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HomeMy WebLinkAbout20 - Design Report - S 19th Widening STORMWATER DESIGN REPORT FOR: SOUTH I9TH WIDENING BOZEMAN, MT Prepared By: MADISON ENGINEERING Madison Engineering 895 Technology Blvd Ste 203 Bozeman, MT 59718 (406) 586-0262 January 22", 2020 STORMWATER DESIGN REPORT FOR: SOUTH 19TH WIDENING BOZEMAN, MT 0 r1 T A N ��C1tiR1S C�• '• ° Cr PF : l u tp � Madison Engineering 895 Technology Blvd Ste 203 Bozeman, MT 59718 (406) 586-0262 January 22nd9 2020 S 19TH WIDENING STORMWATER DESIGN REPORT A. Introduction This design report will give an overview of the proposed stormwater system for the South 19th widening in Bozeman, MT. The widening will require stormwater structures including curb inlets, storm piping, valley gutters, culverts and a detention pond. The following references were used in the preparation of this report: a. COB Design Standards and Specifications Policy, 2017. Addendum #6 b. COB Modifications to Montana Public Works Standard Specifications (MPWSS). Addendum #3 c. Bozeman Stormwater Master Plan - 1982 B. Peak Flow (Runoff) Calculations The project area was divided into drainage areas as shown on Sheet SD1.0, provided in Appendix G. These areas were used to determine the stormwater runoff flows, which in turn were used to determine the size of the storm drain, gutter capacities, curb inlet sizes, and detention pond volumes. The flow coming into Basin 1 from off-site to the south was determined from a stormwater report for Meadow Creek Subdivision done by Engineering Inc in 2006. The 25-year storm event for the off-site basin, Basin 0, was determined in the report to be 3.81 cfs. This is the flow that comes on site through Culvert #1. Peak flow calculations (including an excerpt from the aforementioned Meadow Creek Subdivision report) are provided in Appendix B. C. Storm Drain Piping Culverts Storm drain piping/culverts were sized to carry the 25-year storm event peak runoff flow. All culverts were sized using Manning's Equation for circular channels to determine the pipes capacity to flow stormwater at specified grades. See storm drain schedule and calculations in Appendix A. Culvert #1 is a proposed 15" equivalent arch RCP and is sized to convey the off-site flow from Basin 0. Downstream from this culvert is Culvert #2, which conveys water along the swale underneath a proposed pedestrian walkway. Culvert #2 is also a proposed 15" equivalent arch RCP. Culvert #3 is an extension of an existing culvert that passes flows under S. 191h Ave and into a roadside ditch on the east side of S 19"'. Culvert #4, #5 and #6 are all proposed equivalent 18" arch RCP. Culvert #4 conveys water from the proposed Storm Drain Inlet (SDI#1) to the proposed Flow Control Structure. Culvert #5 will distribute water from the Flow Control Structure to the proposed Detention Pond located West of South 19`' Avenue and South of Grace Bible Church at the far NE corner of the property. Once the Flow Control Structure reaches its capacity, water will then be directed through the flow control structure and through Culvert #6. Culvert #6 will then convey the overflow water to the existing ditch along the West side of South 19"' Avenue flowing North. See Appendix A for calculations. S 19°i Roadway Widening StorniNvater Design Report Page 1 of D. Stormwater Detention Pond One (1) detention pond is proposed for this project, which is designed to handle the 10-year, 2-hr storm event, and discharge the pre-development 10-year flowrate. The pond is designed to capture the basins that have been outlined in the pond schedule in Table 1 of this report. The Basins are identified on Sheet SD1.0 in Appendix G of this report. Outlet structure calculations can be found in Appendix D of this report. Pond sizing calculations can be found in Appendix C of this report. TABLE 1 POND VOLUMES Pond ID Contributing Basins* Required Volume Approx. Proposed C.Y. Volume C.Y. 1 2 72.75 74 * See Sheet SD 1.0 in Appendix G E. Gutter Flow and Curb Inlets Curb inlets are proposed in the gutter line as required. A 25-year storm event was used to calculate the runoff flows. Based on these values, the curb inlet capacities are more than adequate for carrying the 25-year storm event. The gutter-flow capacity is also well above the designed runoff values to avoid overflow encroachment into the drive lane. One (1) double curb inlet is proposed. Gutter flow and curb inlet calculations are provided in Appendix E. Appendices A. Storm Drain Schedule and Calculations B. Peak Flow(runoff) Calculations C. Stormwater Pond Calculations D. Outlet Structure Flow Calculations E Gutter Flow and Curb Inlet Calculations F. Swale Calculations G. Sheet SDI.0 Storm Drainage Basins S 19'h Road«vay Widening Stormwater Design Report Page 2 o f 2 Appendix A: Storm Drain Schedule and Calculations Appendix A Table 1:Storm Drain Schedule Pipe Schedule Culvert ID Size Slope Basins* Required Capacity Actual Capacity CULVERT#1 15"equiv.RCP 3.21% 0 3.81 11.6 CULVERT#2 15"equiv. RCP 2.36% 0+1 3.89 9.9 CULVERT#3 18"PVC 0.70% 0+1+3 3.93 8.8 CULVERT#4 18"equiv.RCP 0.20% 2 4.25 4.7 CULVERT#5 18"equiv.RCP 0.20% 2 4.25 4.7 CULVERT#6 18"equiv.RCP 0.20% 2 4.25 4.7 *See Exhibit SD1.0 in Appendix G for the Basin identification shown in Table 1 above CIRCULAR CHANNEL CULVERT11t'I T Manning's Eqn. Q=1.486 A R 213 StR n ram/ Diameter,do(in)= 15.0 0-Enter Value Diameter,do(ft)= 1.25 THETA Units= 1.486 n= 0.013 Slope,S(ft/ft) 0.0321 Welted Hydraulic Hydraulic bect,011 Lneroy, - Area,A Perimeter,P Radius,R Top Width, Depth,D Factor,Z 0(gpd-8 =V�Qq Depth,y(it) Theta(rad) (it") (it) (it) T(it) (it) (it") Q(cis) 0(gpm) hour day) V(fUs) (it) 0.00 0,00 0.00 0.00 0,00 0.00 OAi: 0.00 0.0 U.0 U.0 0.0 0.00 0.06 0.90 0.02 0.56 0.04 0.54 0.04 0.00 0.1 24.9 11972.8 2.4 0.09 0.13 1.29 0.06 0.80 0.00 0.75 0.09 0.02 0.2 108.4 52053.6 3.8 0.22 0.19 1.69 OA2 0.99 0.12 0.89 0.13 0.04 0.6 252.5 121195.1 4.9 0.37 0.25 1.55 0.17 1.16 0.15 1.00 0.17 0.07 1.0 454.9 218336.9 5.8 0.52 0.31 2.09 0.24 1.31 0.16 1.08 0.22 0.11 1.6 711.5 341529.5 6.6 0.68 0.38 2.32 0.31 1.46 0.21 1.15 0.27 0.16 2.3 1017.2 488255.5 7.3 0.83 0." 2.53 0.38 1.58 0.24 1.19 0.32 0.22 3.0 1365.8 655574.0 8.0 0.98 0.50 2.74 0.46 1.71 0.27 1.22 0.37 0.28 3.9 1750.4 840193.8 8.5 1.12 0.56 2.94 0.54 1,84 0.29 1.24 0.43 0.35 4.8 2163.6 1038511.2 9.0 1.26 0.63 314 0681 1.96 0,31 1.25 0.49 0.43 5.8 2597.1 1246623.5 9.4 1.38 0.69 3.34 0.69 2.09 0.33 1.24 0.56 0.52 6.8 3042.3 1460322.0 9.8 1.49 0.75 3.54 0.77 2.22 0.35 1.22 0.63 0.61 7.8 3489.7 1675063.6 10.1 1.59 0.81 3.75 0.84 2.34 0.36 1.19 0.71 0.71 8.8 3929.0 1885913.1 10.4 1.67 0.88 3.96 0.92 2,48 0.37 1.15 0.00 0.82 9.7 4348.8 2087440.3 10.6 1.73 0.94 4.19 0,99 L62 0.38 1.08 0.91 0.94 10.6 4736.5 2273536.4 10.7 1.77 1.00 4.43 1.05 2.77 0.38 1.00 1.05 1.08 11.3 5077.2 2437066.4 10.7 1.79 1.06 4.69 1.11 2.93 0.38 0.89 1.25 1.24 11.9 5352.4 2569142.6 10.7 1.79 1.13 5,00 1.16 3.12 0.37 0.75 1.55 1.45 12.3 5536.0 2657296.1 10.6 1.75 1.19 5.38 1.20 3.30 0.36 0.54 2.21 1.79 12.4 5581.3 2679030.2 10.3 1.66 1-25 6.28 1.23 3.93 0.31 0.00 1 11.6 5196.0 2494090.1 9.4 1.38 CIRCULAR CHANNEL CULVERT#2 T Manning's Eqn. Q=1.486 A Ry'S'n n Diameter,do(in)= 15.0 4-Enter Value Diameter,do(ft)= 1.25 THETA Units= 1.486 n= 0.013 Slope,S(ftfft) 0.0236 Wetted y rau is Hydraulic c Area,A Perimeter,P Radius,R Top Width, Depth,D Factor,Z Q(gpd-8 =V'12g Depth,y(ft) Theta(rad) (ft) (ft) (ft) T(ft) (ft) (WI) Q(cfs) Q(gpm) hour day) 'V(ftls) (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.00 0.06 0.90 0.02 0.56 0.04 0.54 0.04 0.00 0.0 214 10266.0 2.1 0.07 0.13 1.29 0.06 0.80 0.08 0.75 0.09 0.02 0.2 93.0 44632.8 3.2 0.16 0.19 1.59 0.12 0.99 0.12 0.89 0.13 0.04 0.5 216.5 103917.5 4.2 0.27 0.25 1.85 0.17 1.16 0.15 1.00 0.17 0.07 0.9 390.0 187210.7 5.0 0.38 0.31 2.09 0.24 1.31 0.18 1.08 0.22 0.11 1.4 610.1 292840.9 5.7 0.50 0.38 2.32 0.31 1.45 0.21 1.15 0.27 0.16 1.9 872.2 418649.6 6.3 0.61 0.44 2.53 0.38 1.58 0.24 1.19 0.32 0.22 2.6 1171.1 562115.0 6.8 0.72 0.50 2.74 0.46 1.71 0.27 1.22 0.37 0.28 3.3 1500.9 720415.3 7.3 0.83 0.56 2.94 0.54 1.84 0.29 1.24 0.43 0.35 4.1 1855.1 890460.5 7.7 0.92 0.63 3.14 0.61 1.96 0.31 1.25 0.49 0.43 5.0 22269 10689042 8.1 1.02 0.69 3.34 0.69 2.09 0.33 1.24 0.56 0.52 5.6 2608.6 1252137.8 8.4 1.10 0.75 3.64 0.77 2.22 0.35 1.22 0.63 0.61 6.7 2992.2 14362657 8.7 1.17 0.81 3.75 0.84 2.34 0.36 1.19 0.71 0.71 7.5 3368.9 16170564 8.9 1.23 0.88 3.96 0.92 2.48 0.37 1.15 0.80 0.82 8.3 3728.9 1789853.8 9.1 1.27 0.94 4.19 0.99 2.62 0.38 1.08 0.91 0.94 9.0 4061.3 1949419.9 9.2 1.30 1.00 4.43 1.05 2.77 0.38 1.00 1.05 1.08 9.7 4353.4 2089637-0 9.2 1.32 1.06 4.69 1.11 2.93 0.38 0.89 1.25 1.24 10.2 4589.3 2202884.3 9.2 1.31 1.13 5.00 1.16 3.12 0.37 0.75 1.55 1.45 10.6 4746.8 2278470.6 9.1 1.28 1.19 5.38 1.20 3.36 0.36 0.54 2.21 1.79 10.7 47856 2297106.3 8.9 1.22 1.25 6.28 1.23 3.93 0.31 0.00 9.9 4455.3 21385313 8.1 1.02 CIRCULAR CHANNEL CULVERT#3(SD#3) T Manning's Eqn. Q= 1.486 A Ry'S'"' n Diameter,do(in)= 18.0 4-Enter Value Diameter,do(ft)= 1.50 "THETA Units= 1.486 n= 0.013 Slope,S(ftlft) 0.007 Wetted Hydraulic Hydraulic ec'on Energy, Area,A Perimeter,P Radius,R Top Width, Depth,D Factor,Z Q(gpd-8 =V2l2g Depth,y(ft) Theta(rad) (ft') (it) (11) T(tt) (ft) (ftStl) 0(cfs) Q(gpm) hour day) V(ft/s) (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 00 0.0 0.0 0.00 0.08 0.90 0.03 0.68 0.05 0.65 0.05 0.01 0.0 18.9 9091.7 1.3 0.03 0.15 1.29 0.09 0.97 0.10 0.90 0.10 0.03 0.2 823 39527,3 2.0 0.06 0.23 1.59 0.17 1.19 0.14 1.07 0.16 0.07 0.4 191.7 92030.5 2.6 0.10 0.30 1.85 0.26 1.39 0.18 1.20 0.21 0.12 0.8 345.4 165795.9 3.1 0.15 0.38 2.09 0.35 1.57 0.22 1.30 0.27 0.18 1.2 540.3 259343.1 3.5 0.19 0.45 2.32 0.45 1.74 0.26 1.37 0.32 0.25 1.7 772.4 370760.7 3.9 0.23 0.53 2.53 0.55 1.90 0.29 1.43 0.39 0.34 2.3 1037.1 497815.3 4.2 0.27 0.60 2.74 0.66 2.05 0.32 1.47 0.45 0.44 3.0 1329.2 638007.7 4.5 0.31 0.68 2.94 0.77 2.21 0.35 1.49 0.52 0.55 3.7 1642.9 788601.6 4.7 0.35 0.75 3.14 0.88 2.36 0.38 1.50 0.59 0.68 4.4 1972.2 946633.4 5.0 0.38 0.83 3.34 1.00 2.51 0.40 1.49 0.67 0.81 5.1 2310.2 11089070 5.2 0.41 0.90 3.64 1.11 2.66 0.42 1.47 0.75 0.96 5.9 2649.9 1271972.7 5.3 0.44 0.98 3.75 1.22 2.81 0.43 1.43 0.85 1.12 6.6 2983.5 1432082.9 5.5 0.46 1.05 3.96 1.32 2.97 0.44 1.37 0.96 1.30 7.4 3302.3 1585114.2 5.6 0.48 1.13 4.19 1.42 3.14 0.45 1.30 1.09 1.49 8.0 3596.7 1726427.7 5.6 0.49 1.20 4.43 1.52 3.32 0.46 1.20 1.26 1.70 8.6 3855.4 1850605.5 5.7 0.50 1.28 4.69 1.60 3.52 0.45 1.07 1.49 1.96 9.1 4064.4 1950898.6 5.7 0.50 1.35 5.00 1.68 3.75 0.45 0.90 1.86 2.29 9.4 4203.8 2017838,7 5.6 0.49 1.43 5.38 1.73 4.04 0.43 0.65 2.65 2.82 9.4 4238.2 20343427 5.4 0.46 1.50 6.28 1.77 4.71 0.38 0.00 1 0.8 39456 1893906.9 1 5.0 1 0.38 CIRCULAR CHANNEL Culvert#4 T Manning's Eqn. Q=1.486 A R"'S11' n Diameter,do(in)= 18.0 A-Enter Value Diameter,do(ft)= 1.50 THETA Units= 1.486 n= 0.013 Slope,S(ft/ft) 0.002 Wetted Hydraulic Hydraulic Area,A Perimeter,P Radius,R Top Width, Depth,D Factor,Z Q(gpd-8 =V'/2g Depth,y(ft) Theta(red) (ft') (ft) (ft) T(ft) (ft) (ft") Q(cfs) Q(gpm) hour day) V(ft/s) (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 00 0.0 0.00 0.08 0.90 0.03 0.68 0.05 0.65 0.05 0.01 0.0 101 4859.7 0.7 0.01 0.15 1.29 0.09 0.97 0.10 0.90 0.10 0.03 0.1 44.0 211282 1.1 0.02 0.23 1.59 0.17 1.19 0.14 1.07 0.16 0.07 0.2 102.5 49192.4 1.4 0.03 0.30 1.85 0.25 1.39 0.18 1.20 0.21 0.12 0.4 184.6 88621.6 1.6 0.04 0.38 2.09 0.35 1.57 0.22 1.30 0.27 0.18 0.6 288.8 138624.7 1.9 0.05 0.45 2.32 0.45 1.74 0.26 1.37 0.32 0.25 0.9 412.9 198179.9 2.1 0.07 0.53 2.53 0.55 1.90 0.29 1.43 0.39 0.34 1.2 554.4 266093.4 2.2 0.08 0.60 2.74 0.66 2.05 0.32 1.47 0.45 0.44 1.6 710.5 341029.5 2.4 0.09 0.68 2.94 0.77 2.21 0.35 1.49 0.52 0.55 2.0 878.2 4215253 2.5 0.10 0.75 3.14 0.88 2.36 0.38 1.50 0.59 0.68 2.3 1054.2 505996.8 2.7 0.11 0.83 3.34 1.00 2.51 0.40 1.49 0.67 0.81 2.8 1234.9 592735,7 2.8 0.12 0.90 3.54 1.11 2.66 0.42 1.47 0.75 0.96 3.2 1416.5 679898.0 2.9 0.13 0.98 3.75 1.22 2.81 0.43 1.43 0.85 1.12 3.6 1594.8 765480.5 2.9 0.13 1.05 3.96 1.32 2.97 0.44 1.37 0.96 1.30 3.9 1765.2 847279.2 3.0 0.14 1.13 4.19 1.42 3.14 0.45 1.30 1.09 1.49 4.3 1922.5 922814.4 3.0 0.14 1.20 4.43 1.52 3.32 0.46 1.20 1.26 1.70 4.6 2060.8 989190.3 3.0 0.14 1.28 4.69 1.60 3.52 0.45 1.07 1.49 1.96 4.8 2172.5 1042799.2 3.0 0.14 1.35 5.00 1.68 3.75 0.45 0.90 1.86 2.29 5.0 2247.0 1078580.1 3.0 0.14 1.43 5.38 1.73 4.04 0.43 0.65 2.65 2.82 6.0 2265.4 1087401.9 2.9 0.13 1.50 6.28 1.77 4.71 0.38 0.00 4.7 2109.0 10123358 2.7 0.11 CIRCULAR CHANNEL Culvert*5 T Manning's Eqn. Q=1.486 A R24 S112 n Dlameter,do(in)= 18.0 F-Enter Value Diameter,do(ft)= 1.60 THETA Units= 1.486 n= 0.013 Slope,S(ft/ft) 0.002 Wetted Hydraulic Hydraulic a u±n -:1ef9y,L Area,A Perimeter,P Radius,R Top Width, Depth,D Factor,<'. Q(gpd-8 =V212g Depth,y(ft) Theta(rad) (ft') (ft) (ft) T(ft) (ft) (n ) Q(cfs) Q(gpm) hour day) V(ftls) (ft) 0.00 0 00 0,00 0.00 0.00 0,00 0.60 0 6. 0.0 0.0 0.0 0.0 0.00 0.08 0.90 0.03 0.68 0.05 0.65 0.05 0.01 0.0 10.1 4859.7 0.7 0.01 0.16 1.29 0.09 0.97 0.10 0.90 0.10 0.03 0.1 44.0 21128.2 1.1 0.02 0.23 1.59 0.17 1.19 0.14 1.07 0.16 0.07 0.2 102.5 49192.4 1.4 0.03 0.30 1.85 0.25 1.39 0.18 1.20 0.21 0.12 0.4 184.6 88621.6 1.6 0.04 0.38 2.09 0.35 1.67 0.22 1.30 0.27 0 1 b 0.6 288.8 138624.7 1.9 0.06 0.45 2.32 0.45 1.74 0,26 1.37 0.32 0.25 0.9 412.9 198179.9 2.1 0.07 0.53 2.53 0.55 1.90 0.29 1.43 0.39 0.3 i 1.2 554.4 266093.4 2.2 0.08 0.60 2.74 0.66 2.05 0.32 1A7 0.45 0,44 1.6 710.5 341029.5 2.4 0.09 0.68 2.94 0.77 2.21 0.35 1.49 0.62 0.511, 2.0 878.2 421525.3 2.5 0.10 0.75 3.14 0.88 2.36 0.38 1.60 0.59 0.6° 2.3 1054.2 505996.8 2.7 0.11 0.83 3.34 1.00 2.51 0.40 1.49 0.67 0.81 2.8 1234.9 592735.7 2.6 0.12 0.90 3.54 1.11 2.66 0.42 1.47 0.7E 0.9C 312 1416.5 679898.0 2.9 0.13 0.98 3.75 1.22 2.81 0.43 1.43 0.85 1.12 3.6 1594.8 765480.5 2.9 0.13 1.05 3.96 1.32 2.97 0.44 1.37 0:96 1.30 3.9 1765.2 847279.2 3.0 0.14 1.13 4.19 1.42 3.14 0.45 1.30 1.09 1.49 4.3 1922.5 922814.4 3.0 0.14 1.20 4.43 1,52 3.32 0.46 1.20 1.26 1.711 4-6 2060.8 989190.3 3.0 0.14 1.28 4.69 1.60 3.52 0.45 1.07 1.49 1.90 4,8 2172.5 1042799.2 3.0 0.14 1.35 5.00 1.68 3.75 0.45 0.90 1.86 2.20 5.0 2247.0 1078580.1 3.0 0.14 1.43 5.3.8 1.73 4.04 0.43 0.65 2.65 2.82 5.0 2265A 1087401.9 2.9 0.13 1.50 6.28 1.77 4.71 0.38 0.00 1 4.7 2109.0 1012335.E 2.7 0.11 CIRCULAR CHANNEL Culvert#6 T Manning's Eqn. Q=1.486 A Rw S112 n Diameter,do(in)= 18.0 -111--Enter Value Dlameter,do(ft)= 1.50 THETA Units= 1.486 n= 0.013 Slope,S(fUft) 0.002 Wetter Hydraulic Hydraulic Lneggy, Area,A Perimeter,P Radius,R Top Width, Depth,D Factor,Z Q(gpd-8 =V212g Depth,y(ft) Theta(rad) (it') ift) ift) T(ft) (ft) (ft"') Q(cfs) Q(gpm) hour day) V(ft/s) (ft) 0.00 0.00 0.00 0.00 0,06 0.00 0.00 0.0G 0.0 0.0 0.0 0.0 0.00 0.08 0.90 0.03 0.66 0.05 0.65 0.05 0.01 0.0 10.1 4859.7 0.7 0.01 0.15 1.29 0.09 0.97 0.10 0.90 0.10 0.02 0.1 44.0 21128.2 1.1 0.02 0.23 1.59 0.17 1.19 0.14 1.07 0.16 0.07 0.2 102.5 49192.4 1.4 0.03 0.30 1.65 0.25 1.39 0.18 1.20 0.21 0,12 0.4 184.6 88621.6 1.6 0.04 0.38 2.09 0.35 1.57 0.22 1.30 0.27 0.18 0.6 288.8 138624.7 1.9 0.05 0.45 2.32 0.45 1.74 0.26 1.37 0.32 0.25 0.9 412.9 198179.9 2.1 0.07 0.53 2.53 0.55 1.90 0.29 1.43 0.39 0.34 1.2 554.4 266093.4 2.2 0.08 0.60 2.74 0.86 2.05 0.32 1.47 0.45 0.44 1.6 710.5 341029.5 2.4 0.09 0.68 2.94 0.77 2.21 0.35 1.49 0.52 0.55 2.0 878.2 421525.3 2.5 0.10 0.75 3.14 0.68 2.36 0.38 1.50 0.59 0,66 2.3 1054.2 505996.8 2.7 0.11 0.63 3.34 1.00 2.51 0.40 1.49 0.67 0.81 2.8 1234.9 592735.7 2.8 0.12 0.90 3.64 1.11 2.66 0.42 1.47 0.75 0.9G 3.2 1416.5 679898.0 2.9 0.13 0.98 3.75 1.22 2.81 0.43 1.43 0.65 1.12 3.6 1594.8 765480.5 2.9 0.13 1.05 3.96 1.32 2.97 0.44 1.37 0.98 1.30 3.9 1765.2 847279.2 3.0 0.14 1.13 4.19 1.42 3.14 0.45 1.30 1.09 1.49 4.3 1922.5 922814.4 3.0 0.14 1.20 4.43 1.52 3.32 0,46 1.20 1.26 1.70 4.6 2060.8 989190.3 3.0 0.14 1.28 4.69 1.60 3,52 0.45 1.07 1.49 1.96 4.8 2172.5 1042799.2 3.0 0.14 1.36 5.00 1.68 3.75 0.45 0.90 1.86 2,25; 5.0 2247.0 1078580.1 3.0 0.14 1.43 6.38 1.73 4.04 0.43 0.65 2.65 2 K 5 0 2265.4 1087401.9 2.9 0.13 1.50 6.28 1.77 4.71 0.38 0.00 4.7 2109.0 1012335.8 2.7 0.11 Appendix B: Peak Flow Calculations S 19th Widening BASIN 1 Public Right of Way Only Storm Water Calculations (Reference: Bozeman Stormwater Master Plan - 1982) Design Rainfall Freq. w;.year(see page III -5 of master plan) IDF coefficient a 0.78 IDF coefficient b IDF coefficient n 0.64 Pre/post-development Calculations (no change!) C Areas (ft): open space 18,263 0.20 Total: 18,263 total area: 0.42 acres composite C: 0.20 Overland tr average slope: 1 48 percent travel distance: 888 feet tc: 44 minutes Channel t,. channel tc: minutes Total t,: 44 minutes intensity at t,(fig 23): 0.95 in/hr pre/post-devel peak runoff: 0.08 cfs Q.xls S 19th Widening E1A$—IN-2— Public Right of Way Only Storm Water Calculations Calculation of Reauired Volume for Storm Detention Pond (Reference: Bozeman Stormwater Master Plan-1982) Design Rainfall Freq. year(see page III-5 of master plan) IDF coefficient a 0:78 IDF coefficient b IDF coefficient n 0.64 Pre-development Calculations Post-development Calculations C C Areas(ft): open space 61,111 0.20 Areas(ft2): roadway/sidewalk 100.818 0.90 roadway/sidew 39,707 0.90 Total 100,818 SF Total: 100,618 SF total area: 2.31 acres total area: 2.31 acres composite C: 0.48 composite C: 0.90 Overland tc Overland k average slope: 1 A8 percent average slope: 148 percent travel distance: 1657 feet travel distance: 1657 feet t�: 42 minutes tc: 13 minutes Channel t. Channel t. channel t, minutes channel t, minutes Total tc: 42 minutes Total tc: 13 minutes intensity at tc(fig 23): 0.98 in/hr intensity at tc(fig 23): 2.04 in/hr pre-devel peak runoff: : 09 cfs post-devel peak runoff: +25 cfs Q.xls S 19th Widening BASIN 3 Public Right of Way Only Storm Water Calculations Calculation of Required Volume for Storm Detention Pond (Reference: Bozeman Stormwater Master Plan - 1982) Design Rainfall Freq. 25 year(see page III -5 of master plan) IDF coefficient a 0.78 IDF coefficient b IDF coefficient n 0.64 Pre/post-development Calculations (no change!) C Areas (ft): open space 5.330 0.20 Total: 5,330 total area: 0.12 acres composite C: 0.20 Overland t, average slope: 148 percent travel distance: 247 feet tc: 23 minutes Channel t, channel t, minutes Total%: 23 minutes intensity at t,(fig 23): 1.43 in/hr pre/post-devel peak runoff: 004 Cfs Q.xls Appendix C: Stormwater Pond Calculations South 19th Widening Pond#1 Public Right of Way Only Storm Water Calculations Calculation of Required Volume for Storm Detention Pond (Reference: Bozeman Stormwater Master Plan-1982) Design Rainfall Freq LW,' _' 'year(see page III-5 of master plan) IDF coefficient a 0.64 IDF coefficient b IDF coefficient n 0.65 Pre-development Calculations Post-development Calculations C C Areas(ft'):open space 61,111 0.20 Areas(1`12): roadway/sidewalk iw,; 0 90 roadwaylsldeu 39.707 0.80 Total: 100,818 SF Total: 100,818 SF total area: 2.31 acres total area: 231 acres composite C: 044 composite C: 0.80 Overland tc Overland tc average slope: 1 a' percent average slope:IIPW 1 4F percent travel distance: feet travel distance: 1;5 feet tc: 44 minutes f<: 20 minutes Channel tc Channel tc channel t,. minutes channel tc. minutes Total k: 44 minutes Total t,: 20 minutes intensity at k(fig 23): 0.78 in/hr intensity at I.(fig 23): 1 31 in/hr pre-devel peak runoff: 0.79 cfs post-devel peak runoff: 243 ds Storm Duration Intensity Future Runoff Runoff Release Required (minutes) (in/hr) Rate(cfs) Volume(cf) Volume(cf) Storage(cf) 20 1.31 2.42 2906 951 1956 22 1.23 2.27 3005 1045 1959 24 1 16 2.15 3097 1140 1957 26 1.10 2.04 3185 1235 1950 28 1.05 1.94 3269 1330 1939 30 1.00 1.86 3349 1425 1924 32 0.96 1.78 3425 1520 1905 34 0.93 1.71 3498 1615 1884 36 0.89 1.65 3569 1710 1859 38 0.86 1.59 3637 1805 1833 40 0.83 1.54 3703 1899 1803 42 0.81 1.49 3767 1994 1772 44 0.78 1.45 3828 2089 1739 46 076 1.41 31388 2184 1704 48 0.74 1,37 3947 2279 1668 50 0.72 1.33 4003 2374 1630 52 0.70 1.30 4059 2469 1590 required detention storage(ft')= 1,95? 72 75 CY Volume held between contours: Cumulative Contour Area ff° Delta V(ft) Volume ft' 4953.00 862 4953.5 1.161 506 506 4954.0 1,486 662 1,16E 4954.5 1,836 831 1,998 Design storage at 1.5'depth(ft')= 1,998 Design storage at 1.5'depth(C.Y.)- t Appendix C O.xls Appendix D: Flow Control Structure Calculations Flow Structure Calculations Flow Control Structure(SDMH#3) (Reference: City of Bozeman, Design Standards and Specifications Policy, March 2004, II.D.2, page 24) Note: see Figure A-2 in above reference. Rectangular weir-Q=3.33LH-`' Determine Outlet Slot Width needed: Pre-development flow rate= 0.79 cfs Basin 2 10-year pre-de- Vertical Slot Height= 18 inches Req'd Outlet Slot Width= 0 13 feFI or 5E of an inch Determine Outlet Flow: Outlet Slot Width= 55 inches srac, ifs) cfs Q(apm) L 0.054 24 0.50 0.152 68 0.75 0.279 125 1.00 0.430 193 1.25 0.601 270 1.50 0 790 355 Flow through outlet Stage vs. Discharge 0.90 - 0.80 0.70 0.60 m 0.50 ---— - E' 0.40 - 0.30 M 0.20 — -- --- -- , 0.10 0.00 0 0.5 1 1.5 Stage(ft) Appendix E: Gutter Flow and Curb Inlet Calculations Basin 2 Gutter Capacity Calculations Allowable Pavement Encroachment Given. T= 9 feet(max per city) W= 1.5 feet T - — Ts= 7.5 feet w Ts Sw= 0.08 ft/ft _ Sx= 0.03 ft/ft _ a= 0.96 inches ° d d= 3.24 inches Q. S. n = 0.015 So = 0.0148 j S. Sw/Sx= 2.67 T/W= 6 Capacity for Gutter equations: Q=Q, +QS Where: Qw =E.Q Qs= Discharge within the Roadway above the depressed section (cfs) _ QS Qw= Discharge within the depressed Q ]—Eo (gutter)section (cfs) Cf= 0.56 for English units QS = Cr S�3TS3SO2 Sx= Pavement cross slope (ft/ft) n Ts = Width of flow in the roadway above depressed section So= Gutter longitudinal slope (ft/ft) SW/SX Sw= Gutter depression cross slope(ft/ft) Eo = 1+ g� T= Spread (ft/ft) 1+ S"'/SX(T/W)-1 —1 W= Width of gutter depression (ft/ft) Capacity solution So= 0.0148 Qs= 2.84 cfs Eo= 0.44 cfs Q= 5.10 cfs Gutter flow capability Design Flow Q25 = 4.25 cfs Q25>Q, Design ok Page 1 of 1 Basin 2 Inlet Capacity Calculations ON GRADE Gutter Section Given T= 9 feet T - — W= 1.5 feet Ts = 7.5 feet w Ts Sw= 0.08 ft/ft Sx= 0.03 ft/ft a= 0.96 inches S. d = 3.24 inches d n = 0.015 So= 0.0148 S, From Gutter Capacity ° Qw= 1.84 cfs Qs = 2.33 cfs Capacity for Inlets on Grade Standard 24x36 Curb inlet Cross-sectional area of flow A= 1.22 ft2 Gutter Velocity V= 3.44 ft/sec Fraction of side flow intercepted Rs= 0.214 Total flow capacity intercepted by the inlet Clint= 2.34 cfs Double Curb Inlet= 4.68 Qbybass= 1.83 cfs Design Q for inlet#1 Q25= 4.25 cfs 4.25< 4.68 Inlet Design Ok Page 1 of 2 Appendix F: Swale Calculations Swale Trapezoidal Shaped Channel This is used to determine how much water can be conveyed by this channel Q = 1.486/n*A*R^(")*S^I'/2I Units 1.486 Channel Dimension z 4 SIDE SLOPE b 1 BASE y 1.00 DEPTH Manninq's Equation Q 12.02 cfs n 0.029 ft" A 5.00 ft2 P 9.25 ft R 0.54 ft S 0.005 ft/ft V 2.40 ft/s Based on the Basin rlows from Appendix B the swale must capture Basins 0 (3.81 cfs) + 1 (0.08 cfs) =3.89 cfs. The calculations show the swale to carry 12.02 cfs, which exceeds the minimum requirement of 3.89 cfs. The swale has a 4:1 side slope, a 1' base width, and a V depth, which includes 0.5' of freeboard. Appendix G: Sheet SDI. O Storm Drainage Basins Z W g !. DRAWN BY:EWR REVIEWED 8Y.CGB .~i I PROJECT ENGINEER:CGB DESIGNED BY: CGB i -- CULVERT J2__-- SDNH/2 - CULVE911#5 H max_ _ t-1 CORTROL STRUCTURE) SOMH�1 /'SWALE BASIN 3 _ _ _ POND It ^^'—� CULVERT/6 r F J�t�-J• �__!-���_!��_BASIL 1 C�.20 A=18,W SF�: �� V.-M�....�.�_t �. ! C=0 20 '— (S— —— — ~ a / EXrG CURB CULVEAr M1�.e„� .��+�^ _. A=5,330 SF _ see — ^ ~ INLET - - BASIN 2 - - "^^ l CULVER104 W BASIN 0 ' - - - - A(total)=ID%818 SF A(ea'g pavement)=39,707 SF _ — ,,,..— c � OFrsrrE ——— _ SDI (DOUBLE INLET)J O HAS° I� O c!� U z � q/ N �.WWWWL.I W F-t Q N � � w AH 1 � z SI-IEET SDI.0 U 1QTH I IDENLNG 1 DRAINAGE AkL:AS a PROJECT: 18--127 DATE: APRIL 2019