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HomeMy WebLinkAbout17 - Design Report - South University District Ph 2 - Stormwater Storm Water Plan South University District Phase 2 Subdivision Infrastructure February, 2017 Submitted to: City of Bozeman Engineering Department 20 East Olive Bozeman, MT 59715 Prepared by: Stahly Engineering and Associates 851 Bridger Drive, Suite 1 Bozeman, MT 59715 (406) 522-9526 STAH LY ,, oNTA ,.� �� ° o . !V,q AS CORDELL D, POOL _ o" POOL ; 1 1 T� CENS, '6 ijs/0'N A1.��� Storm Water Plan Contents General Information Existing Conditions and General Design Criteria Storm Drainage Plan Description Estimation of Runoff Pre-development Runoff — Phase 2 & 3 Post-development Runoff— Phase 2 & 3 Storage/Treatment Facilities Outfall Structure Weir Sizing Curb and Gutter Capacity Inlet Capacity Facilities Maintenance Figures and Tables Figure 1 . Inlet Basin Exhibit Figure 2. Inlet Basin Exhibit Table 1. Runoff Calculations — Phase 2 & 3 Table 2. Outfall Structure Sizing Table 3. Curb and Gutter Capacity Calculations Table 4. Phase 2 Inlet Basin and Pipe Capacity Calculations Table 5. Phase 2 and 3 Detention Basin Calculations Storm Water Plan 1 2/1/2017 General Information The South University District (SUD) Phase 2 is a subsequent minor subdivision of Lot 3, SUD Subdivision Phase 1 . The subsequent division will provide right of way dedications for South 14th Avenue, South 11th Avenue, and an additional street on the south side (currently un-named). This subdivision will create a 16.05-acre lot for subsequent site development. Phase 2 is located within the City of Bozeman, south of Campus Boulevard and between South 11 th and South 14th Avenues. Phase 2 is located south of Phase 1 (completed) and Phase 1 B (in progress). Site development on the Phase 2 lot is anticipated to be an 887-bed student housing project. SUD Phase 3 is a future development planned south of Phase 2. SUD Phase 3 will utilize storm water infrastructure installed in Phase 2 and its area is included in this analysis. Storm drainage improvements for SUD Phase 2 utilize infrastructure in Campus Blvd. and the Phase 1 Park. The storm water detention basin serving Phase 2 and 3 was constructed with the Phase 1 Park improvements. A storm water trunk line was installed in Campus Boulevard for Phase 2 and 3. This report also includes a preliminary analysis of Phase 2 on-site storm water mains. The analysis of on-site mains will be re-evaluated and updated with the final site design. The developer's contact information is: Capstone Collegiate Communities, LLC. 431 Office Park Drive Birmingham, AL 35223 Existing Conditions and General Design Criteria As stated previously the detention basin and trunk line in Campus Blvd. serving Phase 2 and Phase 3 was constructed in Phase 1 . The existing storm water detention basin is located in the Phase 1 Park and outfalls to Mandeville Creek. The Phase 1 Park is located between Phase 2 and Mandeville creek to the west. The existing condition at the site is undeveloped agricultural land. The site generally slopes to the north at 1-2%. In accordance with the City of Bozeman Design Standards and Specifications Policy (COB Standards) an engineering analysis has been conducted for SUD Phase 2 and 3 property to limit post-development runoff to pre-development rates. Storm runoff originating on the site will be detained on-site and released at rates less than the pre-development rates. Furthermore, the detention basin will reduce storm water velocity and allow solids, silt, oils, grease, and other pollutants to settle from the runoff before the flows leave the site. Storm Water Plan 2 2/1/2017 Inlets and storm sewers are sized to pass the 25-year event without overtopping roadways. Should a larger event overtop the roadways grading will divert storm water away from structures. Storm Drainage Plan Description The overall storm drainage plan for SUD Phase 2 is depicted on Figure 1 and 2 at the end of this report. Figure 1 shows the Phase 2 improvements, and Figure 2 shows the inclusion of Phase 3 areas. The storm drainage system builds on improvements completed in Phase 1 in the Park and Campus Blvd. Overall drainage direction on the proposed development is indicated by arrows showing the proposed drainage patterns and inlet locations. The existing detention pond previously constructed during Phase 1 will not need to be altered to accommodate Phase 2 or 3. Phase 2 storm water mains will connect to the trunk line in Campus Blvd. A storm drain will be extended in South 14th Avenue and along the south boundary of Phase 2 to serve future development in Phase 3. Estimation of Runoff Runoff estimates are provided for Phase 2 (21.4 acres) and Phase 3 (14.2 acres), with Phase 3 located to the south of Phase 2. Phase 3 estimates are included in this report because the storm water runoff from this offsite area will pass through Phase 2 storm water infrastructure. The rational method was used to estimate peak flow rates and volumes from storm runoff. Standard assumptions in using the rational method include that rainfall is uniformly distributed over a watershed for the duration of a storm event, the peak runoff rate occurs when the storm duration equals the time of concentration, and the runoff coefficient for a watershed is constant for similar land use. Time of concentration was determined from the slope of the basin, rational runoff coefficient and flow length (COB Standards — Equation II.E.6). Pre-development Runoff — Phase 2 and 3 A runoff coefficient of 0.20 for open land was selected for pre-development conditions. An average overland slope of 1.1% over a basin length of 1 ,200 feet provides a time of concentration of 56.5 minutes. The Bozeman IDF curves show a rainfall intensity for the 10-year design storm event of 0.67 in/hr. Applying this over the 35.6 acre site produces a runoff flow rate of 4.74 cfs at the downstream end of the basin. Post-development Runoff— Phase 2 and 3 Post-construction runoff was calculated using a runoff coefficient of 0.60 (commercial neighborhood) to account for future site development in accordance Storm Water Plan 3 2/1/2017 with the master plan. The increased impervious area and proposed site grading reduces the time of concentration to 14.7 minutes. The Bozeman IDP curves show a 10-year storm intensity of 1 .59 in/hr. The rational method provides a 10- year peak runoff rate of 34.07 cfs. The same analysis for a 25-year event provides a peak runoff rate of 44.43 cfs. Table 1 : Runoff Calculations — Phase 2 and 3 Time of Concentration Storm Sewer Calculations Preconstruction Postconstruction Flow Land Use Open Land REMU REMU Drainage Area acres 35.6 35.6 35.6 Slope % 1.1 1.8 1.8 Runoff Coefficients 0.2 0.6 0.6 Frequency Adjustment Factor, Cf 1 1 1.1 Basin Length ft 1200 367 367 Time of Concentration min 56.5 14.7 13.0 Peak Flow Calculations Design Storm 10-Year 10-Year 25-Year Intensity at Tc (Figure 1-2 pg. 29 in/hr 0.67 1.59 2.08 Peak Runoff Rate at Tc Q= CIA cfs 4.74 1 34.07 44.43 In addition to the overall storm runoff calculations for Phase 2 and 3, the 25-year storm runoff flow rate for each storm drainage inlet basin has been determined based on the drainage plan shown on Figure 1 . These calculations are provided in Table 4 at the end of this report. Storage/Treatment Facilities Simple pond routing using the modified rational method is provided for Phase 2 and Phase 3 in Table 5 at the end of the report. This spreadsheet shows a required storage of 32,151 cubic feet of runoff for the 10-year event for Phase 2 and 3. The required storage is provided by a detention basin that was constructed during Phase 1 . The detention basin constructed in Phase 1 has a bottom area of 23,105 square feet and 4:1 side slopes. The bottom elevation is 4931.5 and the surface overflow to the west is provided at an elevation of 4933.0. This 1.5' maximum depth provides a total volume of approximately 36,500 cubic feet. The detention basin is located at the northwest (down-gradient) end of the site and is vegetated with grass. Storm Water Plan 4 2/1/2017 Outfall Structure Weir Sizing The detention basin outflow for both Phase 2 and 3 developments is restricted by a typical control structure as depicted in COB Standards Figure A-2. Using the weir calculation equation given in Section II.D.2 of the COB Standards, the slot width of the outlet structure was determined (See Table 2). The combined slot width for Phase 2 and 3 discharge structure is 9 inches. This slot width limits the discharge from the structure to pre-developed rates at the maximum depth of 1.5 feet. Since this detention pond was constructed during Phase 1 , this outfall structure has already been constructed and meets the requirements of Phase 2 and 3. Table 2 Outfall Structure Weir Sizing Phase 2-3 Pre-developed Runoff cfs 4.47 Weir Coefficient"C" 3.33 Head ft 1.5 Slot Width (in) 9 In the occurrence of an event greater than the 10-year event the ponds are sized for, the overflow of the ponds directs flow to the west to Mandeville Creek. Curb and Gutter Capacity Storm runoff will be collected in street and parking lot curb and gutters. The hydraulic capacity of the curb and gutter was analyzed to determine if the curb would be overtopped in a 25-year event. The maximum 25-year event for any of the curb inlet basins produces approximately 1.95 cfs of runoff. The capacity of the curb at the lowest designed slope of 0.6% is 5.51 cfs at a depth of .15 feet below the top of the curb. Therefore, curb capacities in the development are adequate to carry the 25-year event. Table 3 Curb and Gutter Capacity Calcs Right-side slope X:1 0.05 Left-side slope X:1 33.00 Channel bottom width ft 0 Flow Depth ft 0.350 Flow Area ft^2 2.024 Wetted Perimeter ft 11.906 Width 0.035 Hydraulic Radius ft 0.170 Mannin 's Roughness 0.013 Slope ft/ft 0.006 Average Velocity ft/sec 2.72 Flow ft^3/sec 5.51 Storm Water Plan 5 2/1/2017 Inlet Capacity The curb inlets on the roadways in the development were analyzed to ensure they have capacity to accept flows conveyed to them without reaching a point 0.15 feet from the top of the curb. The COB approved Neenah Foundry R-3067- L inlet structure has a capacity of 5.98 cfs at 0.35 feet of head (0.15 below top of curb). This capacity will convey the necessary flows. Facilities Maintenance The proposed storm drainage facilities will be operated and maintained by the property owner. The owner is responsible for quarterly maintenance of all storm water facilities. The maintenance includes, but is not limited to, visual inspection and removal of sediment from curbs, inlets, detention basins, and outlet structures as well as any necessary repairs to the facilities. Storm Water Plan 6 2/1/2017 Table 5 Phase 2 and Phase 3 Detention Basin Calculations Time of Concentration Calculations Preconstruction Postconstructlon Storm Sewer Flow Land Use Open Land REMU REMU Drainage Area acres 35.6 35.6 35.6 Slope % 1.1 1-8 1.8 Runoff Coefficients 0 2 0.6 0.6 Frequency Ad ustment Factor Cf 1 1 1.1 Basin Length fl 1200 367 367 Basin length based on typical inlet area Time of Concentration min 56.5 14.7 13.0 Peak Flow Calculations Design Storm 10-Year 10-Year 25-Year Intensity at Tc (Figure 1-2 pg.29 in/hr 0.67 1_59 2 08 Peak Runoff Rate at Tc Q=CIA cts 4.74 34.07 44.43 (max release rate) Required Storage Volume MAX VOL. 32151.02 Storm Duration Intensity Future Runoff Rate Runoff Volume Release Volume Required Storage Notes (minutes) (Iruhr) (O=CIA)(c(s) (cf) (co (co 2 5.84 124.71 14965.50 668.75 14396.75 4 3.72 79.48 19074.44 1137.49 17936.94 6 2.86 61.06 21982.84 1706.24 20276.59 8 2.37 50.65 24311.53 2274.99 22036.54 10 2.05 43.81 26286.38 2843.74 23442.64 12 1.82 38.91 28018.46 3412.48 24605.97 14 1.65 35.20 29571.65 3981.23 25590.42 16 1.51 32.28 30986.52 4549.98 26436.54 18 1.40 29.90 32290.60 5118.73 27171.86 20 1.31 27.92 33503.59 5687.47 27816.11 24 1.16 24.80 35711.22 6824.97 28886.25 26 1.10 23.54 36725.82 7393.72 29332.10 28 1.05 22.44 37690.86 7962.46 29728.40 30 1.00 21.45 38612.08 8531.21 30080.87 32 0.96 20.57 39494.20 9099.96 30394.24 34 0.93 19.78 40341.16 9668.70 30672.46 36 0.89 19.05 41156.33 10237.45 30918.88 38 0.86 18.40 41942.57 10806.20 31136.37 40 0.83 17.79 42702.35 11374.95 31327.40 42 0.81 17.24 43437.82 11943.69 31494.13 44 0.78 16.72 44150.87 12512.44 31638.42 46 0.76 16.25 44843.14 13081.19 31761.95 48 0.74 15.80 45516.12 13649.94 31866.18 50 0.72 15.39 46171.11 14218.68 31952.42 52 0.70 15.00 46609,28 14787.43 32021.85 54 0.69 14.64 47431.69 15356.18 32075.51 56 0.67 14.30 48039.29 15924.92 32114.37 58 0.65 13.97 48632.95 16493.67 32139.27 60 0.64 13.67 49213.44 17062.42 32151.02 Required Storage 62 0.63 13.38 49781.49 17631.17 32150.32 64 0.61 13.11 50337.75 18199.91 32137.83 66 0.60 12.85 50882.82 18768.66 32114.16 68 0.59 12.60 51417.26 19337.41 32079.85 70 0.58 12.37 51941.57 19906.16 32035.42 72 0.57 12.14 52456.24 20474.90 31981.34 74 0.56 11.93 52961.70 21043.65 31918.05 76 0.55 11.72 53458.35 21612.40 31845.95 78 0.54 1153 53946.58 22181.15 31765.43 80 0.53 11.34 54426.73 22749.89 31676.84 82 0.52 11.16 54899.15 23318.64 31580.51 84 0.51 1098 55364.14 23887.39 31476.75 86 0.51 10.82 55821.98 24456.13 31365.85 88 0.50 10.66 56272.95 25024.88 31248.07 90 0.49 10.50 56717.32 25593.63 31123.69 92 0.48 10.35 57155.30 26162.38 30992.93 94 0.48 10.21 57587.14 26731.12 30856.02 96 0.47 10-07 58013.05 27299.87 30713.18 98 0.47 9.94 58433.23 27868.62 30564.61 100 0.46 9.81 58847.88 28437.37 30410.51 102 0.45 9.68 59257.16 29006.11 30251.05 104 0.45 9.56 59661.26 29574.86 30086.40 106 0.44 9.44 60060.35 30143.61 29916.74 108 0.44 9.33 60454.56 30712.36 29742.21 110 0.43 9.22 60844.07 31281.10 29562.96 112 0.43 9.11 61228.99 31849.85 29379.14 114 0.42 9.01 61609.47 32418.60 29190.87 116 0.42 8.91 61985.64 32987.34 28998.29 118 0.41 8.81 62357.61 33556.09 28801.52 120 0.41 8.71 62725.51 34124.84 28600.67 Table 4: Phase 2 Inlet Basin and Pipe Capacity Calculations Inlet Drainage Basin Inlet Basin 1D 2D 3D 4D 5D 6D 7D 8D 9D 10D 11D 12D 13D 14D 16D 17D 18D 19D 20D 21D 22D 23D 24D 25D 26D 27D 28D 29D 30D 31D 32D 2B 3B 4B Land Use REMU REMU REMU REMU REMU REMU REMU REMU REMU REMU REMU REMU REMU REMU REMU REMU REMU REMU REMU REMU REMU REMU REMU REMU REMU REMU REMU REMU REMU REMU REMU REMUI REMUI REMU Drainage Area(acres) 0.63 0.43 1.28 0.49 0.47 1.36 0.48 0.43 0.96 0.40 0.43 1.21 0.82 0.94 0.44 1.24 0.42 0.20 0.43 0.46 1.11 1.04 0.40 0.20 1.87 1.55 0.41 0.20 4.98 4.55 4.64 0.33 0.46 1 0.32 Sloe % 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.80 2.1 2.1 1 2.1 Runoff Coefficients 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Frequency Adjustment Factor,Cf 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 Basin Length ft 325 249 784 681 300 297 320 320 249 319 316 1 323 279 1 274 331 1 274 335 335 354 1 354 1 360 240 327 295 762 358 300 301 375 375 375 287 425 275 Time of Concentration min 12.2 10.7 18.9 17.7 11.7 11.7 12.1 12.1 10.7 12.1 12.0 12.2 11.3 11.2 12.3 11.2 12.4 12.4 12.7 12.7 12.8 10.5 12.2 11.6 18.7 12.8 11.7 11.7 13.1 13.1 13.1 10.9 13.2 10.7 Peak Flow Calculations Design Storm 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r 25 r Intensity at Tc (Figure 1-2 pg.29 in/hr 2.16 2.36 1 1.63 1 1.71 2.22 2.23 2.17 2A 7 2.36 2.18 2.18 2.17 2.27 2.28 2.15 2.28 2.14 2.14 2.10 2.10 2.09 2.38 2.16 2.23 1.65 2.10 2.22 2.22 2.07 2.07 2.07 2.33 2.05 2.36 Peak Runoff Rate at Tc(Q=CIA)(cfs) 0.82 0.61 1.25 0.50 0.63 1.82 0.63 0.56 1.36 0.52 0.56 1.57 1.12 1.29 0.57 1.70 0.54 0.26 0.54 0.58 1.39 1.49 0.52 0.27 1.85 1.95 0.55 0.27 6.17 5.64 5.75 1 0.47 1 0.56 0.45 Note:Due to site grading changes,Basin 15 D has been omitted Detention Basin B-Pipe Network Capacity Pie Number 1 D 2D 3D 4D 5D 6D I 7D 8D 9D 10D 11 D 12D 13D 14D 15D 16D 17D 18D 19D 20D 21 D 22D 23D 24D Pipe Size in 30.00 15.00 15.00 15.00 15.00 15.00 15.00 15.00 15.00 15.00 15.00 30.00 15.00 24.00 24.00 24.00 18.00 24.00 15.00 24.00 24.00 15.00 15.00 15.00 Mannin 's"n" PVC 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 Area(ft' 4.91 1.23 1.23 1.23 1.23 1.23 1.23 1.23 1.23 1.23 1.23 4.91 1.23 3.14 3.14 3.14 1.77 3.14 1.23 3.14 3.14 1.23 1.23 1.23 Wetted Perimeter(ft) 7.85 3.93 3.93 3.93 3.93 3.93 3.93 3.93 3.93 3.93 3.93 7.85 3.93 6.28 6.28 6.28 4.71 6.28 3.93 6.28 6.28 3.93 3.93 3.93 Hydraulic Radius ft 0.63 0.31 0.31 0.31 0.31 0.31 0.31 0.31 0.31 0.31 0.31 0.63 0.31 0.50 0.50 0.50 0.38 0.50 0.31 0.50 0.50 0.31 0.31 0.31 Slopeitiit 0.0219 0.0050 0.0050 0.0050 0.0050 0.0050 0.0050 0.0050 0.0050 0.0050 0.0050 0.0079 0.0050 0.0050 0.0050 0.0045 0.0050 0.0045 0.0050 0.0045 0.0050 0.0050 0.0050 0.0050 Full Flow Capacity cfs 60.86 4.58 4.58 4.58 4.58 1 4.58 4.58 4.58 4.58 4.58 4.58 36.55 4.58 16.04 16.04 15.22 7.45 15.22 1 4.58 15.22 16.04 4.58 4.58 4.58 Velocity Wsec 12.40 3.73 3.73 3.73 3.73 1 3.73 3.73 3.73 3.73 3.73 3.73 7.45 3.73 5.11 5.11 4.84 4.21 4.84 3.73 4.84 5.11 3.73 3.73 3.73 Contributing Pipes 12D NONE 4D 5D NONE I NONE 6D 9D NONE 11D NONE 14D NONE 13D 24D 17D NONE 19D NONE 22D NONE 23D NONE NONE 7D 15D 16D 18D 20D 21D 10D Actual Pie Flow cfs 23.51 1 0.50 1 1.82 1 1.82 1.82 1.29 1.29 1.12 0.54 1.70 F�l.70 19.96 11 0.54 11 13.79 6.17 12.99 0.00 12,99 0.52 12.20 1 11.39 0.81 0.55 0.37 %Capacity 39% 11% 40% 40% 40% 28% 28% 25% 12% 37% 37% 55% 12% 86% 38% e:," 0% 85% 11% 80% 71 18% 12% 8% Detention Basin B-Pipe Network Capacity Pipe Number 1 B 2 B 3B 10 B 11 B 12 B 13 B 1 E 4 B 5 B 6 B 7 B 8 B 9 B 1 F 2F 3F 4F 5F 6F 7F 8F 9F 10F 11 F 12F Pipe Size(in) 36.00 36.00 30.00 12.00 12.00 30.00 24.00 15.00 30.00 12.00 30.00 24.00 15.00 12.00 24.00 15.00 24.00 15.00 15.00 15.00 18.00 15.00 15.00 15.00 15.00 15.00 Mannin 's"n" PVC 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 Area ft` 7.07 7.07 4.91 0.79 0.79 4.91 3.14 1.23 4.91 0.79 4.91 3.14 1.23 0.79 3.14 1.23 3.14 1.23 1.23 1.23 1.77 1.23 1.23 1.23 1.23 1.23 'Netted Perimeter ft 9.42 9.42 7.85 3.14 3.14 7.85 6,28 3.93 7.85 3.14 7.85 6.28 3.93 3.14 6.28 3.93 6.28 3.93 3.93 3.93 4.71 3.93 3.93 3.93 3.93 3.93 Hydraulic Radius ft 0.75 0.75 0.63 0.25 0.25 0.63 0.50 0.31 0.63 0.25 0.63 0.50 0.31 0.25 0.50 0.31 0.50 0.31 0.31 0.31 0.38 0.31 0.31 0.31 0.31 0.31 Slope ft/ft 0.0060 0.0060 0.0045 0.0100 0.0100 0.0230 0.0100 0.0050 0.0045 0.0050 0.0045 0.0100 0.0045 0.0050 0.0050 0.0050 0.0050 0.0050 0.0050 0.0050 0.0050 0.0050 0.0050 0.0050 0.0050 0.0050 Full Flow Capacity(cfs) 51.80 51.80 27.59 3.57 3.57 62.37 22.68 4.58 27.59 2.53 27.59 22.68 4.35 2.53 16.04 4.58 16.04 4.58 4.58 4.58 7.45 4.58 4.58 4.58 4.58 4.58 VelocityWsec 7.33 7.33 5.62 4.55 4.55 12.71 7.22 3.73 5 662 3.22 5.62 7.22 3.54 3.22 5.11 3.73 5.11 3.73 3.73 3.73 4.21 3.73 3.73 3.73 3.73 3.73 1 ContributingP 2B 3B 13B NONE NONE 2D 1 E NONE 5B NONE 78 1 F 9B NONE 3F NONE 4F NONE 6F NONE 8F NONE 10F NONE 12F NONE 10B 4B 3D 8D 6B 8B 2F 5F 9F 11F 11B 1D 7F 126 Actual Pipe Flow(cfs) 44.74 44.74 17.01 0.45 0.82 26.46 2.31 0.63 14.70 0.47 13.63 11.81 1.82 0.56 11.81 0.52 10.73 1.36 2.69 1.12 6.68 1.39 3.44 1.49 1.95 1.95 %Capacity 86% 86% 62% t 3% 23 4294, 10% 14% 53% 18% 49% 52% 42°i., 22% 74% 11% 67% 30% 59% 24 90`r 30% 75% 32°% 43% 4314. 1 li H II I�,.. � STAHLY �9 1970 �. 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STE. 1 BOZEMAN,MT 59715 Phone:(408)522-9528 a. I FaK:(408)522-9528 ISSUE/REVISION w. I� No. DATE BY W I -- _ ` 1110 PDH Q \\, "rt on rb DESCRIPTION r - )- - n. in r PRELIMINARY PLAT I Im np4l No. DATE BY p�N$d9 -4-17 1 JD S DESCRIPTION aLuQ M COB SUBMITTAL !` — ' W I yg1 4 — . I .� a I I I I O Z Q y5 No. DATE BY ILIt )n[ia Onaaao �/ F- F a (L O 3 Z �1 _ I O d It DESCRIPTION No. DATE BY 4 'i - - 8`N \• — `. - \ DESCRIPTION 4 E e — e� �� eee� eeeeeeeee� eeee— eeeee� wee eeeeeee� e ee e No.lilt DATE BY --__ -u-'tr v' r•u-11 - _ 5 DESCRIPTION W --f1nJt—I ili-_ - _ /' — — LII_1L�� M a V — FLRDN (- ' M G � M I"a CO o fn 100 -llI- Y' I V Z Q A \A F- b . a.. E[ I - - INLET BASIN JAV Hit T•s _ _ _� �. EXHIBIT ale Iwn nt NI =w a Q PHASE 2 SOUTH a m 3 s a a UNIVERSITY DISTRICT - Il' v&w �. ��� RTR HOLDINGS II LC o BOZEMAN,MONTANANA w O o .` I tioiydNi bbZ DESIGNED:PDH DRAWN: PDH O CHECKED:JDS o f_l- _ 0 75 150 300 DATE: 1SH ET2018 41 IN FEET / FIGURE 2