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CC - Storm Drainage Calcs MERIDIAN, IDAHO Sky Mesa Highlands Subdivision Stormwater Drainage Report October 2020 Prepared by: V'B i J-U-B ENGINEERS, Inc. 2760 W Excursion Lane, Suite 400 Meridian, Idaho 83642 208-376-7330 web.JUB.com SITE LOCATION The project site is located on the northwest corner of the intersection of S. Eagle Road and E. Lake Hazel Road, in the SE 1/4 of Section 32, Township 3 North, Range 1 East, Boise meridian. EXISTING SITE CHARACTERISTICS The 32.9 acre project site is broken into two parts. The part north of the farm road and gravity irrigation system is partially developed. This part is graded per a previously approved grading plan. The part south of the farm road and gravity irrigation system is relatively flat irrigated farmland and slopes down-gradient to the east and north at slopes up to 5%. PROPOSED SITE IMPROVEMENTS The proposed improvements include the construction of 82 residential lots, 10 common lots, 2 common driveway lots, and associated streets, sidewalks, and infrastructure. Lot 28, Block 1, while included in the plat, is not included in these storm drain calculations. This lot is to remain separate from the subdivision and encompasses an existing residence. SOIL CONDITIONS The following geotechnical reports were referenced during design of this stormwater system. Geotechnical Evaluation, Sky Mesa Highlands Subdivision, Meridian, Idaho, dated 28 Jan 2000, prepared by ALLWEST Testing & Engineering, Inc. Groundwater Monitoring, dated July 2020, prepared by ALLWEST Testing & Engineering, Inc. According to the reports, high groundwater can be anticipated at depths from approximately 5.4-ft to over 13-ft below the existing ground surface. Based on the information provided in the geotechnical reports, the roadway finish grade centerline elevations were designed to be more than 3-ft above the anticipated groundwater elevations. Based upon the preliminary soils and subsurface investigation for this subdivision, the existing soils will accept the runoff. Seepage beds are designed based on assumed maximum infiltration rate of 8.0 inches per hour. In the event that during construction the contractor encounters groundwater or rock, or the field percolation test results are lower than the design infiltration rate, a revised design may be prepared to meet the field conditions. DRAINAGE DESIGN CONCEPT The project consists of 10 catchments labeled A through K. Catchment letter I is omitted for clarity. 4 Stormwater in catchments A through H shall flow above grade to designed low points where it shall be collected via curb inlets. The stormwater shall then pass through a pipe network and discharge into a sub-surface seep bed for infiltration through a sand filter into the groundwater network. Catchments J and K flow off-site toward a future phase stormwater system. Temporary drainage shall be provided for existing portions of this phase where the permanent storm drainage system is to be constructed as a portion of a future phase. Storm water shall flow above grade to designated low points into open channels which flow into a temporary pond. Catchment H includes the entirety of catchments J and K. Once the remaining phase is constructed, the ponds for catchments J and K will be removed and the stormwater in these two catchments shall be a part of catchment H. The storm systems in catchment H are designed to include catchments J and K. CALCULATION METHODS The site was divided into catchment areas based on the proposed grading design. These catchment areas were analyzed using the rational method to estimate the peak runoff rates in accordance with ACHD Policy Manual Sections 8000 and 8200 in effect as of August 2017. Peak storage volumes were based on the 100-year, 1-hour design storm event of 0.96 inches per hour. Peak flow rates and conveyance flow rates were calculated for each basin based on the 100-year and 25-year design storms, respectively. The time of concentration for each basin was used as the design storm duration to calculate both the peak flow and conveyance flow rates. Time of concentration values were calculated as a combination of sheet flow from the lots to the road section and gutter flow along the road. Specific equations are shown in the attached drainage calculations. The conveyance flow rate was used to size inlets and pipes and determine acceptable pipe slopes within the system. The catchment areas are shown on the Drainage Plan. Calculations are included with this report for all catchment areas. 5 Catchment A Sky Mesa Highland Project No.10-20-082 Gutter Flow Rational Method (TR-55) Sub- Elev. 1 Elev. 2 Lgutter Intercept Slope(Sp) Vgutter Tc-gutter L gutter catchment (ft) (ft) (ft) Coeff. (k) N (fps) (min) Tc-gutter = 60 V Al 2724.67 2698.59 1154 0.619 2.26 3.05 6.31 gutter A2 2703.95 2698.59 188 0.619 2.85 3.43 0.91 0.007(nL)0.8 Tc-sheet - (p2)0.SS0.4 Vgutter = 3.281kSp0'S Tc = Tc-gutter + Tc-sheet Q = CLA Sheet Flow Calculation Total T, Catchment Parameters Sub- n L P2 s Tc-sheet Tc C, Area, C2 Areal CT AreaT catchment (unitless) (ft) (in) (ft/ft) (min) (min) (ac) (ac) (ac) Al 0.24 55.0 1.2 0.01 19.1 25.4 0.50 2.52 0.50 2.52 A2 0.24 20.0 1.2 0.01 8.5 10.0 0.50 0.19 0.50 0.19 Total Area 2.71 Comp.C 0.5 Design Storm Intensities Design Storm Flow Rates Soil Parameters Sub- i2 i25 iso iloo Q2 Q25 Qso QZoo Infil. Rate 8.00 in/hr catchment (in/hr) (in/hr) (in/hr) (in/hr) (cfs) (cfs) (cfs) (cfs) (F) Al 0.43 1.14 1.35 1.57 0.54 1.44 1.70 1.98 A2 0.69 1.85 2.20 2.58 0.07 0.18 0.21 0.25 0.61 1.62 1.91 2.23 V.2020-03-17 Catchment A Sky Mesa Highland Project No.10-20-082 Seepage Bed (BMP-20) DESIGN OPTIONS ris count for 1st hr of infiltration? No the bed inside the right-of-way? No PARAMETERS Design Storm frequency 100 -year Design Storm duration 1 -hour Design Infiltration rate(Fr) 8.00 in/hr Weighted Runoff Coefficient(C) 0.50 Design Storm Inentsity(i) 0.96 in/hr Catchment Area (A) 2.71 ac Sediment factor(f)= 0 % Required Storage Volume(V100) 4,683 ft 3 Vion = C * i *A * 3600 * 1 + DESIGN Width (W)= 60 ft Depth (D)= 4.5 ft Void Ratio(e)= 40 % Vol (Ve u)= 105.2 ft3 Inlet pipe size(dl)= 18 in Qty(d1I)= 4 Vol (VP1)= 7.07 ft 3 Overflow pipe size(d2)= 12 in Qty(d2q)= 0 Vol (VP2)= 0.00 ft, Infiltration/LF(Fu)= 40.00 ft 3 Storage Vol/LF(Su)= 108.71 ft3 Vol based lenth (Lv)= 43.08 ft Drain based length (Lp)= 2.44 ft RESULTS DESIGN CHECKS Min Design Bed length (L)= 43.08 43.25 ft 368>_L>_Lmin PASS Bed Capacity(V)= 4683 4,702 cf water V>_V100 PASS Time to Drain 90%(t90)= 2.4 hr t90<_48 PASS Min infil rate (FRmin) = 0.50 0.50 in/hr OPTIONAL MULTIPLE SUB-BEDS Sub-Bed# Length Max allowed bed length= 386 ft 1 ft 2 ft 3 ft 4 ft Total Length (ILs b)= ft Single bed design EQUATIONS: Fr rc • d2 • d1g 7c• d2 •d2g F,, = W ' 12 VP1 = 48 VP2 — 48 VeU = e • ((W • D) —VP1 —VP2) Su = VeU +V21 + VP2 + Fu Vioo V100 0.9 • V100 _ 0.9 V100 Lp = S LD V= 48 F• = Sp L t90 = F•u L Fxmin — 4 W • L U a V.2020-03-17 Catchment A Sky Mesa Highland Project No.10-20-082 Pipe Sizing Allowable Limits Velocity(ft/sec) Flow depth (%) Min 3.0 0.0 Max 10.0 90.0 Minimum Pipe Slope Maximum Pipe Slope Pipe Id Design Mannings Pipe Min. V Flow Max. V Flow Flow Size Slope' Depth Slope Depth (cfs) (n) (in) (%) (fps) (%) (%) (fps) (%) CB A2 to CB Al 0.18 0.010 12 1.15 3.00 13.00 19.99 8.13 6.60 CB A2 to S&G A 1.62 0.010 12 0.22 3.04 64.24 5.57 9.99 25.98 Pipe velocity solved using the Mannings equation at the respective flow depth. Flow depth solved using itterative solutions of the Manning's equation 1.49 2 1 Q = .A . R3 . $2 n D Cr hl Y r = — h = 2r —y B = 2 arccos /I D r2(e — sin B) A r A = rc • r2 — 2 Rh = P P = 2rcr — rO h Note: 'Slightly decreased slopes may be considered where the depth of flow will be 0.3 of the diameter or greater for design average flow. (10-State Standards, Paragraph Z Maximum slopes greater than 20%require additional restraint. (10-State Standards, Paragraph 33.46) V.2020-03-17 Catchment A Sky Mesa Highland Project No.10-20-082 Sand and Grease Trap Peak Flow Design Storm 100 -year Water Quality Design Storm 25 -year Peak Flow Rate(QPeak) 2.23 cfs Water Quality Flow Rate(QWQ) 1.62 cfs QwQ = C * iwQ *A Design Calculations Vault Size= 1000 gallon Peak Throat Velocity(VPeak)= 0.33 fps No.of S&G Traps= 1 WQ Throat Velocity(v,r,,Q)= 0.24 fps Baffle Spacing= 20 inch Throat Width = 48 inch Allowed Max Flow rate(QMax,A)= 3.33 cfs Total Throat Area= 6.67 ft 2 Max Flow rate(QMax)= 2.23 cfs Bypass Flow Rate= 0 cfs Checks: VWQ<0.5 PASS Bypass Required FALSE LI LI OUTLET BAFFLE WALL EL. IN-7 FLOW EL. OUT FLOW ' t 20" INLET BAFFLE WALL Modified rom ISPWC SD-624,2017 -__-__-_____-__- Throat velocity is less than 0.5 fps. Manhole used in lieu of Sand and Grease Trap V.2020-03-17 Catchment B Sky Mesa Highland Project No.10-20-082 Gutter Flow Rational Method (TR-55) Sub- Elev. 1 Elev. 2 Lgutter Intercept Slope(Sp) Vgutter Tc-gutter L gutter catchment (ft) (ft) (ft) Coeff. (k) N (fps) (min) Tc-gutter = 60 V B 2724.67 2703.95 974 0.619 2.13 2.96 5.49 gutter 0.007(nL)0.8 Tc-sheet - W2)O.SS0.4 Vgutter = 3.281kSp0'S Tc = Tc-gutter + Tc-sheet Q = CLA Sheet Flow Calculation Total T, Catchment Parameters Sub- n L P2 s Tc-sheet Tc C, Area, CZ Areal CT AreaT catchment (unitless) (ft) (in) (ft/ft) (min) (min) (ac) (ac) (ac) B 0.24 55.0 1.2 0.01 19.1 24.5 0.50 1.46 0.50 1.46 Total Area 1.46 Comp.C 0.5 Design Storm Intensities Design Storm Flow Rates Soil Parameters Sub- i2 i25 iso iioo Q2 Q25 Qso QZoo Infil. Rate 8.00 in/hr catchment (in/hr) (in/hr) (in/hr) (in/hr) (cfs) (cfs) (cfs) (cfs) (F) B 0.44 1.15 1.37 1.60 0.32 0.84 1.00 1.17 0.32 0.84 1.00 1.17 V.2020-03-17 Catchment B Sky Mesa Highland Project No.10-20-082 Seepage Bed (BMP-20) DESIGN OPTIONS ris count for 1st hr of infiltration? No the bed inside the right-of-way? No PARAMETERS Design Storm frequency 100 -year Design Storm duration 1 -hour Design Infiltration rate(Fr) 8.00 in/hr Weighted Runoff Coefficient(C) 0.50 Design Storm Inentsity(i) 0.96 in/hr Catchment Area (A) 1.46 ac Sediment factor(f)= 0 % Required Storage Volume(V100) 2,523 ft 3 Vion = C * i *A * 3600 * 1 + DESIGN Width (W)= 15 ft Depth (D)= 4.5 ft Void Ratio(e)= 40 % Vol (Ve U)= 26.3 ft3 Inlet pipe size(dl)= 18 in Qty(d1I)= 1 Vol (VP1)= 1.77 ft 3 Overflow pipe size(d2)= 12 in Qty(d2q)= 0 Vol (VP2)= 0.00 ft, Infiltration/LF(Fu)= 10.00 ft 3 Storage Vol/LF(Su)= 27.18 ft 3 Vol based lenth (Lv)= 92.84 ft Drain based length (LO)= 5.26 ft RESULTS DESIGN CHECKS Min Design Bed length (L)= 92.84 93.00 ft 368>_L>_Lmin PASS Bed Capacity(V)= 2523 2,527 cf water V>_V100 PASS Time to Drain 90%(t90)= 2.4 hr t90<_48 PASS Min infil rate (FRmin) = 0.50 0.50 in/hr OPTIONAL MULTIPLE SUB-BEDS Sub-Bed# Length Max allowed bed length= 386 ft 1 ft 2 ft 3 ft 4 ft Total Length (ILs b)= ft Single bed design EQUATIONS: Fr rc • d2 • d1g 7c• d2 •d2g F,, = W ' 12 VP1 = 48 VP2 — 48 VeU = e • ((W • D) —VP1 —VP2) Su = VeU +V21 + VP2 + Fu Vioo V100 0.9 • V100 _ 0.9 V100 Lp = S LD V= 48 F = Sp L t90 = F•u L Fxmin — 4 W • L U a V.2020-03-17 Catchment B Sky Mesa Highland Project No.10-20-082 Pipe Sizing Allowable Limits Velocity(ft/sec) Flow depth (%) Min 3.0 0.0 Max 10.0 90.0 Minimum Pipe Slope Maximum Pipe Slope Pipe Id Design Mannings Pipe Min. V Flow Max. V Flow Flow Size Slope' Depth Slope Depth (cfs) (n) (in) (%) (fps) (%) (%) (fps) (%) CB B to S&G B 0.84 0.010 12 0.33 3.01 38.55 9.59 9.99 16.40 Pipe velocity solved using the Mannings equation at the respective flow depth. Flow depth solved using itterative solutions of the Manning's equation 1.49 2 1 Q = .A . R3 . $2 n D Cr hl Y r = — h = 2r —y B = 2 arccos /I D r2(e — sin B) R A r A = rc • r2 — 2 h = P P = 2rcr — rO h Note: 'Slightly decreased slopes may be considered where the depth of flow will be 0.3 of the diameter or greater for design average flow. (10-State Standards, Paragraph Z Maximum slopes greater than 20%require additional restraint. (10-State Standards, Paragraph 33.46) V.2020-03-17 Catchment B Sky Mesa Highland Project No.10-20-082 Sand and Grease Trap Peak Flow Design Storm 100 -year Water Quality Design Storm 25 -year Peak Flow Rate(QPeak) 1.17 cfs Water Quality Flow Rate(QWQ) 0.84 cfs QwQ = C * iwQ *A Design Calculations Vault Size= 1000 gallon Peak Throat Velocity(VPeak)= 0.18 fps No.of S&G Traps= 1 WQ Throat Velocity(vwQ)= 0.13 fps Baffle Spacing= 20 inch Throat Width = 48 inch Allowed Max Flow rate(QMax,A)= 3.33 cfs Total Throat Area= 6.67 ft 2 Max Flow rate(Qmaj= 1.17 cfs Bypass Flow Rate= 0 cfs Checks: VWQ<0.5 PASS Bypass Required FALSE LI LI OUTLET BAFFLE WALL EL. IN-7FLOW EL. OUT FLOW ' t 20" INLET BAFFLE WALL Modified rom ISPWC SD-624,2017 -__-__-_____-__- Throat velocity is less than 0.5 fps. Manhole used in lieu of Sand and Grease Trap V.2020-03-17 Catchment C Sky Mesa Highland Project No.10-20-082 Gutter Flow Rational Method (TR-55) Sub- Elev. 1 Elev. 2 Lgutter Intercept Slope(Sp) Vgutter Tc-gutter L gutter catchment (ft) (ft) (ft) Coeff. (k) N (fps) (min) Tc-gutter = 60 V C1 2703.95 2693.83 517 0.619 1.96 2.84 3.03 gutter C2 2694.67 2693.83 143 0.619 0.59 1.56 1.53 0.007(nL)0.8 Tc-sheet - (p2)0.SS0.4 Vgutter = 3.281kSp0'S Tc = Tc-gutter + Tc-sheet Q = CLA Sheet Flow Calculation Total T, Catchment Parameters Sub- n L P2 s Tc-sheet Tc C, Area, CZ Areal CT AreaT catchment (unitless) (ft) (in) (ft/ft) (min) (min) (ac) (ac) (ac) C1 0.24 64.0 1.2 0.01 21.5 24.5 0.50 0.91 0.50 0.91 C2 0.24 15.0 1.2 0.01 6.7 10.0 0.50 0.13 0.50 0.13 Total Area 1.04 Comp.C 0.5 Design Storm Intensities Design Storm Flow Rates Soil Parameters Sub- i2 i25 iso iioo Q2 Q25 Qso QZoo Infil. Rate 8.00 in/hr catchment (in/hr) (in/hr) (in/hr) (in/hr) (cfs) (cfs) (cfs) (cfs) (F) C1 0.44 1.15 1.37 1.60 0.20 0.52 0.62 0.73 C2 0.69 1.85 2.20 2.58 0.04 0.12 0.14 0.17 0.24 0.64 0.76 0.90 V.2020-03-17 Catchment C Sky Mesa Highland Project No.10-20-082 Seepage Bed (BMP-20) DESIGN OPTIONS ris count for 1st hr of infiltration? No the bed inside the right-of-way? No PARAMETERS Design Storm frequency 100 -year Design Storm duration 1 -hour Design Infiltration rate(Fr) 8.00 in/hr Weighted Runoff Coefficient(C) 0.50 Design Storm Inentsity(i) 0.96 in/hr Catchment Area (A) 1.04 ac Sediment factor(f)= 0 % Required Storage Volume(V100) 1,798 ft 3 V = C * i *A * 3600 * 1 + DESIGN Width (W)= 4 ft Depth (D)= 4.5 ft Void Ratio(e)= 40 % Vol (Ve U)= 6.5 ft 3 Inlet pipe size(d1)= 18 in Qty(d1I)= 1 Vol (VP1)= 1.77 ft 3 Overflow pipe size(d2)= 12 in Qty(d2,)= 0 Vol (VP2)= 0.00 ft, Infiltration/LF(Fu)= 2.67 ft 3 Storage Vol/LF(S,)= 7.38 ft 3 Vol based lenth (Lv)= 243.74 ft Drain based length (LO)= 14.03 ft RESULTS DESIGN CHECKS Min Design Bed length (L)= 243.74 244.00 ft 368>_L>_Lmin PASS Bed Capacity(V)= 1798 1,800 cf water V>_V100 PASS Time to Drain 90%(t90)= 2.5 hr t90<_48 PASS Min infil rate (FRmin) = 0.50 0.50 in/hr OPTIONAL MULTIPLE SUB-BEDS Sub-Bed# Length Max allowed bed length= 386 ft 1 ft 2 ft 3 ft 4 ft Total Length (ILs b)= ft Single bed design EQUATIONS: Fr rc • d2 • d1g 7c• d2 •d2g F,, = W ' 12 VP1 = 48 VP2 — 48 VeU = e • ((W • D) —VP1 —VP2) Su = VeU +V21 + VP2 + Fu Vioo V100 0.9 • V100 _ 0.9 V100 Lp = S LD V= 48 F = Sp L t90 = F•u L Fxmin — 4 W • L U a V.2020-03-17 Catchment C Sky Mesa Highland Project No.10-20-082 Pipe Sizing Allowable Limits Velocity(ft/sec) Flow depth (%) Min 3.0 0.0 Max 10.0 90.0 Minimum Pipe Slope Maximum Pipe Slope Pipe Id Design Mannings Pipe Min. V Flow Max. V Flow Flow Size Slope' Depth Slope Depth (cfs) (n) (in) (%) (fps) (%) (%) (fps) (%) CB C2 to CB C1 0.12 0.010 12 1.63 3.00 9.85 19.99 7.19 5.45 CB C1 to S&G C 0.64 0.010 12 0.41 3.02 31.51 12.08 9.99 13.59 Pipe velocity solved using the Mannings equation at the respective flow depth. Flow depth solved using itterative solutions of the Manning's equation 1.49 2 1 Q = .A . R3 . $2 n D Cr hl Y r = — h = 2r —y B = 2 arccos /I D r2(9 — sin B) A r � A = rc • r2 — 2 Rh = P P = 2rcr — rO h Note: 'Slightly decreased slopes may be considered where the depth of flow will be 0.3 of the diameter or greater for design average flow. (10-State Standards, Paragraph Z Maximum slopes greater than 20%require additional restraint. (10-State Standards, Paragraph 33.46) V.2020-03-17 Catchment C Sky Mesa Highland Project No.10-20-082 Sand and Grease Trap Peak Flow Design Storm 100 -year Water Quality Design Storm 25 -year Peak Flow Rate(QPeak) 0.90 cfs Water Quality Flow Rate(QWQ) 0.64 cfs QwQ = C * iwQ *A Design Calculations Vault Size= 1000 gallon Peak Throat Velocity(VPeak)= 0.14 fps No.of S&G Traps= 1 WQ Throat Velocity(vwQ)= 0.10 fps Baffle Spacing= 20 inch Throat Width = 48 inch Allowed Max Flow rate(QMax,A)= 3.33 cfs Total Throat Area= 6.67 ft 2 Max Flow rate(Qmaj= 0.90 cfs Bypass Flow Rate= 0 cfs Checks: VWQ<0.5 PASS Bypass Required FALSE LI LI OUTLET BAFFLE WALL EL. IN-7FLOW EL. OUT FLOW ' t 20" INLET BAFFLE WALL Modified rom ISPWC SD-624,2017 -__-__-_____-__- Throat velocity is less than 0.5 fps. Manhole used in lieu of Sand and Grease Trap V.2020-03-17 Catchment D Sky Mesa Highland Project No.10-20-082 Gutter Flow Rational Method (TR-55) Sub- Elev. 1 Elev. 2 Lgutter Intercept Slope(Sp) Vgutter Tc-gutter L gutter catchment (ft) (ft) (ft) Coeff. (k) N (fps) (min) Tc-gutter = 60 V D1 2724.67 2697.83 1035 0.619 2.59 3.27 5.28 gutter D2 2724.67 2697.83 1048 0.619 2.56 3.25 5.37 0.007(nL)0.8 Tc-sheet - (p2)0.SS0.4 Vgutter = 3.281kSp0'S Tc = Tc-gutter + Tc-sheet Q = CLA Sheet Flow Calculation Total T, Catchment Parameters Sub- n L P2 s Tc-sheet Tc C, Area, C2 Areal CT AreaT catchment (unitless) (ft) (in) (ft/ft) (min) (min) (ac) (ac) (ac) D1 0.24 80.0 1.2 0.01 25.7 31.0 0.50 2.76 0.50 2.76 D2 0.24 72.0 1.2 0.01 23.6 29.0 0.50 1.73 0.50 1.73 Total Area 4.49 Comp.C 0.5 Design Storm Intensities Design Storm Flow Rates Soil Parameters Sub- i2 i25 i50 iioo Q2 Q25 Qso QZoo Infil. Rate 8.00 in/hr catchment (in/hr) (in/hr) (in/hr) (in/hr) (cfs) (cfs) (cfs) (cfs) (F) D1 0.40 1.04 1.25 1.46 0.55 1.44 1.73 2.01 D2 0.41 1.09 1.30 1.52 0.35 0.94 1.12 1.31 0.90 2.38 2.85 3.32 V.2020-03-17 Catchment D Sky Mesa Highland Project No.10-20-082 Seepage Bed (BMP-20) DESIGN OPTIONS ris count for 1st hr of infiltration? No the bed inside the right-of-way? No PARAMETERS Design Storm frequency 100 -year Design Storm duration 1 -hour Design Infiltration rate(Fr) 8.00 in/hr Weighted Runoff Coefficient(C) 0.50 Design Storm Inentsity(i) 0.96 in/hr Catchment Area (A) 4.49 ac Sediment factor(f)= 0 % Required Storage Volume(V100) 7,759 ft 3 Vion = C * i *A * 3600 * 1 + DESIGN Width (W)= 33.5 ft Depth (D)= 6 ft Void Ratio(e)= 40 % Vol (Ve U)= 79.0 ft 3 Inlet pipe size(dl)= 18 in Qty(d1I)= 2 Vol (VP1)= 3.53 ft 3 Overflow pipe size(d2)= 12 in Qty(d2,)= 0 Vol (VP2)= 0.00 ft3 Infiltration/LF(Fu)= 22.33 ft 3 Storage Vol/LF(Su)= 80.75 ft 3 Vol based lenth (Lv)= 96.08 ft Drain based length (Lp)= 7.24 ft RESULTS DESIGN CHECKS Min Design Bed length (L)= 96.08 96.50 ft 368>_L>_Lmin PASS Bed Capacity(V)= 7759 7,793 cf water V>_V100 PASS Time to Drain 90%(t90)= 3.2 hr t90<_48 PASS Min infil rate (FRmin) = 0.50 0.54 in/hr OPTIONAL MULTIPLE SUB-BEDS Sub-Bed# Length Max allowed bed length= 386 ft 1 ft 2 ft 3 ft 4 ft Total Length (ILs b)= ft Single bed design EQUATIONS: Fr rc • d2 • d1g 7c• d2 •d2g F,, = W ' 12 VP1 = 48 VP2 — 48 VeU = e • ((W • D) —VP1 —VP2) Su = VeU +V21 + VP2 + Fu Vioo V100 0.9 • V100 _ 0.9 V100 Lp = S LD V= 48 F• = Sp L t90 = F•u L Fxmin — 4 W • L U a V.2020-03-17 Catchment D Sky Mesa Highland Project No.10-20-082 Pipe Sizing Allowable Limits Velocity(ft/sec) Flow depth (%) Min 3.0 0.0 Max 10.0 90.0 Minimum Pipe Slope Maximum Pipe Slope Pipe Id Design Mannings Pipe Min. V Flow Max. V Flow Flow Size Slope' Depth Slope Depth (cfs) (n) (in) (%) (fps) (%) (%) (fps) (%) CB D1 to SDMH D2 1.44 0.010 12 0.23 3.02 58.53 6.12 9.99 23.91 CB D2 to SDMH D2 0.94 0.010 12 0.31 3.03 41.70 8.72 9.99 17.73 SDMH D2 through S&G D 2.38 0.010 12 0.24 3.28 86.87 4.10 9.99 34.30 Pipe velocity solved using the Mannings equation at the respective flow depth. Flow depth solved using itterative solutions of the Manning's equation 1.49 2 1 Q = .A . R3 . $2 n D Cr hl Y r = — h = 2r —y B = 2 arccos /I D r2(e — sin B) R A r A = rc • r2 — 2 h = P P = 2rcr — rO h Note: 'Slightly decreased slopes may be considered where the depth of flow will be 0.3 of the diameter or greater for design average flow. (10-State Standards, Paragraph Z Maximum slopes greater than 20%require additional restraint. (10-State Standards, Paragraph 33.46) V.2020-03-17 Catchment D Sky Mesa Highland Project No.10-20-082 Sand and Grease Trap Peak Flow Design Storm 100 -year Water Quality Design Storm 25 -year Peak Flow Rate(QPeak) 3.32 cfs Water Quality Flow Rate(QWQ) 2.38 cfs QwQ = C * iwQ *A Design Calculations Vault Size= 1000 gallon Peak Throat Velocity(VPeak)= 0.50 fps No.of S&G Traps= 1 WQ Throat Velocity(vwQ)= 0.36 fps Baffle Spacing= 20 inch Throat Width = 48 inch Allowed Max Flow rate(QMax,A)= 3.33 cfs Total Throat Area= 6.67 ft 2 Max Flow rate(Qmaj= 3.32 cfs Bypass Flow Rate= 0 cfs Checks: VWQ<0.5 PASS Bypass Required FALSE LI LI OUTLET BAFFLE WALL EL. OUT EL. IN-7FLOW FL.. INLET BAFFLE WALL Modified rom ISPWC SO-624,2017 V.2020-03-17 Catchment E Sky Mesa Highland Project No.10-20-082 Gutter Flow Rational Method (TR-55) Sub- Elev. 1 Elev. 2 Lgutter Intercept Slope(Sp) Vgutter Tc-gutter L gutter catchment (ft) (ft) (ft) Coeff. (k) N (fps) (min) Tc-gutter = 60 V E 2698.43 2695.11 456 0.619 0.73 1.74 4.37 gutter 0.007(nL)0.8 Tc-sheet - W2)O.SS0.4 Vgutter = 3.281kSp0'S Tc = Tc-gutter + Tc-sheet Q = CLA Sheet Flow Calculation Total T, Catchment Parameters Sub- n L P2 s Tc-sheet Tc C, Area, CZ Areal CT AreaT catchment (unitless) (ft) (in) (ft/ft) (min) (min) (ac) (ac) (ac) E 0.24 75.0 1.2 0.01 24.4 28.8 0.50 1.70 0.50 1.70 Total Area 1.7 Comp.C 0.5 Design Storm Intensities Design Storm Flow Rates Soil Parameters Sub- i2 i25 iso iioo Q2 Q25 Qso QZoo Infil. Rate 8.00 in/hr catchment (in/hr) (in/hr) (in/hr) (in/hr) (cfs) (cfs) (cfs) (cfs) (F) E 0.41 1.09 1.30 1.53 0.35 0.93 1.11 1.30 0.35 0.93 1.11 1.30 V.2020-03-17 Catchment E Sky Mesa Highland Project No.10-20-082 Seepage Bed (BMP-20) DESIGN OPTIONS ris count for 1st hr of infiltration? Yes the bed inside the right-of-way? Yes PARAMETERS Design Storm frequency 100 -year Design Storm duration 1 -hour Design Infiltration rate(Fr) 8.00 in/hr Weighted Runoff Coefficient(C) 0.50 Design Storm Inentsity(i) 0.96 in/hr Catchment Area (A) 1.70 ac Sediment factor(f)= 25 % Required Storage Volume(V100) 3,672 ft 3 Vion = C * i *A * 3600 * 1 + DESIGN Width (W)= 17.5 ft Depth (D)= 3.5 ft Void Ratio(e)= 40 % Vol (Ve U)= 23.8 ft 3 Inlet pipe size(dl)= 18 in Qty(d1I)= 1 Vol (VP1)= 1.77 ft 3 Overflow pipe size(d2)= 12 in Qty(d2q)= 0 Vol (VP2)= 0.00 ft3 Infiltration/LF(Fu)= 11.67 ft 3 Storage Vol/LF(Su)= 36.35 ft 3 Vol based lenth (Lv)= 101.03 ft Drain based length (LO)= 6.56 ft RESULTS DESIGN CHECKS Min Design Bed length (L)= 101.03 102.00 ft 368>_L>_Lmin PASS Bed Capacity(V)= 3672 3,707 cf water V>_V100 PASS Time to Drain 90%(t90)= 2.8 hr t90<_48 PASS Min infil rate (FRmin) = 0.50 0.50 in/hr OPTIONAL MULTIPLE SUB-BEDS Sub-Bed# Length Max allowed bed length= 386 ft 1 ft 2 ft 3 ft 4 ft Total Length (ILs b)= ft Single bed design EQUATIONS: Fr rc • d2 • d1g 7c• d2 •d2g F,, = W ' 12 VP1 = 48 VP2 — 48 VeU = e • ((W • D) —VP1 —VP2) Su = VeU +V21 + VP2 + Fu Vioo V100 0.9 • V100 _ 0.9 V100 Lp = S LD V= 48 F = Sp L t90 = F•u L Fxmin — 4 W • L U a V.2020-03-17 Catchment E Sky Mesa Highland Project No.10-20-082 Pipe Sizing Allowable Limits Velocity(ft/sec) Flow depth (%) Min 3.0 0.0 Max 10.0 90.0 Minimum Pipe Slope Maximum Pipe Slope Pipe Id Design Mannings Pipe Min. V Flow Max. V Flow Flow Size Slope' Depth Slope Depth (cfs) (n) (in) (%) (fps) (%) (%) (fps) (%) CB E through S&G E 0.93 0.010 12 0.31 3.02 41.46 8.80 9.99 17.60 Pipe velocity solved using the Mannings equation at the respective flow depth. Flow depth solved using itterative solutions of the Manning's equation 1.49 2 1 Q = .A . R3 . $2 n D Cr hl Y r = — h = 2r —y B = 2 arccos /I D r2(e — sin B) A r A = rc • r2 — 2 Rh = P P = 2rcr — rO h Note: 'Slightly decreased slopes may be considered where the depth of flow will be 0.3 of the diameter or greater for design average flow. (10-State Standards, Paragraph Z Maximum slopes greater than 20%require additional restraint. (10-State Standards, Paragraph 33.46) V.2020-03-17 Catchment E Sky Mesa Highland Project No.10-20-082 Sand and Grease Trap Peak Flow Design Storm 100 -year Water Quality Design Storm 25 -year Peak Flow Rate(QPeak) 1.30 cfs Water Quality Flow Rate(QWQ) 0.93 cfs QwQ = C * iwQ *A Design Calculations Vault Size= 1000 gallon Peak Throat Velocity(VPeak)= 0.20 fps No.of S&G Traps= 1 WQ Throat Velocity(vwQ)= 0.14 fps Baffle Spacing= 20 inch Throat Width = 48 inch Allowed Max Flow rate(QMax,A)= 3.33 cfs Total Throat Area= 6.67 ft 2 Max Flow rate(Qmaj= 1.30 cfs Bypass Flow Rate= 0 cfs Checks: VWQ<0.5 PASS Bypass Required FALSE LI LI OUTLET BAFFLE WALL EL. IN-7 FLOW EL. OUT FLOW ' t 20" INLET BAFFLE WALL Modified rom ISPWC SD-624,2017 -__-__-_____-__- Throat velocity is less than 0.5 fps. Manhole used in lieu of Sand and Grease Trap V.2020-03-17 Catchment F Sky Mesa Highland Project No.10-20-082 Gutter Flow Rational Method (TR-55) Sub- Elev. 1 Elev. 2 Lgutter Intercept Slope(Sp) Vgutter Tc-gutter L gutter catchment (ft) (ft) (ft) Coeff. (k) N (fps) (min) Tc-gutter = 60 V F 2694.57 2692.76 251 0.619 0.72 1.72 2.43 gutter 0.007(nL)0.8 Tc-sheet - W2)O.SS0.4 Vgutter = 3.281kSp0'S Tc = Tc-gutter + Tc-sheet Q = CLA Sheet Flow Calculation Total T, Catchment Parameters Sub- n L P2 s Tc-sheet Tc C, Area, C2 Areal CT AreaT catchment (unitless) (ft) (in) (ft/ft) (min) (min) (ac) (ac) (ac) F 0.24 75.0 1.2 0.01 24.4 26.9 0.50 1.85 0.50 1.85 Total Area 1.85 Comp.C 0.5 Design Storm Intensities Design Storm Flow Rates Soil Parameters Sub- i2 i25 iso iioo Q2 Q25 Qso QZoo Infil. Rate 8.00 in/hr catchment (in/hr) (in/hr) (in/hr) (in/hr) (cfs) (cfs) (cfs) (cfs) (F) F 0.42 1.12 1.33 1.55 0.39 1.04 1.23 1.43 0.39 1.04 1.23 1.43 V.2020-03-17 Catchment F Sky Mesa Highland Project No.10-20-082 Vertical Sand Filter (BMP-21) DESIGN OPTIONS ris count for 1st hr of infiltration? Yes the bed inside the right-of-way? No PARAMETERS Design Storm frequency 100 2 -year Design Storm duration 1 1 -hour Design Infiltration rate(Fr) 8.00 8.00 in/hr Weighted Runoff Coefficient(C) 0.50 0.50 Design Storm Inentsity(i) 0.96 0.26 in/hr Catchment Area (A) 1.85 1.85 ac Required Storage Volume(VRe ) 3,197 866 ft 3 V100 = C * i *A * 3600 DESIGN Length (L)= 100 ft Depth (D)= 3.5 ft Void Ratio(e)= 40 Primary pipe size (dl)= 12 in Qty(d1q)= 1 Vol (VP1)= 78.53 ft3 Overflow pipe size(d2)= 18 in Qty(d2 )= 1 Vol (VP2)= 176.71 ft 3 RESULTS DESIGN CHECKS Min Design Chamber 1 Width (WI)= 6.13 6.50 ft Chamber 2 Width (W2)= 15.39 15.50 ft Total width= 23.02 23.50 ft Ch 1 Req Vol (Vregl)= 866 cf water Ch 1 Vol (V1)= 866 918 cf water V2>_VRegz PASS Ch 2 Req Vol (Vreg2)= 2,171 cf water Ch 2 Vol (V2)= 2,172 2,188 cf water V1>VReg100 PASS Time to Drain 90%(t90)= 44.6 hr t90<_48 PASS Min infil rate(FRm;,,)= 0.50 0.50 in/hr FRmin?0.5 PASS V.2020-03-17 Catchment F Sky Mesa Highland Project No.10-20-082 Pipe Sizing Allowable Limits Velocity(ft/sec) Flow depth (%) Min 3.0 0.0 Max 10.0 90.0 Minimum Pipe Slope Maximum Pipe Slope Pipe Id Design Mannings Pipe Min. V Flow Max. V Flow Flow Size Slope' Depth Slope Depth (cfs) (n) (in) (%) (fps) (%) (%) (fps) (%) CB F to S&G F 1.04 0.010 12 0.28 3.00 45.41 8.01 9.99 19.02 Pipe velocity solved using the Mannings equation at the respective flow depth. Flow depth solved using itterative solutions of the Manning's equation 1.49 2 1 Q = .A . R3 . $2 n D Cr hl Y r = — h = 2r —y B = 2 arccos /I D r2(e — sin B) R A r A = rc • r2 — 2 h = P P = 2rcr — rO h Note: 'Slightly decreased slopes may be considered where the depth of flow will be 0.3 of the diameter or greater for design average flow. (10-State Standards, Paragraph Z Maximum slopes greater than 20%require additional restraint. (10-State Standards, Paragraph 33.46) V.2020-03-17 Catchment F Sky Mesa Highland Project No.10-20-082 Sand and Grease Trap Peak Flow Design Storm 100 -year Water Quality Design Storm 25 -year Peak Flow Rate(QPeak) 1.43 cfs Water Quality Flow Rate(QWQ) 1.04 cfs QwQ = C * iwQ *A Design Calculations Vault Size= 1000 gallon Peak Throat Velocity(VPeak)= 0.21 fps No.of S&G Traps= 1 WQ Throat Velocity(vwQ)= 0.16 fps Baffle Spacing= 20 inch Throat Width = 48 inch Allowed Max Flow rate(QMax,A)= 3.33 cfs Total Throat Area= 6.67 ft 2 Max Flow rate(Qmaj= 1.43 cfs Bypass Flow Rate= 0 cfs Checks: VWQ<0.5 PASS Bypass Required FALSE LI LI OUTLET BAFFLE WALL EL. IN-7FLOW EL. OUT FLOW ' t 20" INLET BAFFLE WALL Modified rom ISPWC SD-624,2017 -__-__-_____-__- Throat velocity is less than 0.5 fps. Manhole used in lieu of Sand and Grease Trap V.2020-03-17 Catchment G Sky Mesa Highland Project No.10-20-082 Gutter Flow Rational Method (TR-55) Sub- Elev. 1 Elev. 2 Lgutter Intercept Slope(Sp) Vgutter Tc-gutter L gutter catchment (ft) (ft) (ft) Coeff. (k) N (fps) (min) Tc-gutter = 60 V G1 2697.83 2694.00 732 0.619 0.52 1.46 8.36 gutter G2 2694.69 2694.00 139 0.619 0.50 1.44 1.61 0.007(nL)0.8 Tc-sheet - (p2)0.SS0.4 Vgutter = 3.281kSp0'S Tc = Tc-gutter + Tc-sheet Q = CLA Sheet Flow Calculation Total T, Catchment Parameters Sub- n L P2 s Tc-sheet Tc C, Area, CZ Areal CT AreaT catchment (unitless) (ft) (in) (ft/ft) (min) (min) (ac) (ac) (ac) G1 0.24 75.0 1.2 0.01 24.4 32.8 0.50 2.63 0.50 2.63 G2 0.24 75.0 1.2 0.01 24.4 26.0 0.50 0.53 0.50 0.53 Total Area 3.16 Comp.C 0.5 Design Storm Intensities Design Storm Flow Rates Soil Parameters Sub- i2 i25 i50 iloo Q2 Q25 Qso Q100 Infil. Rate 8.00 in/hr catchment (in/hr) (in/hr) (in/hr) (in/hr) (cfs) (cfs) (cfs) (cfs) (F) G1 0.37 0.98 1.17 1.37 0.49 1.29 1.54 1.80 G2 0.43 1.13 1.34 1.57 0.11 0.30 0.36 0.42 0.60 1.59 1.90 2.22 V.2020-03-17 Catchment G Sky Mesa Highland Project No.10-20-082 Seepage Bed (BMP-20) DESIGN OPTIONS ris count for 1st hr of infiltration? Yes the bed inside the right-of-way? Yes PARAMETERS Design Storm frequency 100 -year Design Storm duration 1 -hour Design Infiltration rate(Fr) 8.00 in/hr Weighted Runoff Coefficient(C) 0.50 Design Storm Inentsity(i) 0.96 in/hr Catchment Area (A) 3.16 ac Sediment factor(f)= 25 % Required Storage Volume(V,00) 6,826 ft3 V = C * i *A * 3600 * 1 + DESIGN Width (W)= 12.5 ft Depth (D)= 3.25 ft Void Ratio(e)= 40 % Vol (Ve U)= 15.5 ft3 Inlet pipe size(dl)= 18 in Qty(d1I)= 1 Vol (VPJ)= 1.77 ft3 Overflow pipe size(d2)= 12 in Qty(d2q)= 0 Vol (VP2)= 0.00 ft3 Infiltration/LF(Fu)= 8.33 ft3 Storage Vol/LF(Su)= 24.76 ft3 Vol based lenth (Lv)= 275.72 ft Drain based length (LO)= 17.07 ft RESULTS DESIGN CHECKS Min Design Bed length (L)= 275.72 277.00 ft 368>_L>_Lmin PASS Bed Capacity(V)= 6826 6,858 cf water V>_V100 PASS Time to Drain 90%(t90)= 2.7 hr t90<_48 PASS Min infil rate (FRmin) = 0.50 0.50 in/hr OPTIONAL MULTIPLE SUB-BEDS Sub-Bed# Length (ft) Volume(ft) Max allowed bed length= 386 ft 1 172 4,258 2 105 2,599 3 4 Total Length (ILs b)= 277 6,857 No volume match EQUATIONS: F,. rc • di dlq rc d2 d2q Fu — W 12 VP1 — 48 VP2 — 48 Veu = e • ((W • D) —VP1 —VP2) Su V= VU + Zl + VP2 + Fu _ 0.9 • V 0.9 Vioo S Lv _Uoo Lo __ 48?00 V — SU L t90 F o FRmin — 4 W L U U U L V.2020-03-17 Catchment G Sky Mesa Highland Project No.10-20-082 Pipe Sizing Allowable Limits Velocity(ft/sec) Flow depth (%) Min 3.0 0.0 Max 10.0 90.0 Minimum Pipe Slope Maximum Pipe Slope Pipe Id Design Mannings Pipe Min. V Flow Max. V Flow Flow Size Slope' Depth Slope Depth (cfs) (n) (in) (%) (fps) (%) (%) (fps) (%) CB G2 to CB G1 0.30 0.010 12 0.75 3.00 18.48 19.99 9.49 8.40 CB G1 through S&G G 1.59 0.010 12 0.22 3.03 63.42 5.65 9.99 25.64 Pipe velocity solved using the Mannings equation at the respective flow depth. Flow depth solved using itterative solutions of the Manning's equation 1.49 2 1 Q = .A . R3 . $2 n D Cr hl Y r = — h = 2r —y B = 2 arccos /I D r2(9 — sin B) A r � A = rc • r2 — 2 Rh = P P = 2rcr — rO h Note: 'Slightly decreased slopes may be considered where the depth of flow will be 0.3 of the diameter or greater for design average flow. (10-State Standards, Paragraph Z Maximum slopes greater than 20%require additional restraint. (10-State Standards, Paragraph 33.46) V.2020-03-17 Catchment G Sky Mesa Highland Project No.10-20-082 Sand and Grease Trap Peak Flow Design Storm 100 -year Water Quality Design Storm 25 Peak Flow Rate(QPeak) 2.22 in/hr Water Quality Flow Rate(QWQ) 1.59 ac QwQ = C * iwQ *A Design Calculations Vault Size= 1000 gallon Peak Throat Velocity(VPeak)= 0.33 fps No.of S&G Traps= 1 WQ Throat Velocity(v,r,,Q)= 0.24 fps Baffle Spacing= 20 inch Throat Width = 48 inch Allowed Max Flow rate(QMax,A)= 3.33 cfs Total Throat Area= 6.67 ft 2 Max Flow rate(QMax)= 2.22 cfs Bypass Flow Rate= 0 cfs Checks: VWQ<0.5 PASS Bypass Required FALSE LI LI OUTLET BAFFLE WALL EL. IN-7 FLOW EL. OUT FLOW ' t 20" INLET BAFFLE WALL Modified rom ISPWC SD-624,2017 -__-__-_____-__- Throat velocity is less than 0.5 fps. Manhole used in lieu of Sand and Grease Trap V.2020-03-17 Catchment H Sky Mesa Highland Project No.10-20-082 Gutter Flow Rational Method (TR-55) Sub- Elev. 1 Elev. 2 Lgutter Intercept Slope(Sp) Vgutter Tc-gutter L gutter catchment (ft) (ft) (ft) Coeff. (k) N (fps) (min) Tc-gutter = 60 V H1 2693.74 2688.72 576 0.619 0.87 1.89 5.08 gutter H2 2691.36 2688.72 414 0.619 0.64 1.62 4.26 0.007(nL)0.8 Tc-sheet - (p2)0.SS0.4 Vgutter = 3.281kSp0'S Tc = Tc-gutter + Tc-sheet Q = CLA Sheet Flow Calculation Total T, Catchment Parameters Sub- n L P2 s Tc-sheet Tc C, Area, CZ Areal CT AreaT catchment (unitless) (ft) (in) (ft/ft) (min) (min) (ac) (ac) (ac) H 1 0.24 65.0 1.2 0.01 21.8 26.9 0.50 1.50 0.50 1.50 H2 O.24 60.0 1.2 0.01 20.4 24.7 0.50 1.14 0.50 1.14 Total Area 2.64 Comp.C 0.5 Design Storm Intensities Design Storm Flow Rates Soil Parameters Sub- i2 i25 iso iloo Q2 Q25 Qso QZoo Infil. Rate 8.00 in/hr catchment (in/hr) (in/hr) (in/hr) (in/hr) (cfs) (cfs) (cfs) (cfs) (F) H1 0.42 1.12 1.33 1.55 0.32 0.84 1.00 1.16 H2 O.43 1.15 1.36 1.59 0.25 0.66 0.78 0.91 0.57 1.50 1.78 2.07 V.2020-03-17 Catchment H Sky Mesa Highland Project No.10-20-082 Seepage Bed (BMP-20) DESIGN OPTIONS ris count for 1st hr of infiltration? No the bed inside the right-of-way? No PARAMETERS Design Storm frequency 100 -year Design Storm duration 1 -hour Design Infiltration rate(Fr) 8.00 in/hr Weighted Runoff Coefficient(C) 0.50 Design Storm Inentsity(i) 0.96 in/hr Catchment Area (A) 2.64 ac Sediment factor(f)= 0 % Required Storage Volume(V100) 4,562 ft 3 Vion = C * i *A * 3600 * 1 + DESIGN Width (W)= 30 ft Depth (D)= 4.5 ft Void Ratio(e)= 40 % Vol (Ve U)= 52.6 ft 3 Inlet pipe size(dl)= 18 in Qty(d1I)= 2 Vol (VP1)= 3.53 ft 3 Overflow pipe size(d2)= 12 in Qty(d2q)= 0 Vol (VP2)= 0.00 ft3 Infiltration/LF(Fu)= 20.00 ft 3 Storage Vol/LF(Su)= 54.35 ft 3 Vol based lenth (Lv)= 83.93 ft Drain based length (Lp)= 4.75 ft RESULTS DESIGN CHECKS Min Design Bed length (L)= 83.93 84.00 ft 368>_L>_Lmin PASS Bed Capacity(V)= 4562 4,566 cf water V>_V100 PASS Time to Drain 90%(t90)= 2.4 hr t90<_48 PASS Min infil rate (FRmin) = 0.50 0.50 in/hr OPTIONAL MULTIPLE SUB-BEDS Sub-Bed# Length Max allowed bed length= 386 ft 1 ft 2 ft 3 ft 4 ft Total Length (ILs b)= ft Single bed design EQUATIONS: Fr rc • d2 • d1g 7c• d2 •d2g F,, = W ' 12 VP1 = 48 VP2 — 48 VeU = e • ((W • D) —VP1 —VP2) Su = VeU +V21 + VP2 + Fu Vioo V100 0.9 • V100 _ 0.9 V100 Lp = S LD V= 48 F• = Sp L t90 = F•u L Fxmin — 4 W • L U a V.2020-03-17 Catchment H Sky Mesa Highland Project No.10-20-082 Pipe Sizing Allowable Limits Velocity(ft/sec) Flow depth (%) Min 3.0 0.0 Max 10.0 90.0 Minimum Pipe Slope Maximum Pipe Slope Pipe Id Design Mannings Pipe Min. V Flow Max. V Flow Flow Size Slope' Depth Slope Depth (cfs) (n) (in) (%) (fps) (%) (%) (fps) (%) CB H1 to SDMH H5 0.84 0.010 12 0.33 3.01 38.55 9.59 9.99 a16 16.40 CB H2 to SDMH H5 0.66 0.010 12 0.40 3.02 32.22 11.76 9.99 1113.89 CB H3 to SDMH H7 0.42 0.010 12 0.57 3.01 23.37 17.33 9.99 1110.19 CB H4 to SDMH H7 0.08 0.010 12 2.31 3.00 7.49 19.99 6.35 1 4.51 SDMH H5 to SDMH H4 1.50 0.010 12 0.23 3.04 60.10 5.92 9.99 1124.61 SDMH H7 to SDMH H4 0.50 0.010 12 0.49 3.00 26.51 14.92 9.99 1111.48 SDMH H4 to Bed H 2.00 0.010 12 0.22 3.15 75.45 4.70 9.99 1130.22 Pipe velocity solved using the Mannings equation at the respective flow depth. Flow depth solved using itterative solutions of the Manning's equation 1.49 2 1 Q = .A . R3 . $2 n D Cr hl Y r = - h = 2r -y B = 2 arccos /I _ r2(e - sin B) R A r A = rc • r2 - 2 h = P P = 2rcr - rO h Note: 'Slightly decreased slopes may be considered where the depth of flow will be 0.3 of the diameter or greater for design average flow. (10-State Standards, Paragraph Z Maximum slopes greater than 20%require additional restraint. (10-State Standards, Paragraph 33.46) V.2020-03-17 Catchment H Sky Mesa Highland Project No.10-20-082 Sand and Grease Trap Peak Flow Design Storm 100 -year Water Quality Design Storm 25 -year Peak Flow Rate(QPeak) 2.07 cfs Water Quality Flow Rate(QWQ) 1.50 cfs QwQ = C * iwQ *A Design Calculations Vault Size= 1000 gallon Peak Throat Velocity(VPeak)= 0.31 fps No.of S&G Traps= 1 WQ Throat Velocity(vwQ)= 0.23 fps Baffle Spacing= 20 inch Throat Width = 48 inch Allowed Max Flow rate(QMax,A)= 3.33 cfs Total Throat Area= 6.67 ft 2 Max Flow rate(Qmaj= 2.07 cfs Bypass Flow Rate= 0 cfs Checks: VWQ<0.5 PASS Bypass Required FALSE LI LI OUTLET BAFFLE WALL EL. IN-7FLOW EL. OUT FLOW ' t 20" INLET BAFFLE WALL Modified rom ISPWC SD-624,2017 -__-__-_____-__- Throat velocity is less than 0.5 fps. Manhole used in lieu of Sand and Grease Trap V.2020-03-17 Catchment J Sky Mesa Highland Project No.10-20-082 Gutter Flow Rational Method (TR-55) Sub- Elev. 1 Elev. 2 Lgutter Intercept Slope(Sp) Vgutter Tc-gutter L gutter catchment (ft) (ft) (ft) Coeff. (k) N (fps) (min) Tc—gutter = J 0.619 60 • Vgutter 0.007(nL)0.8 Tc—sheet — W2)O.SS0.4 Vgutter = 3.281kSO--' Tc = Tc—gutter + Tc—sheet Q = CLA Sheet Flow Calculation Total T, Catchment Parameters Sub- n L P2 s Tc-sheet Tc C, Area, CZ Areal CT AreaT catchment (unitless) (ft) (in) (ft/ft) (min) (min) (ac) (ac) (ac) J 0.24 20.0 1.2 0.01 8.5 10.0 0.50 0.02 0.50 0.02 Total Area 0.02 Comp.C 0.5 Design Storm Intensities Design Storm Flow Rates Soil Parameters Sub- i2 i25 iso iioo Q2 Q25 Qso QZoo Infil. Rate 8.00 in/hr catchment (in/hr) (in/hr) (in/hr) (in/hr) (cfs) (cfs) (cfs) (cfs) (F) J 0.69 1.85 2.20 2.58 0.01 0.02 0.02 0.03 0.01 0.02 0.02 0.03 V.2020-03-17 Catchment J Sky Mesa Highland Project No.10-20-082 Pond Design Storm frequency 100 -year Design Storm duration 60 -minutes Soil Infiltration rate(rf) 8.00 in/hr Weighted Runoff Coefficient(C) 0.50 Design Storm Inentsity(i) 0.96 in/hr Catchment Area (A) 0.02 ac Req.Storage Volume(V100) 35 ft3 V = C * i *A * 3600 Infiltration area (AF)= 24.14 ftz Account for 1st hr of infiltration? No Pond infiltration rate(PF)= 16.09 ft3/hr Time for 90%infiltration (t90%)= 1.96 hr t90%<48 PASS First hour infiltration (F1)= 0 ft 3 Adj. Req.Storage Volume(VAd)= 35 ft3 Mainbay volume(VP)= 66 ft 3 Forebay Size Forebay Required= FALSE Required volume(VR) = ft Forebay volume(VF)1= ft3 VF>VR N/R Total Pond Volume(VT) 66 ft3 Check: VT>VAdi PASS Equations rf PF = AF . rf VAd j = V100 — F1 12 0.9 - V100 t9o�io = PF V.2020-03-17 Catchment K Sky Mesa Highland Project No.10-20-082 Gutter Flow Rational Method (TR-55) Sub- Elev. 1 Elev. 2 Lgutter Intercept Slope(Sp) Vgutter Tc-gutter L gutter catchment (ft) (ft) (ft) Coeff. (k) N (fps) (min) Tc—gutter = K 0.619 60 • Vgutter 0.007(nL)0.8 Tc—sheet — W2)O.SS0.4 Vgutter = 3.281kSO--' Tc = Tc—gutter + Tc—sheet Q = CLA Sheet Flow Calculation Total T, Catchment Parameters Sub- n L P2 s Tc-sheet Tc C, Area, CZ Areal CT AreaT catchment (unitless) (ft) (in) (ft/ft) (min) (min) (ac) (ac) (ac) K 0.24 20.0 1.2 0.01 8.5 10.0 0.50 0.02 0.50 0.02 Total Area 0.02 Comp.C 0.5 Design Storm Intensities Design Storm Flow Rates Soil Parameters Sub- i2 i25 iso iioo Q2 Q25 Qso QZoo Infil. Rate 8.00 in/hr catchment (in/hr) (in/hr) (in/hr) (in/hr) (cfs) (cfs) (cfs) (cfs) (F) K 0.69 1.85 2.20 2.58 0.01 0.02 0.02 0.03 0.01 0.02 0.02 0.03 V.2020-03-17 Catchment K Sky Mesa Highland Project No.10-20-082 Pond Design Storm frequency 100 -year Design Storm duration 60 -minutes Soil Infiltration rate(rf) 8.00 in/hr Weighted Runoff Coefficient(C) 0.50 Design Storm Inentsity(i) 0.96 in/hr Catchment Area (A) 0.02 ac Req.Storage Volume(Vloo) 35 ft3 V = C * i *A * 3600 Infiltration area (AF)= 24.14 ftz Account for 1st hr of infiltration? No Pond infiltration rate(PF)= 16.09 ft3/hr Time for 90%infiltration (t90%)= 1.96 hr t90%<48 PASS First hour infiltration (F1)= 0 ft 3 Adj. Req.Storage Volume(VAd)= 35 ft3 Mainbay volume(VP)= 66 ft 3 Forebay Size Forebay Required= FALSE Required volume(VR) = ft Forebay volume(VF)1= ft3 VF>VR N/R Total Pond Volume(VT) 66 ft3 Check: VT>VAdi PASS Equations rf PF = AF . rf VAd j = V100 — F1 12 0.9 - V100 t9o�io = PF V.2020-03-17 ACHD Intensity-Duration-Frequency Intensity(inches per hour) Design Storm 2 5 10 25 50 100 Tc(hr) Tc(min) 0.17 10 0.69 1.15 1.48 1.85 2.20 2.58 0.25 15 0.59 0.97 1.22 1.56 1.86 2.18 0.33 20 0.49 0.81 1.01 1.30 1.54 1.81 0.42 25 0.43 0.71 0.89 1.14 1.35 1.58 0.50 30 0.41 0.67 0.85 1.08 1.29 1.51 0.58 35 0.34 0.56 0.70 0.90 1.07 1.25 0.67 40 0.31 0.51 0.64 0.82 0.98 1.15 0.75 45 0.29 0.48 0.60 0.77 0.91 1.07 0.83 50 0.27 0.45 0.56 0.72 0.85 1.00 0.92 55 0.26 0.43 0.54 0.69 0.82 0.96 1.00 60 0.26 0.43 0.54 0.69 0.82 0.96 2.00 120 0.16 0.25 0.31 0.39 0.46 0.54 3.00 180 0.13 0.19 0.23 0.29 0.34 0.40 6.00 360 0.09 0.12 0.14 0.18 0.21 0.25 12.00 720 0.06 0.08 0.10 0.12 0.14 0.16 24.00 1440 0.04 0.06 0.06 0.08 0.09 0.10 Intensity Duration Frequency 3.00 2 -)K-5 -x-10 2.50 -�25 t 50 2.00 100 i t 1.50 c ' x 1.00 � \x x\X,x\x--x� \)K- _ x� 0.50 - � � )\ -.-.- -------------x------ � =�„ 0.00 1--- 10 15 20 25 30 35 40 45 50 55 60 120 180 360 720 1440 Duration (minutes) TabIG 3-2. Manning's Roughness Coefficient(n)for Overland Shoat Flcw.16' Estimated Runoff Coefficients for Various Surfaces Surface Description n Type of Surface Runoff Coefficients"C" Smooth asphalt 0.011 Business Smooth concrete 0.012 Downtown areas 0.70-0.95 Ordinary concrete lining U-013 Urban neighborhoods 0.50-0.70 Good wood 0.014 Residential Brick with cement mortar 1313114 Single Family 0.35-0.50 Multi--family 0.60-0.75 Vitrified clay 0-015 Residential(rural) 0.25-0.40 Cast iron 0-015 Apartrnent❑wellingAreas 0.70 Corrugated metal pipe 0.024 Industrial and Commercial Cement rubble surface 0.024 tight areas 0.80 Fallcm (no residue) 0-O5 Heavyareas 0.90 Cultivated soils Parks,Cemeteries 0.10-0.25 Residue cover s 20% p.pg Playgrounds 0.20-0.35 Residue cover> 20% 0.17 Railroad yard areas 0.20-0.40 Unimproved areas 0.10-0.30 Range(natural) 0-13 Streets Grass Asphalt 0.95 Short grass prairie 0.15 Concrete 0.95 L)ense grasses U-24 Brick 0.95 Bermuda grass 0-41 Roofs 0.95 Woods' Gravel 0.75 Light underbrush 0.40 Fields:Sandy soil Soil Type Dense underbrush 0-BO slope A B C ❑ *When selecting n. consider cover to a height of about 30 rnrn- This is only part of 0.04 0.07 0.11 0.15 the la nt cover that wil I obstruct sheet flow. Flat:t}2% Average:2-696 0.09 0.1.2 0.15 0.20 Table 3-3. Intercept Coefficients far Velocity vs.Slope Relationshlp of Equation 3-4 Steep:>6% 0.13 0.18 0.23 0.28 Land CoverlFlow Regirne k Adapted from ASCE Forest with heavy ground litter:hay meadow(overland flow) 0-076 Recommend Standards for Wastewater Facilities Trash fallow or minimum tillage cultivation:contour or strip cropped;wood)and 0-152 overhand flow) Table 33.41 Recommended Minimum Slopes Short grass pasture overland flow) 0.213 llinirnum Slope in Feet Cultivated straig ht.row(overland flow) 0.274 Nominal Surer Size P,r 100 Feet mr( '1DD m) IN early bare and unfilled(overland Flow):alluvial fans in western mountain regiions 0.305 8 uich(2DO mm) D-40 Grassed waterwa shatlOvv concentrated floc 0.457 10 mch(250mm) D-28 Unpaved(shallow ooncenlrated Flow) 0-491 Paved area(sh elilow commnVBted flOw);small upland gullies 0-619 12 inch(300 mm) D-22 Tab1a 3-4. Typical Rarlpa of Manning%Coaffiolant(n)for Chanrm"and Plp"- 14 mch(350 mm) D-17 Ganovat 15 inch(375 mm) D_15 Cla.ae Cawuiu 16 inch(400 mm) D-14 c«lcrama I 0-010-0-015 18 inch(450 mm) D-12 CMP 0.0111-4,03T Plasslc PIP& smootR 0.000-0.015 21 inch(525 mm) D-10 Waste P1 P, corn. arse o-01$-0.025 24 inch(600 mm) D-D8 Pavamn.UbWtnr ae%r 0.012-0.016 Small open chanr+aas 27 inch(675 mm) 0-067 GOl%crato 0.01 y-0.015 30 inch(750 mm) 0-058 R.bbra or ri 0-o2a.0.035 v slat o 0.02a-a.1g0 33 nch(825 mm} 0-D52 sera sa:a 0-01e_o-925 36 inch(900 mm) 0-046 Rvck c.t 1 0.025-0.045 Natural cnanaais iminp alraems.top wletrl at Roos stage;30 m(100 R)) 39 inch(975 mm} 0-041 Fain war—U— 1 0.02E-0.050 42 inch(1050 mm) 0-037 ftraqu10,so*t:pn wRh pools 0.040-0-150 1ILLP.//1VOl4lC»l 11 1­ 111/V-ICV MIS 11U 1U PU1 -Lower v94uaa aid pip.* artd chanrt616 H2 1.14 o so goo ■■■■■■■■ SCALE IN FEET H1 H 1.50 LEGEND J K 0.02 K 0.02 — — PROJECT BOUNDARY A2 � ■ C2 CATCHMENT BOUNDARY 0.19 0.13 mi ME — — — — — — — SUB—CATCHMENT BOUNDARY •� 6 91 0 3 —i FLOW DIRECTION 0.■ Al INFILTRATION BED LOCATION ■�■Emom ■■■■■ F E ® POND LOCATION F E1 1'85 24 CATCHMENT AREA (AC) 1.70 G1 I I i Al 2.52 B 1.46 D2 D1 1.73 2.76 ■ o m ■ Q ■ O 0 w l •••,•���44 w ��1 1 � I a I 0 0 E. LAKE HAZEL ROAD f VU lz Y 6 U O a U a� m SKY MESA HIGHLANDS MERIDIAN, IDAHO STORM DRAIN CATCHMENT MAP s Fire:oaaiNa e J-U-B ENGINEERS,INC.