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Home My WebLink About18 - Design Report - Crestview Condos - Water WATER DESIGN REPORT FOR: CRESTVIEW CONDOMINIUMS BOZEMAN, MT Prepared By: MADISON ENGINEERING Madison Engineering 895 Technology Drive, Suite 203 Bozeman, MT 59718 (406) 586-0262 NOVEMBER 2018 WATER DESIGN REPORT FOR: CRESTVIEW CONDOMINIUMS BOZEMAN, MT I3UDF�K.I o Madison Engineering 895 Technology Blvd Ste 203 Bozeman, MT 59718 (406) 586-0262 NOVEMBER 2018 CRESTVIEW CONDOMINIUMS WATER SYSTEM DESIGN REPORT A. General This design report will give an overview of the proposed water main extension for the development of Crestview Condominiums infrastructure improvements. Improvements are anticipated to be constructed during the winter of 2018. Once the water main is constructed and approved,the main will become a part of the City of Bozeman system. The following references were used in the preparation of this report: a. COB Design Standards and Specifications Policy, 2017. Addendum#6 b. COB Modifications to Montana Public Works Standard Specifications (MPWSS). c. WQB Circular No. 1 d. City of Bozeman Zoning Map e. City of Bozeman Water Facility Plan f. 2015 International Fire Code Existing System The proposed water main extension will be served by the existing City of Bozeman water distribution system, which will be tied into at the corner of Thomas Drive and Sartain Street. The following information was obtained by the City of Bozeman on November 16, 2018. Fire Hydrants: 1870 and 2213 Static Pressure: 100 psi Pitot Pressure: 90 psi Residual pressure: 94 psi Hydrant discharge: 1,590 gpm from 2.5" port Distribution Main Capacity—Fire flow at minimum residual pressure Qr= Qt[(I's—I'm)/(ps—Pt)]0.54 Q,= 1,590 [(100—20)/(100—90)]0.54 Q, =4,888 gpm Qt= Hydrant Discharge during Test Qr= Fire Flow at Residual Pressure Ps= Static Pressure Pm = Minimum Residual Pressure =20 psi Pr= Residual Pressure Pt= Pitot Pressure Crestview Condominiums Water Design Report Page I of 3 B. Proposed Water System The proposed water main extension consists of approximately 217 linear feet of 8" ductile iron pipe that will connect to the existing 12" water main at Sartain St and Thomas Dr. The layout of the proposed water main meets the COB design criteria and will be located within the easements/right of way and separated from the proposed sanitary sewer main by a minimum of 10 feet. Fire hydrants will be installed within COB design criteria and will not exceed the recommended distance. C. Capacity Analysis The Crestview Condominium water main extension is proposed for the development for two condominiums comprised of 22 units, which is 0.85 acres of R-4 (Residential High Density) zoning.An estimation of the water flow rate was based on the City of Bozeman's design standards and specification policy, which suggests using an average daily flow rate of 2.11 people per dwelling unit and 170-gallons per capita per day. Applied to the 22 units,the required water flow rate is calculated: ( residents gallons 22 units * 2.11 unit * 170 capita day� = 7,891gpd Based on these parameters, the 22 unit development at full build out will have an estimated water usage of 7,891 gpd (5.48 gpm). The main will be connecting to the existing City of Bozeman system and will serve the future condominiums. In addition to the average daily demand, the water main extension must account for peak periods of daily use. Peaking factors are applied to the demand and account for these peak periods in daily use. The peaking factors used are maximum daily use and peak hour and are obtained from the City of Bozeman Design Standards. Table 1 shows the peaking factors and the resultant flows from those factors when applied to the average daily demand of 5.48 gpm. TABLE 1 PEAKING FACTORS Flow Designation Peaking Factor Flow (gpm) Average Day Demand 1 5.48 Maximum Day Demand 2.3 12.60 Maximum Hour 3 16.44 Demand Based on communication with the architect, the maximum square footage of the two individual buildings will be roughly 14,024 sf and 10,128 sf total for the 12-plex and 10-plex buildings, respectively. The units will be a V-B type construction with fire sprinklers. A Type V-B 14,024 sf building requires 3,250 gpm for a 3-hour flow duration per the 2015 International Fire Code,Table B 105.1(2). The flow capacity for the 12-plex was chosen to be more conservative. Based on the Crestview Condominiums Water Design Report Page 2 of 3 2015 International Fire Code's Table B105.2, the 3,250 gpm fire flow can be reduced by 75% because of the sprinkling system, resulting in a fire flow requirement of 813 gpm. A Hazen-Williams"C"Factor of 130 was used in the pipe evaluation. The working residual water pressure shall not be less than 20 psi at any point in the water distribution system under maximum day plus fire flow. The velocity shall not exceed 15 feet per second through the main line. Results Based on the analysis outlined above, the required fire flow is 813 gpm and with the maximum hour demand of 16.44 gpm, a maximum hour flow of 829 gpm is required. Flow analysis shows that an 8-inch DI pipe with a C value of 130 can provide the required flow of 829 gpm with a pressure drop of 1.03 psi from 100 psi to 98.97 psi, remaining above the minimum of 20 psi. The pipe velocity is 5.29 ft/s. A Conclusion Based on this analysis, the proposed 8-inch ductile iron water main serving Crestview Condominiums extension provides adequate service to meet the 22-unit peak hour demand and fire flows for the condominiums. The water main design is consistent with the City of Bozeman Water Facility Plan. This project will require the approval of the City Engineer and MDEQ. Crestview Condominiums Water Design Report Page 3 of 3 Crestview Condos - Water Project Description Friction Method Hazen-Williams Formula Solve For Pressure at 2 Input Data Pressure 1 100.00 psi Elevation 1 4711.93 ft Elevation 2 4711.50 ft Length 217.00 ft Roughness Coefficient 130.000 Diameter 8.00 in Discharge 829.00 gal/min Results Pressure 2 98.97 psi Headloss 2.80 ft Energy Grade 1 4943.02 ft Energy Grade 2 4940.22 ft Hydraulic Grade 1 4942.59 ft Hydraulic Grade 2 4939.79 ft Flow Area 0.35 ftz Wetted Perimeter 2.09 ft Velocity 5.29 ft/s Velocity Head 0.44 ft Friction Slope 0.01291 ft/ft Bentley Systems,Inc. Haestad Methods Soli@b7diO ffiewMaster V81(SELECTseries 1) [08.11.01.03] 11/21/2018 10:20:09 AM 27 Siemons Company Drive Suite 200 W Watertown,CT 06795 USA +1-203-755-1666 Page 1 of 1