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HomeMy WebLinkAbout20 - Design Report - Cattail & Max Roundabout STORMWATER MANAGEMENT DESIGN REPORT FOR: CATTAIL & MAX ROUNDABOUT BOZEMAN, MT Prepared By: Madison Engineering 895 Technology Drive, Suite 203 Bozeman, MT 59718 (406) 586-0262 UPDATED SEPTEMBER 2020 CATTAIL AND MAX ROUNDABOUT STORMWATER DESIGN REPORT A. Introduction This design report will give an overview of the stormwater system for the proposed roundabout improvements at the existing intersection of Cattail St and Max Ave in Bozeman, Montana. The roundabout improvements will replace the existing two way stop sign at the intersection. The existing stormwater facilities at the intersection consist of limited curb and gutter, culverts, detention ponds, and drainage ditches. In general, the proposed stormwater facilities modify the existing scenario at the intersection to provide an overall improvement in stormwater capture and treatment. The modifications include removing some of the existing culverts and replacing them with storm drain inlets and piping, installing new culverts, installing new curb and gutter, increasing the volume of the existing detention pond to the Southwest of the intersection, and utilizing the existing pond outfall structure and outfall piping. The following references were used in the preparation of this report: a. COB Design Standards and Specifications Policy, 2004. Addendum #7 b. COB Modifications to Montana Public Works Standard Specifications (MPWSS) B. Existing “Pre-Developed” Condition Summary The existing drainage basins at the existing intersection are delineated on sheet SD1.0, included herein. Basin boundaries were determined by evaluating the existing ground contours, spot elevations picked up by the surveyors, existing as-built information, and engineering judgement. Where possible, the existing basins include the future sidewalk along existing Cattail St and were delineated near to the existing right of way line where possible and if the contours allowed. Detailed basin areas and calculations are included in the Appendix. The existing basins currently drain to the following locations: Existing Basin Runoff "Drains Into" Summary Basin ID Drains Into: EX 1.0 SW Pond EX 1.1 Directly into East Catron Creek EX 2.0 SW Pond EX 2.1 Directly into East Catron Creek EX 3 SW Pond EX 4 Catron St Pond EX 5 Catron St Pond EX 6 Catron St Pond The SW pond is the existing pond adjacent to the Southwest corner of the intersection with a flow control structure and piping. East Catron Creek borders the intersection to the east. The Catron St Pond is the existing detention pond located on the southwest side of the intersection of Catron St and Max Ave, near the Target Shopping Center. Runoff is conveyed from the existing basins primarily by existing culverts and drainage swales adjacent to the asphalt pavement of existing Cattail St and Max Ave. These existing drainage features near to the intersection are displayed on sheet SD1.0. The drainage swales continue north along Max Ave off of the sheet, eventually entering the Catron St pond. Where the Max Ave swales encounter existing intersecting driveways and streets, they enter into existing culverts, until they eventually drain into the existing Catron St detention pond. C. Proposed “Post-Developed” Condition Summary The proposed drainage basins at the intersection are delineated on Sheet SD1.1, included herein. The Post-developed basin boundaries widen and adjust from the pre-developed basins to accommodate the overall area increase due to the installation of the roundabout. The pre to post basin boundaries are maintained as much as practical engineering judgement would warrant. Since the overall impervious area increases due to the installation of the roundabout, the delineated post-development basins also increase in area. The post-development basins include the future sidewalk along Cattail St and Max Ave. Detailed basin areas and calculations are included in the Appendix. The post-development basins, to the greatest extent possible, drain to the same downstream storage feature as the pre-development basins. If possible, the proposed basins were modified to improve the runoff configuration. For example, there is no longer any drainage directly into East Catron Creek. The post-developed basins will drain to the following locations: Proposed Basin Runoff "Drains Into" Summary Basin ID Drains Into: 1 SW Pond 2 SW Pond 3 SW Pond 4 SW Pond 5 Catron St Pond 6 Catron St Pond 6.1 SW Pond Runoff from these basins is conveyed by modification of the existing stormwater features and installing new stormwater features as displayed on Sheet SD1.0 and C2.2. The modifications include removing existing culverts where possible, constructing new curb and gutter, construction new curb inlets and piping where practical, adding two new culverts, and widening the existing SW detention pond to accommodate the additional runoff in the post-developed condition. D. Comparison of Pre-Developed and Post-Developed Runoff Rates In accordance with the City of Bozeman Design Standards, to the best extent possible the post- developed runoffs are limited to the pre-developed runoffs. This was accomplished by re- directing flows from Basins 4 and 6.1 from the Catron St Pond into the SW Pond, and by utilizing the existing pond flow control weir. The Pre-Developed and Post-Developed runoff rates were calculated using the Rational Method, detailed calculations are included in the Appendix. The 10-year 2-hr peak runoffs are summarized below: Pre to Post Development Summation of 10-year 2-hr Flows with respect to Downstream Pond Downstream Drainage Feature: East Catron Creek SW Pond Catron St Pond Pre-Development 10-Year 2-hr Q (cfs) 0.33 1.56 1.95 Post-Development 10-Year 2-hr Q (cfs) 0.00 3.55 1.30 As the summary shows, the Post-Development runoff rate is less than the Pre-Development rates for every downstream feature except for the SW Pond. The SW Pond, however, has an existing 3.25” wide flow control weir, which will be relocated and re-used. The weir restricts the flow and reduces the runoff to a lesser rate. At a head of 1.4’, the release rate is 1.49 cfs, less than the Pre-development rate. The SW Pond will also be enlarged to accommodate the additional runoffs, as described later in this report. Unfortunately, the stormwater design report for the existing SW pond was not able to be obtained. Existing pond weir calculations are included in the Appendix. E. Conveyance Structures 25-year storm event runoff rates were calculated for the post-developed basins utilizing the rational method in accordance with the COB design standards. The basin areas, C values, and 25- year flow rates are summarized in the table below, detailed calculations are included in the Appendix: Drainage Basin No. Total Area (SF) Impervious (SF) C = 0.9 Landscaped (SF) C = 0.2 Weighted C Q 25 Yr (cfs) 1 15,615 12,342 3,273 0.75 1.03 2 14,661 11,991 2,670 0.77 0.99 3 28,252 17,550 10,702 0.63 1.01 4 26,269 16,898 9,371 0.65 0.96 5 13,870 11,637 2,233 0.79 0.96 6 8,526 7,022 1,504 0.78 0.58 6.1 3,139 2,854 285 0.84 0.23 The conveyance structures include existing grass drainage swales, new concrete curb and gutter, two new culverts, and new storm drain piping. The curb & gutter capacity at the minimum project slope of 0.5% without overtopping a depth of 0.15’ below the top of the curb is 2.86 cfs, exceeding the peak runoffs. Runoff from Basins 1, 2, and 6.1 enters storm drain curb inlets and is then piped via 15” round pipe to the existing SW detention pond. Basin 3 runoff is conveyed by an existing grass drainage swale and then enters a new 18” PVC culvert to the SW pond. The existing grass drainage swale, designed by TD&H, has an estimated capacity of 7.69 cfs at a 0.5% slope, exceeding the peak runoffs. Basin 4 flows via the existing grass drainage swale into a new 11”x18” arch culvert, then into the SW Pond. Basins 5 and 6 flow via curb and gutter into the existing swales on Max Ave. The existing SW pond conveyance structures consist of a flow control manhole and weir, an 18”x29” RCP arch outflow culvert, and a 22”x36” RCP arch outflow culvert under the roadway discharging into East Catron Creek. The intent of the design is to maintain the current outfall configuration, all outfall structure inverts will remain the same. The proposed improvements re- use the existing outfall pipes by extending them to a new manhole located at the extended intersection of the pipes. In addition, a new 18”x29” RCP arch pipe is proposed to go from the bottom of the adjusted pond to the existing rectangular intake on the flow control manhole. The 18”x29” RCP has an equivalent area of about 3.1 sf, exceeding the area of the existing rectangular intake of 2.1 sf. The proposed modifications to the pond and its outfall structures are displayed on sheet C2.2, included herein. Calculations for all conveyance facilities are included in the Appendix. F. Inlet Grate Sizing The curb inlets receiving runoff from drainage Basins 1, 2, and 6.1 were checked for capacity. The selected inlet has a capacity of 2.51 cfs. This exceeds the maximum 25-year storm runoff tributary to that point of 1.03 cfs. The swale inlet receiving flows from Basin 4 was also checked. The swale inlet has an estimated flow capacity of 12.24 cfs, which exceeds the Basin 4 25-year peak flow of 1.19 cfs. Calculations are included in the Appendix. G. Stormwater Detention & Treatment The existing SW Pond is proposed to be increased in volume to store the increased runoff from the increase in roadway area as well as for the modifications to the existing drainage pattern of Basins 4 and 6.1. The proposed increase to the pond volume will occur within the existing common space lot designated for the pond. The increase in contributing areas was determined and utilized to calculate the required detention storage as summarized below: Detention Volume Summary Pre-Development Area (sf) 49,242 Pre-Development Weighted C 0.56 Post-Development Area (sf) 87,936 Post-Development Weighted C 0.69 Required Detention Increase (cf) 973 Existing Pond Volume (cf) 33,921 Expanded Pond Volume (cf) 39,199 Volume Increase (cf) 5,278 The proposed contours of the modified pond are displayed on Sheet C2.2, included herein. Treatment is provided by providing additional storage volume below the weir crest elevation. This provides retention storage and allows sediments to settle out prior to leaving the pond. The required retention volume was calculated based on the net increase in impervious areas from pre to post development and the 0.5” storm over a 24-hour period. The weir crest was set to the elevation above the pond bottom to satisfy the storage requirement. The retention volume is summarized in the table below. Retention Volume Summary Net Increase in Impervious Areas (sf) 36620 0.5" Storm Volume (cf) 1,430 Volume of Retention at Weir Crest (cf) 1,468 Standing Water Depth at Weir Crest (ft) 0.77 Pond Overflow Depth (ft) 2.35 Detailed detention and retention pond calculations are included in the appendix. H. Stormwater Facility Maintenance The proposed storm drainage facilities will be privately operated and maintained by the owner, Gallatin Center LP, Gene Graf III. A stormwater facility maintenance plan for this project is included in the Appendix. Appendices A. Drawings and Exhibits B. Basin and Runoff Calculations C. Conveyance Structure Calculations D. Inlet Calculations E. Detention Calculations F. Stormwater Maintenance Plan Appendix A – Drawings & Exhibits 1" = 0 SCALE 50 1002550 SHEETMADISON ENGINEERING895 TECHNOLOGY BLVD, SUITE 203BOZEMAN, MT 59718(406) 586-0262 (406) 586-5740 FAX2131 GRAF STORM DRAIN SD1.0CATTAIL & MAXEXISTING STORM BASIN EXHIBITROUNDABOUTBOZEMAN, MTCACACACACA CACACACACACA CA CA CA CA MAX AVENUE60' R/WMAX AVENUE60' R/WCATTAIL STREET 90' R/WN 27TH AVE65' R/W FUTURE PHASE BLDG PAD BASIN EX 1.0 8,581 SF IMPERVIOUS = 5,302 LANDSCAPED = 3,279 BASIN EX 2.0 8,749 SF IMPERVIOUS = 4,318 LANDSCAPED = 4,431 BASIN EX 3 31,912 SF IMPERVIOUS = 15,395 LANDSCAPED = 16,517 BASIN EX 4 32,300 SF IMPERVIOUS = 20,863 LANDSCAPED = 11,437 BASIN EX 6 9,864 SF IMPERVIOUS = 7,603 LANDSCAPED = 2,261 BASIN EX 5 7,708 SF IMPERVIOUS = 5,913 LANDSCAPED = 1,795 BASIN EX 2.1 2,289 SF IMPERVIOUS = 1,203 LANDSCAPED = 1,086 BASIN EX 1.1 4,629 SF IMPERVIOUS = 3,193 LANDSCAPED = 1,436 LEGEND 1" = 0 SCALE 50 1002550 SHEETMADISON ENGINEERING895 TECHNOLOGY BLVD, SUITE 203BOZEMAN, MT 59718(406) 586-0262 (406) 586-5740 FAX2131 GRAF STORM DRAIN SD1.1CATTAIL & MAXPROPOSED STORM BASIN EXHIBITROUNDABOUTBOZEMAN, MTBASIN 1 15,615 SF IMPERVIOUS = 12,342 LANDSCAPED = 3,273 CACACACACA CACACACACACA CA CA CA CA MAX AVENUE60' R/WMAX AVENUE60' R/WCATTAIL STREET 90' R/WN 27TH AVE65' R/W FUTURE PHASE BLDG PAD BASIN 2 14,661 SF IMPERVIOUS = 11,991 LANDSCAPED = 2,670 BASIN 3 28,252 SF IMPERVIOUS = 17,550 LANDSCAPED = 10,702 BASIN 4 26,269 SF IMPERVIOUS = 16,898 LANDSCAPED = 9,371 BASIN 6 8,526 SF IMPERVIOUS = 7,022 LANDSCAPED = 1,504 BASIN 5 13,870 SF IMPERVIOUS = 11,637 LANDSCAPED = 2,233 BASIN 6.1 3,139 SF IMPERVIOUS = 2,854 LANDSCAPED = 285 LEGEND Appendix B – Basin and Runoff Calculations Drainage Basin No. Total Area (SF) IMPERVIOUS (SF) C = 0.9 LANDSCAPED (SF) C = 0.2 Weighted C Basin Length (ft)Slope % Tc (min) Cf = 1 i 25-yr (in/hr) Q 25 (cfs) i 10-yr (in/hr) Q 10 (cfs) Drains into: EX 1.0 8581 5302 3279 0.63 250 1 5.00 3.83 0.48 3.22 0.40 SW Pond EX 1.1 4629 3193 1436 0.68 70 1 5.00 3.83 0.28 3.22 0.23 East Catron Creek EX 2 8749 4318 4431 0.55 250 1 5.00 3.83 0.42 3.22 0.35 SW Pond EX 2.1 2289 1203 1086 0.57 70 1 5.00 3.83 0.11 3.22 0.10 East Catron Creek EX 3 31912 15395 16517 0.54 650 1 10.00 2.46 0.97 2.05 0.81 SW Pond EX 4 32300 20863 11437 0.65 650 1 10.00 2.46 1.19 2.05 0.99 Catron St Pond EX 5 7708 5913 1795 0.74 250 1 5.00 3.83 0.50 3.22 0.42 Catron St Pond EX 6 9864 7603 2261 0.74 250 1 5.00 3.83 0.64 3.22 0.54 Catron St Pond Subtotal 106032 63790 42242 1 15615 12342 3273 0.75 300 1 5.00 3.83 1.03 3.22 0.87 SW Pond 2 14661 11991 2670 0.77 300 1 5.00 3.83 0.99 3.22 0.84 SW Pond 3 28252 17550 10702 0.63 650 1 10.00 2.46 1.01 2.05 0.84 SW Pond 4 26269 16898 9371 0.65 650 1 10.00 2.46 0.96 2.05 0.80 SW Pond 5 13870 11637 2233 0.79 300 1 5.00 3.83 0.96 3.22 0.81 Catron St Pond 6 8526 7022 1504 0.78 250 1 5.00 3.83 0.58 3.22 0.49 Catron St Pond 6.1 3139 2854 285 0.84 100 1 5.00 3.83 0.23 3.22 0.19 SW Pond Subtotal 110332 80294 30038 Manual estimates Pre to Post Development Summation of 10-year 2-hr Flows with respect to Downstream Pond Drains into: Catron Creek SW Pond Catron St Pond Pre-Development 10-Year 2-hr Q (cfs) 0.33 1.56 1.95 Post-Development 10-Year 2-hr Q (cfs) 0.00 3.55 1.30 CATTAIL AND MAX ROUNDABOUT Peak flow calculations Drainage Areas - Pre (Ex) and Post Development Page 1 of 1 Appendix C – Conveyance Structure Calculations Right Side Slope X:1 3.0 Left Side Slope X:1 3.0 Channel Bottom Width 0.0 ft Flow depth 1.0 ft Wetted Perimeter 6.32 ft Width 6.0 ft Flow Area 3.0 sf Hydraulic Radius 0.47 ft Manning's Roughness 0.025 Slope 0.005 Average Velocity 2.56 ft/s Flow (mannings eqn) 7.69 cfs Swale Capacity Calculations Cattail and Max Roundabout Allowable Pavement Encroachment Given: T =9 feet (max per city) W =1.5 feet Ts =7.5 feet Sw =0.0625 ft/ft Sx =0.03 ft/ft a =0.59 inches d =3.24 inches n =0.015 Sw/Sx =2.08 T/W =6 Capacity for Gutter equations: Where: Qs = Discharge within the Roadway above the depressed section (cfs) Qw = Discharge within the depressed (gutter) section (cfs) Cf = 0.56 for English units Sx = Pavement cross slope (ft/ft) Ts = Width of flow in the roadway above depressed section So = Gutter longitudinal slope (ft/ft) Sw = Gutter depression cross slope (ft/ft) T = Spread (ft) W = Width of gutter depression (ft) Capacity solution Gutter Capacity - Drainage Basin 9 So =0.0050 *Minimum project slope of 0.5% Qs =1.65 cfs Eo =0.42 cfs Q =2.86 cfs A =1.215 sf V =2.35 ft/s BASIN Gutter Capacity (cfs) 25 Yr Design Flow (cfs) Capacity greater than 25- yr flow? 1 2.86 1.03 Yes 2 2.86 0.99 Yes 3 2.86 1.01 Yes 4 2.86 0.96 Yes 5 2.86 0.96 Yes 6 2.86 0.58 Yes 6.1 2.86 0.23 Yes Summary Gutter Capacity Calculations The gutter capacity is adequate for each drainage area. Cattail and Max Roundabout SWQQQ QEQoW 0 S E1 QQ 2 1 O3 8 S3 5 X f S STSn CQ   1 8/3 XW XWo 11T/W /SS1 /SS1E             Page 1 of 1 Cattail and Max Roundabout Pipe 1 Sizing, Basins 1, 2, & 6.1 CIRCULAR CHANNEL Manning's Eqn.1.486 A R2/3 S1/2 n Diameter,do (in) =15.0 Enter Value Diameter,do (ft) =1.25 Units =1.486 n =0.013 Slope, S (ft/ft)0.005 Depth, y (ft) Theta (rad) Area, A (ft 2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.00 0.06 0.90 0.02 0.56 0.04 0.54 0.04 0.00 0.02 9.8 4725.3 1.0 0.01 0.13 1.29 0.06 0.80 0.08 0.75 0.09 0.02 0.10 42.8 20543.9 1.5 0.03 0.19 1.59 0.12 0.99 0.12 0.89 0.13 0.04 0.22 99.6 47831.9 1.9 0.06 0.25 1.85 0.17 1.16 0.15 1.00 0.17 0.07 0.40 179.5 86170.7 2.3 0.08 0.31 2.09 0.24 1.31 0.18 1.08 0.22 0.11 0.63 280.8 134790.9 2.6 0.11 0.38 2.32 0.31 1.45 0.21 1.15 0.27 0.16 0.89 401.5 192699.1 2.9 0.13 0.44 2.53 0.38 1.58 0.24 1.19 0.32 0.22 1.20 539.0 258734.4 3.1 0.15 0.50 2.74 0.46 1.71 0.27 1.22 0.37 0.28 1.54 690.8 331598.0 3.4 0.18 0.56 2.94 0.54 1.84 0.29 1.24 0.43 0.35 1.90 853.9 409867.7 3.6 0.20 0.63 3.14 0.61 1.96 0.31 1.25 0.49 0.43 2.28 1025.0 492003.1 3.7 0.22 0.69 3.34 0.69 2.09 0.33 1.24 0.56 0.52 2.68 1200.7 576343.1 3.9 0.23 0.75 3.54 0.77 2.22 0.35 1.22 0.63 0.61 3.07 1377.3 661094.9 4.0 0.25 0.81 3.75 0.84 2.34 0.36 1.19 0.71 0.71 3.46 1550.6 744310.5 4.1 0.26 0.88 3.96 0.92 2.48 0.37 1.15 0.80 0.82 3.82 1716.3 823847.0 4.2 0.27 0.94 4.19 0.99 2.62 0.38 1.08 0.91 0.94 4.17 1869.4 897293.2 4.2 0.28 1.00 4.43 1.05 2.77 0.38 1.00 1.05 1.08 4.46 2003.8 961833.4 4.2 0.28 1.06 4.69 1.11 2.93 0.38 0.89 1.25 1.24 4.71 2112.4 1013959.7 4.2 0.28 1.13 5.00 1.16 3.12 0.37 0.75 1.55 1.45 4.87 2184.9 1048751.1 4.2 0.27 1.19 5.38 1.20 3.36 0.36 0.54 2.21 1.79 4.91 2202.8 1057328.9 4.1 0.26 1.25 6.28 1.23 3.93 0.31 0.00 4.57 2050.7 984338.8 3.7 0.22 Basin 1+2+6.1 Q =2.25 cfs Capacity?OK Q = 0.00 1.00 2.00 3.00 4.00 5.00 6.00 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA Cattail and Max Roundabout Pipe 2, Basin 1 & 6.1 Pipe Sizing CIRCULAR CHANNEL Manning's Eqn.1.486 A R2/3 S1/2 n Diameter,do (in) =15.0 Enter Value Diameter,do (ft) =1.25 Units =1.486 n =0.013 Slope, S (ft/ft)0.005 Depth, y (ft) Theta (rad) Area, A (ft 2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.00 0.06 0.90 0.02 0.56 0.04 0.54 0.04 0.00 0.02 9.8 4725.3 1.0 0.01 0.13 1.29 0.06 0.80 0.08 0.75 0.09 0.02 0.10 42.8 20543.9 1.5 0.03 0.19 1.59 0.12 0.99 0.12 0.89 0.13 0.04 0.22 99.6 47831.9 1.9 0.06 0.25 1.85 0.17 1.16 0.15 1.00 0.17 0.07 0.40 179.5 86170.7 2.3 0.08 0.31 2.09 0.24 1.31 0.18 1.08 0.22 0.11 0.63 280.8 134790.9 2.6 0.11 0.38 2.32 0.31 1.45 0.21 1.15 0.27 0.16 0.89 401.5 192699.1 2.9 0.13 0.44 2.53 0.38 1.58 0.24 1.19 0.32 0.22 1.20 539.0 258734.4 3.1 0.15 0.50 2.74 0.46 1.71 0.27 1.22 0.37 0.28 1.54 690.8 331598.0 3.4 0.18 0.56 2.94 0.54 1.84 0.29 1.24 0.43 0.35 1.90 853.9 409867.7 3.6 0.20 0.63 3.14 0.61 1.96 0.31 1.25 0.49 0.43 2.28 1025.0 492003.1 3.7 0.22 0.69 3.34 0.69 2.09 0.33 1.24 0.56 0.52 2.68 1200.7 576343.1 3.9 0.23 0.75 3.54 0.77 2.22 0.35 1.22 0.63 0.61 3.07 1377.3 661094.9 4.0 0.25 0.81 3.75 0.84 2.34 0.36 1.19 0.71 0.71 3.46 1550.6 744310.5 4.1 0.26 0.88 3.96 0.92 2.48 0.37 1.15 0.80 0.82 3.82 1716.3 823847.0 4.2 0.27 0.94 4.19 0.99 2.62 0.38 1.08 0.91 0.94 4.17 1869.4 897293.2 4.2 0.28 1.00 4.43 1.05 2.77 0.38 1.00 1.05 1.08 4.46 2003.8 961833.4 4.2 0.28 1.06 4.69 1.11 2.93 0.38 0.89 1.25 1.24 4.71 2112.4 1013959.7 4.2 0.28 1.13 5.00 1.16 3.12 0.37 0.75 1.55 1.45 4.87 2184.9 1048751.1 4.2 0.27 1.19 5.38 1.20 3.36 0.36 0.54 2.21 1.79 4.91 2202.8 1057328.9 4.1 0.26 1.25 6.28 1.23 3.93 0.31 0.00 4.57 2050.7 984338.8 3.7 0.22 Basin 1 + 6.1 Q =1.26 cfs Capacity?OK Q = 0.00 1.00 2.00 3.00 4.00 5.00 6.00 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA Cattail and Max Roundabout Pipe 3, Basin 6.1 Pipe Sizing CIRCULAR CHANNEL Manning's Eqn.1.486 A R2/3 S1/2 n Diameter,do (in) =15.0 Enter Value Diameter,do (ft) =1.25 Units =1.486 n =0.013 Slope, S (ft/ft)0.005 Depth, y (ft) Theta (rad) Area, A (ft 2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.00 0.06 0.90 0.02 0.56 0.04 0.54 0.04 0.00 0.02 9.8 4725.3 1.0 0.01 0.13 1.29 0.06 0.80 0.08 0.75 0.09 0.02 0.10 42.8 20543.9 1.5 0.03 0.19 1.59 0.12 0.99 0.12 0.89 0.13 0.04 0.22 99.6 47831.9 1.9 0.06 0.25 1.85 0.17 1.16 0.15 1.00 0.17 0.07 0.40 179.5 86170.7 2.3 0.08 0.31 2.09 0.24 1.31 0.18 1.08 0.22 0.11 0.63 280.8 134790.9 2.6 0.11 0.38 2.32 0.31 1.45 0.21 1.15 0.27 0.16 0.89 401.5 192699.1 2.9 0.13 0.44 2.53 0.38 1.58 0.24 1.19 0.32 0.22 1.20 539.0 258734.4 3.1 0.15 0.50 2.74 0.46 1.71 0.27 1.22 0.37 0.28 1.54 690.8 331598.0 3.4 0.18 0.56 2.94 0.54 1.84 0.29 1.24 0.43 0.35 1.90 853.9 409867.7 3.6 0.20 0.63 3.14 0.61 1.96 0.31 1.25 0.49 0.43 2.28 1025.0 492003.1 3.7 0.22 0.69 3.34 0.69 2.09 0.33 1.24 0.56 0.52 2.68 1200.7 576343.1 3.9 0.23 0.75 3.54 0.77 2.22 0.35 1.22 0.63 0.61 3.07 1377.3 661094.9 4.0 0.25 0.81 3.75 0.84 2.34 0.36 1.19 0.71 0.71 3.46 1550.6 744310.5 4.1 0.26 0.88 3.96 0.92 2.48 0.37 1.15 0.80 0.82 3.82 1716.3 823847.0 4.2 0.27 0.94 4.19 0.99 2.62 0.38 1.08 0.91 0.94 4.17 1869.4 897293.2 4.2 0.28 1.00 4.43 1.05 2.77 0.38 1.00 1.05 1.08 4.46 2003.8 961833.4 4.2 0.28 1.06 4.69 1.11 2.93 0.38 0.89 1.25 1.24 4.71 2112.4 1013959.7 4.2 0.28 1.13 5.00 1.16 3.12 0.37 0.75 1.55 1.45 4.87 2184.9 1048751.1 4.2 0.27 1.19 5.38 1.20 3.36 0.36 0.54 2.21 1.79 4.91 2202.8 1057328.9 4.1 0.26 1.25 6.28 1.23 3.93 0.31 0.00 4.57 2050.7 984338.8 3.7 0.22 Basin 6.1 Q =0.23 cfs Capacity?OK Q = 0.00 1.00 2.00 3.00 4.00 5.00 6.00 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA Cattail and Max Roundabout Pipe 4, Existing Pond Outfall Pipe 18"x28.5" RCP Arch Pipe CIRCULAR CHANNEL - Use Diameter that is the Approximate Equivalent Round Diameter of the Specified Arch Pipe Manning's Eqn.1.486 A R2/3 S1/2 n Arch Pipe Size = 18"x28.5" Diameter,do (in) =24.0 Enter Value Diameter,do (ft) =2.00 Units =1.486 n =0.013 Slope, S (ft/ft)0.005 Depth, y (ft) Theta (rad) Area, A (ft 2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.00 0.10 0.90 0.06 0.90 0.07 0.87 0.07 0.02 0.08 34.5 16548.1 1.3 0.03 0.20 1.29 0.16 1.29 0.13 1.20 0.14 0.06 0.33 149.9 71945.4 2.0 0.06 0.30 1.59 0.30 1.59 0.19 1.43 0.21 0.13 0.78 349.0 167508.8 2.6 0.11 0.40 1.85 0.45 1.85 0.24 1.60 0.28 0.24 1.40 628.7 301772.5 3.1 0.15 0.50 2.09 0.61 2.09 0.29 1.73 0.35 0.37 2.19 983.4 472042.0 3.6 0.20 0.60 2.32 0.79 2.32 0.34 1.83 0.43 0.52 3.13 1405.9 674838.1 4.0 0.24 0.70 2.53 0.98 2.53 0.39 1.91 0.51 0.70 4.21 1887.7 906095.9 4.3 0.29 0.80 2.74 1.17 2.74 0.43 1.96 0.60 0.91 5.39 2419.3 1161266.5 4.6 0.33 0.90 2.94 1.37 2.94 0.47 1.99 0.69 1.14 6.66 2990.4 1435369.2 4.9 0.37 1.00 3.14 1.57 3.14 0.50 2.00 0.79 1.39 8.00 3589.6 1723009.8 5.1 0.40 1.10 3.34 1.77 3.34 0.53 1.99 0.89 1.67 9.37 4204.9 2018371.4 5.3 0.43 1.20 3.54 1.97 3.54 0.56 1.96 1.00 1.97 10.75 4823.3 2315174.6 5.5 0.46 1.30 3.75 2.16 3.75 0.58 1.91 1.13 2.30 12.10 5430.4 2606598.3 5.6 0.49 1.40 3.96 2.35 3.96 0.59 1.83 1.28 2.66 13.39 6010.7 2885137.5 5.7 0.50 1.50 4.19 2.53 4.19 0.60 1.73 1.46 3.05 14.59 6546.6 3142348.5 5.8 0.52 1.60 4.43 2.69 4.43 0.61 1.60 1.68 3.50 15.64 7017.4 3368370.1 5.8 0.52 1.70 4.69 2.85 4.69 0.61 1.43 1.99 4.02 16.48 7397.7 3550918.0 5.8 0.52 1.80 5.00 2.98 5.00 0.60 1.20 2.48 4.69 17.05 7651.6 3672758.6 5.7 0.51 1.90 5.38 3.08 5.38 0.57 0.87 3.54 5.80 17.19 7714.2 3702798.3 5.6 0.48 2.00 6.28 3.14 6.28 0.50 0.00 16.00 7181.6 3447184.8 5.1 0.40 Pond Outflow =1.83 * cfs Capacity?OK * calculated at a head of 1.6' above the weir Q = 0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 0.00 0.50 1.00 1.50 2.00 2.50 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA Cattail and Max Roundabout Pipe 5 Existing Pond Outfall Pipe 22.5"X36" RCP Arch Pipe CIRCULAR CHANNEL - Use Diameter that is the Approximate Equivalent Round Diameter of the Specified Arch Pipe Manning's Eqn.1.486 A R2/3 S1/2 n Arch Pipe Size = 22.5"X36" Diameter,do (in) =30.0 Enter Value Diameter,do (ft) =2.50 Units =1.486 n =0.013 Slope, S (ft/ft)0.0035 Depth, y (ft) Theta (rad) Area, A (ft 2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.00 0.13 0.90 0.09 1.13 0.08 1.09 0.08 0.03 0.12 52.3 25103.0 1.3 0.03 0.25 1.29 0.26 1.61 0.16 1.50 0.17 0.11 0.51 227.4 109138.6 2.0 0.06 0.38 1.59 0.46 1.99 0.23 1.79 0.26 0.23 1.18 529.4 254105.0 2.6 0.10 0.50 1.85 0.70 2.32 0.30 2.00 0.35 0.41 2.13 953.7 457778.5 3.0 0.14 0.63 2.09 0.96 2.62 0.37 2.17 0.44 0.64 3.32 1491.8 716071.4 3.5 0.19 0.75 2.32 1.24 2.90 0.43 2.29 0.54 0.91 4.75 2132.7 1023706.2 3.8 0.23 0.88 2.53 1.53 3.17 0.48 2.38 0.64 1.23 6.38 2863.6 1374516.2 4.2 0.27 1.00 2.74 1.83 3.42 0.54 2.45 0.75 1.59 8.18 3670.0 1761601.3 4.5 0.31 1.13 2.94 2.14 3.68 0.58 2.49 0.86 1.99 10.11 4536.3 2177405.6 4.7 0.35 1.25 3.14 2.45 3.93 0.63 2.50 0.98 2.43 12.13 5445.3 2613746.6 4.9 0.38 1.38 3.34 2.77 4.18 0.66 2.49 1.11 2.92 14.21 6378.7 3061799.9 5.1 0.41 1.50 3.54 3.08 4.43 0.69 2.45 1.26 3.45 16.30 7316.8 3512040.1 5.3 0.44 1.63 3.75 3.38 4.69 0.72 2.38 1.42 4.02 18.36 8237.7 3954119.9 5.4 0.46 1.75 3.96 3.67 4.96 0.74 2.29 1.60 4.65 20.32 9118.0 4376654.2 5.5 0.48 1.88 4.19 3.95 5.24 0.75 2.17 1.82 5.33 22.13 9930.9 4766834.4 5.6 0.49 2.00 4.43 4.21 5.54 0.76 2.00 2.10 6.11 23.72 10645.2 5109701.5 5.6 0.49 2.13 4.69 4.45 5.87 0.76 1.79 2.49 7.02 25.00 11222.1 5386620.3 5.6 0.49 2.25 5.00 4.65 6.25 0.75 1.50 3.10 8.20 25.86 11607.2 5571448.4 5.6 0.48 2.38 5.38 4.82 6.73 0.72 1.09 4.42 10.13 26.07 11702.1 5617017.5 5.4 0.45 2.50 6.28 4.91 7.85 0.63 0.00 24.27 10894.3 5229260.7 4.9 0.38 Pond Outflow =1.83 * cfs Capacity?OK * calculated at a head of 1.6' above the weir Q = 0.00 5.00 10.00 15.00 20.00 25.00 30.00 0.00 0.50 1.00 1.50 2.00 2.50 3.00 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA Cattail and Max Roundabout Pipe 6, Pond Outfall Pipe 18"x28.5" RCP Arch Pipe CIRCULAR CHANNEL - Use Diameter that is the Approximate Equivalent Round Diameter of the Specified Arch Pipe Manning's Eqn.1.486 A R2/3 S1/2 n Arch Pipe Size = 18"x28.5" Diameter,do (in) =24.0 Enter Value Diameter,do (ft) =2.00 Units =1.486 n =0.012 Slope, S (ft/ft)0.048 Depth, y (ft) Theta (rad) Area, A (ft 2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.00 0.10 0.90 0.06 0.90 0.07 0.87 0.07 0.02 0.26 115.7 55545.2 4.4 0.30 0.20 1.29 0.16 1.29 0.13 1.20 0.14 0.06 1.12 503.1 241490.8 6.9 0.73 0.30 1.59 0.30 1.59 0.19 1.43 0.21 0.13 2.61 1171.4 562257.5 8.8 1.21 0.40 1.85 0.45 1.85 0.24 1.60 0.28 0.24 4.70 2110.3 1012925.1 10.5 1.72 0.50 2.09 0.61 2.09 0.29 1.73 0.35 0.37 7.36 3300.9 1584449.3 12.0 2.23 0.60 2.32 0.79 2.32 0.34 1.83 0.43 0.52 10.51 4719.1 2265151.9 13.3 2.73 0.70 2.53 0.98 2.53 0.39 1.91 0.51 0.70 14.12 6336.2 3041388.3 14.4 3.22 0.80 2.74 1.17 2.74 0.43 1.96 0.60 0.91 18.09 8120.6 3897890.3 15.4 3.69 0.90 2.94 1.37 2.94 0.47 1.99 0.69 1.14 22.36 10037.4 4817939.5 16.3 4.13 1.00 3.14 1.57 3.14 0.50 2.00 0.79 1.39 26.85 12048.8 5783430.0 17.1 4.54 1.10 3.34 1.77 3.34 0.53 1.99 0.89 1.67 31.45 14114.2 6774836.3 17.8 4.90 1.20 3.54 1.97 3.54 0.56 1.96 1.00 1.97 36.07 16189.8 7771081.5 18.3 5.22 1.30 3.75 2.16 3.75 0.58 1.91 1.13 2.30 40.61 18227.6 8749270.3 18.8 5.48 1.40 3.96 2.35 3.96 0.59 1.83 1.28 2.66 44.95 20175.4 9684210.7 19.1 5.69 1.50 4.19 2.53 4.19 0.60 1.73 1.46 3.05 48.96 21974.1 10547561.5 19.4 5.83 1.60 4.43 2.69 4.43 0.61 1.60 1.68 3.50 52.48 23554.6 11306222.5 19.5 5.89 1.70 4.69 2.85 4.69 0.61 1.43 1.99 4.02 55.33 24831.2 11918960.1 19.4 5.87 1.80 5.00 2.98 5.00 0.60 1.20 2.48 4.69 57.23 25683.2 12327928.6 19.2 5.73 1.90 5.38 3.08 5.38 0.57 0.87 3.54 5.80 57.69 25893.2 12428759.3 18.7 5.44 2.00 6.28 3.14 6.28 0.50 0.00 53.71 24105.8 11570770.8 17.1 4.54 Pond Outflow =1.83 * cfs Capacity?OK * calculated at a head of 1.6' above the weir Q = 0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 0.00 0.50 1.00 1.50 2.00 2.50 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA Water Surface Profile Plot for Culvert: Culvert 1 Site Data - Culvert 1 Site Data Option: Culvert Invert Data Inlet Station: 0.00 ft Inlet Elevation: 4684.20 ft Outlet Station: 107.00 ft Outlet Elevation: 4684.00 ft Number of Barrels: 1 Culvert Data Summary - Culvert 1 Barrel Shape: Pipe Arch Barrel Span: 18.00 in Barrel Rise: 11.00 in Barrel Material: Concrete Embedment: 0.00 in Barrel Manning's n: 0.0120 Culvert Type: Straight Inlet Configuration: Grooved Edge Projecting Inlet Depression: None Table 1 - Culvert Summary Table: Culvert 1 Total Discharge (cfs) Culvert Discharge (cfs) Headwater Elevation (ft) Inlet Control Depth (ft) Outlet Control Depth (ft) Flow Type Normal Depth (ft) Critical Depth (ft) Outlet Depth (ft) Tailwater Depth (ft) Outlet Velocity (ft/s) Tailwater Velocity (ft/s) 0.00 0.00 4684.20 0.000 0.000 0-NF 0.000 0.000 0.000 0.000 0.000 0.000 0.20 0.20 4684.39 0.168 0.193 2-M2c 0.163 0.129 0.129 0.097 1.733 1.042 0.40 0.40 4684.48 0.243 0.278 2-M2c 0.231 0.186 0.186 0.150 2.123 1.350 0.61 0.61 4684.55 0.304 0.348 2-M2c 0.286 0.231 0.231 0.194 2.396 1.564 0.81 0.81 4684.61 0.357 0.409 2-M2c 0.334 0.270 0.270 0.233 2.616 1.732 1.01 1.01 4684.66 0.405 0.464 2-M2c 0.379 0.305 0.305 0.270 2.803 1.871 1.21 1.21 4684.72 0.450 0.517 2-M2c 0.422 0.337 0.337 0.304 2.969 1.991 1.41 1.41 4684.77 0.497 0.567 2-M2c 0.463 0.367 0.367 0.337 3.120 2.097 1.62 1.62 4684.81 0.544 0.614 2-M2c 0.504 0.395 0.395 0.369 3.260 2.191 1.82 1.82 4684.86 0.589 0.661 2-M2c 0.546 0.422 0.422 0.399 3.392 2.277 2.02 2.02 4684.91 0.633 0.708 2-M2c 0.589 0.447 0.447 0.429 3.519 2.355 Water Surface Profile Plot for Culvert: Culvert 1 Site Data - Culvert 1 Site Data Option: Culvert Invert Data Inlet Station: 0.00 ft Inlet Elevation: 4684.20 ft Outlet Station: 107.00 ft Outlet Elevation: 4684.00 ft Number of Barrels: 1 Culvert Data Summary - Culvert 1 Barrel Shape: Pipe Arch Barrel Span: 18.00 in Barrel Rise: 11.00 in Barrel Material: Concrete Embedment: 0.00 in Barrel Manning's n: 0.0120 Culvert Type: Straight Inlet Configuration: Grooved Edge Projecting Inlet Depression: None Table 1 - Culvert Summary Table: Culvert 1 Total Discharge (cfs) Culvert Discharge (cfs) Headwater Elevation (ft) Inlet Control Depth (ft) Outlet Control Depth (ft) Flow Type Normal Depth (ft) Critical Depth (ft) Outlet Depth (ft) Tailwater Depth (ft) Outlet Velocity (ft/s) Tailwater Velocity (ft/s) 0.00 0.00 4684.20 0.000 0.000 0-NF 0.000 0.000 0.000 0.000 0.000 0.000 0.20 0.20 4684.39 0.168 0.193 3-M1t 0.163 0.129 0.200 0.200 0.965 1.350 0.40 0.40 4684.48 0.243 0.280 3-M1t 0.231 0.186 0.328 0.328 1.024 1.643 0.61 0.61 4684.56 0.304 0.359 3-M1t 0.286 0.231 0.445 0.445 1.063 1.817 0.81 0.81 4684.65 0.357 0.448 3-M1t 0.334 0.270 0.556 0.556 1.103 1.938 1.01 1.01 4684.75 0.405 0.547 3-M1t 0.379 0.305 0.664 0.664 1.151 2.027 1.21 1.21 4684.85 0.450 0.652 3-M1t 0.422 0.337 0.770 0.770 1.217 2.098 1.41 1.41 4684.97 0.497 0.765 3-M1t 0.463 0.367 0.875 0.875 1.312 2.154 1.62 1.62 4685.10 0.544 0.898 3-M1f 0.504 0.395 0.917 0.979 1.479 2.201 1.82 1.82 4685.24 0.589 1.038 4-FFf 0.546 0.422 0.917 1.082 1.664 2.240 2.02 2.02 4685.38 0.633 1.177 4-FFf 0.589 0.447 0.917 1.184 1.849 2.274 Water Surface Profile Plot for Culvert: Culvert 1 Site Data - Culvert 1 Site Data Option: Culvert Invert Data Inlet Station: 0.00 ft Inlet Elevation: 4685.60 ft Outlet Station: 57.00 ft Outlet Elevation: 4684.00 ft Number of Barrels: 1 Culvert Data Summary - Culvert 1 Barrel Shape: Circular Barrel Diameter: 1.50 ft Barrel Material: PVC Embedment: 0.00 in Barrel Manning's n: 0.0110 Culvert Type: Straight Inlet Configuration: Mitered to Conform to Slope Inlet Depression: None Table 1 - Culvert Summary Table: Culvert 1 Total Discharge (cfs) Culvert Discharge (cfs) Headwater Elevation (ft) Inlet Control Depth (ft) Outlet Control Depth (ft) Flow Type Normal Depth (ft) Critical Depth (ft) Outlet Depth (ft) Tailwater Depth (ft) Outlet Velocity (ft/s) Tailwater Velocity (ft/s) 0.00 0.00 4685.60 0.000 0.000 0-NF 0.000 0.000 0.000 0.000 0.000 0.000 0.20 0.20 4685.84 0.239 0.0*1-S2n 0.103 0.165 0.103 0.097 3.804 1.042 0.40 0.40 4685.94 0.342 0.0*1-S2n 0.144 0.235 0.144 0.150 4.655 1.350 0.61 0.61 4686.02 0.421 0.0*1-S2n 0.175 0.289 0.175 0.194 5.255 1.564 0.81 0.81 4686.09 0.490 0.0*1-S2n 0.201 0.334 0.201 0.233 5.713 1.732 1.01 1.01 4686.15 0.551 0.0*1-S2n 0.224 0.375 0.224 0.270 6.100 1.871 1.21 1.21 4686.21 0.606 0.0*1-S2n 0.245 0.412 0.245 0.304 6.444 1.991 1.41 1.41 4686.26 0.658 0.0*1-S2n 0.264 0.446 0.264 0.337 6.735 2.097 1.62 1.62 4686.31 0.706 0.0*1-S2n 0.282 0.477 0.282 0.369 7.011 2.191 1.82 1.82 4686.35 0.753 0.0*1-S2n 0.299 0.507 0.299 0.399 7.254 2.277 2.02 2.02 4686.40 0.798 0.0*1-S2n 0.315 0.536 0.315 0.429 7.480 2.355 Water Surface Profile Plot for Culvert: Culvert 1 Site Data - Culvert 1 Site Data Option: Culvert Invert Data Inlet Station: 0.00 ft Inlet Elevation: 4685.60 ft Outlet Station: 57.00 ft Outlet Elevation: 4684.00 ft Number of Barrels: 1 Culvert Data Summary - Culvert 1 Barrel Shape: Circular Barrel Diameter: 1.50 ft Barrel Material: PVC Embedment: 0.00 in Barrel Manning's n: 0.0110 Culvert Type: Straight Inlet Configuration: Mitered to Conform to Slope Inlet Depression: None Table 2 - Culvert Summary Table: Culvert 1 Total Discharge (cfs) Culvert Discharge (cfs) Headwater Elevation (ft) Inlet Control Depth (ft) Outlet Control Depth (ft) Flow Type Normal Depth (ft) Critical Depth (ft) Outlet Depth (ft) Tailwater Depth (ft) Outlet Velocity (ft/s) Tailwater Velocity (ft/s) 0.00 0.00 4685.60 0.000 0.000 0-NF 0.000 0.000 0.000 0.000 0.000 0.000 0.20 0.20 4685.84 0.239 0.0*1-S2n 0.103 0.165 0.103 0.292 3.804 1.381 0.40 0.40 4685.94 0.342 0.0*1-JS1t 0.144 0.235 0.506 0.506 0.770 1.595 0.61 0.61 4686.02 0.421 0.0*1-JS1t 0.175 0.289 0.711 0.711 0.735 1.705 0.81 0.81 4686.09 0.490 0.0*1-JS1t 0.201 0.334 0.911 0.911 0.719 1.774 1.01 1.01 4686.15 0.551 0.0*1-JS1t 0.224 0.375 1.109 1.109 0.721 1.821 1.21 1.21 4686.21 0.606 0.0*1-JS1t 0.245 0.412 1.307 1.307 0.742 1.855 1.41 1.41 4686.26 0.658 0.0*1-JS1f 0.264 0.446 1.500 1.503 0.800 1.882 1.62 1.62 4686.31 0.706 0.130 1-JS1f 0.282 0.477 1.500 1.699 0.914 1.903 1.82 1.82 4686.35 0.753 0.334 1-JS1f 0.299 0.507 1.500 1.894 1.029 1.920 2.02 2.02 4686.40 0.798 0.538 1-JS1f 0.315 0.536 1.500 2.089 1.143 1.934 Appendix D – Inlet Calculations Gutter Section Given:T =9.0 feet W =1.50 feet Ts =7.50 feet Sw =0.0625 ft/ft Sx =0.03 ft/ft a =0.59 inches d =3.24 inches n =0.015 Where: Qs =Discharge within the Roadway above the depressed section (cfs) Qw =Discharge within the depressed (gutter) section (cfs) Capacity for Inlets on Grade Cf =0.56 for English units (Standard 24x36 Curb inlet)Sx =Pavement cross slope (ft/ft) Ts =Width of flow in the roadway above Maximum Design Flow Basin depressed section So =Gutter longitudinal slope (ft/ft) Qw =1.95 cfs Sw =Gutter depression cross slope (ft/ft) Qs =2.66 cfs T =Spread (ft) Cross-sectional area of flow W =Width of gutter depression (ft) A =1.22 ft2 Gutter Velocity V =3.79 ft/sec Fraction of side flow intercepted Rs =0.18 Total flow capacity intercepted by the inlet Qint =2.51 cfs Qbypass =2.10 cfs Maximum Design Flow inlet Q25 =1.03 cfs Single Inlet Sufficient Inlet Capacity Calculations Cattail and Max Roundabout Page 1 of 1 Assume the grated opening acts as a broad crested weir, with a lesser width because of the bars. Q= CLH ^1.5 Weir Coefficient C 3.33 Head 1.5 Width 24 (in) Flow 12.24 cfs Contributing Flow 1.19 cfs *Basin 4 25-year event Cattail and Max Roundabout Swale Inlet Capacity Calculations Appendix E – Detention Calculations Cattail & Max Roundabout 9/2/2020 Stormwater Detention Pond Calculations Calculation of Required Volume for Storm Detention Pond (Reference: Bozeman Stormwater Master Plan - 1982) Design Rainfall Freq.10 year IDF coefficient a 0.64 IDF coefficient b 0.00 IDF coefficient n 0.65 Pre-development Calculations Post-development Calculations Basins EX 1.0, EX 2.0, & EX 3 C Basins 1, 2, 3, 4, and 6.1 C Areas (ft2):Landscape 24,227 0.20 Areas (ft2):Landscape 26,301 0.20 Impervious 25,015 0.90 Impervious 61,635 0.90 Total:49,242 Total:87,936 total area:1.13 acres total area:2.02 acres composite C:0.56 composite C:0.69 Total tc:10 minutes Total tc:10 minutes Manual Estimates intensity at tc (fig 23):2.05 in/hr intensity at tc (fig 23):2.05 in/hr pre-devel peak runoff:1.29 cfs post-devel peak runoff:2.86 cfs Storm Duration Intensity Future Runoff Runoff Release Required (minutes)(in/hr)Rate (cfs)Volume (cf)Volume (cf)Storage (cf) 2 5.84 8.14 977 155 822 4 3.72 5.19 1245 309 936 5 3.22 4.49 1346 386 960 7 2.59 3.61 1514 541 973 10 2.05 2.86 1716 773 943 12 1.82 2.54 1829 928 901 14 1.65 2.30 1930 1082 848 16 1.51 2.11 2023 1237 786 18 1.40 1.95 2108 1391 716 20 1.31 1.82 2187 1546 641 22 1.23 1.71 2261 1700 561 24 1.16 1.62 2331 1855 476 26 1.10 1.54 2397 2010 388 28 1.05 1.46 2460 2164 296 30 1.00 1.40 2520 2319 201 Required Detention Storage (ft3) =973 Existing Detention Pond Volume Modification Calculations: Existing Pond Volume Existing Volume based on Contours Contour Elev (ft)Area (sf)volume (cf)cummulative volume (cf) 4682 2 4683 932 467 467 4684 11613 6273 6740 4685 13761 12687 19427 4686 15228 14495 33921 Existing storage (ft3) =33,921 Proposed Pond Volume Modified Volume based on Contours Contour Elev (ft)Area (sf)volume (cf)cummulative volume (cf) 4682 662 4682.5 1781 611 611 4682.8 4312 914 1525 * Retention up to this point since the pond wier slot elevation is 4682.77 4683 4546 886 2410 4684 12010 8278 10688 4685 14410 13210 23898 4686 16192 15301 39199 Proposed storage (ft3) =39,199 Volume Increase (ft3) =5,278 SEE NEXT PAGE FOR 0.5" STORM CALCS Detention pond COB.xls 0.5 inch stormwater in roadways calculations: Post Developed Increase in Impervious Areas Contributing to the SW Pond Pre-developed Impervious =25015 sf Post-developed Impervious =61635 sf Delta increse in impervious =36620 sf Delta increse in impervious =0.841 ac I=0.021 in/hr * 0.5" in 24 hrs C=0.9 Q=0.016 cfs 0.5" Volume = 1,430 cf Elevated Weir Elevation above pond bottom Use Interpolation to solve for the pond height at the required volume 0.5" storm Volume 1,430 cf Volume of Pond at 4682'= 0 cf Volume of Pond at 4682.8'= 1,525 cf Interpolated Weir Elevation= 4,682.77 ft Overflow Elevation = 4684.35 ft * The existing weir slot is 1'-7" tall Pond Depth @ Weir = 0.77 ft * Max Standing Water Depth Pond Depth @ Overflow = 2.35 ft Detention pond COB.xls The existing slot is 3.25" wide with a height of approximately 19" Flow at a head of 1.4' or 16.8" Q= CLH ^1.5 Weir Coefficient C 3.33 Head 1.4 Width 3.25 (in) Flow 1.49 cfs Flow at a head of 1.6' or 19" Q= CLH ^1.5 Weir Coefficient C 3.33 Head 1.6 Width 3.25 (in) Flow 1.83 cfs Cattail and Max Roundabout Existing Pond Outfall Weir Flow Calc Appendix F – Stormwater Maintenance Plan Appendix F – Stormwater Maintenance Plan CATTAIL AND MAX ROADWAY IMPROVEMENTS Storm Water Facilities Maintenance Plan Owner’s responsibility for routine inspection and maintenance 1. Keep the culverts, curb inlets, pipe inlets and outlets, area drains and pipes free of sediment, leaves, rocks, and other debris. 2. Periodically inspect and clean culverts, curb inlets, pipe inlets and outlets, area drains and pipes. 3. Remove sediment from storm structure sumps by hand during the summer months whenever sediment has accumulated to greater than 3” in the bottom of the basin. 4. See that litter and other debris are removed from grates in order to reduce obstruction of flow. 5. Inspect the flow control manhole and outflow pipes semi-annually. Clean the manhole and pipes when soil and vegetation buildup interfere with flow. Remove sediment from the manhole sump. 6. Annually inspect the detention pond area and ensure that it is free of trash, debris, and other impinging items. 7. Owner to maintain and fund Operation and Maintenance of facilities. __________________________________ Owner – Gallatin Center LP, Gene Graf III