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Home My WebLink AboutCitadel Storage - Storm Drainage CalculationsSTORM DRAINAGE CALCULATIONS for CITADEL STORAGE 875 E. Chinden Boulevard Meridian, ID 83646 January 23, 2013 ROCK SOLID CIVIL Jim E. Coslett, P.E. 181 E. 50th Street Garden City, ID 83714 208-342-3277 j coslett?rocksolidcivil.com � F• COSH/ CALCULATION METHODOLOGY PRE -DEVELOPED FLOW AND VOLUME CALCULATIONS - NOT APPLICABLE ON THIS PROJECT The pre -developed flow for the project site and the upstream area from the site are calculated using the Rational Method. The time of concentration is based on overland flow to a point of channelization and then the travel time in the existing channel to the downstream end of the concerned area. The pre -developed volume is calculated using the SCS Triangular Unit Hydrograph. Pre -developed volumes and flows are based on the 15, 25 and 100 -year storm events. POST -DEVELOPED FLOW AND VOLUME CALCULATIONS Post -developed flow for the basin areas are also calculated using the Rational Method. The time of concentration is based on a combination of lot to street time, gutter time and applicable pipe time prior to reaching the detention pond area. The lot time is calculated using Manning's kinematic solution (Overton and Meadows 1976). This equation is also used for sheet flow of less than 300 feet. The gutter time is calculated using the travel length along the gutter and the gutter velocity at the design slope. Pipe time is calculated using the pipe travel length and an average pipe velocity. The post -developed volume is calculated using the SCS Triangular Unit Hydrograph. Post -developed volumes and flows are based on the City of Boise 50 -year design storm event. DETENTION VOLUME CALCULATIONS - NOT APPLICABLE ON THIS PROJECT Two methods are used for the detention volume calculation. The more conservative (larger volume) method is utilized in detention pond sizing. The first method calculates the required detention volume by subtracting the calculated pre -developed volume from the post -developed SCS Triangular Unit Hydrograph. Then the volume is increased by 15 percent to compensate for detention volume losses due to sediment between maintenance periods. The second method simply applies 1 inch of water over the right-of-way area in the basin. This volume is also increased by 15 percent for similar reasons. WET POND VOLUME CALCULATIONS - NOT APPLICABLE ON THIS PROJECT The pond volume calculations are based on an average of the 100 year water surface area and the groundwater area, applied over the design pond depth. The groundwater area is that area of the pond based on the seasonal high groundwater elevation. PIPE SIZING AND HYDRAULIC GRADE CALCULATIONS These calculations employ the Manning Equation combined with flow entering the pipe. The hydraulic grade is based on predetermined flow and pipe size. SAND AND GREASE TRAP SIZING CALCULATIONS The sand and grease traps were sized based on the post -developed flow draining to them. The throat width is calculated with this flow and a maximum velocity of 0.5 fps through the throat. The exiting discharge is assumed to equal the entering discharge. ORIFICE SIZING CALCULATIONS - NOT APPLICABLE ON THIS PROJECT The Orifice Equation is used to determine orifice diameter. Pre -developed flows and orifice head are utilized to calculate the required orifice area. The orifice head is the distance from the pond water surface to the top of the orifice hole. BIOFILTRATION SWALE DESIGN - NOT APPLICABLE ON THIS PROJECT S = Longitudinal slope of swale, 0.5% to 4% preferred Z = Sideslope ratio, 3:1 max Y = Depth of water flow, (5" to 8" max) n = Mannings N = 0.14 for grass lined swale B = Width of bottom of swale, 8' max A = Area R = Hydraulic radius Q = Discharge use 0.34 in/hr for W.Q. storm V = Velocity of water flow, hold 0.9 fps, 1.5 fps max HRT = Hydraulic Residence Time, = U(V'60) > 9 minutes EQUATIONS USED IN CALCULATIONS RATIONAL METHOD Q=CiA where: Q = Runoff Rate, cfs C = Runoff Coefficient i = Storm Intensity, in./hr. A = Basin Area(s), acres OVERLAND TIME OF CONCENTRATION (WRIGHT-McLAUGHLIN, 1969) tc=1.8(1.1-C)L12 I S"" where: tc = Overland Time of Concentration, min. C = Runoff Coefficient L = Overland Flow Length, ft. S = Overland Slope, % CHANNEL TIME OF CONCENTRATION t�=(L/V) / 60 where: t� = Channel Time of Concentration, min. L = Channel Length, ft. V = Velocity, fps (from Manning Equations) MANNING EQUATION V=1.49R21IS112 / n where: V = Velocity, fps R = Hydraulic Radius, ft. S = Channel Slope, ft./ft. n = Manning Roughness Coefficient MANNING'S KINEMATIC SOLUTION (OVERTON AND MEADOWS, 1976) tt=0.007(nL)°'B / TO' 1 where: tt = Travel Time, hr. n = Manning Roughness Coefficient L = Flow Length, ft., 300' max. Pz = 2 -Year, 24 -Hour Rainfall, in. s = Slope of Hydraulic Grade Line, ft./ft. ORIFICE EQUATION Q=CpA2(2gOh)112 where: Co = Discharge Coefficient Az =Orifice Area, sq. ft. g = 32.2 ft./sec.2 Ah = Head. ft. VOLUME FROM THE SCS TRIANGULAR UNIT HYDROGRAPH METHOD V=2.67Qt60 / 2 where: V = Volume, cu. ft. Q = Flow, cfs tc = time of concentration, min. STORM DURATION TIME FROM THE SCS TRIANGULAR UNIT HYDROGRAPH METHOD tb = 2.67*tc where: tb = time of Storm Duration, min OTHER EQUATIONS USED Q=VA AREA OF A TRAPEZOID A=Y(B+ZY) t, = time of concentration, min. where: Q = Flow, cfs V = Velocity, fps A = Cross Sectional Area, sq. ft. where: A = Cross Sectional Area, sq. ft. B = Width of swale bottom Z = Swale sideslope ratio Y = Height of trapezoid Seepage Bed #1 Calculation ProjecYLocation DA 1 + DA 13 Using Zone "A" OF Curve Predevelopment Rate (if any): Return Period? 50 Void Volume: (V,°id) Are.intt` 19,146 Pipe Size(diameter-in): Drainage Area (acres) Area in Acres 044 Pipe Area (ft (A uno oe Icient c 0.95 Percolation Rate Inches/Hr 8 Infiltration Calculation t ypel Width ,- _ _ _ 10 Surface Length (ft)• 39•Area 390 Of Seepage Bed D FFJi) I____.7,lnclu ingl-ft freeboard 42-/- 0%Area 12 0.79 Side cfs max Compute Volume Storm Duration I Q Runoff Vol Percolation Vol PreDev. Vol VF, Required Vol Min Hr in/hr cfs ft3 ft3 ft ft3 10 0.17 2.61 1.09 654 51 0 603 22.5 0.38 1.9 0.79 1,071 114 0 957 30 0.50 1.43 0.60 1,075 152 0 922 1 0.89 0.37 1,338 305 0 1,033 2 0.53 0.22 1,593 610 0 984 3 0.399 0.17 1 1,799 915 0 1 885 4 0.315 0.13 1,894 1,220 0 674 5 0.273 0.11 2,052 1,524 0 527 6 0.245 0.10 2,210 1,829 0 380 8 0.195 0.08 2,345 2,439 0 -94 10 0.165 0.07 2,480 3,049 0 -569 12 0.14 0.06 2,525 3,659 0 -1,133 18 0.092 0.04 2,489 5,488 0 -2,999 24 0.078 0.03 2,814 7 317 0 -4,503 Enter Total Design Vol. 1 033 Size Seepage Bed Width DepthAG AP AN Does it Check? ft ft ft ft3 Width Yes 10 6 60 0.79 1 24.47 Length Storage Volume Available (ftr) 1033 15% Sed. 1188 Adjusted for 150% Sediment Width 10 Depth with 1 foot freeboard 1 7 Adj. Length 39 Time to Drain 3.9 Hours References: Relevant Equations Q=CIA Q= Flow Rate (cfs) C= Runoff Coefficien 1= Rain Intensity A= Drainage Area VH AN AG Ap VV°;d Required Volume Net x -Sectional Area Gross Sectional Area WxD Pipe x -Section Void Volume Ao = Width X Depth AN = [AG-Aa]1VV0IDI+AP Seepage Bed #2 Calculation Project/Location DA 2 Using Zone "A" OF Curve Predevelopment Rate (if any): Return Period? 50 Void Volume: (v„°;d) Area inn 13,093 Pipe Size(diameter-in): Drainage Area (acres) Area in Acres 0.30 Pipe Area (): (Ap) uno oe Icent (c 0.95 Percolation Rate Inches/Hr 8 F Infiltration Calculation type Width (ft1 10 Surface Length (ftp 26 -Area 260 Of Seepage Bed Depth (ft)1_ _ _ _ _ 7 . Inc uding 1 -ft free oard . J. Compute Volume 400% 12 0.79 Side cfs max Storm Duration I Q Runoff Vol Percolation Vol PreDev. Vol VR Required Vol Min Hr in/hr cfs ft' ft' ft3 ft3 10 0.17 2.61 0.75 447 37 0 410 22.5 0.38 1.9 0.54 732 84 0 648 30 0.50 1.43 0.41 735 112 0 623 1 0.89 0.25 915 224 0 691 2 0.53 0.15 1,090 448 0 642 3 1 0.399 0.11 1,230 672 0 558 4 0.315 0.09 1 1,295 896 0 399 5 0.273 0.08 1,403 1,120 0 283 6 0.245 0.07 1,511 1,344 0 167 8 0.195 0.06 1,604 1,792 0 -188 10 0.165 0.05 1,696 2,240 0 1 -544 12 0.14 0.04 1,727 2,688 0 -961 18 0.092 0.03 1,702 4,032 0 -2,330 24 0.078 0.02 1,924 5 376 0 -3 452 Enter Total Design Vol. 691 Size Seepage Bed Width Depth AG Ap AN Does it Check? ft ft ft ft' ft3 Width Yes 10 6 60 0.79 24.47 Len h Storage Volume Available ft3 691 15% Sed. 795 Adjusted for 150% Sediment Width 10 Depth (with 1 foot freeboard 7 Adj. Length 25 Time to Drain 3.5 Hours References: Relevant Equations Q=CIA Q= Flow Rate (cfs) C= Runoff Coefficien 1= Rain Intensity A= Drainage Area VR AN AG Ap VV°d Required Volume Net x -Sectional Area Gross Sectional Area WxD Pipe x -Section Void Volume AG = Width X Depth AN = [AG-Ap][VVOIDI+Ap Seepage Bed #3 Calculation Project/Location DA 3 Using Zone "A" OF Curve Predevelopment Rate (if any): Return Period? 50 Void Volume: (VI°;d) — Area in; A° ft'13,301 Pipe Size(diameter-in): rainage Area (acres) Araa0.31Pipe Area ( ): (AP) Runoff Coefficient c 0.95 Percolation Rate mhe.M, 8 F Infiltration Calculation type WOW(W)II _ _ 10ySurface Of Seepage Bed Eength (ft)• _ _ _ _26•Area 260 Depth (ft) I 7 t nc u mg 1- freeboard 1ompute qO79 Side cis max . . CVolume Storm Duration 1 Q Runoff Vol Percolation Vol PreDev. Vol VR Required Vol Min Hr in/hr cfs W ft3 ft" ft3 10 0.17 2.61 0.76 454 37 0 417 22.5 0.38 1.9 0.55 744 84 0 660 30 0.50 1.43 0.41 747 112 0 635 1 0.89 0.26 929 224 0 705 2 0.53 0.15 1,107 448 0 659 3 0.399 0.12 1,250 672 0 578 4 1 0.315 0.09 1,316 896 0 420 5 0.273 0.08 1,425 1,120 0 305 6 0.245 0.07 1,535 1,344 0 191 8 0.195 0.06 1,629 1,792 0 -163 10 0.165 0.05 1,723 2,240 0 -517 12 0.14 0.04 1,754 2,688 0 -934 18 0.092 0.03 1,729 4,032 0 -2,303 24 0.078 0.02 1,955 5 376 0 -3 421 Enter Total Design Vol. 1 705 Size Seepage Bed Width Depth AG Ap AN Does it Check? ft ft ft. ff ft3 Width Yes 10 6 60 0.79 1 24.47 Length Storage Volume Available(ft") 705 15% Sed. 1 811 Adjusted for 15% Sediment Width 10 Depth with 1 foot freeboard) 1 7 Adj. Length 26 Time to Drain 3.6 Hours References: Relevant Equations Q=CIA Q= Flow Rate (cfs) C= Runoff Coefficien 1= Rain Intensity A= Draina a Area VR AN AG Ap VV°;d Required Volume Net x -Sectional Area Gross Sectional Area wxD Pipe x -Section Void Volume Ao = Width X Depth AN = [AG-AP][VVc;p]+AP Seepage Bed #4 Calculation Project/Location DA 6 + DA 15 Using Zone "A" OF Curve Predevelopment Rate (if any): Return Period? 50 01 o ume: (vv°,d) 40% Area inn - 25,745 Pipe Size(diameter-in): 12 Drainage Area (acres) Area in Acres 0.59 Pipe Area ( ): (A,) 0.79 i u ff Coe icient (c 0.95 Percolation Rate Inches/Hr 8 Infiltration Calculation type Side N%i7F(ft1 10 Surface Length (ftp_ _ _ 54.Area540 Of Seepage Bed Depth (ftJ_.___ 7 ,Inclu Ing 1 -ft ree oard cfs max Compute Volume Storm Duration I Q Runoff Vol Percolation Vol PreDev. Vol Vn Required Vol Min Hr in/hr cfs ft3 ft, fts fts 10 0.17 2.61 1.47 879 66 0 813 22.5 0.38 1.9 1.07 1,440 149 0 1,291 30 0.50 1.43 0.80 1,445 199 0 1,246 1 0.89 0.50 1,799 398 0 1,401 2 0.53 0.30 2,143 796 0 1,346 3 0.399 0.22 1 2,419 1,195 0 1 1,225 4 0.315 0.18 2,547 1,593 0 1 954 5 0.273 0.15 2,759 1,991 0 768 6 0.245 0.14 2,971 2 389 0 582 8 0.195 0.11 3,153 3,186 0 -33 10 0.165 0.09 3,335 3,982 0 -647 12 0.14 0.08 3,396g9"557 779 0 -1,383 18 0.092 0.05 3,347168 0 -3,821 24 0.078 0.04 3,784 0 -5,773 Enter Total Design Vol. 1 1,401 Size Seepage Bed Width Depth AG Ap AN Does it Check? ft ft ft, ft,ft3 Width Yes 10 6 60 0.79 24.47 Len th Storage Volume Available ft3 1401 15% Sed. 1611 Adjusted for 15% Sediment Width 10 Depth with 1 foot freeboard 1 7 Adj. Length 53 Time to Drain 4.0 Hours References: Relevant Equations Q=CIA Q= Flow Rate (cfs) C= Runoff Coefficien 1= Rain Intensity A= Drainage Area VH AN AG A, VV°;d Required Volume Net x -Sectional Area Gross Sectional Area w:D Pipe x -Section Void Volume AG = Width X Depth AN = [AG-AP][VVOIDI+AP Seepage Bed #5 Calculation Projecftocation DA 7 + DA 4 Using Zone "A" OF Curve Predevelopment Rate (if any): Return Period? 50 Void Volume: (v °d) Areain 22,956 Pipe Size(diameter-in): Drainage Area (acres) Area in Acres 0.53 Pipe Area (ft): (AP) Runoff Coefficient c 0.95 Percolation Rate Inches/Hr 8 Infiltration Calculation type Width (n1 . . 10 Surface Length (ft)• _ _ -84—Area 480 Of Seepage Bed Depth (ft1 7 ncu Ing 1- ree oard J. 40% 12 0.79 Side cfs max Compute Volume Storm Duration I Q Runoff Vol Percolation Vol PreDev. Vol VR Required Vol Min Hr in/hr cfs ft3 ft3 ft3 ft3 10 0.17 2.61 1.31 784 60 0 724 22.5 0.38 1.9 0.95 1,284 135 0 1,149 30 0.50 1.43 0.72 1,289 180 0 1,108 1 0.89 0.45 1,604 361 0 1,243 2 0.53 0.27 1,910 722 0 1,189 3 1 0.399 0.20 2,157 1,083 0 1 1,075 4 0.315 0.16 2,271 1,444 0 827 5 0.273 0.14 2,460 1,804 0 656 6 0.245 0.12 2,649 2,165 0 484 8 0.195 0.10 2,812 2,887 0 -75 10 0.165 0.08 2,974 3,609 0 -635 12 0.14 0.07 3,028 4,331 0 -1,303 18 0.092 0.05 2,985 6,496 0 -3,511 24 0.078 0.04 3,3 74 8 661 0 -5,287 Enter Total Design Vol. 1 243 Size Seepage Bed Width Depth Ac AP AN Does it Check? ft ft ft ft3 Width Yes 10 6 60 0.79 24.47 Len th Storage Volume Available ft3 1243 15% Sed. 1430 Adjusted for 15% Sediment Width 10 Depth with 1 foot freeboard 7 Adj. Length 47 Time to Drain 4.0 Hours References: Relevant Equations Q=CIA Q= Flow Rate (cfs) C= Runoff Coefficien 1= Rain Intensity A= Drainage Area VR AN AG AP VV°id Required Volume Net x -Sectional Area Gross Sectional Area WxD Pipe x -Section Void Volume AG = Width X Depth AN = [AG-AP][VVOIDI+AP Seepage Bed #6 Calculation Projelaftocation DA 8 Using Zone "A" OF Curve Predevelopment Rate (if any): Return Period? 5 of Volume: (V1e;d) _-- Aream 12,956 Pipe Size(diameter-in): Drainage Area (acres) Area m Acres 0.30 Pipe Area (ft): (AP) Runoff Coefficient c 0.95 Percolation Rate Inches/Hr 8 Infiltration Calculation type Width (Fi 10 Surface Eength (ft)• ' _26 Area E260 Of Seepage Bed Depth (tt) 7 �— nc u mg 1 -ft freeboard �. 40% 12 0.79 Slde Jcfs, max Compute Volume Storm Duration 1 Q Runoff Vol Percolation Vol PreDev. Vol VA Required Vol Min Hr in/hr cfs W ft3 ft3 ft3 10 0.17 2.61 0.74 442 37 0 405 22.5 0.38 1.9 0.54 725 84 0 641 30 0.50 1.43 0.40 727 112 0 615 1 0.89 0.25 905 224 0 681 2 0.53 0.15 1,078 448 0 630 3 0.399 0.11 1,218 672 0 546 4 1 0.315 0.09 1,282 896 0 386 5 0.273 0.08 1,388 1,120 0 268 6 0.245 0.07 1,495 1,344 0 151 8 0.195 0.06 1,587 1,792 0 -205 10 0.165 0.05 1,678 2,240 0 1 -562 12 0.14 0.04 1,709 2,688 -979 18 0.092 0.03 1,684 4,032 -2,348 24 0.078 0.02 1,904 5!376 4Desion -3,472 Enter Totol. 681 Size Seepage Bed Width Depth AG Aa AN Does it Check? ft ft ft, ft ft3 Width Yes 10 6 60 0.79 24.47 Len til Storage Volume Availableft3 68115% Sed. 784 Adjusted for 15% Sediment Width 10 Depth (with i toottreeboard 7 Adj. Length 25 Time to Drain 3.5 Hours References: Relevant Equations Q=CIA Q= Flow Rate (cfs) C= Runoff Coefficien 1= Rain Intensity A= Drainage Area VA AN AG Ap Vve;d Required Volume Net x -Sectional Area Gross Sectional Area wxo Pipe x -Section Void Volume AG = Width X Depth AN = iAG APjiVVO1D)+AP Seepage Bed #7 Calculation Project/Location DA 9 + DA 16 + DA 5 Using Zone "A" OF Curve Predevelopment Rate (if any): Return Period? 50 of o ume: (v °�) Area in 31,518 Pipe Size(diameter-in): Drainage Area (acres) Area in Acres 0.72 Pipe Area ( ): (AP) uno -Coe icient c 0.95 Percolation Rate inches/Hr 8 Infiltration Calculation type Width (it1� '10 Surface Length (ft)• � � _ _ _66 -Area 660 Of Seepage Bed Depth (ft�� 7 nclu ino 1 -ft ree oard 40% 12 0.79 Side cfs max Compute Volume Storm Duration 1 Q Runoff Vol Percolation Vol PreDev. Vol VR Required Vol Min Hr in/hr cfs ft" ft" ft3 ft" 10 0.17 2.61 1.79 1,076 79 0 998 22.5 0.38 1.9 1.31 1,763 177 0 1,586 30 0.50 1.43 0.98 1,769 236 0 1,533 1 0.89 0.61 2,202 473 0 1,729 2 0.53 0.36 2,623 946 0 1,677 3 1 0.399 0.27 2,962 1,419 0 1,543 4 0.315 0.22 3,118 1,892 0 1,226 5 0.273 0.19 3,378 2,364 0 1,013 6 0.245 0.17 3,638 2,837 0 800 8 0.195 0.13 3,860 3,783 0 77 10 0.165 0.11 4,083 4,729 0 -646 12 0.14 0.10 4,157 5,675 0 -1,517 18 0.092 0.06 4,098 8,512 0 -4,414 24 0.078 0.05 4,632 11,349 0 -6,717 Enter Total Design Vol. 1,729 Size Seepage Bed Width Depth AG Ap AN Does it Check? ft ft ft ft3 Width Yes 10 6 60 0.79 1 24.47 Length Storage Volume Available ft3 1729 15% Sed. 1989 Adj. Length 66 Width De th(with 1 foot freeboard) Adjusted for 15°/ Sediment 10 1 7 Time to Drain 4.2 Hours References: Relevant Equations Q=CIA Q= Flow Rate (cfs) C= Runoff Coefficien 1= Rain Intensity A= Drainage Area VR AN AG Ap Uv°d Required Volume Net x -Sectional Area Gross Sectional Area WxD Pipe x -Section Void Volume Ac = Width X Depth AN= [Ao-Apl[Vvoio]+AP Seepage Bed #8 Calculation Project/Location DA 10 Using Zone "A" OF Curve Predevelopment Rate (if any): Return Period? 50 of o ume: (void) Area in 12,289 Pipe Size(diameter-in): Drainage Area (acres) Area in Acres 0.28 Pipe Area (f ): (AR) Runoff Coefficient c 0.95 Percolation Rate Inches/Hr 8 L Infiltration Calculation type W idth (ft1 " 10 Surface Length (ft)4 _ _ _ 'r4 -Area, 240 Of Seepage Bed 7 F- nc u 1- e Depth (ft� ingt re oard 407/6 12 0.79 Side cfs max Compute Volume Storm Duration I Q Runoff Vol Percolation Vol PreDev. Vol VR Required Vol Min Hr in/hr cfs ft3 ft3 ft3 ft3 10 0.17 2.61 0.70 420 35 0 384 22.5 0.38 1.9 0.51 687 79 0 608 30 0.50 1.43 0.38 690 106 0 584 1 0.89 0.24 859 212 0 647 2 0.53 0.14 1,023 423 0 600 3 0.399 0.11 1 1,155 635 0 1 520 4 0.315 0.08 1,216 846 0 369 5 0.273 0.07 1,317 1,058 0 259 6 0.245 0.07 1,418 1,269 0 149 8 0.195 0.05 1,505 1,692 0 -187 10 0.165 0.04 1,592 2,116 0 -524 12 0.14 0.04 1,621 2,539 0 -918 18 0.092 0.02 1,598 3,808 0 -2,210 24 0.078 10.02 1 806 5 077 0 3,271 Enter Total Design Vol. 647 Size Seepage Bed Width Depth AG AR AN Does it Check? ft ft ft, ftft3 Width Yes 10 6 60 0.79 1 24.47 Length Storage Volume Available ft3 647 15% Sed. 1 744 Adj. Length 24 Width I Depth with 1 foot freeboard Adjusted for 15% Sediment 10 7 Time to Drain 3.5 Hours References: Relevant Equations Q=CIA Q= Flow Rate (cfs) C= Runoff Coefficien 1= Rain Intensity A= Drainage Area VR AN AG AR VVoid Required Volume Net x -Sectional Area Gross Sectional Area WxD Pipe x -Section Void Volume AG = Width X Depth AN = IAG APIIVVOIDj+AP Seepage Bed #9 Calculation Projecftocation DA 11 Using Zone "A" OF Curve Predevelopment Rate (if any): Return Period? 50 Vo—id-Volume: (V1eld) Area in 8,089 Pipe Size(diameter-in): Drainage Area (acres) Area in Acres 0.1g Pipe Area (ft): (AP) Runoff Coefficient (c 0.95 Percolation Rate Inches/Hr 8 Infiltration Calculation type Width (ft -W , 10 Surface —•--- " 15•Area 150 Of Seepage Bed Length (ft)• _ _ Depth (ft1'" 7 Including 1 -ft Fee and 40% 12 0.79 Side cfs max Compute Volume Storm Duration I Q Runoff Vol Percolation Vol PreDev. Vol VR Required Vol Min Hr in/hr cfs ft3 ft3 ft3 ft3 10 0.17 2.61 0.46 276 26 0 250 22.5 0.38 1.9 0.34 452 58 0 394 30 0.50 1.43 0.25 454 78 0 376 1 0.89 0.16 565 156 0 410 2 0.53 0.09 673 311 0 362 3 0.399 0.07 760 467 1 0 294 4 1 0.315 0.06 800 622 0 178 5 0.273 0.05 867 778 0 89 6 0.245 0.04 934 933 0 0 8 0.195 0.03 991 1,244 0 -254 10 0.165 0.03 1,048 1,556 0 -508 12 0.14 0.02 1,067 1,867 0 -800 18 0.092 0.02 1,052 2,800 0 -1,748 24 0.078 0.01 1 189 3 733 0 -2,544 Enter Total Design Vol. 410 Size Seepage Bed Width Depth Ac Ap AN Does it Check? ft ft ft, ft, ft3 Width Yes 10 6 60 0.79 24.47 Cenath Storage Volume Available ft3 410F15% Sed. 1 471 Adjusted for 15% Sediment Width 10 Depth with t foot freeboard 7 Adj. Length 14 Time to Drain 3.0 Hours References: Relevant Equations Q=CIA Q= Flow Rate (cfs) C= Runoff Coefficien 1= Rain Intensity A= Drainage Area VR AN Ac, A, VVoid Required Volume Net x -Sectional Area Gross Sectional Area wxD Pipe x -Section Void Volume AG = Width X Depth AN = [Ar-AP)IVvoIDj+AP Seepage Bed #10 Calculation Projelaftocation DA 12 Using Zone "A" OF Curve Predevelopment Rate (if any): Return Period? 50 Void VoFme: Knid) Area info--- 10,817 Pipe Size(diameter-in): rainage Area (acres) Area in Acres 0.25 Pipe Area (ft): (Ap) Runoffoe icient c 0.95 Percolation Rate inches/Hr 8 Infiltration Calculation type Width (tt1 _ _ _ _ 10 Surface 21 •Area 210 Of Seepage Bed Depth (ft� 7 �— nc u ing l41 ree oard . r. 40% 12 0.79 I Side cfs max Compute Volume Storm Duration I Q Runoff Vol Percolation Vol PreDev. Vol VR Required Vol Min Hr in/hr cfs ft3 ft3 ft3 ft3 10 0.17 2.61 0.62 369 32 0 337 22.5 0.38 1.9 0.45 605 72 0 533 30 0.50 1.43 0.34 607 96 0 511 1 0.89 0.21 756 193 0 563 2 0.53 0.13 900 386 0 514 3 0.399 0.09 1,017 579 0 438 4 1 0.315 0.07 1,070 772 0 299 5 0.273 0.06 1,159 964 0 195 6 0.245 0.06 1,248 1,157 0 91 8 0.195 0.05 1,325 1,543 0 -218 10 0.165 0.04 1,401 1,929 0 -528 12 0.14 0.03 1,427 2,315 0 -888 18 0.092 0.02 1,406 3,472 0 -2,066 24 0.078 0.02 1,590 4 629 0 1 -3,040 Enter Total Design Vol. 563 Size Seepage Bed Width Depth Ac Ap Ar, Does it Check? ft ft ft, ft, ft3 Width Yes 10 6 60 Storage Volume Available(ft) 1 0.79 563 1 24.47 15% Sed. 1 647 Len th Adjusted for 15% Sediment Width 10 Depth with 1 foot freeboard 7 Adj. Length 20 Time to Drain 3.4 Hours References: Relevant Equations Q=CIA Q= Flow Rate (cfs) C= Runoff Coefficien 1= Rain Intensity A= Drainage Area VR A, Ao Ap VVom Required Volume Net x -Sectional Area Gross Sectional Area WxD Pipe x -Section Void Volume Ac = Width X Depth AN= [AG-Ap]1Vv01o1+Ap A rwm �4� 11AIJ 01'105 N��tl (�� TI MO TE %OIA I®LLKiANIM IB119N �AA33W 1MXtT AICWNtl ➢LLLLMtlS IVW �wNd z ixuronvu w stl rmNw P31VLOd SIC6 ONSY3X 3NI qm IHiMA05M1 3raveo'�'�aa aroryS�V3�d 3JtlN!!LS 134V1YJ 3� � �� g M. & ` 4 � � � � T wmo ,w p sN9�tl -www a s NouonH15N0o HOd 03AOHddV ioNM31A3HAoN3JV Rg ?sRseoao�$<�g�^s 3a i egiiggi 99Hg35^a= aG 3a I t §Q _ a g � pq Em C I �m � � I dx O tl tl Y V v P N - 0 W Y N N - G O 8,,OH 83d S3HONI NI AIISN31NI �IV�INIVd 0 m 0 O 0 M 0 (D r 0 (D r 0 r 0 0 M 0 0 I� 0 0 N 0 0 M 0 0 T 0 0 M 0 0 M 0 0 T 0 0 M 0 O O O O O m TFTM m m m O N 00 Lt7 r M O T h (D d' 00LO W LM (`7 (+7 N N N N r r r 0 0 0 i N r 0 0 0 0 0 0 0 0 0 0 0 L — r- 0 0 0 0 0 0 N N I- r O M If1 00 M Ill r 00 M M Lti M M M Q) N ('i I. V M N N N r T T 0 �= N r O O O O O O O O O O C lIcco::)), 0 0 0 0 0 OCD O O O4t m N N CV DS O# V I,- N r r T 0 r 0� 0 0 0 0 0 0 0 0 O c N co T 0 0 0 0 00 O O Ill O O (z O m m O O rl m M O mrl- (O m O In M N N r T T T 0 0 0 0 T 0 0 0 0 0 0 0 0 0 0 0 0 O O O O LO O T CO (D t) f1/7 i =_ _ _ 2 2 2 O N OO V N co d' T N (sainuiW ui) uoileana 0 m