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Home My WebLink AboutWaterDesignReport_07262021 Water Design Report Annie Subdivision Phase 4 Bozeman, Mt 109 E. MAIN STREET, BOZEMAN, MT 59715 I OFFICE 406.728.4611 I EMAIL wgm@wgmgroup.com ANNIE SUBDIVISION PHASE 4 Engineer’s Water Design Report REPORT DATE: May 2021 AUTHOR: Mathias Hanssen, E.I. Staff Engineer WGM Group, Inc. Hunter Morrical, P.E. Project Engineer WGM Group, Inc. ANNIE SUBDIVISION PHASE 4 Engineer’s Water Design Report CONTENTS 1.0 INTRODUCTION AND PROJECT DESCRIPTION ............................ 1 2.0 WATER DISTRIBUTION SYSTEM SIZING ........................................ 2 3.0 HYRAULIC ANALYSIS ...................................................................... 3 APPENDICES A – WATERCAD MODEL DATA B – WATERCAD MODEL MAP 1 ANNIE SUBDIVISION PHASE 4 Water Design Report 1.0 INTRODUCTION AND PROJECT DESCRIPTION The proposed project type is a major subdivision consisting of twenty (20) lots in total. Sixteen (16) are planned to be townhouse lots, two (2) are planned to be four-plex lots, and one (1) is planned to be a single-family home lot. The remaining lot will be common open space. This design report summarizes the projected average, maximum day, and peak water demands for the residential development. Annie Subdivision Phase 4 will involve connecting two existing dead-end, 8-inch diameter ductile iron pipe (DIP) water mains, one dead-end which exists at the western property boundary within Daffodil Street and one dead-end which exists at the northern property boundary within Roger’s Way. Existing fire hydrants are located to the west side of the project site (hydrant #2145), adjacent to the east side of the site (hydrant #1015), and multiple along Durston Road. Infrastructure as-builts for Annie Subdivision Phase 3C dated May 2007 were also evaluated as part of the project. The following image shows existing City infrastructure per the City of Bozeman’s GIS website. Figure 1 - City of Bozeman GIS This project is located within the City of Bozeman’s South pressure zone. An eight-inch water main is proposed to extend through the project site and connect the existing water mains in Daffodil Street and Rogers Way. The proposed layout of new water infrastructure is shown on drawings attached with the preliminary plat application. The water main installed will be class 51 ductile iron as required by City 2 ANNIE SUBDIVISION PHASE 4 Water Design Report design standards. This project will accomplish city objectives by creating a looped water main between Daffodil Street and Rogers Way. Water services to the proposed townhome and single-family home lots are to be 3/4” water lines. The services to the proposed four-plex lots will be 1” water lines. 2.0 WATER DISTRIBUTION SYSTEM SIZING An average daily demand of 170 gallons per capita per day unit has been used per City of Bozeman Design Standards and Specifications Policy. Water main sizing has been in accordance with the City of Bozeman Design Standards. Design Parameters: Average daily use: 170 gallons/capita/day Average Population Density: 2.11 persons/dwelling unit Minimum Fire Hydrant Flow: 1,500 gpm Residual Pressure Required: 20 psi for Fire Flow Average Day Demand: Peaking Factor = 1.0 Maximum Day Demand: Peaking Factor = 2.3 Maximum Hour Demand: Peaking Factor = 3.0 This proposed development will include 25 units. The residential usages of the proposed development are as follows: Average daily use: (170 gpcpd x 25 units x 2.11 persons/DU) = 8,968 gpd = 6.2 gpm Maximum daily use: (6.2 gpm x 2.3) = 14.3 gpm Peak hourly use: (6.2 gpm x 3.0) = 18.6 gpm Demand Summary Average Day Demand = 6.2 gpm or 8,968 gpd Maximum Day Demand = 14.3 gpm or 26,784 gpd 3 ANNIE SUBDIVISION PHASE 4 Water Design Report Peak Hour Demand = 18.6 gpm As part of the proposed development, WGM reached out to the City’s Water/Sewer District regarding system pressure and hydrant flow testing. On March 5, 2021, the City conducted a fire hydrant flow test on Daffodil Street, east of North 25th Ave., adjacent to the project site (hydrant #2145). The flow data from the hydrant flow test is summarized as follows: Static Pressure: 144 psi Residual Pressure: 138 psi Pitot (2.5” nozzle): 120 psi Flow Rate: 1840 gpm A WaterCad model is enclosed with this report that shows an 8-inch water main has the capacity to serve the flows calculated above. The model was built using City of Bozeman Water department information from the hydrant flow test. 3.0 HYDRAULIC ANALYSIS The method used to model the connection was by using a reservoir and fictitious pump with a 3-point characteristic pump curve based on the COB hydrant flow data. The following equation based on the Hazen Williams equation was used to create a pump curve for system modeling: Qr = Qf * [(Hr / Hf) ^ 0.54] Where: Qr = Flow available at the desired fire flow residual pressure Qf = Flow during the test Hr = Static Pressure minus the chosen Design Pressure Hf = Static Pressure minus the residual pressure during the flow test All pipes in the system were modeled as ductile iron class 51 with a roughness coefficient of 130. A hydrant was placed at the end of the line in the proposed model to analyze the impacts of available pressures and flows during a peak hour demand event that coincides with the hydrant in Roger’s Way 4 ANNIE SUBDIVISION PHASE 4 Water Design Report being used for fire flows. Since the system will create a loop between Daffodil Street and Rogers Way, this was a conservative method to analyze flows for the loop. A minimum of 1,500 gallons per minute at 20 psi was used for the hydrant in the scenario. The results of the attached model show that the proposed 8-inch ductile iron pipe connection at Daffodil Street provides adequate capacity to serve the development under the peak hour demand. The static pressures shown are relatively high based on the existing hydrant test, thus the home builders may consider installing individual pressure reducing valves so to protect home appliances from pressure deterioration. This is a conservative model, as the development will also tie into the water main within Roger’s Way, making capacity likely greater than what has been estimated in this exercise. 5 ANNIE SUBDIVISION PHASE 4 Water Design Report APPENDIX A WATERCAD MODEL DATA Scenario Summary ReportScenario: Automated Fire Flow AnalysisScenario Summary46IDAutomated Fire Flow AnalysisLabelNotesBase Active TopologyActive TopologyBase PhysicalPhysicalBase DemandDemandBase Initial SettingsInitial SettingsBase OperationalOperationalBase AgeAgeBase ConstituentConstituentBase TraceTraceBase Fire FlowFire FlowBase Energy CostEnergy CostBase TransientTransientBase Pressure Dependent DemandPressure Dependent DemandBase Failure HistoryFailure HistoryBase SCADASCADABase User Data ExtensionsUser Data ExtensionsFire FlowSteady State/EPS Solver Calculation OptionsBase Calculation OptionsTransient Solver Calculation OptionsHydraulic SummarySteady StateTime Analysis TypeTrueUse simple controls during steady state?Hazen-WilliamsFriction MethodFalseIs EPS Snapshot?0.001Accuracy12:00:00 AMStart Time40TrialsFire FlowCalculation TypePage 1 of 127 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-16664/23/2021WaterCAD[10.02.03.06]Bentley Systems, Inc. Haestad Methods Solution CenterAnnie Water Model.wtg Pump Definition Detailed Report: Daffodil HydrantElement Details40IDNotesDaffodil HydrantLabelPump Definition TypeStandard (3 Point)Pump Definition Typeft325.71Design Headgpm0Shutoff Flowgpm1,840Maximum Operating Flowft332.64Shutoff Headft318.78Maximum Operating Headgpm1,265Design FlowPump Efficiency TypeBest Efficiency PointPump Efficiency Type%100.0Motor Efficiency%100.0BEP EfficiencyFalseIs Variable Speed Drive?gpm0BEP FlowTransient (Physical)lb·ft²0.000Inertia (Pump and Motor)SI=25, US=1280Specific Speedrpm0Speed (Full)TrueReverse Spin Allowed?Page 1 of 227 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-16664/23/2021WaterCAD[10.02.03.06]Bentley Systems, Inc. Haestad Methods Solution CenterAnnie Water Model.wtg Pump Definition Detailed Report: Daffodil HydrantGraphHead (ft)350.00300.00250.00200.00150.00100.0050.000.00Pump Efficiency (%)120.0100.080.060.040.020.00.0Flow (gpm)10,0008,7507,5006,2505,0003,7502,5001,2500Page 2 of 227 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-16664/23/2021WaterCAD[10.02.03.06]Bentley Systems, Inc. Haestad Methods Solution CenterAnnie Water Model.wtg FlexTable: Pipe TableLength (User Defined)(ft)Headloss Gradient(ft/ft)Velocity(ft/s)Flow(gpm)Hazen-Williams CMaterialDiameter(in)LabelID50.0000.1219130.0Ductile Iron8.0P-23650.0000.1219130.0Ductile Iron8.0P-3374000.0000.1219130.0Ductile Iron8.0P-43890.0000.000130.0Ductile Iron6.0P-543Page 1 of 127 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-16664/23/2021WaterCAD[10.02.03.06]Bentley Systems, Inc. Haestad Methods Solution CenterAnnie Water Model.wtg Fire Flow Node FlexTable: Fire Flow ReportJunction w/ Minimum Pressure (Zone)Pressure (Calculated Zone Lower Limit)(psi)Pressure (Calculated Residual)(psi)Pressure (Residual Lower Limit)(psi)Flow (Total Available)(gpm)Flow (Total Needed)(gpm)Fire Flow (Needed)(gpm)ZoneLabelJ-39188203,5001,5001,500Zone - 1H-1H-1123123203,5001,5001,500Zone - 1J-2H-19191203,5191,5191,500Zone - 1J-3Page 1 of 127 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-16664/23/2021WaterCAD[10.02.03.06]Bentley Systems, Inc. Haestad Methods Solution CenterAnnie Water Model.wtg FlexTable: Junction TablePressure(psi)Hydraulic Grade(ft)Demand(gpm)Demand CollectionZoneElevation(ft)LabelID144333.640<Collection: 0 items>Zone - 11.00J-234144333.6319<Collection: 1 items>Zone - 11.00J-335Page 1 of 127 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-16664/23/2021WaterCAD[10.02.03.06]Bentley Systems, Inc. Haestad Methods Solution CenterAnnie Water Model.wtg 6 ANNIE SUBDIVISION PHASE 4 Water Design Report APPENDIX B WATERCAD MODEL MAP Scenario: Automated Fire Flow AnalysisP-4P-3P-2J-3J-2PMP-1R-1H-1Page 1 of 127 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-16664/23/2021WaterCAD[10.02.03.06]Bentley Systems, Inc. Haestad Methods Solution CenterAnnie Water Model.wtgP-5J-3Annie Phase 4 WaterCad Model MapPump modeled fromHydrant No. 2145 datain Daffodil StreetHydrant insertedto model Hydrantin Rogers Way