by {enter your company name here} HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment P1: Drainage Area P1 Runoff = 1.21 cfs@ 12.07 hrs, Volume= 0.080 af, Depth> 5.85" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10 Year Rainfall=?.40" Area (sf) 2,264 4,903 7,167 CN Description 74 >75% Grass cover, Good, HSG C 98 Paved parking & roofs 90 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) Page 13 9/11/2006 15.5 90 0.0250 0.1 Sheet Flow, Overland Flow at Proposed Building Site Grass: Bermuda n= 0.410 P2= 4.50" Subcatchment P1: Drainage Area P1 Type 1124-hr 10 Year Rainfall=7 .40" Hydrograph Runoff Area=7, 167 sf Runoff Volume=0.080 af Runoff Depth>S.85" Flow Length=90' Tc=15.5 min CN=90 1.21 cfs 0 .. •t I I I ' ' ' I 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) I-Runoff I 0289T1RA Westerheim Custom Homes Type II 24-hr 10 Year Rainfal/=7.40" Prepared by {enter your company name here} HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment X1: Drainage Area X1 Runoff = 1.15 cfs @ 12.07 hrs, Volume= 0.074 af, Depth> 5.39" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10 Year Rainfall=7.40" Area (sf) 2,504 4 663 7,167 CN Description 98 Paved parking & roofs 79 50-75% Grass cover, Fair HSG C 86 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) Page 14 9/11/2006 15.5 90 0.0250 0.1 Sheet Flow, Overland Flow at Proposed Building Site Grass: Bermuda n= 0.410 P2= 4.50" Subcatchment X1: Drainage Area X1 Hydrograph Type II 24-hr 10 Year Rainfall=7 .40" Runoff Area=7, 167 sf Runoff Volume=0.074 af Runoff Depth>S.39" Flow Length=90' Tc=15.5 min CN=86 1.15 cfs o-L. ..................... -.,._.. . ._._~.~. ~ .. .-.•.~.~ .. ~ .. ~ .. :;::;::;::;::;:;::;::::;::::......_...__...._:::::::;::;:;:;:;:;:::;:;::;:;;;::;::;::;::;:;;;::;:;:;:l 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) I-Runoff~ 0289T1RA Westerheim Custom Ho.mes Type II 24-hr 10 Year Rainfa//=7.40" Prepared by {enter your company name here} HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment X1: Drainage Area X1 Runoff = 1.15 cfs @ 12.07 hrs, Volume= 0.074 af, Depth> 5.39" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10 Year Rainfall=7.40" Area (sf) 2,504 4,663 7,1 67 CN Description 98 Paved parking & roofs 79 50-75% Grass cover, Fair, HSG C 86 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet)-(fUft) (fUsec) (cfs) Page 14 9/11/2006 15.5 '' 90 0.0250 0.1 Sheet Flow, Overland Flow at Proposed Building Site Grass: Bermuda n= 0.41 O P2= 4.50" Subcatchment X1: Drainage Area X1 Type II 24-hr 10 Year Rainfall=7 .40" Hydrograph Runoff Area=7, 167 sf Runoff Volume=0.074 af Runoff Depth>S.39" Flow Length=90' Tc=15.5 min CN=86 I 1.15 cfs I 0 ... , .. '. I ' '•1 • ' I ' I ' ''I ' I ' ''I ' ''I'''' I ''' 'I'''' I 'I ''' 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) I-Runoff I 0289T1RA Westerheim Custom Homes Type II 24-hr 10 Year Rainfal/=7.40" Prepared by {enter your company name here} HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Inflow Area= Inflow = Outflow = Primary = Pond 1 P: Detention Facility 0.165 ac, Inflow Depth > 5.85" for 1.21 cfs@ 12.07 hrs, Volume= 1.16 cfs@ 12.10 hrs, Volume= 1.16 cfs@ 12.10 hrs, Volume= 10 Year event 0.080 af 0.080 af, Atten= 4%, Lag= 2.0 min 0.080 af Routing by Stor-lnd method, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 99.36'@ 12.10 hrs Surf.Area= 169 sf Storage= 54 cf Plug-Flow detention time= 0.3 min calculated for 0.080 af (100% of inflow) Center-of-Mass det. time= 0.3 min ( 749.7 -749.4) Volume Invert Avail.Storage Storage Description #1 98.50' 314 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation (feet) 98.50 99.00 99.50 100.00 Device Routing #1 Primary Surf.Area (sq-ft) 0 56 215 715 Inc.Store (cubic-feet) 0 14 68 233 Cum.Store (cubic-feet) 0 14 82 314 Invert Outlet Devices 98.50' 6.0" x 15.0' long Culvert X 2.00 CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 98.35' S= 0.0100 '/' Cc= 0.900 n= 0.011 PVC, smooth interior Primary Outflow Max=1 .16 cfs@ 12.10 hrs HW=99.36' (Free Discharge) L1 =Culvert (Inlet Controls 1.16 cfs @ 3. O fps) Page 15 9/11/2006 0289T1RA Westerheim Custom Homes Type II 24-hr 10 Year Rainfa/1=7.40" Prepared by {enter your company name here} HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC - Pond 1 P: Detention Facility Hydrograph Inflow Area=0.165 ac 1-Peak Elev=99.36' Storage=54 cf I 1.21 cfs I l1.16cfs l ~ 6.0" x 15.0' Culvert ~ ii: l c 0 ~ iii 0 100 99 0 2 0 50 3 4 5 6 100 150 200 ' ' ' ' 7 8 9 10 11 12 13 14 Time (hours) Pond 1 P: Detention Facility Stage-Area-Storage Surface/Horizontal/Wetted Area (sq-ft) 250 300 350 400 450 500 ' I 15 16 17 18 19 20 550 600 650 700 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Storage (cubic-feet) Page 16 9/11/2006 -Inflow -Primary -Surface -Storage 0289T1RA Westerheim Custom f-1omes Type II 24-hr 10 Year Rainfal/=7.40" Prepared by {enter your company name here} HydroCAD® 7 .10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Pond 1 P: Detention Facility . Hydrograph Inflow Area=0.165 ac 1-Peak Elev=99.36' Storage=54 cf I 1.21 cfs I ]1.16cfsl ~ 6.0" x 15.0' Culvert ~ ii: 0 ,, I' '' I'•' '' ' • • i • 'I '' 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Time. (hours) Pond 1 P: Detention Facility Stage-Area-Storage Surface/Horizontal/Wetted Area (sq-ft) . '. ''' 15 16 17 18 19 20 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 c: 0 .. ~ .. i.ij 100 ' ' ' ' ' 99 'I. •I '''I' I '''' I'' I'' 'I'' I ' ''I' 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Storage (cubic-feet) Page 16 9/11/2006 -Inflow -Primary -Surface -Storage 0289T1RA Westerheim Custom Homes Type II 24-hr 25 Year Rainfal/=8.80" Prepared by {enter your company name here} Page 17 9/11/2006 HydroCAD® 7 .10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Time span=0.00-20.00 hrs, dt=0.05 hrs, 401 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Star-Ind+ Trans method -Pond routing by Star-Ind method Subcatchment P1: Drainage Area P1 Subcatchment X1: Drainage Area X1 Pond 1 P: Detention Facility Runoff Area=?, 167 sf Runoff Depth>7.15" Flow Length=90' Tc=15.5 min CN=90 Runoff=1.46 cfs 0.098 af Runoff Area=?, 167 sf Runoff Depth>6.67" Flow Length=90' Tc=15.5 min CN=86 Runoff=1.40 cfs 0.091 af Peak Elev=99.57' Storage=100 cf lnflow=1.46 cfs 0.098 af 6.0" x 15.0' Culvert Outflow=1 .35 cfs 0.098 af Total Runoff Area= 0.329 ac Runoff Volume= 0.190 af Average Runoff Depth= 6.91" 0289T1RA Westerheim Custom Homes Type II 24-hr 25 Year Rainfaf/=8. 80" Prepared by {enter your company name here} HydroCAD® 7.10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment P1: Drainage Area P1 Runoff = 1.46 cfs @ 12.07 hrs, Volume= 0.098 af, Depth> 7.15" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 25 Year Rainfall=8.80" Area (sf) 2,264 4,903 7,167 CN Description 74 >75% Grass cover, Good, HSG C 98 Paved parking & roofs 90 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) Page 18 9/11/2006 15.5 90 0.0250 0.1 Sheet Flow, Overland Flow at Proposed Building Site Grass: Bermuda n= 0.410 P2= 4.50" Subcatchment P1: Drainage Area P1 Hydrograph Type II 24-hr 25 Year Rainfall=8.80" Runoff Area=7,167 sf Runoff Volume=0.098 af Runoff Depth>7.15" Flow Length=90' Tc=15.5 min CN=90 I 1-46 cts I o-l-_,........,~..,._-.....-~. ~--~.~-~-~.;:::;:::;::;::;:;:;;~.~-=-;,: .. ::... ...................... .:::::.:.:;:;:.,~.;:;:::;:;:,::;:;::;:;;:;:;:;:;:;;:;:;:;::;:J 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) l-Runoff~ 0289T1RA Westerheim Custom Homes Type 1124-hr 25 Year Rainfal/=8.80" Prepared by {enter your company name here} HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment P1: Drainage Area P1 Runoff = 1.46 cfs@ 12.07 hrs, Volume= 0.098 af, Depth> 7.1 5" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 25 Year Rainfall=8.80" Area (sf) 2,264 4,903 7,167 CN Description 74 >?5% Grass cover, Good, HSG C 98 Paved parking & roofs 90 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) · ( cfs) Page 18 9/11/2006 15.5 90 0.0250 0.1 Sheet Flow, Overland Flow at Proposed Building Site Grass: Bermuda n= 0.41 O P2= 4.50" 1- 0 0 Subcatchment P1: Drainage Area P1 Hydrograph Type II 24-h r 25 Year Rainfall=8.80" Runoff Area=7, 167 sf Runoff Volume=0.098 af Runoff Depth>7.15" Flow Length=90' Tc=15.5 min CN=90 . , . , . ' . . . ' . . . .. . , . 1 2 3 4 5 6 7 8 9 Time ' . 10 11 (hours) I 1.46 cfs I .. . ,. . . .. . ' 12 13 14 15 I-Runoff I . , . .. . , . ' . . . . ' 16 17 18 19 20 0289T1RA Westerheim Custom Homes Type II 24-hr 25 Year Rainfal/=8. 80" Prepared by {enter your company name here} HydroCAD® 7 .10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment X1: Drainage Area X1 Runoff = 1.40 cfs @ 12.07 hrs, Volume= 0.091 af, Depth> 6.67" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 25 Year Rainfall=8.80" Area (sf) 2,504 4,663 7,167 CN Description 98 Paved parking & roofs 79 50-75% Grass cover, Fair, HSG C 86 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) Page 19 9/11/2006 15.5 90 0.0250 0.1 Sheet Flow, Overland Flow at Proposed Building Site Grass: Bermuda n= 0.410 P2= 4.50" Subcatchment X1: Drainage Area X1 Hydrograph Type II 24-hr 25 Year Rainfall=S.80" Runoff Area=7, 167 sf Runoff Volume=0.091 af Runoff Depth>6.67" Flow Length=90' Tc=15.5 min CN=86 1.40 cfs o-L.------.-.----...-.-~;;;;:;::;:;:;:;;:;:;:;;::::: ______ _..=:::=:;:;;:;:;:;:;::;:;:;;::;::;:;::;;:;:;:;:;~ 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) I-RunoffJ 0289T1RA Westerheim Custom Homes Type II 24-hr 25 Year Rainfal/=8.80" Prepared by {enter your company name here} HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Inflow Area= Inflow = Outflow = Primary = Pond 1 P: Detention Facility 0.165 ac, Inflow Depth> 7.15" 1.46 cfs@ 12.07 hrs, Volume= 1.35 cfs @ 12.12 hrs, Volume= 1.35 cfs @ 12.12 hrs, Volume= for 25 Year event 0.098 af 0.098 af, Atten= 7%, Lag= 2.9 min 0.098 af Routing by Ster-Ind method, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 99.57' @ 12.12 hrs Surf.Area= 288 sf Storage= 100 cf Plug-Flow detention time= 0.4 min calculated for 0.098 af (100% of inflow) Center-of-Mass det. time= 0.4 min ( 745.2 -744.8) Volume Invert Avail.Storage Storage Description #1 98.50' 314 cf Custom Stage Data (Prismatic} Listed below (Recalc) Elevation (feet) Surf.Area (sq-ft) Inc.Store (cubic-feet) Cum .Store (cubic-feet) 98 .50 99.00 99.50 100.00 Device Routing #1 Primary 0 56 215 715 0 14 68 233 0 14 82 314 Invert Outlet Devices 98.50' 6.0" x 15.0' long Culvert X 2.00 CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 98 .35' S= 0.0100 '/' Cc= 0.900 n= 0.011 PVC , smooth interior Primary OutFlow Max=1 .34 cfs@ 12.12 hrs HW=99.56' (Free Discharge) L1=Culvert (Inlet Controls 1.34 cfs@ 3.4 fps) Page 20 9/11/2006 0289T1RA Westerheim Custom Homes Type II 24-hr 25 Year Rainfal/=8.80" Prepared by {enter your company name here} HydroCAD® 7.10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Inflow Area= Inflow = Outflow = Primary = Pond 1 P: Detention Facility 0.165 ac, Inflow Depth> 7.15" 1.46 cfs@ 12.07 hrs, Volume= 1.35 cfs @ ·. 12.12 hrs, Volume= 1.35 cfs @ 12.12 hrs, Volume= for 25 Year event 0.098 af 0.098 af, Atten= 7%, Lag= 2.9 min 0.098 af Routing by Stor-lnd method, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 99.57' @ 12.12 hrs Surf.Area= 288 sf Storage= 100 cf Plug-Flow detention time= 0.4 min calculated for 0.098 af (100% of inflow) Center-of-Mass det. time= 0.4 min ( 745.2 -744.8) Volume Invert Avail.Storage Storage Description #1 98.50' 314 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation (feet) Surf.Area (sq-ft) Inc.Store (cubic-feet) Cum.Store (cubic-feet) 98.50 99.00 99.50 100.00 Device Routing #1 Primary 0 56 215 715 ·0 14 68 233 0 14 82 314 Invert Outlet Devices 98 .50' 6.0" x 15.0' long Culvert X 2.00 CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 98.35' S= 0.0100 '/' ·Cc= 0.900 n= 0.011 PVC, smooth interior ' Primary OutFlow Max=1.34 cfs@ 12.12 hrs HW=99.56' (Free Discharge) L1=Culvert (Inlet Controls 1.34 cfs@ 3.4 fps) Page 20 9/11/2006 0289T1RA Westerheim Custom Homes Type II 24-hr 25 Year Rainfal/=8.80" Prepared by {enter your company name here} HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC 1- 0 0 Pond 1P: Detention Facility Hydrograph ' Inflow Area=0 .165 ac Peak Elev=99.57' Storage=100 cf 6.0" x 15.0' Culvert , .. ··1· ' 2 3 4 5 6 7 8 9 10 11 Time (hours) I 1.46 cfs I I I 1.35 cfs I '. 12 13 14 Pond 1 P: Detention Facility Stage-Area-Storage Surface/Horizontal/Wetted Area (sq-ft) 15 16 17 18 19 20 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 l c 0 ;; .. > .. iii 100 ' 99 0 I 20 40 60 I I • I ' ' l' 80 100 120 140 160 180 200 220 240 260 280 300 Storage (cubic-feet) Page 21 9/11/2006 -Inflow -Primary -Surface -Storage 0289T1RA Westerheim Custom Homes Type II 24-hr 50 Year Rainfal/=9.80" Prepared by {enter your company name here} Page 22 9/11/2006 HydroCAD® 7 .1 O s/n 003394 © 2005 HydroCAD Software Solutions LLC Time span=0.00-20.00 hrs, dt=0.05 hrs, 401 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-lnd+ Trans method -Pond routing by Stor-lnd method Subcatchment P1: Drainage Area P1 Subcatchment X1: Drainage Area X1 Pond 1 P: Detention Facility Runoff Area=?, 167 sf Runoff Depth>8.09" Flow Length=90' Tc=15.5 min CN=90 Runoff=1 .64 cfs 0.111 af Runoff Area=?,167 sf Runoff Depth>?.60" Flow Length=90' Tc=15.5 min CN=86 Runoff=1.59 cfs 0.104 af Peak Elev=99.71' Storage=149 cf lnflow=1 .64 cfs 0.111 af 6.0" x 15.0' Culvert Outflow=1.46 cfs 0.111 af Total Runoff Area= 0.329 ac Runoff Volume= 0.215 af Average Runoff Depth= 7.84" 0289T1RA Westerheim Custom Homes Type II 24-hr 50 Year Rainfal/=9. 80" Prepared by {enter your company name here} Page 22 9/11/2006 HydroCAD® 7.10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Time span=0.00-20.00 hrs, dt=0.05 hrs, 401 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-lnd+ Trans method -Pond routing by Stor-lnd method Subcatchment P1: Drainage Area P1 Subcatchment X1: Drainage Area X1 Pond 1 P: Detention Facility Runoff Area=?, 167 sf Runoff Depth>B.09" Flow Length=90' Tc=15.5 min CN=90 Runoff=1 .64 cfs 0.111 af Runoff Area=?,167 sf Runoff Depth>?.60" Flow Length=90' Tc=15.5 min CN=86 Runoff=1 .59 cfs 0.104 af Peak Elev=99. 71' Storage= 149 cf Inflow= 1 . 64 cfs 0. 111 af 6.0" x 15.0' Culvert Outflow=1.46 cfs 0.111 af Total Runoff Area= 0.329 ac Runoff Volume= 0.215 af Average Runoff Depth= 7.84" 0289T1RA Westerheim Custom Homes Type II 24-hr 50 Year Rainfa//=9.80" Prepared by {enter your company name here} HydroCAD® 7 .10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment P1: Drainage Area P1 Runoff = 1.64 cfs@ 12.07 hrs, Volume= 0.111 af, Depth> 8.09" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 50 Year Rainfall=9.80" Area (sf) 2,264 4,903 7,167 CN Description 74 >75% Grass cover, Good, HSG C 98 Paved parking & roofs 90 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) Page 23 9/11/2006 15.5 90 0.0250 0.1 Sheet Flow, Overland Flow at Proposed Building Site Grass: Bermuda n= 0.410 P2= 4.50" Subcatchment P1: Drainage Area P1 Hydrograph Type II 24-hr 50 Year Rainfall=9.80" Runoff Area=7, 167 sf Runoff Volume=0.111 af Runoff Depth>S.09" Flow Length=90' Tc=15.5 min CN=90 1.64 cfs o_t..,.....,.,...._....,,........_..,~.""""'l!=i=i=i=;:;::;;:;::;:;::;:;:;:;::;:;;:;:;:;::;:;:::::::.,.,........,._....,.....::;:;:;;;:;:;:;:;:;;:;:;:;::;.~,.~.~-.;::;:;;;;;:;:;:;:J .. 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) I-Runoff~ 0289T1RA Westerheim Custom Homes Type II 24-hr 50 Year Rainfal/=9. 80" Prepared by {enter your company name here} HydroCAD® 7.10 si n 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment X1: Drainage Area X1 Runoff = 1.59 cfs@ 12.07 hrs, Volume= 0.104 af, Depth> 7.60" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 50 Year Rainfall=9.80" Area (sf) 2,504 4,663 7,167 CN Description 98 Paved parking & roofs 79 50-75% Grass cover Fair HSG C 86 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) Page 24 9/11/2006 15.5 90 0.0250 0.1 Sheet Flow, Overland Flow at Proposed Building Site Grass: Bermuda n= 0.41 O P2= 4.50" Subcatchment X1: Drainage Area X1 Type 1124-hr 50 Year Rainfall=9.80" Hydrograph Runoff Area=7, 167 sf ~ 1-Runoff Volume=0.104 af Runoff Depth>7 .60" Flow Length=90' Tc=15.5 min CN=86 1.59 cfs o-l-....,..,........,........__.., __ ~..-ii~~:;::;:;;::;;;;:;:;:::;:~..,...........,......::;::::;:;:;::;;;::;:;:;::;:;:;:;:~;:;r:;:;~ 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) I-Runoff I 0289T1RA Westerheim Custon:i Homes Type II 24-hr 50 Year Rainfal/=9. 80" Prepared by {enter your company name here} HydroCAD® 7 .1 0 s/n 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment X1: Drainage· Area X1 Runoff = 1.59 cfs @ 12.07 hrs, Volume= 0.1 04af, Depth> 7.60" Runoff by SGS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 50 Year Rainfall=9.80" Area (sf) 2,504 4,663 7,1 67 CN Description 98 Paved parking & roofs 79 50-75% Grass cover, Fair, HSG C -- 86 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (tt/ft) (ft/sec) (cfs) Page 24 9/11/2006 15.5 90 0.0250 · · 0.1 Sheet Flow, Overland Flow at Proposed Building Site Grass: Bermuda n= 0.41 O P2= 4.50" 0 . Subcatchment X1: Drainage Area X1 Hydrograph Type II 24-hr 50 Year Rainfall=9.80" Runoff Area=7, 167 sf Runoff Volume=0.104 af Runoff Depth>7 .60" Flow Length=90' Tc=15.5 min CN=86 I 1.59 cfs I 1 •'•'I '•' •1 •' 'I ' 'I ''' 'I ' ''I ' ''I ' 'I '' 'I '' 'I '''' ' 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Time (hours) I-Runoff I '. . ' 17 18 19 20 0289T1RA Westerheim Custom Homes Type II 24-hr 50 Year Rainfal/=9.80" Prepared by {enter your company name here} HydroCAD® 7.10 sin 003394 © 2005 HydroCAD Software Solutions LLC Inflow Area= Inflow = Pond 1P: Detention Facility for 50 Year event 0.111 af Page 25 9/11/2006 Outflow = Primary = O .165 ac, Inflow Depth > 8. 09" 1.64 cfs@ 12.07 hrs, Volume= 1.46 cfs @ 12.13 hrs, Volume= 1.46 cfs @ 12.13 hrs, Volume= 0.111 af, Atten= 11 %, Lag= 3.6 min 0.111 af Routing by Stor-lnd method, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 99. 71' @ 12.13 hrs Surf.Area= 425 sf Storage= 149 cf Plug-Flow detention time= 0.5 min calculated for 0.111 af (100% of inflow) Center-of-Mass det. time= 0.5 min ( 742.5 -742.0) Volume Invert Avail.Storage Storage Description #1 98.50' 314 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation (feet) Surf.Area (sq-ft) Inc.Store (cubic-feet) Cum.Store (cubic-feet) 98.50 99.00 99.50 100.00 Device Routing #1 Primary 0 56 215 715 0 14 68 233 0 14 82 314 Invert Outlet Devices 98 .50' 6.0" x 15.0' long Culvert X 2.00 CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 98.35' S= 0.0100 '/' Cc= 0.900 n= 0.011 PVC, smooth interior Primary OutFlow Max=1.45 cfs @ 12.13 hrs HW=99. 70' (Free Discharge) L1=Culvert (Inlet Controls 1.45 cfs@ 3.7 fps) 0289T1RA Westerheim Custom Homes Type II 24-hr 50 Year Rainfal/=9.80" Prepared by {enter your company name here} HydroCAD® 7 .1 O s/n 003394 © 2005 HydroCAD Software Solutions LLC 0 0 Pond 1P: Detention Facility Hydrograph 1.64 cfs Inflow Area=0.165 ac 1.46cfs Peak Elev=99. 71' Storage=149 cf 6.0" x 15.0' Culvert ' 2 3 4 5 6 7 8 9 10 11 12 Time (hours) ., 13 14 Pond 1 P: Detention Facility Stage-Area-Storage Surface/Horizontal/Wetted Area (sq-ft) 15 16 17 18 19 20 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 c 0 :;:; ~ .. iii 100 99 0 40 I '' I 80 100 120 140 160 180 200 220 240 260 280 300 Storage (cubic-feet) Page 26 9/11/2006 -Inflow -Primary -Surface -Storage 0289T1RA Westerheim Custom Homes Type II 24-hr 50 Yea r Rainfal/=9.80" Prepared by {enter your company name here} HydroCAD® 7.10 s/n 003394 © 2005 HydroCAD Software Solutions LLC 0 0 Pond 1 P: Detention Facility Hydrograph Inflow Area=0.165 ac Peak Elev=99.71' Storage=149 cf 6.0" x 15.0' Culvert ., . . '. 1 2 3 4 5 6 7 8 9 10 11 Time (hours) I 1.64cfs I I 1.46 cfs I 12 13 14 Pond 1 P: Detention Facility Stage-Area-Storage Surface/Horizontal/Wetted Area (sq-ft) • ·1 • ,. . ' . 15 16 17 18 19 20 0 50 100 150 200 250 300 350 . 400 450 500 550 600 650 . 700 c 0 ;:; ., > ., w 100 ' 99 ' ' ' ' ' ' ''•I '''I''•' I·''' I 'I I ' I' 'I' I' 100 120 140 160 180 200 220 240 260 280 300 Storage (cubic-feet) Page 26 9/11/2006 -Inflow -Primary -Surface -Storage 0289T1RA Westerheim Custom Homes Type II 24-hr 100 Year Rainfal/=11 .00" Prepared by {enter your company name here} Page 27 9/11/2006 HydroCAD® 7.10 sin 003394 © 2005 HydroCAD Software Solutions LLC Time span=:0.00-20.00 hrs, dt=0.05 hrs, 401 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-lnd+ Trans method -Pond routing by Stor-lnd method Subcatchment P1: Drainage Area P1 Subcatchment X1: Drainage Area X1 Pond 1 P: Detention Facility Runoff Area=?, 167 sf Runoff Depth>9.22" Flow Length=90' Tc=15.5 min CN=90 Runoff=1.86 cfs 0.126 af Runoff Area=?,167 sf Runoff Depth>8.71" Flowlength=90' Tc=15.5min CN=86 Runoff=1 .80cfs 0.119af Peak Elev=99.86' Storage=223 cf lnflow=1 .86 cfs 0.126 af 6.0" x 15.0' Culvert Outflow=1 .57 cfs 0.126 af Total Runoff Area= 0.329 ac Runoff Volume= 0.246 af Average Runoff Depth= 8.96" 0289T1RA Westerheim Custom Homes Type If 24-hr 100 Year Rainfal/=11.00" Prepared by {enter your company name here} HydroCAD® 7 .10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment P1: Drainage Area P1 Runoff = 1.86 cfs @ 12.07 hrs, Volume= 0.126 af, Depth> 9.22" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100 Year Rainfall=11 .00" Area (sf) 2,264 4,903 7,167 CN Description 74 >75% Grass cover, Good, HSG C 98 Paved parking & roofs 90 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) Page 28 9/11/2006 15.5 90 0.0250 0.1 Sheet Flow, Overland Flow at Proposed Building Site Grass: Bermuda n= 0.410 P2= 4.50" 2 Subcatchment P1: Drainage Area P1 Hydrograph Type II 24-hr 100 Year Rainfall=11.00" Runoff Area=7, 167 sf Runoff Volume=0.126 af Runoff Depth>9.22" Flow Length=90' Tc=15.5 min CN=90 I 1.86 cts I o-l-....,.........,,..._.~ .......... ~.""""""..,:;:~.~.;:;:::;:;:::;::;:;:;:;:;::;:;::;:;::::::;:::,.............,., ......... ......,:::::.;,~.~-~ .. :;:;::;:;:;:;:;: .. ~.~-~-:;:;:;:;:;J 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) I-Runottj 0289T1RA Westerheim Custom J-iomes Type II 24-hr 100 Year Rainfa/1=11.00" Prepared by {enter your company name here} HydroCAD® 7 .10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment P1: Drainage Area P1 Runoff = 1.86 cfs@ 12.07 hrs, Volume= 0.126 af, Depth> 9.22" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100 Year Rainfall=11.00" Area (sf) 2,264 4,903 7,167 CN Description 74 >75% Grass cover, Good, HSG C 98 Paved parking & roofs 90 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) ·Page 28 9/11/2006 15.5 90 0.0250 0.1 Sheet Flow, Overland Flow at Proposed Building Site Grass: Bermuda n= 0.410 P2= 4.50" 2 Subcatchment P1: Drainage Area P1 Hydrograph Type II 24-hr 100 Year Rainfall=11.00" Runoff Area=7, 167 sf Runoff Volume=0.126 af I 1.86 cfs I ~ 1-Runoff Depth>9.22" u: 0 '. 0 Flow Length=90' Tc=15.5 min CN=90 . ' . ' . ''I''•' t ' ••'I '''' I 2 3 4 5 6 7 ''I ' I I 8 10 11 12 13 14 15 16 17 18 19 20 Time (hours) I-Runoff~ 0289T1RA Westerheim Custom Homes Type 1124-hr 100 Year Rainfal/=11.00" Prepared by {enter your company name here} HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment X1: Drainage Area X1 Runoff = 1.80 cfs@ 12.07 hrs, Volume= 0.119 af, Depth> 8. 71" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100 Year Rainfall=11 .00" Area (sf) 2,504 4 663 7,167 CN Description 98 Paved parking & roofs 79 50-75% Grass cover Fair HSG C 86 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) Page 29 9/11/2006 15.5 90 0.0250 0.1 Sheet Flow, Overland Flow at Proposed Building Site Grass: Bermuda n= 0.41 O P2= 4.50" Subcatchment X1: Drainage Area X1 Hydrograph Type II 24-hr 100 Year Rainfall=11.00" Runoff Area=7,167 sf Runoff Volume=0.119 af Runoff Depth>8. 71" Flow Length=90' Tc=15.5 min CN=86 1.80 cfs o-L... ............................. ._.. •. ~.~. ~-~.-.;;;;;::;:~.~.-~.:::;::;::;::;::;:;;:;::::............,..,.,..,..,, ....... :::.;.::;;:;:;:;:;:;::;:;::;:;:;::;;;:;:;:;:, ~-~-~ 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) I-Runoff I 0289T1RA Westerheim Custom Homes Type 1124-hr 100 Year Rainfal/=11 .00" Prepared by {enter your company name here} HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Pond 1 P: Detention Facility [85] Warning: Oscillations may require Finer Routing>1 Inflow Area= Inflow = 0.165 ac, Inflow Depth > 9.22" for 1.86 cfs @ 12.07 hrs, Volume= 100 Year event 0.126 af Page 30 9/11/2006 Outflow = Primary = 1.57 cfs@ 12.14 hrs, Volume= 1.57 cfs @ 12.14 hrs, Volume= 0.126 af, Atten= 15%, Lag= 4.4 min 0.126 af Routing by Star-Ind method, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 99.86' @ 12.14 hrs Surf.Area= 573 sf Storage= 223 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 0. 7 min ( 739.8 -739 .1 ) Volume , Invert Avail.Storage Storage Description #1 98.50' 314 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation (feet) Surf.Area (sq-ft) Inc.Store (cubic-feet) Cum.Store (cubic-feet) 98.50 99.00 99.50 100.00 Device Routing #1 Primary 0 56 215 715 0 14 68 233 0 14 82 314 Invert Outlet Devices 98.50' 6.0" x 15.0' long Culvert X 2.00 CPP, projecting , no headwall, Ke= 0.900 Outlet Invert= 98.35' S= 0.0100 '/' Cc= 0.900 n= 0.011 PVC, smooth interior Primary OutFlow Max=1.57 cfs@ 12.14 hrs HW=99.85' (Free Discharge) L1=Culvert (Inlet Controls 1.57 cfs @ 4.0 fps) 0289T1RA Westerheim Custom Homes Type II 24-hr 100 Year Rainfal/=11.00" Prepared by {enter your company name here} HydroCAD® 7 .10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Pond 1 P: Detention Facility [85] Warning: Oscillations may require Finer Routing>1 Inflow Area = Inflow = 0.165 ac, Inflow Depth> 9.22" for 1.86 cfs@ 12.07 hrs, Volume= 1 00 Year event 0.126 af Page 30 9/11/2006 Outflow = Primary = 1.57 cfs@ 12.14 hrs, Volume= 1.57cfs@ 12.14hrs, Volume= 0.126 af, Atten= 15%, Lag= 4.4 min 0.126 af Routing by Stor-lnd method, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 99.86' @ 12.14 hrs Surf.Area= 573 sf Storage= 223 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 0.7 min ( 739.8-739.1) Volume , Invert Avail.Storage Storage Description #1 98.50' 314 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation (feet) Surf.Area (sq-ft) Inc.Store .. (cubic-feet) Cum :Store . . ·, . (cubic-feet) 98.50 99.00 99 .50 100.00 Device Routing #1 Primary 0 56 215 715 0 14 68 233 0 14 82 314 Invert Outlet Devices 98.50' 6.0" x 15.0' long Culvert X 2.00 CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 98.35' S= 0.0100 '/' Cc= 0.900 n= 0.011 PVC, smooth interior Primary OutFlow Max=1 .57 cfs@ 12.14 hrs HW=99.85' (Free Discharge) L1=Culvert (Inlet Controls 1.57 cfs@ 4.0 fps) 0289T1RA Westerheim Custom Homes Type II 24-hr 100 Year Rainfal/=11 .00" Prepared by {enter your company name here} HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC 2 Pond 1 P: Detention Facility Hydrograph Inflow Area=0.165 ac Peak Elev=99.86' Storage=223 cf ! 6.0" x 15.0' Culvert ~ ii: 0 0 2 3 4 5 6 7 6 9 10 11 12 13 14 Time (hours) Pond 1 P: Detention Facility Stage-Area-Storage Surface/Horizontal/Wetted Area (sq-ft) ' ' ' 15 16 17 16 19 20 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 100 99 0 custom s Data 20 40 60 60 1 I l l I I 100 120 140 160 160 200 220 240 260 260 300 Storage (cubic-feet) Page 31 9/11/2006 -Inflow -Primary -Surface -Storage