The URL can be used to link to this page

Home My WebLink About009_Water ReportWater Design Report Beall Townhomes (1608 W. Beall St.) Bozeman, MT 109 E. MAIN STREET, BOZEMAN, MT 59715 I OFFICE 406.728.4611 I EMAIL wgm@wgmgroup.com REPORT DATE: May 2022 AUTHOR: Gary Fox, P.E. Project Engineer WGM Group, Inc. CONTENTS 1.0 INTRODUCTION AND PROJECT DESCRIPTION .............................. 2.0 WATER DISTRIBUTION SYSTEM SIZING .......................................... 3.0 HYRAULIC ANALYSIS ........................................................................ APPENDICES A – WATERCAD MODEL DATA B – WATERCAD MODEL MAP BEALL TOWNHOMES Water Design Report 1.0 INTRODUCTION AND PROJECT DESCRIPTION The proposed Beall Townhome project is located at 1608 W. Beall in Bozeman, Montana. The project consists of 11 townhome units within two buildings. Six of the townhome units will have 2-bedrooms and five of the townhome units will have 3-bedrooms. The project will require tapping into an existing water main which runs east to west within Beall St. The existing main is 12-inch diameter cast iron. A new water main extension will be built south into the project site and will be 8-inch diameter. The new water main has one dead-end on the south side of the project site. This dead-end will have a blowoff valve installed. The water main will be installed in the City standard location and located 10 feet or more away from the proposed sewer main. Per field inspection, the approximate depth to the top of the water main is 6 feet. Existing fire hydrants are located near the site at the intersection of W. Beall St. and N 17th Ave. and at the intersection of W. Beall St. and N 16th Ave. Fire hydrants are also located southwest of the site, per City GIS. Due to the proximity of existing hydrants near the site, no new hydrants are proposed as part of this development. The following image shows existing City water infrastructure from the City’s GIS website. BEALL TOWNHOMES Water Design Report This design report summarizes the projected average, maximum day, and peak water demands for the development. 2.0 WATER DISTRIBUTION SYSTEM SIZING A WaterCAD analysis has been provided with this report to analyze the new main extension. The connection to the existing system has been modeled as a pump curve using data obtained from the City of Bozeman Water Department including static, residual, and pitot pressures. This data was used to develop the pump curve using a connection point to model the system (see below). 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 Proposed Residential: 11 units (2.11 persons/DU) Average residential demand: 170 gpcpd x 11 units x 2.11 persons/DU = 3,945.7 gpd = 2.7 gpm Total Average Day Demand: 2.7 gpm Maximum Day Demand: (2.7 gpm x 2.3) = 6.2 gpm Peak Hour Demand: (2.7 gpm x 3.0) = 8.1 gpm BEALL TOWNHOMES Water Design Report As part of the proposed development, WGM reached out to the City’s Water/Sewer District regarding system pressure and hydrant flow testing. On November 11, 2021, the City of Bozeman conducted a fire hydrant flow test on GIS hydrant ID #464 southwest of the project site with an adjacent main of 8-inch diameter cast iron. Results from this test were provided in Microsoft Excel and are attached to this report. The data modeled a hydrant curve with available flow and residual pressure. This data was used to create the WaterCAD model as described below. The hydrant curve is shown below. The flow data is summarized as follows: Static Pressure: 127.7 psi (pressure at 0 gpm flow) Residual Pressure: 117 psi (at 1,500 gpm) Flow Rate: 1500 gpm (minimum per City) Note the available Flow at minimum residual pressure required (20 psi): ~6,000 gpm BEALL TOWNHOMES Water Design Report 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 City 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 The three-point pump curve points were as follows: shutoff: 0 gpm and 293 feet of head (static pressure), 1,200 gpm and 277.8 feet of head (design), and max operating: 1,500 gpm and 269 feet of head (residual pressure). 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. This was determined to be a conservative method to analyze flows. A minimum of 1,500 gpm at 20 psi was used for the hydrant in this scenario. The results of the attached model show that the proposed 8-inch ductile iron pipe extension provides adequate capacity to serve the development under the peak hour demand. BEALL TOWNHOMES Water Design Report APPENDIX A WATERCAD MODEL DATA Scenario Summary Report Scenario: Automated Fire Flow Analysis Scenario Summary 46ID Automated Fire Flow AnalysisLabel Notes Base Active TopologyActive Topology Base PhysicalPhysical Base DemandDemand Base Initial SettingsInitial Settings Base OperationalOperational Base AgeAge Base ConstituentConstituent Base TraceTrace Base Fire FlowFire Flow Base Energy CostEnergy Cost Base TransientTransient Base Pressure Dependent DemandPressure Dependent Demand Base Failure HistoryFailure History Base SCADASCADA Base User Data ExtensionsUser Data Extensions Fire FlowSteady State/EPS Solver Calculation Options Base Calculation OptionsTransient Solver Calculation Options Hydraulic Summary Steady StateTime Analysis Type TrueUse simple controls during steady state? Hazen- WilliamsFriction Method FalseIs EPS Snapshot? 0.001Accuracy 12:00:00 AMStart Time 40Trials Fire FlowCalculation Type Page 1 of 127 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 1/4/2022 WaterCAD [10.02.03.06] Bentley Systems, Inc. Haestad Methods Solution CenterBeall WaterCAD 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 (Available)(gpm)Fire Flow (Needed)(gpm)LabelJ-45151203,5001,5003,5001,500H-1J-45757203,5001,5003,5001,500J-2J-45151203,5001,5003,5001,500J-3H-15151203,5081,5083,5001,500J-4Page 1 of 127 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-16661/4/2022WaterCAD[10.02.03.06]Bentley Systems, Inc. Haestad Methods Solution CenterBeall WaterCAD Water Model.wtg FlexTable: Pipe TableLength (User Defined)(ft)Velocity(ft/s)Flow(gpm)Hazen-Williams CMaterialDiameter(in)LabelID10.058130.0Ductile Iron8.0P-2361280.058130.0Ductile Iron8.0P-337740.058130.0Ductile Iron8.0P-43820.000130.0Ductile Iron6.0P-54350.058130.0Ductile Iron8.0P-749Page 1 of 127 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-16661/4/2022WaterCAD[10.02.03.06]Bentley Systems, Inc. Haestad Methods Solution CenterBeall WaterCAD Water Model.wtg Pump Definition Detailed Report: Connection to BeallElement Details40IDNotesConnection to BeallLabelPump Definition TypeStandard (3 Point)Pump Definition Typeft277.80Design Headgpm0Shutoff Flowgpm1,500Maximum Operating Flowft293.00Shutoff Headft269.00Maximum Operating Headgpm1,200Design 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 +1-203-755-16661/4/2022WaterCAD[10.02.03.06]Bentley Systems, Inc. Haestad Methods Solution CenterBeall WaterCAD Water Model.wtg Pump Definition Detailed Report: Connection to BeallGraphHead (ft)300.00275.00250.00225.00200.00175.00150.00125.00100.0075.0050.0025.000.00Pump Efficiency (%)120.0100.080.060.040.020.00.0Flow (gpm)5,0004,3753,7503,1252,5001,8751,2506250Page 2 of 227 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-16661/4/2022WaterCAD[10.02.03.06]Bentley Systems, Inc. Haestad Methods Solution CenterBeall WaterCAD Water Model.wtg FlexTable: Junction TablePressure(psi)Hydraulic Grade(ft)Demand(gpm)Demand CollectionZoneElevation(ft)LabelID127294.000<Collection: 0 items>Zone - 11.00J-234127294.000<Collection: 0 items>Zone - 11.00J-335127294.008<Collection: 1 items>Zone - 11.00J-448Page 1 of 127 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-16661/4/2022WaterCAD[10.02.03.06]Bentley Systems, Inc. Haestad Methods Solution CenterBeall WaterCAD Water Model.wtg GIS Hydrant #Available Flow (gpm) Residual Pressure (psi)16080 127.66200 127.16400 126.38600 125.34800 124.061,000.00 122.551,200.00 120.81,400.00 118.841,600.00 116.661,800.00 114.272,000.00 111.672,200.00 108.862,400.00 105.862,600.00 102.652,800.00 99.253,000.00 95.663,200.00 91.873,400.00 87.893,600.00 83.733,800.00 79.374,000.00 74.834,200.00 70.114,400.00 65.24,600.00 60.114,800.00 54.835,000.00 49.385,200.00 43.745,400.00 37.935,600.00 31.945,800.00 25.776,000.00 19.436,200.00 12.916,400.00 6.226,581.43 0.01Hydrant Curve 0204060801001201400 1000 2000 3000 4000 5000 6000 7000Residual Pressure (psi)Available Flow (gpm)Hydrant Curve 1608Data Disclaimer: Water distribution information is calculated using hydraulic modeling software and is subject to variation. Actual field conditions may vary. This information is provided to the requestor for evaluation purposes only, without warranty of any kind, including, but not limited to any expressed or implied warranty arising by contract, stature, or law. In no event regardless of cause, shall the City be liable for any direct, indirect, special, punitive or consequential damages of any kind whether such damages arise under contract, tort, strict liability or inequity. BEALL TOWNHOMES Water Design Report APPENDIX B WATERCAD MODEL MAP Scenario: Automated Fire Flow Analysis P-5Page 1 of 127 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 1/4/2022 WaterCAD [10.02.03.06] Bentley Systems, Inc. Haestad Methods Solution CenterBeall WaterCAD Water Model.wtg