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HomeMy WebLinkAbout017_Churn Creek Bridge Crossing MemoMEMORANDUM PAGE 1 OF 2 June 2026 MEMORANDUM To: City of Bozeman Engineering Department From: Sanbell Date: 8/3/2026 Reference: Bikefill Bike Park Hydraulics – Bridge Crossings The purpose of this memorandum is to briefly summarize the hydraulics of Churn Creek and an unnamed drainage at the locations of the proposed bridges to be installed as part of the Bikefill Bike Park trail system. The contractor is proposing to utilize either a forest service style bridge or a steel beam version for spans over 20 feet without additional mechanically driven supports. There are three proposed bridges to be installed across Churn Creek, labeled CH 1, CH 2, and CH 3 in the attached exhibits. A bridge is also proposed across the unnamed drainage which runs approximately parallel to the north of Churn Creek through the site. This crossing labeled as INT 2 in the attached exhibits. The intention is for these bridges to be installed with 1-foot of freeboard above the 100-year flood event. Based on our previous hydrology calculations in the drainage report for the park, the 100-year flood in Churn Creek was determined to be 142 cfs. The 100-year event for INT 2 was calculated to be 94.7 cfs using StreamStats. Hydraulics were calculated at each bridge location to determine the 100-year water surface elevation. The maximum depth of the 100- year flood varied from 1.72 feet at INT-2 to 2.13 feet at CH-2. The forest service bridges are to be installed at least 3.13 feet above the thalweg of the Churn Creek, to provide at least 1-foot of freeboard above the 100-year storm event. All bridges are to be installed perpendicular to the flowline of the creek/drainage as shown in the attached exhibits. All embedded structural elements and piers will be driven below the maximum calculated scour depth. Sanbell will observe all proposed bridge installations prior to construction to confirm adequate freeboard is being provided and scour depths are accounted for, where necessary. Attached to this memorandum are the hydraulic calculations and proposed bridge location exhibits. MEMORANDUM PAGE 2 OF 2 June 2026 If you have any questions regarding this memorandum, please reach out to me directly at 406- 922-4308 or begeberg@sanbell.com Sincerely, Bobby Egeberg, PE Hydraulic Analysis Report Project Data Project Title: Bikefill Bike Park Hydraulics – Bridge Crossings Designer: Bobby Egeberg, PE Project Date: Thursday, June 18, 2026 Project Units: U.S. Customary Units Notes: Included analysis of Churn Creek crossings (CH-1, CH-2, and CH-3) and unnamed drainage crossing (INT-2). Scour analysis for local pier scour to calculate maximum pier scour for two pier options in thalweg. Channel Analysis: INT-2 Notes: Input Parameters Channel Type: Custom Cross Section Cross Section Data Station (ft Elevation (ft) Manning's n 0.00 4816.46 0.0400 2.89 4816.00 0.0400 3.78 4815.85 0.0400 4.33 4815.77 0.0400 4.47 4815.74 0.0400 5.96 4815.50 0.0400 7.38 4815.16 0.0400 7.44 4815.15 0.0400 8.09 4815.00 0.0400 10.24 4814.59 0.0400 10.67 4814.50 0.0400 10.92 4814.44 0.0400 10.94 4814.44 0.0400 13.21 4814.00 0.0400 13.27 4813.98 0.0400 13.37 4813.96 0.0400 13.74 4813.88 0.0400 14.01 4813.83 0.0400 14.17 4813.80 0.0400 14.84 4813.66 0.0400 14.98 4813.64 0.0400 15.95 4813.51 0.0400 16.00 4813.50 0.0400 16.02 4813.50 0.0400 17.07 4813.32 0.0400 17.54 4813.19 0.0400 18.24 4813.00 0.0400 18.26 4812.99 0.0400 19.37 4812.50 0.0400 19.80 4812.31 0.0400 20.49 4812.00 0.0400 21.55 4811.52 0.0400 21.60 4811.50 0.0400 21.68 4811.46 0.0400 21.99 4811.32 0.0400 22.63 4811.02 0.0400 22.68 4811.00 0.0400 22.72 4810.98 0.0400 22.83 4810.93 0.0400 22.86 4810.92 0.0400 22.98 4810.87 0.0400 23.78 4810.50 0.0400 24.54 4810.00 0.0400 25.27 4809.50 0.0400 25.64 4809.23 0.0400 26.01 4809.00 0.0400 26.65 4808.65 0.0350 26.91 4808.50 0.0350 27.09 4808.43 0.0350 27.51 4808.31 0.0350 27.75 4808.26 0.0350 28.77 4808.18 0.0350 29.07 4808.14 0.0350 29.15 4808.13 0.0350 29.21 4808.12 0.0350 29.46 4808.12 0.0350 29.70 4808.14 0.0350 30.13 4808.21 0.0350 31.00 4808.50 0.0350 31.73 4808.77 0.0350 32.36 4809.00 0.0350 32.48 4809.01 0.0350 33.21 4809.20 0.0350 33.68 4809.31 0.0350 34.23 4809.42 0.0400 34.36 4809.45 0.0400 34.43 4809.46 0.0400 34.92 4809.47 0.0400 34.96 4809.48 0.0400 35.37 4809.50 0.0400 36.10 4809.50 0.0400 36.20 4809.50 0.0400 36.30 4809.50 0.0400 36.68 4809.51 0.0400 36.78 4809.51 0.0400 36.85 4809.51 0.0400 36.88 4809.51 0.0400 36.95 4809.51 0.0400 37.10 4809.51 0.0400 40.23 4809.78 0.0400 41.63 4809.90 0.0400 42.41 4809.97 0.0400 42.73 4810.00 0.0400 42.84 4810.00 0.0400 42.89 4810.00 0.0400 42.91 4810.00 0.0400 43.28 4810.00 0.0400 53.90 4810.43 0.0400 54.92 4810.47 0.0400 54.98 4810.47 0.0400 55.04 4810.47 0.0400 55.14 4810.47 0.0400 55.23 4810.48 0.0400 55.23 4810.48 0.0400 55.27 4810.48 0.0400 55.28 4810.48 0.0400 55.65 4810.50 0.0400 56.34 4810.50 0.0400 56.46 4810.50 0.0400 57.00 4810.50 0.0400 57.29 4810.50 0.0400 57.66 4810.50 0.0400 57.96 4810.50 0.0400 59.14 4810.50 0.0400 60.76 4810.50 0.0400 61.13 4810.50 0.0400 61.47 4810.50 0.0400 62.40 4810.50 0.0400 62.65 4810.50 0.0400 62.99 4810.50 0.0400 63.06 4810.50 0.0400 63.43 4810.35 ----- Longitudinal Slope: 0.0356 ft/ft Flow 94.7000 cfs Result Parameters Depth 1.7153 ft Area of Flow 12.1624 ft^2 Wetted Perimeter 16.6818 ft Hydraulic Radius 0.7291 ft Average Velocity 7.7863 ft/s Top Width 16.0433 ft Froude Number: 1.5759 Critical Depth 2.0550 ft Critical Velocity 5.0782 ft/s Critical Slope: 0.0134 ft/ft Critical Top Width 23.29 ft Calculated Max Shear Stress 3.8104 lb/ft^2 Calculated Avg Shear Stress 1.6196 lb/ft^2 Composite Manning's n Equation: Lotter method Manning's n: 0.0292 Channel Analysis: CH-1 Notes: Input Parameters Channel Type: Custom Cross Section Cross Section Data Station (ft Elevation (ft) Manning's n 0.00 4763.00 0.0400 0.02 4763.00 0.0400 0.31 4763.00 0.0400 1.81 4762.76 0.0400 1.92 4762.74 0.0400 1.98 4762.73 0.0400 2.05 4762.72 0.0400 2.35 4762.63 0.0400 2.60 4762.59 0.0400 2.74 4762.57 0.0400 2.92 4762.56 0.0400 3.06 4762.56 0.0400 3.54 4762.57 0.0400 3.63 4762.57 0.0400 3.71 4762.56 0.0400 6.12 4762.60 0.0400 8.33 4762.60 0.0400 8.65 4762.59 0.0400 8.94 4762.59 0.0400 10.45 4762.51 0.0400 10.56 4762.51 0.0400 10.82 4762.51 0.0400 10.91 4762.51 0.0400 11.11 4762.51 0.0400 12.06 4762.50 0.0400 12.10 4762.50 0.0400 12.24 4762.48 0.0400 12.34 4762.46 0.0400 15.03 4762.01 0.0400 15.12 4762.00 0.0400 15.14 4762.00 0.0400 15.59 4761.85 0.0400 16.51 4761.54 0.0400 16.62 4761.50 0.0400 17.39 4761.16 0.0400 17.76 4761.00 0.0400 18.15 4760.83 0.0400 18.27 4760.77 0.0400 19.02 4760.50 0.0400 19.79 4760.25 0.0400 19.81 4760.24 0.0400 19.84 4760.24 0.0400 20.30 4760.09 0.0400 20.59 4760.00 0.0400 21.47 4759.79 0.0400 22.67 4759.53 0.0400 22.82 4759.50 0.0400 25.18 4759.21 0.0400 25.89 4759.12 0.0400 27.10 4759.00 0.0400 27.53 4758.93 0.0400 28.02 4758.85 0.0400 28.39 4758.78 0.0400 28.71 4758.73 0.0400 29.19 4758.64 0.0400 30.05 4758.50 0.0400 31.24 4758.27 0.0400 31.71 4758.18 0.0400 32.49 4758.00 0.0400 33.43 4757.74 0.0400 33.84 4757.63 0.0400 34.11 4757.56 0.0400 34.17 4757.54 0.0400 34.27 4757.52 0.0400 34.34 4757.50 0.0400 34.56 4757.44 0.0400 34.72 4757.39 0.0400 35.12 4757.29 0.0400 36.14 4757.00 0.0400 36.97 4756.82 0.0400 37.29 4756.75 0.0400 37.53 4756.71 0.0400 38.56 4756.50 0.0400 40.36 4756.11 0.0400 40.93 4756.00 0.0400 41.44 4755.85 0.0400 42.65 4755.50 0.0400 42.67 4755.49 0.0400 43.19 4755.35 0.0400 43.50 4755.30 0.0400 44.63 4755.09 0.0400 44.95 4755.03 0.0400 45.09 4755.00 0.0400 45.55 4754.92 0.0400 46.29 4754.79 0.0500 46.92 4754.68 0.0500 48.17 4754.50 0.0500 48.33 4754.49 0.0500 48.33 4754.49 0.0500 48.64 4754.45 0.0500 48.65 4754.45 0.0500 48.89 4754.43 0.0500 50.84 4754.25 0.0500 51.08 4754.23 0.0500 52.12 4754.15 0.0500 52.56 4754.12 0.0500 53.62 4754.04 0.0500 53.68 4754.03 0.0500 53.74 4754.03 0.0500 53.75 4754.03 0.0500 53.76 4754.03 0.0500 53.82 4754.03 0.0500 54.38 4754.00 0.0500 55.28 4753.94 0.0500 55.51 4753.92 0.0500 56.89 4753.89 0.0500 57.26 4753.87 0.0500 58.57 4753.88 0.0500 58.84 4753.88 0.0500 58.89 4753.87 0.0500 58.99 4753.87 0.0500 59.03 4753.87 0.0500 59.99 4753.80 0.0500 60.43 4753.85 0.0500 61.07 4753.94 0.0500 61.19 4753.95 0.0500 61.43 4754.00 0.0500 62.15 4754.21 0.0500 62.46 4754.22 0.0500 62.98 4754.29 0.0500 63.40 4754.35 0.0500 63.46 4754.36 0.0500 63.73 4754.37 0.0500 63.96 4754.40 0.0500 64.86 4754.44 0.0500 65.08 4754.47 0.0500 65.28 4754.50 0.0500 65.75 4754.50 0.0500 65.95 4754.51 0.0500 66.18 4754.50 0.0500 66.37 4754.50 0.0500 67.04 4754.38 0.0500 67.50 4754.29 0.0350 69.16 4754.00 0.0350 69.43 4753.98 0.0350 70.65 4753.74 0.0350 71.23 4753.66 0.0350 71.34 4753.65 0.0350 72.30 4753.50 0.0350 72.96 4753.33 0.0350 73.00 4753.32 0.0350 73.03 4753.31 0.0350 74.14 4753.04 0.0350 74.16 4753.03 0.0350 74.18 4753.03 0.0350 74.25 4753.02 0.0350 74.26 4753.02 0.0350 74.31 4753.00 0.0350 75.56 4752.75 0.0350 76.50 4752.50 0.0350 76.61 4752.48 0.0350 76.74 4752.47 0.0350 76.78 4752.47 0.0350 78.01 4752.38 0.0350 78.09 4752.37 0.0350 78.17 4752.36 0.0350 78.97 4752.34 0.0350 79.89 4752.46 0.0350 80.25 4752.45 0.0350 80.56 4752.47 0.0350 80.72 4752.47 0.0350 80.95 4752.48 0.0350 81.11 4752.49 0.0350 81.29 4752.50 0.0350 81.75 4752.63 0.0350 82.84 4753.00 0.0350 83.50 4753.27 0.0350 84.08 4753.50 0.0350 84.95 4753.94 0.0350 85.07 4754.00 0.0350 85.67 4754.23 0.0350 86.38 4754.50 0.0350 87.25 4754.66 0.0350 87.81 4754.72 0.0500 88.46 4754.81 0.0500 88.98 4754.89 0.0500 89.68 4754.93 0.0500 90.53 4754.98 0.0500 90.58 4754.98 0.0500 90.61 4754.99 0.0500 90.80 4755.00 0.0500 90.81 4755.00 0.0500 90.89 4755.00 0.0500 91.02 4755.00 0.0500 91.81 4755.01 0.0500 92.16 4754.96 0.0500 92.30 4754.40 0.0500 97.46 4754.91 0.0500 97.82 4754.95 0.0500 98.51 4755.02 0.0400 102.31 4755.36 0.0400 104.55 4755.56 0.0400 106.95 4755.78 0.0400 112.18 4756.25 0.0400 115.24 4756.52 0.0400 116.55 4756.64 0.0400 127.84 4757.19 0.0400 129.56 4757.39 0.0400 132.69 4757.75 0.0400 135.67 4758.09 0.0400 139.41 4758.52 0.0400 141.56 4758.76 0.0400 143.43 4758.98 0.0400 144.84 4759.14 0.0400 146.17 4759.29 0.0400 147.86 4759.60 0.0400 150.36 4760.06 0.0400 152.29 4760.42 0.0400 155.15 4760.95 0.0400 158.30 4761.53 0.0400 161.18 4762.07 ----- Longitudinal Slope: 0.0265 ft/ft Flow 142.0000 cfs Result Parameters Depth 1.8650 ft Area of Flow 21.7494 ft^2 Wetted Perimeter 28.9328 ft Hydraulic Radius 0.7517 ft Average Velocity 6.5289 ft/s Top Width 28.3474 ft Froude Number: 1.3135 Critical Depth 2.0561 ft Critical Velocity 5.1252 ft/s Critical Slope: 0.0154 ft/ft Critical Top Width 33.96 ft Calculated Max Shear Stress 3.0839 lb/ft^2 Calculated Avg Shear Stress 1.2430 lb/ft^2 Composite Manning's n Equation: Lotter method Manning's n: 0.0306 Channel Analysis: CH-2 Notes: Input Parameters Channel Type: Custom Cross Section Cross Section Data Station (ft Elevation (ft) Manning's n 0.00 4795.56 0.0400 0.38 4795.50 0.0400 0.39 4795.50 0.0400 0.52 4795.49 0.0400 0.53 4795.49 0.0400 2.65 4795.36 0.0400 3.92 4795.29 0.0400 4.77 4795.25 0.0400 4.91 4795.24 0.0400 5.52 4795.20 0.0400 5.85 4795.18 0.0400 6.13 4795.17 0.0400 9.22 4795.00 0.0400 9.89 4794.95 0.0400 9.91 4794.95 0.0400 10.04 4794.94 0.0400 10.13 4794.94 0.0400 10.55 4794.92 0.0400 12.52 4794.76 0.0400 13.00 4794.73 0.0400 13.38 4794.71 0.0400 13.70 4794.69 0.0400 13.96 4794.67 0.0400 14.69 4794.65 0.0400 15.25 4794.63 0.0400 17.05 4794.59 0.0400 17.22 4794.59 0.0400 17.70 4794.58 0.0400 18.20 4794.57 0.0400 18.30 4794.57 0.0400 18.40 4794.57 0.0400 18.43 4794.57 0.0400 18.49 4794.56 0.0400 18.60 4794.56 0.0400 20.46 4794.56 0.0400 20.62 4794.56 0.0400 20.80 4794.56 0.0400 20.96 4794.56 0.0400 21.15 4794.57 0.0400 21.21 4794.57 0.0400 21.34 4794.58 0.0400 22.69 4794.57 0.0400 24.14 4794.54 0.0400 24.24 4794.54 0.0400 24.26 4794.54 0.0400 24.39 4794.54 0.0400 24.53 4794.53 0.0400 25.27 4794.51 0.0400 25.28 4794.51 0.0400 25.29 4794.51 0.0400 25.70 4794.50 0.0400 25.85 4794.50 0.0400 25.95 4794.49 0.0400 25.99 4794.48 0.0400 26.32 4794.41 0.0400 28.10 4794.00 0.0500 28.30 4793.91 0.0500 29.29 4793.50 0.0500 30.13 4793.15 0.0500 30.63 4793.00 0.0500 31.83 4792.61 0.0500 32.20 4792.50 0.0500 33.56 4792.02 0.0500 33.61 4792.00 0.0500 33.85 4791.92 0.0500 35.33 4791.50 0.0500 36.00 4791.34 0.0500 36.39 4791.20 0.0500 37.01 4791.00 0.0500 38.00 4790.66 0.0500 38.39 4790.50 0.0500 39.04 4790.24 0.0500 39.13 4790.21 0.0500 39.63 4790.00 0.0500 39.95 4789.86 0.0500 40.72 4789.50 0.0500 41.24 4789.27 0.0500 41.86 4789.00 0.0500 42.74 4788.58 0.0500 42.92 4788.50 0.0500 43.11 4788.39 0.0500 43.83 4788.00 0.0500 44.50 4787.62 0.0500 44.69 4787.50 0.0500 45.02 4787.32 0.0500 45.74 4787.00 0.0500 46.43 4786.75 0.0500 46.47 4786.74 0.0350 47.17 4786.50 0.0350 47.87 4786.21 0.0350 48.46 4786.00 0.0350 48.47 4786.00 0.0350 48.48 4785.99 0.0350 49.65 4785.50 0.0350 49.93 4785.50 0.0350 49.97 4785.50 0.0350 50.69 4785.50 0.0350 50.73 4785.50 0.0350 50.77 4785.51 0.0350 51.71 4785.84 0.0350 52.43 4786.00 0.0350 53.02 4786.11 0.0350 55.90 4786.50 0.0350 55.94 4786.50 0.0350 56.07 4786.51 0.0350 56.14 4786.51 0.0400 56.97 4786.60 0.0400 58.23 4786.68 0.0400 59.26 4786.80 0.0400 60.00 4786.87 0.0400 61.23 4787.00 0.0400 62.04 4787.12 0.0400 62.65 4787.19 0.0400 63.35 4787.27 0.0400 64.94 4787.44 0.0400 64.95 4787.44 0.0400 64.97 4787.45 0.0400 64.99 4787.45 0.0400 65.36 4787.50 0.0400 65.77 4787.55 0.0400 66.50 4787.63 0.0400 66.63 4787.64 0.0400 66.98 4787.68 0.0400 67.93 4787.74 0.0400 67.96 4787.74 0.0400 68.00 4787.75 0.0400 70.03 4788.00 0.0400 70.52 4788.10 0.0400 70.65 4788.12 0.0400 70.90 4788.17 0.0400 72.02 4788.35 0.0400 72.65 4788.47 0.0400 72.78 4788.50 0.0400 73.50 4788.70 0.0400 73.81 4788.80 0.0400 74.49 4789.00 0.0400 75.15 4789.21 0.0400 75.91 4789.50 0.0400 76.86 4789.80 0.0400 77.50 4790.00 0.0400 79.19 4790.45 0.0400 79.34 4790.50 0.0400 79.57 4790.57 0.0400 81.03 4791.00 0.0400 82.04 4791.27 0.0400 82.28 4791.33 0.0400 82.59 4791.40 0.0400 82.94 4791.50 0.0400 84.58 4791.94 0.0400 84.77 4792.00 0.0400 84.82 4792.01 0.0400 86.45 4792.50 0.0400 87.80 4792.88 0.0400 88.00 4792.94 0.0400 88.21 4793.00 0.0400 88.48 4793.08 0.0400 88.94 4793.21 0.0400 89.96 4793.50 0.0400 90.47 4793.65 0.0400 90.58 4793.69 0.0400 91.46 4794.00 0.0400 92.02 4794.22 0.0400 92.89 4794.50 0.0400 94.20 4794.87 0.0400 94.61 4795.00 0.0400 96.18 4795.39 0.0400 96.62 4795.50 0.0400 97.25 4795.61 0.0400 99.03 4795.91 0.0400 99.75 4795.99 0.0400 99.78 4796.00 0.0400 99.78 4796.00 0.0400 99.88 4796.00 0.0400 100.27 4796.00 0.0400 100.33 4796.00 0.0400 100.95 4796.00 0.0400 100.96 4796.00 0.0400 100.97 4796.00 0.0400 101.60 4796.00 0.0400 101.66 4796.00 0.0400 101.80 4796.00 0.0400 102.98 4796.01 0.0400 104.13 4796.00 0.0400 104.18 4796.00 0.0400 104.18 4796.00 0.0400 104.26 4796.00 0.0400 104.29 4796.00 0.0400 104.67 4796.02 0.0400 104.77 4796.02 0.0400 105.85 4796.04 ----- Longitudinal Slope: 0.0192 ft/ft Flow 142.0000 cfs Result Parameters Depth 2.1275 ft Area of Flow 22.2317 ft^2 Wetted Perimeter 22.5795 ft Hydraulic Radius 0.9846 ft Average Velocity 6.3873 ft/s Top Width 21.9759 ft Froude Number: 1.1191 Critical Depth 2.2264 ft Critical Velocity 5.8028 ft/s Critical Slope: 0.0151 ft/ft Critical Top Width 23.40 ft Calculated Max Shear Stress 2.5489 lb/ft^2 Calculated Avg Shear Stress 1.1796 lb/ft^2 Composite Manning's n Equation: Lotter method Manning's n: 0.0319 Channel Analysis: CH-3 Notes: Input Parameters Channel Type: Custom Cross Section Cross Section Data Station (ft Elevation (ft) Manning's n 0.00 4845.19 0.0400 0.08 4845.19 0.0400 0.25 4845.21 0.0400 0.49 4845.23 0.0400 1.13 4845.28 0.0400 1.56 4845.31 0.0400 1.87 4845.34 0.0400 2.13 4845.35 0.0400 2.43 4845.35 0.0400 3.45 4845.36 0.0400 4.63 4845.33 0.0400 5.11 4845.34 0.0400 5.22 4845.33 0.0400 5.50 4845.33 0.0400 5.91 4845.28 0.0400 6.05 4845.26 0.0400 6.07 4845.26 0.0400 6.96 4845.25 0.0400 7.90 4845.03 0.0400 7.90 4845.03 0.0400 7.90 4845.03 0.0400 8.06 4845.00 0.0400 9.27 4844.64 0.0400 9.68 4844.50 0.0400 11.62 4844.01 0.0400 11.65 4844.00 0.0400 11.68 4844.00 0.0400 13.39 4843.92 0.0400 14.72 4843.88 0.0400 15.00 4843.86 0.0400 15.38 4843.83 0.0400 15.98 4843.76 0.0400 16.02 4843.75 0.0400 16.48 4843.72 0.0400 17.77 4843.56 0.0400 17.89 4843.55 0.0400 17.95 4843.54 0.0400 17.97 4843.54 0.0400 18.02 4843.54 0.0400 18.07 4843.54 0.0400 18.29 4843.50 0.0400 19.98 4843.00 0.0400 19.99 4843.00 0.0400 20.88 4842.67 0.0400 21.17 4842.55 0.0400 21.28 4842.50 0.0400 21.54 4842.39 0.0400 22.28 4842.02 0.0400 22.32 4842.00 0.0400 22.36 4841.98 0.0400 23.11 4841.63 0.0400 23.38 4841.50 0.0400 24.06 4841.16 0.0400 24.41 4841.00 0.0400 25.01 4840.70 0.0400 25.40 4840.50 0.0400 25.97 4840.24 0.0400 26.57 4840.00 0.0400 27.35 4839.72 0.0400 28.01 4839.50 0.0400 28.47 4839.34 0.0400 29.42 4839.00 0.0400 29.71 4838.89 0.0400 30.64 4838.50 0.0400 30.84 4838.43 0.0400 31.00 4838.38 0.0400 32.15 4838.00 0.0400 32.20 4837.99 0.0400 33.81 4837.50 0.0400 33.97 4837.45 0.0400 34.06 4837.44 0.0400 34.14 4837.41 0.0400 34.45 4837.33 0.0400 35.29 4837.13 0.0400 35.88 4837.00 0.0400 35.94 4836.99 0.0400 35.96 4836.99 0.0400 37.10 4836.87 0.0400 37.38 4836.81 0.0400 38.02 4836.71 0.0400 39.33 4836.50 0.0400 39.92 4836.42 0.0400 40.14 4836.39 0.0400 40.64 4836.32 0.0400 40.86 4836.29 0.0400 41.78 4836.21 0.0400 42.33 4836.17 0.0400 42.36 4836.17 0.0400 43.76 4836.13 0.0400 43.83 4836.12 0.0400 44.89 4836.10 0.0400 46.19 4836.03 0.0400 46.42 4836.00 0.0400 46.46 4836.00 0.0400 46.57 4836.00 0.0400 47.03 4836.00 0.0400 47.12 4836.00 0.0400 47.18 4836.00 0.0400 47.23 4835.99 0.0400 47.33 4835.95 0.0400 47.87 4835.81 0.0400 48.63 4835.50 0.0400 48.74 4835.45 0.0400 49.13 4835.26 0.0350 49.60 4835.04 0.0350 49.66 4835.00 0.0350 50.17 4834.74 0.0350 50.53 4834.50 0.0350 51.50 4834.25 0.0350 51.64 4834.22 0.0350 52.49 4834.14 0.0350 53.00 4834.13 0.0350 53.31 4834.18 0.0350 53.39 4834.19 0.0350 54.24 4834.34 0.0350 55.01 4834.49 0.0350 55.14 4834.49 0.0350 55.18 4834.50 0.0350 55.25 4834.50 0.0350 55.86 4834.70 0.0350 56.72 4835.00 0.0350 56.87 4835.05 0.0400 58.11 4835.50 0.0400 59.30 4835.77 0.0400 60.10 4836.00 0.0400 61.71 4836.32 0.0400 61.91 4836.35 0.0400 62.74 4836.50 0.0400 63.63 4836.70 0.0400 64.90 4837.00 0.0400 65.54 4837.21 0.0400 66.39 4837.50 0.0400 67.25 4837.75 0.0400 67.43 4837.81 0.0400 68.02 4838.00 0.0400 69.31 4838.36 0.0400 69.44 4838.40 0.0400 69.62 4838.45 0.0400 69.82 4838.50 0.0400 70.83 4838.77 0.0400 71.73 4839.00 0.0400 73.20 4839.31 0.0400 73.57 4839.39 0.0400 74.08 4839.50 0.0400 75.07 4839.73 0.0400 76.18 4840.00 0.0400 77.37 4840.34 0.0400 77.93 4840.50 0.0400 78.91 4840.71 0.0400 80.82 4841.00 0.0400 81.02 4841.03 0.0400 81.31 4841.09 0.0400 83.44 4841.50 0.0400 84.61 4841.67 0.0400 87.07 4842.00 0.0400 87.91 4842.14 0.0400 88.02 4842.16 0.0400 88.11 4842.18 0.0400 89.89 4842.50 0.0400 94.30 4842.93 0.0400 94.51 4842.95 0.0400 94.62 4842.96 0.0400 94.95 4843.00 0.0400 95.08 4843.00 0.0400 95.28 4843.01 0.0400 96.40 4843.16 0.0400 97.27 4843.26 0.0400 97.99 4843.36 0.0400 98.33 4843.39 0.0400 99.13 4843.49 0.0400 99.43 4843.48 0.0400 99.52 4843.50 0.0400 100.73 4843.59 0.0400 100.81 4843.59 0.0400 101.07 4843.62 0.0400 101.40 4843.65 0.0400 102.36 4843.76 0.0400 104.36 4844.00 0.0400 104.42 4844.00 0.0400 104.44 4844.00 0.0400 104.48 4844.00 0.0400 104.52 4844.00 0.0400 105.31 4844.08 0.0400 107.62 4844.28 ----- Longitudinal Slope: 0.0350 ft/ft Flow 142.0000 cfs Result Parameters Depth 1.9799 ft Area of Flow 15.2979 ft^2 Wetted Perimeter 16.9468 ft Hydraulic Radius 0.9027 ft Average Velocity 9.2823 ft/s Top Width 16.2891 ft Froude Number: 1.6880 Critical Depth 2.4266 ft Critical Velocity 5.7532 ft/s Critical Slope: 0.0124 ft/ft Critical Top Width 24.01 ft Calculated Max Shear Stress 4.3242 lb/ft^2 Calculated Avg Shear Stress 1.9715 lb/ft^2 Composite Manning's n Equation: Lotter method Manning's n: 0.0280 Bridge Scour Analysis:CH-1 SCOUR Notes: Scenario: CH-1-SCOUR Local Scour at Piers Summary Pier Name:2" Sch 80 Computation Method: HEC-18 Pier Scour Depth 0.80 ft Total Scour at Pier 0.00 ft Pier Name:6" Square Computation Method: HEC-18 Pier Scour Depth 1.78 ft Total Scour at Pier 0.00 ft Pier Details Pier Name: 2" Sch 80 Pier Scour Computation Type: HEC-18 Input Parameters Pier Shape: Circular Cylinder Bed Condition: Clear-Water Scour Depth Upstream of Pier: 1.86 ft Velocity Upstream of Pier: 6.53 ft/s Width of Pier: 0.17 ft Length of Pier: 0.17 ft Angle of Attack: 0.00 Degrees Result Parameters Froude Number Upstream: 0.84 Correction Factor for Pier Nose Shape (K1): 1.00 Correction Factor of Angle of Attack (K2): 1.00 Pier Length to Pier Width (L/a): 1.00 Correction Factor for Bed Condition (K3): 1.10 Scour Depth: 0.80 ft Pier Name: 6" Square Pier Scour Computation Type: HEC-18 Input Parameters Pier Shape: Square Nose Bed Condition: Clear-Water Scour Depth Upstream of Pier: 1.86 ft Velocity Upstream of Pier: 6.53 ft/s Width of Pier: 0.50 ft Length of Pier: 0.50 ft Angle of Attack: 0.00 Degrees Result Parameters Froude Number Upstream: 0.84 Correction Factor for Pier Nose Shape (K1): 1.10 Correction Factor of Angle of Attack (K2): 1.00 Pier Length to Pier Width (L/a): 1.00 Correction Factor for Bed Condition (K3): 1.10 Scour Depth: 1.78 ft Scour Summary Table Long Term Degradation Contraction Scour Local Scour at Piers Parameter Value Units Notes Piers Pier Name 2" Sch 80 Pier Computation Method HEC-18 Pier Scour Depth 0.80 ft Total Scour at 0.80 ft Longterm Pier degradation + contraction scour + pier scour Piers Pier Name 6" Square Pier Computation Method HEC-18 Pier Scour Depth 1.78 ft Total Scour at Pier 1.78 ft Longterm degradation + contraction scour + pier scour Bridge Scour Analysis:CH-2 SCOUR Notes: Scenario: CH-2-SCOUR Local Scour at Piers Summary Pier Name:2" Sch 80 Computation Method: HEC-18 Pier Scour Depth 0.81 ft Total Scour at Pier 0.00 ft Pier Name:6" Square Computation Method: HEC-18 Pier Scour Depth 1.80 ft Total Scour at Pier 0.00 ft Pier Details Pier Name: 2" Sch 80 Pier Scour Computation Type: HEC-18 Input Parameters Pier Shape: Circular Cylinder Bed Condition: Clear-Water Scour Depth Upstream of Pier: 2.13 ft Velocity Upstream of Pier: 6.39 ft/s Width of Pier: 0.17 ft Length of Pier: 0.17 ft Angle of Attack: 0.00 Degrees Result Parameters Froude Number Upstream: 0.77 Correction Factor for Pier Nose Shape (K1): 1.00 Correction Factor of Angle of Attack (K2): 1.00 Pier Length to Pier Width (L/a): 1.00 Correction Factor for Bed Condition (K3): 1.10 Scour Depth: 0.81 ft Pier Name: 6" Square Pier Scour Computation Type: HEC-18 Input Parameters Pier Shape: Square Nose Bed Condition: Clear-Water Scour Depth Upstream of Pier: 2.13 ft Velocity Upstream of Pier: 6.39 ft/s Width of Pier: 0.50 ft Length of Pier: 0.50 ft Angle of Attack: 0.00 Degrees Result Parameters Froude Number Upstream: 0.77 Correction Factor for Pier Nose Shape (K1): 1.10 Correction Factor of Angle of Attack (K2): 1.00 Pier Length to Pier Width (L/a): 1.00 Correction Factor for Bed Condition (K3): 1.10 Scour Depth: 1.80 ft Scour Summary Table Long Term Degradation Contraction Scour Local Scour at Piers Parameter Value Units Notes Piers Pier Name 2" Sch 80 Pier Computation Method HEC-18 Pier Scour Depth 0.81 ft Total Scour at Pier 0.81 ft Longterm degradation + contraction scour + pier scour Piers Pier Name 6" Square Pier Computation Method HEC-18 Pier Scour Depth 1.80 ft Total Scour at Pier 1.80 ft Longterm degradation + contraction scour + pier scour Bridge Scour Analysis:CH-3 SCOUR Notes: Scenario: CH-3-SCOUR Local Scour at Piers Summary Pier Name:2" Sch 80 Computation Method: HEC-18 Pier Scour Depth 0.94 ft Total Scour at Pier 0.00 ft Pier Name:6" Square Computation Method: HEC-18 Pier Scour Depth 2.09 ft Total Scour at Pier 0.00 ft Pier Details Pier Name: 2" Sch 80 Pier Scour Computation Type: HEC-18 Input Parameters Pier Shape: Circular Cylinder Bed Condition: Clear-Water Scour Depth Upstream of Pier: 1.98 ft Velocity Upstream of Pier: 9.28 ft/s Width of Pier: 0.17 ft Length of Pier: 0.17 ft Angle of Attack: 0.00 Degrees Result Parameters Froude Number Upstream: 1.16 Correction Factor for Pier Nose Shape (K1): 1.00 Correction Factor of Angle of Attack (K2): 1.00 Pier Length to Pier Width (L/a): 1.00 Correction Factor for Bed Condition (K3): 1.10 Scour Depth: 0.94 ft Pier Name: 6" Square Pier Scour Computation Type: HEC-18 Input Parameters Pier Shape: Square Nose Bed Condition: Clear-Water Scour Depth Upstream of Pier: 1.98 ft Velocity Upstream of Pier: 9.28 ft/s Width of Pier: 0.50 ft Length of Pier: 0.50 ft Angle of Attack: 0.00 Degrees Result Parameters Froude Number Upstream: 1.16 Correction Factor for Pier Nose Shape (K1): 1.10 Correction Factor of Angle of Attack (K2): 1.00 Pier Length to Pier Width (L/a): 1.00 Correction Factor for Bed Condition (K3): 1.10 Scour Depth: 2.09 ft Scour Summary Table Long Term Degradation Contraction Scour Local Scour at Piers Parameter Value Units Notes Piers Pier Name 2" Sch 80 Pier Computation Method HEC-18 Pier Scour Depth 0.94 ft Total Scour at Pier 0.94 ft Longterm degradation + contraction scour + pier scour Piers Pier Name 6" Square Pier Computation Method HEC-18 Pier Scour Depth 2.09 ft Total Scour at Pier 2.09 ft Longterm degradation + contraction scour + pier scour Bridge Scour Analysis:INT-2-SCOUR Notes: Scenario: INT-2-SCOUR Pier Name:2" Sch 80 Computation Method: HEC-18 Pier Scour Depth 0.86 ft Total Scour at Pier 0.00 ft Pier Name:6" Square Computation Method: HEC-18 Pier Scour Depth 1.90 ft Total Scour at Pier 0.00 ft Pier Details Pier Name: 2" Sch 80 Pier Scour Computation Type: HEC-18 Input Parameters Pier Shape: Circular Cylinder Bed Condition: Clear-Water Scour Depth Upstream of Pier: 1.72 ft Velocity Upstream of Pier: 7.79 ft/s Width of Pier: 0.17 ft Length of Pier: 0.17 ft Angle of Attack: 0.00 Degrees Result Parameters Froude Number Upstream: 1.05 Correction Factor for Pier Nose Shape (K1): 1.00 Correction Factor of Angle of Attack (K2): 1.00 Pier Length to Pier Width (L/a): 1.00 Correction Factor for Bed Condition (K3): 1.10 Scour Depth: 0.86 ft Pier Name: 6" Square Pier Scour Computation Type: HEC-18 Input Parameters Pier Shape: Square Nose Bed Condition: Clear-Water Scour Depth Upstream of Pier: 1.72 ft Velocity Upstream of Pier: 7.79 ft/s Width of Pier: 0.50 ft Length of Pier: 0.50 ft Angle of Attack: 0.00 Degrees Result Parameters Froude Number Upstream: 1.05 Correction Factor for Pier Nose Shape (K1): 1.10 Correction Factor of Angle of Attack (K2): 1.00 Pier Length to Pier Width (L/a): 1.00 Correction Factor for Bed Condition (K3): 1.10 Scour Depth: 1.90 ft Scour Summary Table Long Term Degradation Contraction Scour Local Scour at Piers Parameter Value Units Notes Piers Pier Name 2" Sch 80 Pier Computation Method HEC-18 Pier Scour Depth 0.86 ft Total Scour at Pier 0.86 ft Longterm degradation + contraction scour + pier scour Piers Pier Name 6" Square Pier Computation Method HEC-18 Pier Scour Depth 1.90 ft Total Scour at Pier 1.90 ft Longterm degradation + contraction scour + pier scour Project: Status: Author: Date:1/29/2025 Adam Johnson Draft/Final Bikefill Mountain Bike Park Project Location USGS The National Map: National Boundaries Dataset, 3DEP Elevation Program, Geographic Names Information System, National Hydrography Dataset, National Land Cover Database, National Structures Dataset, and National Transportation Dataset; USGS Global Ecosystems; U.S. Census Bureau TIGER/Line data; USFS Road data; Natural Earth Data; U.S. Department of State HIU; NOAA National Centers for Environmental Information. Data refreshed April, 2024. 0 1 20.5 Miles´ Project Location REVISIONSHEETDESIGNED BY:QUALITY CHECK:JOB NO.FIELDBOOKDRAWN BY:DATE:DRAWING3REV DATE NOT FORCONSTRUCT ION.DWGEngineering tdhengineering.com Drawing3.dwg, 10/5/2017 1:09:22 PM, KBP BIKEFILL BIKE PARK PHASE I ENVIRONMENTAL SITE ASSESSMENT BOZEMAN, MONTANA B25-012FIGURE 2AAW Project: Status: Author: Date: Exhibit B: Bikefill Mountain Bike Park Project Boundaries Draft Adam Johnson 11/5/2024 Vantor 0 0.20.1 MilesÜ Bozeman GIS, Bureau of Land Legend Bikefill Project Boundary City Parcel Boundary Snowfill Recreation Area Bozeman Solid Waste Division Bikefill Project Boundary - 66 acres Project: Status: Author: Date: Bikefill Bike Park: Trail Bridge locations Adam Johnson 4/10/2026 SD SD SD SD SD SD SD SD SDSD C h ur nC re e kVALLEY RIDGEMC I L HATTANSTORYMILLCH 2 CH 1 CH 3 INT 2 INT 1 0 820410Feet¯ Bozeman GIS, Bureau of Land Note: Contour lines = 1 ft interval Not included in this report. EXHIBIT CH-1 010 SCALE:1" = 20' 2010 View of CH 1: (right) view from standing on the south bank (left) channel view from standing on the north bank EXHIBIT CH-2 010 SCALE:1" = 20' 2010 View of CH 2: (top) wide view from standing on the north bank (bottom) channel view standing on the north bank EXHIBIT CH-3 010 SCALE:1" = 20' 2010 View of CH 3: (right) wide view from standing on the north bank (left) channel view from standing on the north bank EXHIBIT INT-2 010 SCALE:1" = 20' 2010 View of INT 2: (top) view to the East standign on west bank across stream (bottom) view facing west across channel from east. 55, PLUS SCOURDEPTH ALTERNATIVE BRIDGE OPTION FOR SPANS OVER 20': 3/16" THICK 6"SQUARE TUBE STRINGERS WELDED TO 1/4" PLATE FOOTERSANCHORED WITH REBAR