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HomeMy WebLinkAbout09_AppendixAStormwater Calculations Pond Sizing10 yr Existing ConditionsProposed ConditionsBasin Sizing CalculationsWeighted C Value (Pre-Dev) Weighted C Value (Pre-Dev) Infiltration*Only used for 100-year analysisArea Area Area AreaObserved Percolation Rate 7.50 min/in(ft2) (acres) (ft2) (acres)8.00 in/hr 0.73 0.00 0.00 0.73 324470 7.45 5.440.50 0.00 0.00 0.50 1018729 23.39 11.69 Design Percolation Rate 4.00 in/hr0.60 0.00 0.00 0.60 0 0.00 0.00 Infiltrative Area 16410ft20.20 1531570 35.16 7.03 0.20 188322 4.32 0.86 Design Infiltration Rate 1.519 cfs1531570 35.16 7.03 1531521 35.16 18.00Duration Duration Intensity Q Runoff Release Required0.200.51min hr in/hr cfs Volume Volume Storage 5 0.08 3.22 57.92 17376 749.3 16626Time To Concentration TcTime To Concentration Tc10 0.17 2.05 36.91 22146 1498.5 20648Tc Overland Flow (Up to 400ft) Tc Overland Flow (Up to 400ft)15 0.25 1.58 28.36 25523 2247.8 23275Tc = 1.87(1.1-CCf)D0.5)/S1/3 (City of Bozeman Design Standards) Tc = 1.87(1.1-CCf)D0.5)/S1/3 (City of Bozeman Design Standards)20 0.33 1.31 23.52 28227 2997.0 2523025 0.42 1.13 20.35 30519 3746.3 26773C = Weighted C Factor 0.20 C = Weighted C Factor 0.51 30 0.50 1.00 18.07 32530 4495.5 28035Cf = Frequency Factor1.00Cf = Frequency Factor1.00 60 1.00 0.64 11.52 41462 8991.0 32471D = Length 400.00ftD = Length 400.00ft90 1.50 0.49 8.85 47784 13486.5 34298 S = Slope % 2.61%S = Slope % 2.40%120 2.00 0.41 7.34 52846 17982.0 34864150 2.50 0.35 6.35 57139 22477.5 34661Tc = 24.45MinutesTc = 16.43Minutes180 3.00 0.31 5.64 60904 26973.0 33931210 3.50 0.28 5.10 64280 31468.5 32811Tc Shallow Concentrated Flow (After 400ft) Tc Shallow Concentrated Flow (After 400ft)240 4.00 0.26 4.68 67355 35964.0 31391V = KukSp0.5 (HEC 22 eqn 3-4) V = KukSp0.5 (HEC 22 eqn 3-4)270 4.50 0.24 4.33 70190 40459.5 29730300 5.00 0.22 4.05 72827 44955.0 27872Ku = Conversion Factor3.28English UnitsKu = Conversion Factor3.28English Units330 5.50 0.21 3.80 75297 49451 25847k = Intercept Coefiicient 0.21HEC 22 Table 3-3k = Intercept Coefiicient 0.21HEC 22 Table 3-3Runoff Treatment Volume (Initial 0.5")Sp = Slope %1.19%Sp = Slope %1.20%Ia = 0.4 in0.5" - Ia=0.1 inV = 0.76ft/sV = 0.77ft/s1531521.00ft2D = 1023.00ftD = 960.00ft12763ft3Tc =22.37MinutesTc =20.91Minutes34864ft3Total Tc (Overland and Shallow Concentrated) Total Tc (Overland and Shallow Concentrated)Outlet Structure Q = CLH3/2 (City of Bozeman Design Standards)Tc = 46.82 Minutes Tc = 37.34 MinutesQ = Discharge 2.50 cfsRunoff Rate (Intensity @ Tc) Runoff Rate (Intensity @ Tc)C = Weir Coefficient 3.33i = 0.64x-0.65 (COB Design Standards, Fig. I-3, 10 yr) i = 0.64x-0.65 (COB Design Standards, Fig. I-3, 10 yr)H = Head 1 ftx = storm duration (hrs.) 0.78hrs.x = storm duration (hrs.) 0.62hrs.i = 0.75in/hri = 0.87in/hrL = Weir Width 0.750 ftQ = CiAQ = 5.29cfsQ = CiAQ = 15.68cfsL = Weir Width9.00inches100-Year Storm Design Check:Storm Event (yr):2 10 25 100V100YR/2HR :82,251.92cf V100YR/24HR :186,756.55cf*Storm Coeff. A:0.36 0.64 0.78 1.01Pond Area:16,410.00sfPond Area:16,410.00sf*Storm Coeff. B: 0.60 0.65 0.64 0.67Infiltration Rate:4.00in/hr Infiltration Rate:4.00in/hrComposite C:0.51 0.51 0.51 0.51 Volume Infiltrated : 10,940.00 cf Volume Infiltrated : 131,280.00 cf2-Hr Storm Intensity (in/hr):0.24 0.41 0.50 0.63 Max Pond Storage: 35,013.00 cf Max Pond Storage: 35,013.00 cf24-Hr Storm Intensity (in/hr):0.05 0.08 0.10 0.12 Max Pond Capacity45,953.00cf Max Pond Capacity166,293.00cf2 Hr Post-Dev Qp (cfs):4.27 7.34 9.01 11.42 24 Hr Post-Dev Qp (cfs):0.96 1.46 1.84 2.16C*Area100 Year StormRunoff Rate (City of Bozeman):Area = Initial 0.5" Pond Volume Req. =Minimum Pond Size Required = Urban + Farm Phase 2Basin A Detention Pond VolumeDesign Storm Frequency =R.O.W.Dense ResidentialCW =Land UseTotalsCW =CommercialOpen LandTotalsLand UseC C*AreaR.O.W.Dense ResidentialCommercialOpen LandC 10yrBasin Area (ac):29.741,295,474.40 (sq ft)Post-Dev C (weighted):0.53Storm Duration (min)120.00Area Runoff (acres) Coefficient CalculationsR.O.W.8.35 0.73 6.10Dense Residential17.53 0.50 8.77Open Land3.86 0.20 0.77Totals29.74 15.63Cw =0.53Storm Event (yr):2-yr, 2-hr 10-yr, 2-hr 25-yr, 2-hr 100-yr, 2-hr 100-yr, 24-hr*Storm Coeff. A:0.36 0.64 0.78 1.01 1.01*Storm Coeff. B:0.60 0.65 0.64 0.67 0.67Composite C:0.53 0.53 0.53 0.53 0.53Storm Intensity (in/hr):0.24 0.41 0.50 0.63 0.12Post-Dev Qp (cfs):3.71 6.38 7.82 9.92 1.88V100YR/2HR :71,448.35cf V100YR/24HR :162,226.58cf10-Year, 2 Hour StormPond Area:21,534.00sfPond Area:21,534.00sfDuration Time:7,200.00sec Infiltration Rate:4.00in/hr Infiltration Rate:2.00in/hrV10YR/2HR :45,906cfVolume Infiltrated :14,356.00cf Volume Infiltrated :86,136.00cfMax Pond Storage: 46,158.00cf Max Pond Storage: 46,158.00cfMax Pond Capacity 60,514.00 cf Max Pond Capacity 132,294.00 cfCN= 85S= 1.8 inIa = 0.4 in0.5" - Ia=0.1 inV1/2":15,876 cf*Values are from COB Design Standards Figure 2 - Rainfall Intensity Duration in MinutesUrban + Farm Phase 2Retention Pond BDesign Storm Frequency =Runoff Rate (Rational Method):100 Year Storm (Includes Infiltration)Runoff Treatment Volume (Initial 0.5"):Design Storm: 10-Year, 2-Hour (City of Bozeman)Weighted Runoff Co-efficent:Pond Size: 10 yr Existing ConditionsProposed ConditionsBasin Sizing CalculationsWeighted C Value (Pre-Dev) Weighted C Value (Pre-Dev) Infiltration*Only used for 100-year analysisArea Area Area AreaObserved Percolation Rate 7.50 min/in(ft2) (acres) (ft2) (acres)8.00 in/hr 0.73 0.00 0.00 0.73 139933 3.21 2.350.50 0.00 0.00 0.50 208470 4.79 2.39 Design Percolation Rate 4.00 in/hr 0.60 0.00 0.00 0.60 110699 2.54 1.52 Infiltrative Area 6300ft20.20 515315 11.83 2.37 0.20 56418 1.30 0.26 Design Infiltration Rate 0.583 cfs 515315 11.83 2.37 515520 11.83 6.52Duration Duration Intensity Q Runoff Release Required0.200.55min hr in/hr cfs Volume Volume Storage 2 0.03 5.84 38.08 4569 252.6 4317Time To Concentration TcTime To Concentration Tc4 0.07 3.72 24.27 5824 505.3 5319Tc Overland Flow (Up to 400ft) Tc Overland Flow (Up to 400ft)6 0.10 2.86 18.64 6712 757.9 5954Tc = 1.87(1.1-CCf)D0.5)/S1/3 (City of Bozeman Design Standards) Tc = 1.87(1.1-CCf)D0.5)/S1/3 (City of Bozeman Design Standards)8 0.13 2.37 15.46 7423 1010.6 641210 0.17 2.05 13.38 8026 1263.2 6763C = Weighted C Factor 0.20 C = Weighted C Factor 0.55 15 0.25 1.58 10.28 9250 1894.8 7355Cf = Frequency Factor1.00Cf = Frequency Factor1.00 20 0.33 1.31 8.52 10230 2526.5 7703D = Length 400.00ftD = Length 400.00ft25 0.42 1.13 7.37 11061 3158.1 7902 S = Slope % 2.31%S = Slope % 2.31%30 0.50 1.00 6.55 11789 3789.7 8000 35 0.58 0.91 5.93 12443 4421.3 8022Tc = 25.46MinutesTc = 15.53Minutes40 0.67 0.83 5.43 13038 5052.9 7985 45 0.75 0.77 5.03 13587 5684.5 7902Tc Shallow Concentrated Flow (After 400ft) Tc Shallow Concentrated Flow (After 400ft)50 0.83 0.72 4.70 14097 6316.1 7781V = KukSp0.5 (HEC 22 eqn 3-4) V = KukSp0.5 (HEC 22 eqn 3-4)55 0.92 0.68 4.42 14575 6947.7 7628 60 1.00 0.64 4.17 15026 7579.4 7447Ku = Conversion Factor3.28English UnitsKu = Conversion Factor3.28English Units65 1.08 0.61 3.96 15453 8211 7242k = Intercept Coefiicient 0.21HEC 22 Table 3-3k = Intercept Coefiicient 0.21HEC 22 Table 3-3Runoff Treatment Volume (Initial 0.5")Sp = Slope %2.31%Sp = Slope %1.61%Ia = 0.4 in0.5" - Ia=0.1 inV = 1.06ft/sV = 0.89ft/s515520.00ft2D = 680.00ftD = 1005.00ft4296ft3Tc =10.67MinutesTc =18.90Minutes8022ft3Total Tc (Overland and Shallow Concentrated) Total Tc (Overland and Shallow Concentrated)Outlet Structure Q = CLH3/2 (City of Bozeman Design Standards)Tc = 36.14 Minutes Tc = 34.43 MinutesQ = Discharge 1.67 cfsRunoff Rate (Intensity @ Tc) Runoff Rate (Intensity @ Tc)C = Weir Coefficient 3.33i = 0.64x-0.65 (COB Design Standards, Fig. I-3, 10 yr) i = 0.64x-0.65 (COB Design Standards, Fig. I-3, 10 yr)H = Head 1 ftx = storm duration (hrs.) 0.60hrs.x = storm duration (hrs.) 0.57hrs.i = 0.89in/hri = 0.92in/hrL = Weir Width 0.500 ftQ = CiAQ = 2.11cfsQ = CiAQ = 5.99cfsL = Weir Width6.00inches100-Year Storm Design Check:Storm Event (yr):2 10 25 100V100YR/2HR :29,795.98cf V100YR/24HR :67,653.07cf*Storm Coeff. A:0.36 0.64 0.78 1.01Pond Area:6,300.00sfPond Area:6,300.00sf*Storm Coeff. B: 0.60 0.65 0.64 0.67Infiltration Rate:4.00in/hr Infiltration Rate:4.00in/hrComposite C:0.55 0.55 0.55 0.55 Volume Infiltrated : 4,200.00 cf Volume Infiltrated : 50,400.00 cf2-Hr Storm Intensity (in/hr):0.24 0.41 0.50 0.63 Max Pond Storage: 8,430.00 cf Max Pond Storage: 8,430.00 cf24-Hr Storm Intensity (in/hr):0.05 0.08 0.10 0.12 Max Pond Capacity12,630.00cf Max Pond Capacity58,830.00cf2 Hr Post-Dev Qp (cfs):1.55 2.66 3.26 4.14 24 Hr Post-Dev Qp (cfs):0.35 0.53 0.67 0.78Area = Initial 0.5" Pond Volume Req. =Minimum Pond Size Required = Runoff Rate (City of Bozeman):100 Year StormOpen Land Open LandTotalsTotalsCW =CW =R.O.W.R.O.W.Dense Residential Dense ResidentialCommercial CommercialUrban + Farm Phase 2Basin C1 Detention Pond VolumeDesign Storm Frequency =Land UseC C*AreaLand UseC C*Area 10 yr Existing ConditionsProposed ConditionsBasin Sizing CalculationsWeighted C Value (Pre-Dev) Weighted C Value (Pre-Dev) Infiltration*Only used for 100-year analysisArea Area Area AreaObserved Percolation Rate 7.50 min/in(ft2) (acres) (ft2) (acres)8.00 in/hr 0.73 0.00 0.00 0.73 84048 1.93 1.410.50 0.00 0.00 0.50 194638 4.47 2.23 Design Percolation Rate 4.00 in/hr 0.60 0.00 0.00 0.60 98224 2.25 1.35 Infiltrative Area 6255ft20.20 452588 10.39 2.08 0.20 75522 1.73 0.35 Design Infiltration Rate 0.579 cfs 452588 10.39 2.08 452432 10.39 5.34Duration Duration Intensity Q Runoff Release Required0.200.51min hr in/hr cfs Volume Volume Storage 2 0.03 5.84 31.19 3743 227.7 3515Time To Concentration TcTime To Concentration Tc4 0.07 3.72 19.88 4771 455.4 4315Tc Overland Flow (Up to 400ft) Tc Overland Flow (Up to 400ft)6 0.10 2.86 15.27 5498 683.2 4815Tc = 1.87(1.1-CCf)D0.5)/S1/3 (City of Bozeman Design Standards) Tc = 1.87(1.1-CCf)D0.5)/S1/3 (City of Bozeman Design Standards)8 0.13 2.37 12.67 6081 910.9 517010 0.17 2.05 10.96 6574 1138.6 5436C = Weighted C Factor 0.20 C = Weighted C Factor 0.51 15 0.25 1.58 8.42 7577 1707.9 5869Cf = Frequency Factor1.00Cf = Frequency Factor1.00 20 0.33 1.31 6.98 8380 2277.2 6102D = Length 400.00ftD = Length 400.00ft25 0.42 1.13 6.04 9060 2846.5 6214 S = Slope % 2.31%S = Slope % 2.31%30 0.50 1.00 5.37 9657 3415.8 6241 35 0.58 0.91 4.85 10193 3985.1 6208Tc = 25.46MinutesTc = 16.57Minutes40 0.67 0.83 4.45 10680 4554.4 6126 45 0.75 0.77 4.12 11130 5123.7 6006Tc Shallow Concentrated Flow (After 400ft) Tc Shallow Concentrated Flow (After 400ft)50 0.83 0.72 3.85 11548 5693.0 5855V = KukSp0.5 (HEC 22 eqn 3-4) V = KukSp0.5 (HEC 22 eqn 3-4)55 0.92 0.68 3.62 11940 6262.3 5677 60 1.00 0.64 3.42 12309 6831.5 5477Ku = Conversion Factor3.28English UnitsKu = Conversion Factor3.28English Units65 1.08 0.61 3.25 12658 7401 5258k = Intercept Coefiicient 0.21HEC 22 Table 3-3k = Intercept Coefiicient 0.21HEC 22 Table 3-3Runoff Treatment Volume (Initial 0.5")Sp = Slope %2.31%Sp = Slope %1.61%Ia = 0.4 in0.5" - Ia=0.1 inV = 1.06ft/sV = 0.89ft/s452432.00ft2D = 590.00ftD = 710.00ft3770ft3Tc =9.26MinutesTc =13.35Minutes6241ft3Total Tc (Overland and Shallow Concentrated) Total Tc (Overland and Shallow Concentrated)Outlet Structure Q = CLH3/2 (City of Bozeman Design Standards)Tc = 34.72 Minutes Tc = 29.92 MinutesQ = Discharge 1.67 cfsRunoff Rate (Intensity @ Tc) Runoff Rate (Intensity @ Tc)C = Weir Coefficient 3.33i = 0.64x-0.65 (COB Design Standards, Fig. I-3, 10 yr) i = 0.64x-0.65 (COB Design Standards, Fig. I-3, 10 yr)H = Head 1 ftx = storm duration (hrs.) 0.58hrs.x = storm duration (hrs.) 0.50hrs.i = 0.91in/hri = 1.01in/hrL = Weir Width 0.500 ftQ = CiAQ = 1.90cfsQ = CiAQ = 5.37cfsL = Weir Width6.00inches100-Year Storm Design Check:Storm Event (yr):2 10 25 100V100YR/2HR :24,425.64cf V100YR/24HR :55,459.48cf*Storm Coeff. A:0.36 0.64 0.78 1.01Pond Area:6,255.00sfPond Area:6,255.00sf*Storm Coeff. B: 0.60 0.65 0.64 0.67Infiltration Rate:4.00in/hr Infiltration Rate:4.00in/hrComposite C:0.51 0.51 0.51 0.51 Volume Infiltrated : 4,170.00 cf Volume Infiltrated : 50,040.00 cf2-Hr Storm Intensity (in/hr):0.24 0.41 0.50 0.63 Max Pond Storage: 6,677.00 cf Max Pond Storage: 6,677.00 cf24-Hr Storm Intensity (in/hr):0.05 0.08 0.10 0.12 Max Pond Capacity10,847.00cf Max Pond Capacity56,717.00cf2 Hr Post-Dev Qp (cfs):1.27 2.18 2.67 3.39 24 Hr Post-Dev Qp (cfs):0.29 0.43 0.55 0.64Area = Initial 0.5" Pond Volume Req. =Minimum Pond Size Required = Runoff Rate (City of Bozeman):100 Year StormOpen Land Open LandTotalsTotalsCW =CW =R.O.W.R.O.W.Dense Residential Dense ResidentialCommercial CommercialUrban + Farm Phase 2Basin C2 Detention Pond VolumeDesign Storm Frequency =Land UseC C*AreaLand UseC C*Area 10 yr Existing ConditionsProposed ConditionsBasin Sizing CalculationsWeighted C Value (Pre-Dev) Weighted C Value (Pre-Dev) Infiltration*Only used for 100-year analysisArea Area Area AreaObserved Percolation Rate 7.50 min/in(ft2) (acres) (ft2) (acres)8.00 in/hr 0.73 0.00 0.00 0.73 0.00 0.00 0.50 0.00 0.00 0.50 40251 0.92 0.46 Design Percolation Rate 4.00 in/hr 0.60 0.00 0.00 0.60 0.00 0.00 Infiltrative Area 886ft20.20 40251 0.92 0.18 0.20 0.00 0.00 Design Infiltration Rate 0.082 cfs 40251 0.92 0.18 40251 0.92 0.46Duration Duration Intensity Q Runoff Release Required0.200.50min hr in/hr cfs Volume Volume Storage 2 0.03 5.84 2.70 324 23.5 300Time To Concentration TcTime To Concentration Tc4 0.07 3.72 1.72 413 46.9 366Tc Overland Flow (Up to 400ft) Tc Overland Flow (Up to 400ft)6 0.10 2.86 1.32 475 70.4 405Tc = 1.87(1.1-CCf)D0.5)/S1/3 (City of Bozeman Design Standards) Tc = 1.87(1.1-CCf)D0.5)/S1/3 (City of Bozeman Design Standards)8 0.13 2.37 1.10 526 93.9 43210 0.17 2.05 0.95 569 117.3 451C = Weighted C Factor 0.20 C = Weighted C Factor 0.50 15 0.25 1.58 0.73 655 176.0 479Cf = Frequency Factor1.00Cf = Frequency Factor1.00 20 0.33 1.31 0.60 725 234.7 490D = Length 265.00ftD = Length 318.00ft25 0.42 1.13 0.52 784 293.4 490S = Slope % 1.47%S = Slope % 1.47%30 0.50 1.00 0.46 835 352.0 48335 0.58 0.91 0.42 881 410.7 471Tc = 24.10MinutesTc = 17.60Minutes40 0.67 0.83 0.38 924 469.4 45445 0.75 0.77 0.36 963 528.1 434Tc Shallow Concentrated Flow (After 400ft) Tc Shallow Concentrated Flow (After 400ft)50 0.83 0.72 0.33 999 586.7 412V = KukSp0.5 (HEC 22 eqn 3-4) V = KukSp0.5 (HEC 22 eqn 3-4)55 0.92 0.68 0.31 1033 645.4 38760 1.00 0.64 0.30 1064 704.1 360Ku = Conversion Factor3.28English UnitsKu = Conversion Factor3.28English Units65 1.08 0.61 0.28 1095 763 332k = Intercept Coefiicient 0.21HEC 22 Table 3-3k = Intercept Coefiicient 0.21HEC 22 Table 3-3Runoff Treatment Volume (Initial 0.5")Sp = Slope %1.47%Sp = Slope %1.47%Ia = 0.4 in0.5" - Ia=0.1 inV = 0.85ft/sV = 0.85ft/s40251.00ft2D = 182.00ftD = 250.00ft335ft3Tc =3.58MinutesTc =4.92Minutes490ft3Total Tc (Overland and Shallow Concentrated) Total Tc (Overland and Shallow Concentrated)Outlet Structure Q = CLH3/2 (City of Bozeman Design Standards)Tc = 27.68 Minutes Tc = 22.52 MinutesQ = Discharge 0.20 cfsRunoff Rate (Intensity @ Tc) Runoff Rate (Intensity @ Tc)C = Weir Coefficient 3.33i = 0.64x-0.65 (COB Design Standards, Fig. I-3, 10 yr) i = 0.64x-0.65 (COB Design Standards, Fig. I-3, 10 yr)H = Head 0.5 ftx = storm duration (hrs.) 0.46hrs.x = storm duration (hrs.) 0.38hrs.i = 1.06in/hri = 1.21in/hrL = Weir Width 0.167 ftQ = CiAQ = 0.20cfsQ = CiAQ = 0.56cfsL = Weir Width2.00inches100-Year Storm Design Check:Storm Event (yr):2 10 25 100V100YR/2HR :2,111.65cf V100YR/24HR :4,794.60cf*Storm Coeff. A:0.36 0.64 0.78 1.01Pond Area:886.00sfPond Area:886.00sf*Storm Coeff. B: 0.60 0.65 0.64 0.67Infiltration Rate:4.00in/hr Infiltration Rate:4.00in/hrComposite C:0.50 0.50 0.50 0.50 Volume Infiltrated : 590.67 cf Volume Infiltrated : 7,088.00 cf2-Hr Storm Intensity (in/hr):0.24 0.41 0.50 0.63 Max Pond Storage: 1,450.00 cf Max Pond Storage: 1,450.00 cf24-Hr Storm Intensity (in/hr):0.05 0.08 0.10 0.12 Max Pond Capacity2,040.67cf Max Pond Capacity8,538.00cf2 Hr Post-Dev Qp (cfs):0.11 0.19 0.23 0.29 24 Hr Post-Dev Qp (cfs):0.02 0.04 0.05 0.06Urban + Farm Phase 2Basin D1 Detention Pond VolumeDesign Storm Frequency =Land UseC C*AreaLand UseC C*AreaCW =R.O.W.R.O.W.Dense Residential Dense ResidentialCommercial Commercial Area = Initial 0.5" Pond Volume Req. =Minimum Pond Size Required = Runoff Rate (City of Bozeman):100 Year StormOpen Land Open LandTotalsTotalsCW = 10 yr Existing ConditionsProposed ConditionsBasin Sizing CalculationsWeighted C Value (Pre-Dev) Weighted C Value (Pre-Dev) Infiltration*Only used for 100-year analysisArea Area Area AreaObserved Percolation Rate 7.50 min/in(ft2) (acres) (ft2) (acres)8.00 in/hr 0.73 0.00 0.00 0.73 17661 0.41 0.300.50 0.00 0.00 0.50 0.00 0.00 Design Percolation Rate 4.00 in/hr0.60 0.00 0.00 0.60 44701 1.03 0.62 Infiltrative Area 502ft20.20 62362 1.43 0.29 0.20 0.00 0.00 Design Infiltration Rate 0.046 cfs 62362 1.43 0.29 62362 1.43 0.91Duration Duration Intensity Q Runoff Release Required0.200.64min hr in/hr cfs Volume Volume Storage 2 0.03 5.84 5.32 639 34.9 604Time To Concentration TcTime To Concentration Tc4 0.07 3.72 3.39 814 69.8 744Tc Overland Flow (Up to 400ft) Tc Overland Flow (Up to 400ft)6 0.10 2.86 2.61 938 104.7 834Tc = 1.87(1.1-CCf)D0.5)/S1/3 (City of Bozeman Design Standards) Tc = 1.87(1.1-CCf)D0.5)/S1/3 (City of Bozeman Design Standards)8 0.13 2.37 2.16 1038 139.6 89810 0.17 2.05 1.87 1122 174.5 947C = Weighted C Factor 0.20 C = Weighted C Factor 0.64 15 0.25 1.58 1.44 1293 261.7 1031Cf = Frequency Factor1.00Cf = Frequency Factor1.00 20 0.33 1.31 1.19 1430 349.0 1081D = Length 300.00ftD = Length 300.00ft25 0.42 1.13 1.03 1546 436.2 1110S = Slope % 1.46%S = Slope % 1.46%30 0.50 1.00 0.92 1648 523.4 112535 0.58 0.91 0.83 1739 610.7 1129Tc = 25.70MinutesTc = 13.22Minutes40 0.67 0.83 0.76 1823 697.9 112545 0.75 0.77 0.70 1899 785.1 1114Tc Shallow Concentrated Flow (After 400ft) Tc Shallow Concentrated Flow (After 400ft)50 0.83 0.72 0.66 1971 872.4 1098V = KukSp0.5 (HEC 22 eqn 3-4) V = KukSp0.5 (HEC 22 eqn 3-4)55 0.92 0.68 0.62 2038 959.6 107860 1.00 0.64 0.58 2101 1046.9 1054Ku = Conversion Factor3.28English UnitsKu = Conversion Factor3.28English Units65 1.08 0.61 0.55 2160 1134 1026k = Intercept Coefiicient 0.21HEC 22 Table 3-3k = Intercept Coefiicient 0.21HEC 22 Table 3-3Runoff Treatment Volume (Initial 0.5")Sp = Slope %1.46%Sp = Slope %1.46%Ia = 0.4 in0.5" - Ia=0.1 inV = 0.84ft/sV = 0.84ft/s62362.00ft2D = 192.00ftD = 250.00ft520ft3Tc =3.79MinutesTc =4.94Minutes1129ft3Total Tc (Overland and Shallow Concentrated) Total Tc (Overland and Shallow Concentrated)Outlet Structure Q = CLH3/2 (City of Bozeman Design Standards)Tc = 29.49 Minutes Tc = 18.16 MinutesQ = Discharge 0.29 cfsRunoff Rate (Intensity @ Tc) Runoff Rate (Intensity @ Tc)C = Weir Coefficient 3.33i = 0.64x-0.65 (COB Design Standards, Fig. I-3, 10 yr) i = 0.64x-0.65 (COB Design Standards, Fig. I-3, 10 yr)H = Head 0.5 ftx = storm duration (hrs.) 0.49hrs.x = storm duration (hrs.) 0.30hrs.i = 1.02in/hri = 1.39in/hrL = Weir Width 0.250 ftQ = CiAQ = 0.29cfsQ = CiAQ = 1.27cfsL = Weir Width3.00inches100-Year Storm Design Check:Storm Event (yr):2 10 25 100V100YR/2HR :4,166.87cf V100YR/24HR :9,461.06cf*Storm Coeff. A:0.36 0.64 0.78 1.01Pond Area:502.00sfPond Area:502.00sf*Storm Coeff. B: 0.60 0.65 0.64 0.67Infiltration Rate:4.00in/hr Infiltration Rate:4.00in/hrComposite C:0.64 0.64 0.64 0.64 Volume Infiltrated : 334.67 cf Volume Infiltrated : 4,016.00 cf2-Hr Storm Intensity (in/hr):0.24 0.41 0.50 0.63 Max Pond Storage: 1,450.00 cf Max Pond Storage: 1,450.00 cf24-Hr Storm Intensity (in/hr):0.05 0.08 0.10 0.12 Max Pond Capacity1,784.67cf Max Pond Capacity5,466.00cf2 Hr Post-Dev Qp (cfs):0.22 0.37 0.46 0.58 24 Hr Post-Dev Qp (cfs):0.05 0.07 0.09 0.11Urban + Farm Phase 2Basin D2 Detention Pond VolumeDesign Storm Frequency =Land UseC C*AreaLand UseC C*AreaCW =R.O.W.R.O.W.Dense Residential Dense ResidentialCommercial Commercial Area = Initial 0.5" Pond Volume Req. =Minimum Pond Size Required = Runoff Rate (City of Bozeman):100 Year StormOpen Land Open LandTotalsTotalsCW = 10yrBasin Area (ac):0.6729,185.20 (sq ft)Post-Dev C (weighted):0.55Storm Duration (min)120.00Area Runoff (acres) Coefficient CalculationsR.O.W.0.14 0.73 0.10Dense Residential0.53 0.50 0.27Open Land0.00 0.20 0.00Totals0.67 0.37C w =0.55Storm Event (yr):2-yr, 2-hr 10-yr, 2-hr 25-yr, 2-hr 100-yr, 2-hr 100-yr, 24-hr*Storm Coeff. A:0.36 0.64 0.78 1.01 1.01*Storm Coeff. B:0.60 0.65 0.64 0.67 0.67Composite C:0.55 0.55 0.55 0.55 0.55Storm Intensity (in/hr):0.24 0.41 0.50 0.63 0.12Post-Dev Qp (cfs):0.09 0.15 0.18 0.23 0.04V100YR/2HR :1,678.29cf V100YR/24HR :3,810.63cf10-Year, 2 Hour StormPond Area:590.00sfPond Area:590.00sfDuration Time:7,200.00sec Infiltration Rate:4.00in/hr Infiltration Rate:2.00in/hrV10YR/2HR :1,078cfVolume Infiltrated :393.33cf Volume Infiltrated :2,360.00cfMax Pond Storage: 1,254.00cf Max Pond Storage: 1,254.00cfMax Pond Capacity 1,647.33 cf Max Pond Capacity 3,614.00 cfCN= 85S= 1.8 inIa = 0.4 in0.5" - Ia=0.1 inV1/2":358 cf*Values are from COB Design Standards Figure 2 - Rainfall Intensity Duration in MinutesPond Size: 100 Year Storm (Includes Infiltration)Runoff Treatment Volume (Initial 0.5"):Urban + Farm Phase 2Retention Pond EDesign Storm Frequency =Design Storm: 10-Year, 2-Hour (City of Bozeman)Weighted Runoff Co-efficent:Runoff Rate (Rational Method): 10yrBasin Area (ac):0.146,098.40 (sq ft)Post-Dev C (weighted):0.71Storm Duration (min)120.00Area Runoff (acres) Coefficient CalculationsR.O.W.0.13 0.73 0.09Dense Residential0.01 0.50 0.01Open Land0.00 0.20 0.00Totals0.14 0.10C w =0.71Storm Event (yr):2-yr, 2-hr 10-yr, 2-hr 25-yr, 2-hr 100-yr, 2-hr 100-yr, 24-hr*Storm Coeff. A:0.36 0.64 0.78 1.01 1.01*Storm Coeff. B:0.60 0.65 0.64 0.67 0.67Composite C:0.71 0.71 0.71 0.71 0.71Storm Intensity (in/hr):0.24 0.41 0.50 0.63 0.12Post-Dev Qp (cfs):0.02 0.04 0.05 0.06 0.01V100YR/2HR :456.59cf V100YR/24HR :1,036.71cf10-Year, 2 Hour StormPond Area:210.00sfPond Area:210.00sfDuration Time:7,200.00sec Infiltration Rate:4.00in/hr Infiltration Rate:2.00in/hrV10YR/2HR :293cfVolume Infiltrated :140.00cf Volume Infiltrated :840.00cfMax Pond Storage: 297.00cf Max Pond Storage: 297.00cfMax Pond Capacity 437.00 cf Max Pond Capacity 1,137.00 cf CN= 85S= 1.8 inIa = 0.4 in0.5" - Ia=0.1 inV1/2":75 cf *Values are from COB Design Standards Figure 2 - Rainfall Intensity Duration in MinutesPond Size: 100 Year Storm (Includes Infiltration)Runoff Treatment Volume (Initial 0.5"):Urban + Farm Phase 2Retention Pond FDesign Storm Frequency =Design Storm: 10-Year, 2-Hour (City of Bozeman)Weighted Runoff Co-efficent:Runoff Rate (Rational Method): Pond Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Monday, 11 / 20 / 2023 Pond No. 1 - Pond A Pond Data UG Chambers -Invert elev. = 4810.00 ft, Rise x Span = 2.50 x 2.50 ft, Barrel Len = 285.00 ft, No. Barrels = 14, Slope = 0.00%, Headers = Yes Encasement -Invert elev. = 4809.00 ft, Width = 4.50 ft, Height = 3.50 ft, Voids = 40.00% Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft) 0.00 4809.00 n/a 0 0 0.35 4809.35 n/a 2,594 2,594 0.70 4809.70 n/a 2,594 5,187 1.05 4810.05 n/a 2,651 7,838 1.40 4810.40 n/a 3,788 11,626 1.75 4810.75 n/a 4,402 16,029 2.10 4811.10 n/a 4,675 20,704 2.45 4811.45 n/a 4,747 25,451 2.80 4811.80 n/a 4,644 30,095 3.15 4812.15 n/a 4,342 34,437 3.50 4812.50 n/a 3,624 38,061 Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise (in)= 0.00 0.00 0.00 0.00 Span (in)= 0.00 0.00 0.00 0.00 No. Barrels = 0 0 0 0 Invert El. (ft)= 0.00 0.00 0.00 0.00 Length (ft)= 0.00 0.00 0.00 0.00 Slope (%)= 0.00 0.00 0.00 n/a N-Value = .013 .013 .013 n/a Orifice Coeff.= 0.60 0.60 0.60 0.60 Multi-Stage = n/a No No No Crest Len (ft)= 0.75 0.00 0.00 0.00 Crest El. (ft)= 4811.00 0.00 0.00 0.00 Weir Coeff.= 3.33 3.33 3.33 3.33 Weir Type = Rect --- --- --- Multi-Stage = No No No No Exfil.(in/hr)= 0.000 (by Wet area) TW Elev. (ft)= 0.00 Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). Stage / Storage / Discharge Table Stage Storage Elevation Clv A Clv B Clv C PrfRsr Wr A Wr B Wr C Wr D Exfil User Total ft cuft ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs 0.00 0 4809.00 --- --- --- --- 0.00 --- --- --- --- --- 0.000 0.35 2,594 4809.35 --- --- --- --- 0.00 --- --- --- --- --- 0.000 0.70 5,187 4809.70 --- --- --- --- 0.00 --- --- --- --- --- 0.000 1.05 7,838 4810.05 --- --- --- --- 0.00 --- --- --- --- --- 0.000 1.40 11,626 4810.40 --- --- --- --- 0.00 --- --- --- --- --- 0.000 1.75 16,029 4810.75 --- --- --- --- 0.00 --- --- --- --- --- 0.000 2.10 20,704 4811.10 --- --- --- --- 0.08 --- --- --- --- --- 0.079 2.45 25,451 4811.45 --- --- --- --- 0.75 --- --- --- --- --- 0.754 2.80 30,095 4811.80 --- --- --- --- 1.79 --- --- --- --- --- 1.786 3.15 34,437 4812.15 --- --- --- --- 3.08 --- --- --- --- --- 3.080 3.50 38,061 4812.50 --- --- --- --- 4.59 --- --- --- --- --- 4.588 Pond Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Monday, 11 / 20 / 2023 Pond No. 2 - Pond C1 Pond Data UG Chambers -Invert elev. = 4821.00 ft, Rise x Span = 2.00 x 2.00 ft, Barrel Len = 100.00 ft, No. Barrels = 19, Slope = 0.00%, Headers = Yes Encasement -Invert elev. = 4820.00 ft, Width = 4.00 ft, Height = 3.00 ft, Voids = 40.00% Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft) 0.00 4820.00 n/a 0 0 0.30 4820.30 n/a 985 985 0.60 4820.60 n/a 985 1,970 0.90 4820.90 n/a 985 2,955 1.20 4821.20 n/a 1,187 4,142 1.50 4821.50 n/a 1,540 5,683 1.80 4821.80 n/a 1,673 7,356 2.10 4822.10 n/a 1,721 9,077 2.40 4822.40 n/a 1,697 10,774 2.70 4822.70 n/a 1,598 12,372 3.00 4823.00 n/a 1,348 13,720 Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise (in)= 0.00 0.00 0.00 0.00 Span (in)= 0.00 0.00 0.00 0.00 No. Barrels = 0 0 0 0 Invert El. (ft)= 0.00 0.00 0.00 0.00 Length (ft)= 0.00 0.00 0.00 0.00 Slope (%)= 0.00 0.00 0.00 n/a N-Value = .013 .013 .013 n/a Orifice Coeff.= 0.60 0.60 0.60 0.60 Multi-Stage = n/a No No No Crest Len (ft)= 0.50 0.00 0.00 0.00 Crest El. (ft)= 4822.00 0.00 0.00 0.00 Weir Coeff.= 3.33 3.33 3.33 3.33 Weir Type = Rect --- --- --- Multi-Stage = No No No No Exfil.(in/hr)= 0.000 (by Wet area) TW Elev. (ft)= 0.00 Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). Stage / Storage / Discharge Table Stage Storage Elevation Clv A Clv B Clv C PrfRsr Wr A Wr B Wr C Wr D Exfil User Total ft cuft ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs 0.00 0 4820.00 --- --- --- --- 0.00 --- --- --- --- --- 0.000 0.30 985 4820.30 --- --- --- --- 0.00 --- --- --- --- --- 0.000 0.60 1,970 4820.60 --- --- --- --- 0.00 --- --- --- --- --- 0.000 0.90 2,955 4820.90 --- --- --- --- 0.00 --- --- --- --- --- 0.000 1.20 4,142 4821.20 --- --- --- --- 0.00 --- --- --- --- --- 0.000 1.50 5,683 4821.50 --- --- --- --- 0.00 --- --- --- --- --- 0.000 1.80 7,356 4821.80 --- --- --- --- 0.00 --- --- --- --- --- 0.000 2.10 9,077 4822.10 --- --- --- --- 0.05 --- --- --- --- --- 0.053 2.40 10,774 4822.40 --- --- --- --- 0.42 --- --- --- --- --- 0.421 2.70 12,372 4822.70 --- --- --- --- 0.98 --- --- --- --- --- 0.976 3.00 13,720 4823.00 --- --- --- --- 1.66 --- --- --- --- --- 1.665 Pond Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Monday, 11 / 20 / 2023 Pond No. 3 - Pond C2 Pond Data UG Chambers -Invert elev. = 4814.70 ft, Rise x Span = 2.00 x 2.00 ft, Barrel Len = 455.00 ft, No. Barrels = 4, Slope = 0.00%, Headers = Yes Encasement -Invert elev. = 4813.70 ft, Width = 4.00 ft, Height = 3.00 ft, Voids = 40.00% Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft) 0.00 4813.70 n/a 0 0 0.30 4814.00 n/a 889 889 0.60 4814.30 n/a 889 1,778 0.90 4814.60 n/a 889 2,667 1.20 4814.90 n/a 1,071 3,739 1.50 4815.20 n/a 1,390 5,129 1.80 4815.50 n/a 1,510 6,639 2.10 4815.80 n/a 1,554 8,193 2.40 4816.10 n/a 1,531 9,724 2.70 4816.40 n/a 1,442 11,166 3.00 4816.70 n/a 1,217 12,383 Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise (in)= 0.00 0.00 0.00 0.00 Span (in)= 0.00 0.00 0.00 0.00 No. Barrels = 0 0 0 0 Invert El. (ft)= 0.00 0.00 0.00 0.00 Length (ft)= 0.00 0.00 0.00 0.00 Slope (%)= 0.00 0.00 0.00 n/a N-Value = .013 .013 .013 n/a Orifice Coeff.= 0.60 0.60 0.60 0.60 Multi-Stage = n/a No No No Crest Len (ft)= 0.50 0.00 0.00 0.00 Crest El. (ft)= 4815.70 0.00 0.00 0.00 Weir Coeff.= 3.33 3.33 3.33 3.33 Weir Type = Rect --- --- --- Multi-Stage = No No No No Exfil.(in/hr)= 0.000 (by Wet area) TW Elev. (ft)= 0.00 Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). Stage / Storage / Discharge Table Stage Storage Elevation Clv A Clv B Clv C PrfRsr Wr A Wr B Wr C Wr D Exfil User Total ft cuft ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs 0.00 0 4813.70 --- --- --- --- 0.00 --- --- --- --- --- 0.000 0.30 889 4814.00 --- --- --- --- 0.00 --- --- --- --- --- 0.000 0.60 1,778 4814.30 --- --- --- --- 0.00 --- --- --- --- --- 0.000 0.90 2,667 4814.60 --- --- --- --- 0.00 --- --- --- --- --- 0.000 1.20 3,739 4814.90 --- --- --- --- 0.00 --- --- --- --- --- 0.000 1.50 5,129 4815.20 --- --- --- --- 0.00 --- --- --- --- --- 0.000 1.80 6,639 4815.50 --- --- --- --- 0.00 --- --- --- --- --- 0.000 2.10 8,193 4815.80 --- --- --- --- 0.05 --- --- --- --- --- 0.053 2.40 9,724 4816.10 --- --- --- --- 0.42 --- --- --- --- --- 0.421 2.70 11,166 4816.40 --- --- --- --- 0.98 --- --- --- --- --- 0.976 3.00 12,383 4816.70 --- --- --- --- 1.66 --- --- --- --- --- 1.665 Pond Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Monday, 11 / 20 / 2023 Pond No. 4 - Pond D Pond Data Contours -User-defined contour areas. Conic method used for volume calculation. Begining Elevation = 4817.25 ft Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft) 0.00 4817.25 600 0 0 0.50 4817.75 975 390 390 1.00 4818.25 1,365 582 972 1.50 4818.75 1,771 782 1,754 Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise (in)= 0.00 0.00 0.00 0.00 Span (in)= 0.00 0.00 0.00 0.00 No. Barrels = 0 0 0 0 Invert El. (ft)= 0.00 0.00 0.00 0.00 Length (ft)= 0.00 0.00 0.00 0.00 Slope (%)= 0.00 0.00 0.00 n/a N-Value = .013 .013 .013 n/a Orifice Coeff.= 0.60 0.60 0.60 0.60 Multi-Stage = n/a No No No Crest Len (ft)= 0.33 0.00 0.00 0.00 Crest El. (ft)= 4818.25 0.00 0.00 0.00 Weir Coeff.= 3.33 3.33 3.33 3.33 Weir Type = Rect --- --- --- Multi-Stage = No No No No Exfil.(in/hr)= 0.000 (by Wet area) TW Elev. (ft)= 0.00 Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). Stage / Storage / Discharge Table Stage Storage Elevation Clv A Clv B Clv C PrfRsr Wr A Wr B Wr C Wr D Exfil User Total ft cuft ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs 0.00 0 4817.25 --- --- --- --- 0.00 --- --- --- --- --- 0.000 0.50 390 4817.75 --- --- --- --- 0.00 --- --- --- --- --- 0.000 1.00 972 4818.25 --- --- --- --- 0.00 --- --- --- --- --- 0.000 1.50 1,754 4818.75 --- --- --- --- 0.39 --- --- --- --- --- 0.389