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Home My WebLink AboutCC - Storm DrainStorm Drainage Master for Turin Plaza Subdivision Client: McCarter-Moorhouse 4660 N. Penngrove Way Suite 100 Meridian, ID 83646 jma5on & A,5,5ociabf'51n,c. Professional Engineers, Land Surveyors and Planners 924 3rd St. So., Suite B, Nampa, ID 83651 Ph (208) 454-0256 Fax (208) 467-4130 Job No. MR0622 Date: September 19, 2022 SCE Y 9212 O of Mason & Associates1 t MR0622SD.xlsx Cover 1 of CALCULATION METHODOLOGY FLOW CALCULATIONS Flow for the basin areas are calculated using the Rational Method. The "C" coefficient used in the calculations is based on weighted values as shown. Conveyance facilities are designed for a 25-year return frequency storm and the worst case condition between 10 minutes and 1 hour. The worst case storm for flow is the 10-minute duration. HYDRAULIC GRADE CALCULATIONS These calculations employ the Manning Equation. The hydraulic grade is based on calculated flow. 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 MANNING EQUATION V=1.49R1/3S'12 / n where: V = Velocity, fps R = Hydraulic Radius, ft. S = Channel Slope, ft./ft. n = Manning Roughness Coefficient Mason f3 Associates] MR0622SD.xlsx Cover 2 of 2 PEAK FLOW CALCULATIONS FOR SUB -BASINS POST -DEVELOPED RUNOFF COEFFICIENT (C) = LOT TRAVEL TIME = 0.92 Area 1 weighted landscape/roof/asphalt 0.83 Area 2 weighted landscape/roof/asphalt 0.85 Area 3 weighted landscape/roof/asphalt 0.84 Area 4 weighted landscape/roof/asphalt 2.3 min DROP INLET CAPACITIES: VERTICAL CURB = 4.26 cfs (depth at top of curb) ROLLED CURB = 3.15 cfs (depth at top of curb) Location AREA DATA CALCULATIONS SUB -BASIN AREA # SUB -BASIN AREA ac CURB TYPE (V,R) GUTTER LENGTH ft AVERAGE GUTTER SLOPE GUTTER TIME min GUTTER CAPACITY cfs TOTAL TIME Tc 50yr I in/hr Q cfs 1 0.16 R 115 2.20% 0.5 4.04 10.0 3.16 0.47 2 0.21 R 110 1.90% 0.5 3.76 10.0 3.16 0.55 3 0.65 R 200 2.00% 0.9 3.86 10.0 3.16 1.75 4 0.24 R 55 2.00% 0.3 3.86 10.0 3.161 0.64 Mason & Associates /^l MR0622SD.xlsx Conveyance SAND AND GREASE TRAP CALCULATION BASIN: 1 SEDIMENT/GREASE TRAP SIZING NUMBER OF TANKS 1 0.47 DISCHARGE (CFS) VELOCITY -MAXIMUM (FPS) 0.50 REQUIRED THROAT AREA (SF) 0.93 TANK SIZE (gal) DB-350 TANK WIDTH (FT) 3.42 THROAT -WIDTH (in) 5 VELOCITY -ACTUAL (fps) 0.33 BASIN: 2 SEDIMENT/GREASE TRAP SIZING NUMBER OF TANKS 1 0.55 DISCHARGE (CFS) VELOCITY -MAXIMUM (FPS) 0.50 REQUIRED THROAT AREA (SF) 1.10 TANK SIZE (gal) DB-350 TANK WIDTH (FT) 3.42 THROAT -WIDTH (in) 5 VELOCITY -ACTUAL (fps) 0.39 BASIN: 3 SEDIMENT/GREASE TRAP SIZING NUMBER OF TANKS 1 1.75 DISCHARGE (CFS) VELOCITY -MAXIMUM (FPS) 0.50 REQUIRED THROAT AREA (SF) 3.49 TANK SIZE (gal) 1,000 TANK WIDTH (FT) 4.00 THROAT -WIDTH (in) 12 VELOCITY -ACTUAL (fps) 0.44 BASIN: 4 SEDIMENT/GREASE TRAP SIZING NUMBER OF TANKS 1 0.64 DISCHARGE (CFS) VELOCITY -MAXIMUM (FPS) 0.50 REQUIRED THROAT AREA (SF) 1.28 TANK SIZE (gal) DB-350 TANK WIDTH (FT) 3.42 THROAT -WIDTH (in) 5 VELOCITY -ACTUAL (fps) 0.45 S&G TRAP DETENTION TIME NUMBER OF TANKS 1 DISCHARGE (CFS) 0.47 S&G STORAGE VOLUME (CF) 33.00 DETENTION TIME, T (SEC) 71 IS T>40 SEC.? YES S&G TRAP DETENTION TIME NUMBER OF TANKS 1 DISCHARGE (CFS) 0.55 S&G STORAGE VOLUME (CF) 33.00 DETENTION TIME, T (SEC) 60 IS T>40 SEC.? YES S&G TRAP DETENTION TIME NUMBER OF TANKS 1 DISCHARGE (CFS) 1.75 S&G STORAGE VOLUME (CF) 152.00 DETENTION TIME, T (SEC) 87 IS T>40 SEC.? YES S&G TRAP DETENTION TIME NUMBER OF TANKS 1 DISCHARGE (CFS) 0.64 S&G STORAGE VOLUME (CF) 33.00 DETENTION TIME, T (SEC) 52 IS T>40 SEC.? YES Mason & Associates 1^4 MR0622SD.xlsx Conveyance Pipe Capacity- min. pipe slope req'd Area Pipe Size, in., variable Pipe Slope, %, variable Mannings, n, variable PVC Pipe Capacity, cfs 1-4 12 0 0 0.22% 0.22% 0.22% 0.009 0.009 0.009 2.41 0.00 0.00 Mason �y A55oc;arPsi� MR0622SD.xlsx Conveyance RETENTION BASIN AREA NO. 1 WORST CASE STORM VOLUME, 100-yr BASIN AREA 0.16 acres RUNOFF COEFFICIENT (C) 0.92 weighted coefficient PERCOLATION RATE 8.00 in/hr PERCOLATION AREA 162 sf SYSTEM VOID SPACE 515 cf OFFSITE DISCHARGE 0 cfs PEAK MIN. 100 YR PEAK LESS FLOW VOIDS PERC POND DURATION DURATION INTENSITY' FLOW DISCH. VOLUME VOLUME VOLUME VOLUME (min) (hrs) (in/hr) (cfs) (cfs) (d) (cf) (co (cQ 10 0.17 3.11 0.458 0.458 275 515 18 0 15 0.25 2.62 0.386 0.386 347 515 27 0 30 0.50 1.82 0.268 0.268 482 515 54 0 60 1.00 1.15 0.169 0.169 609 515 108 0 RETENTION DESIGN BASIN TOTAL STORAGE REQ'D= 609 cf WORST CASE STORM DURATION 60 minutes OFFSITE DISCHARGE 0.00 cfs SWALE VOLUME CALCULATION SWALE TOP AREA= 1:1ft sf SWALE BOTTOM AREA= sf SWALE AVE. END AREA= sf SWALE DEPTH= SWALE STORAGE = 0 cf SWALE INFILTRATION = 0 cf PIPE VOLUME CALCULATION PIPE AREA 24" DIA= 3.14 sf PIPE LENGTH= 105 sf PIPE BARRELS= 0.00 PIPE STORAGE = 0 cf INFILTRATION BED CALCULATION W L INFILTRATION AREA = 162 sf ROCK 10 735ROCK BED DEPTH = 1.8 ft SAND 10 SAND BED DEPTH = 3 ft VOID SPACE IN SAND= 25% VOID SPACE IN DRAIN ROCK= 40% PERCOLATION RATE = 8.00 in/hr VOLUME IN VOIDS = 515 cf PERCOLATION VOLUME = 108 cf INFILTRATION BED STORAGE = 623 cf TOTAL STORED VOLUME = 623 cf > 609 cf THEREFORE STORAGE IS ADEQUATE TIME REQUIRED TO DISSIPATE VOLUME TIME = 1 hours Mason Aseocialt" MR0622SD.xlsx SD Area 1 1 of 1 RETENTION BASIN AREA NO. 2 WORST CASE STORM VOLUME, 100-yr BASIN AREA 0.21 acres RUNOFF COEFFICIENT (C) 0.83 weighted coefficient PERCOLATION RATE 8.00 in/hr PERCOLATION AREA 184 sf SYSTEM VOID SPACE 603 cf OFFSITE DISCHARGE 0 cfs PEAK MIN. 100 YR PEAK LESS FLOW VOIDS PERC POND DURATION DURATION INTENSITY` FLOW DISCH. VOLUME VOLUME VOLUME VOLUME (min) (hrs) (in/hr) Ids) Ids) (d) (cq (d) (CO 10 0.17 3.11 0.542 0.542 325 603 20 0 15 0.25 2.62 0.457 0.457 411 603 31 0 30 0.50 1.82 0.317 0.317 571 603 61 0 60 1.00 1.16 0.200 0.200 722 603 122 0 RETENTION DESIGN BASIN TOTAL STORAGE REQ'D= 722 cf WORST CASE STORM DURATION 60 minutes OFFSITE DISCHARGE 0.00 cfs SWALE VOLUME CALCULATION SWALE TOP AREA= 1:1ft sf SWALE BOTTOM AREA= sf SWALE AVE. END AREA= sf SWALE DEPTH= SWALE STORAGE = 0 cf SWALE INFILTRATION = 0 cf PIPE VOLUME CALCULATION PIPE AREA 24" DIA= 3.14 sf PIPE LENGTH= 105 sf PIPE BARRELS= 1 0.00 PIPE STORAGE = 0 cf INFILTRATION BED CALCULATION W L INFILTRATION AREA = 184 sf ROCK 10 41 ROCK BED DEPTH = 1.8 ft SAND 10 41 SAND BED DEPTH = 3 ft VOID SPACE IN SAND= 25% VOID SPACE IN DRAIN ROCK= 40% PERCOLATION RATE = 8.00 in/hr VOLUME IN VOIDS = 603 cf PERCOLATION VOLUME = 122 cf INFILTRATION BED STORAGE = 725 cf TOTAL STORED VOLUME = 725 cf > 722 cf THEREFORE STORAGE IS ADEQUATE TIME REQUIRED TO DISSIPATE VOLUME TIME = 1 hours Mason �. A550clates", MR0622SD.xlsx SD Area 2 1 of 1 RETENTION BASIN AREA NO. 3 WORST CASE STORM VOLUME, 100-yr BASIN AREA 0.65 acres RUNOFF COEFFICIENT (C) 0.85 weighted coefficient PERCOLATION RATE 8.00 in/hr PERCOLATION AREA 450 sf SYSTEM VOID SPACE 1993 cf OFFSITE DISCHARGE 0 cfs PEAK MIN. 100 YR PEAK LESS FLOW VOIDS PERC POND DURATION DURATION INTENSITY` FLOW DISCH. VOLUME VOLUME VOLUME VOLUME (min) (hrs) (in/hr) (cfs) (cfs) (cf) (co (cf) (cQ 10 0.17 3.11 1.718 1.718 1,031 1,993 50 0 15 0.25 2.62 1.448 1.448 1,303 1,993 75 0 30 0.50 1.82 1.006 1.006 1,810 1,993 150 0 60 1.00 1.16 0.636 0.635 2,287 1,993 300 0 RETENTION DESIGN BASIN TOTAL STORAGE REQ'D= 2,287 cf WORST CASE STORM DURATION 60 minutes OFFSITE DISCHARGE 0.00 cfs SWALE VOLUME CALCULATION SWALE TOP AREA= 1:1ft sf SWALE BOTTOM AREA= sf SWALE AVE. END AREA= sf SWALE DEPTH= SWALE STORAGE = 0 cf SWALE INFILTRATION = 0 cf PIPE VOLUME CALCULATION PIPE AREA 24" DIA= 3.14 sf PIPE LENGTH= 105 sf PIPE BARRELS= 0.00 PIPE STORAGE = 0 cf INFILTRATION BED CALCULATION W L INFILTRATION AREA = 450 sf ROCK 12 113 ROCK BED DEPTH = 1.8 ft SAND 12 113 SAND BED DEPTH = 3 ft VOID SPACE IN SAND= 25% VOID SPACE IN DRAIN ROCK= 40% PERCOLATION RATE = 8.00 in/hr VOLUME IN VOIDS = 1993 cf PERCOLATION VOLUME = 300 cf INFILTRATION BED STORAGE = 2293 cf TOTAL STORED VOLUME = 2293 cf > 2287 cf THEREFORE STORAGE IS ADEQUATE TIME REQUIRED TO DISSIPATE VOLUME TIME = 1 hours Mason t Associatesij MR0622SD.xlsx SD Area 3 1 of 1 RETENTION BASIN AREA NO. 4 WORST CASE STORM VOLUME, 100-yr BASIN AREA 0.24 acres RUNOFF COEFFICIENT (C) 0.84 weighted coefficient PERCOLATION RATE 8.00 in/hr PERCOLATION AREA 259 sf SYSTEM VOID SPACE 669 cf OFFSITE DISCHARGE 0 cfs PEAK MIN. 100 YR PEAK LESS FLOW VOIDS PERC POND DURATION DURATION INTENSITY` FLOW DISCH. VOLUME VOLUME VOLUME VOLUME (min) (hrs) (in/hr) (cfs) (cfs) (cf) (cf) (cf) (co 10 0.17 3.11 0.627 0.627 376 669 29 0 15 0.25 2.62 0.528 0.528 475 669 43 0 30 0.50 1.82 0.367 0.367 660 669 86 0 60 1.00 1.15 0.232 0.232 835 669 173 0 RETENTION DESIGN BASIN TOTAL STORAGE REQ'D= 835 cf WORST CASE STORM DURATION 60 minutes OFFSITE DISCHARGE 0.00 cfs SWALE VOLUME CALCULATION SWALE TOP AREA= sf SWALE BOTTOM AREA= sf SWALE AVE. END AREA= 1:1ft sf SWALE DEPTH= SWALE STORAGE = 0 cf SWALE INFILTRATION = 0 cf PIPE VOLUME CALCULATION PIPE AREA 24" DIA= 3.14 sf PIPE LENGTH= 1051 sf PIPE BARRELS= 0.00 PIPE STORAGE = 0 cf INFILTRATION BED CALCULATION W L INFILTRATION AREA = 259 sf ROCK 7 65 ROCK BED DEPTH = 1.8 ft SAND 7 65 SAND BED DEPTH = 3 ft VOID SPACE IN SAND= 25% VOID SPACE IN DRAIN ROCK= 40% PERCOLATION RATE = 8.00 in/hr VOLUME IN VOIDS = 669 cf PERCOLATION VOLUME = 173 cf INFILTRATION BED STORAGE = 842 cf TOTAL STORED VOLUME = 842 cf > 835 cf THEREFORE STORAGE IS ADEQUATE TIME REQUIRED TO DISSIPATE VOLUME TIME = 1 hours Mason t Associates"t MR0622SD.xlsx SD Area 4 1 of 1 00 1020 Scale: i"-- o' a 0 ig .._AREA 7 AREA SURFACE5105 SF T a 900 SF I, - Ub - I S - AREA /3 HARD S RFiCE: 8,647 SF LANDSCAPE: 848 SLOPE: 2. 2R I, C U - o I j .... .. ft00F: 7775 SF 'LANDSC E Z4 9 -- RUN: 115' I - SLOPE:2 2 II RUN: 200 II Fl�, _ Lzss y W WW N 6 N �� 11 ! l i p I AREA ,{4 HARD SURFACE:5.790 SF 8 I ROOF: 3,550 SF E. 79LANDSCAP O paw 2' c-. II jI ,RUN: 55'000 �SLOPE20R AREA o s /2 --HARD SURFACE: 7,205 SF I I - — - ROOF. 900 SF CAPE: 944 <I ._LANDS SLOPE: 1.9% 't g gI 9 -- - — RUN: 110' 1 — _ I � _ S CL K w