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Home My WebLink About18 - Design Report - Gran Cielo - Water WATER MAIN DESIGN REPORT FOR: GRAN CIELO SUBDIVISION BOZEMAN, MT Prepared By: MADISON r F 0 s ENGINEERING kj_� t Madison Engineering • • ' 895 Technology Drive, Suite 203 Bozeman, MT 59718 (406) 586-0262 NOVEMBER 2018 L) `- C, L WATER MAIN DESIGN REPORT FOR: GRAN CIELO SUBDIVISION BOZEMAN, MT n Pn ® •i H"Rs G.,I • a . 'f'�•'•�/ �Sty{'O.•�� '� At J Mitt► Madison Engineering 895 Technology Blvd Ste 203 Bozeman, MT 59718 (406) 586-0262 NOVEMBER 2018 GRAN CIELO SUBDIVISION WATER MAIN DESIGN REPORT A. General This design report will give an overview of the proposed 8" and 12" water main extensions for the development of the Gran Cielo Subdivision, located at the intersection of S. 27th Ave and Graf Street in Bozeman. The 48.75-acre subdivision is zoned R-3 and R-4, and will consist of single-unit, two-unit, and multi-unit residences. The proposed improvements are anticipated to be phased, with the first phase being constructed during the spring/summer of 2018. This report includes a description of the proposed water main extensions and design parameters. Once the water main is constructed and approved, the main will become a part of the City of Bozeman(COB) system. The following references were used in the preparation of this report: a. COB Design Standards and Specifications Policy, 2004. Addendum #6 b. COB Modifications to Montana Public Works Standard Specifications(MPWSS),Addendum#3. c. WQB Circular No. 1 d. City of Bozeman Zoning Map e. Uniform Plumbing Code f. City of Bozeman Water Facility Plan Update, July 2017 B. Existing Water Supply The proposed water main extensions will be served from the existing COB water distribution system at the corner of Graf Street and S. 27th Avenue. The following information regarding pressures of the existing system was obtained from the City of Bozeman. The City conducted a test on 3/16/18 at the intersection of Lantern Lane and Enterprise Boulevard: Static Pressure: 65 psi Pitot Pressure: 56 psi Residual Pressure: 57 psi Hydrant Discharge: 1,250 gpm from 2.5" orifice Distribution Main Capacity—Fire flow at minimum residual pressure Q,=Qt[(Ps—P.-AP,—p,)]0.54 Q,= 1,250[(65 —20)/(65—56)]0.54 Q,=2,981 gpm at 20 psi Qt= Hydrant Discharge During Test(gpm) Q,= Fire Flow at Minimum Residual Pressure(psi) Ps= Static Pressure (psi) P. = Minimum Residual Pressure(psi) Pr = Residual Pressure(psi) Pt= Pitot Pressure(psi) Gran Cielo Subdivision Water Design Report Page 1 of 3 C. Proposed Water System The proposed water main extensions will consist of approximately 12,078 linear feet (2.3 miles) of Class 51 Ductile Iron Pipe. The proposed 12" water main will connect to the existing 12" ductile iron stub at the intersection of Graf St and S. 271" and extend west along the proposed extension to Graf St for approximately 1,304 linear feet as well as north along S. 27th Ave for approximately 2,058 linear feet. The connection points will be isolated via new gate valves in order to provide separate connections. Approximately 8,716 linear feet of 8" water main will be looped throughout the site to provide service to the remainder of the subdivision. The water main sized according to the City of Bozeman Water Facility Plan Update. A figure of the proposed COB system by water main diameter is provided in the Appendix. 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 distance of 10 feet. Fire hydrants will be installed so not to exceed 600' spacing, fulfilling the distance requirement for fire hydrant spacing, as well as assisting in flushing of the main. Gate valves will be installed at the connection point to the existing mains as well as pipe intersections, per City standards. Blow-offs have been designed for all 8" dead-end lines that will be extended in the future, and hydrants have been provided for the 12" dead-end lines in Graf Street and S. 27th Ave. D. Capacity Analysis A capacity analysis was performed on the proposed water main extension. The water main will serve all four proposed phases of the Gran Cielo Subdivision, which consists of 39.80 acres of R- 3, residential medium density, and 8.95 acres of R-4, residential high density. The water main extension has been designed to meet the maximum day demand plus fire flow during the peak hour. Based on Table 4.13.4 of the City of Bozeman Water Facility Plan, the City's design standards for an R-3 and R-4 residential lot is 6.5 and 10.4 units per gross acre, respectively. The analysis was completed based on 170 gpd per capita usage and 2.11 persons per unit. The main will be looped into the existing City of Bozeman system, however calculations were based on a dead end line to be conservative. Table 1 shows the water demand for the entire subdivision. TABLE 1 WATER DEMAND—RESIDENTIAL Units/ Density Total Per Capita Flow Flow Zoning Acres Acre residents/unit Residents d/resident d R-3 39.80 6.5 2.11 546 170 92,820 R-4 8.95 10.4 2.11 197 170 33,490 Total Flow ( d) 126,310 Total Flow m 263 Gran Cielo Subdivision Water Design Report Page 2 of 3 It is anticipated the average daily demand for the residential units will be 263 gpm, based on an 8-hour day. 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 2 shows the peaking factors and the resultant flows from those factors when applied to the average daily demand of 263 gpm. TABLE 2 PEAKING FACTORS Flow Designation Peaking Factor Flow m) Average Day Demand 1 263 Maximum Day Demand 2.3 605 Maximum Hour Demand 3 789 The required fire flow for a Type V-B structure is 1,500 gpm. With a fire flow demand of 1,500 gpm and a peak hour demand of 789 gpm, a peak hour flow of 2,289 gpm (5.10 cfs) is required. 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. E. Results Flow analysis of the 8-inch D.I. pipe with a C value of 130 can provide the required 2,289 gpm with a maximum pipe velocity of 14.6 ft/s. The pressure will not drop below the minimum of 20 psi. Flow analysis of the 12-inch D.I. pipe with a C value of 130 can provide the required 2,289 gpm with a maximum pipe velocity of 6.5 ft/s. The pressure will not drop below the minimum of 20 psi. Capacity analysis calculations outlining the capacity of the proposed 8-inch and 12- inch pipes is included in the appendix of this report. F. Conclusion Based on this analysis, the proposed 8-inch and 12-inch water main extensions for the proposed Gran Cielo Subdivision provide adequate service to meet the peak hour demand and fire flows for the development. This project will require the approval of the City Engineer and MDEQ. Appendix 1. Water Main Capacity Analysis 2. Capacity Analysis Exhibit 3. City of Bozeman Proposed Water Distribution System Figure 9-2 Gran Cielo Subdivision Water Design Report Page 3 of 3 8" Ductile Iron Water Main Project Description Friction Method Hazen-Williams Formula Solve For Pressure at 2 Input Data Pressure 1 65.00 psi Elevation 1 C4946.1D8ft Elevation 2 Length 1336.00 ft Roughness Coefficient 130.000 Diameter 8.00 in Discharge 2289.00 gal/min Results Pressure 2 25.32 psi Headloss 113.15 ft Energy Grade 1 5121.04 ft Energy Grade 2 5007.90 ft Hydraulic Grade 1 5117.73 ft Hydraulic Grade 2 5004.58 ft Flow Area 0.35 ft2 Wetted Perimeter 2.09 ft Velocity 14.61 ft/s Velocity Head 3.32 ft Friction Slope 0.08469 ft/ft Bentley Systems,Inc. Haestad Methods Soh@WrtlA�pfftewMaster V81(SELECTseries 1) [08.11.01.03) 11/20/2018 9:15:50 AM 27 Siemons Company Drive Suite 200 W Watertown,CT 06795 USA +1-203-755-1666 Page 1 of 1 12" Ductile Iron Water Main Project Description Friction Method Hazen-Williams Formula Solve For Pressure at 2 Input Data Pressure 1 65.00 psi Elevation 1 4969.92 ft Elevation 2 4939.60 ft Length 2037.00 ft Roughness Coefficient 130.000 Diameter 12.00 in Discharge 2289.00 gal/min Results Pressure 2 67.76 psi Headloss 23.94 ft Energy Grade 1 5120.50 ft Energy Grade 2 5096.56 ft Hydraulic Grade 1 5119.85 ft Hydraulic Grade 2 5095.90 ft Flow Area 0.79 ftz Wetted Perimeter 3.14 ft Velocity 6.49 ft/s Velocity Head 0.66 ft Friction Slope 0.01175 ft/ft Bentley Systems,Inc. Haestad Methods Sol i@irntlOpfftewMaster V8i(SELECTseries 1) [08.11.01.03] 11/20/2018 9:23:43 AM 27 Siemons Company Drive Suite 200 W Watertown,CT 06795 USA +1-203-755-1666 Page 1 of 1 _W_ _ �II rDN/ zDl0 IIIIII i � A�m / liJ c(i)D o� IIl /�/ �2� (( i l m� ii �� or Zi II s A D OmD Z A rn�� N)z D II' %/ I�IlII ,ODD I I I� II l III I� wcnz II o •/� i (I B_EN NI 1D pr-- - -_— - i Iii iil lii iil lii _ j I z I II II� III Ili 111 � I I Ills nln u u I II I l Iii iilll lii � ill Iii l e it1 I� I Iu li .�u u In if sil fir' (u l �� I ( II 4 .II it Im II �\ IF 111 Ill 11 ills-lll s u n u p � u u— if — u ; I — - I \� II II � _ � I - 11` �0 I'l r � ul Ili 9 l i� Iii z J Ii I CiELO i l _ F i •1'1r_t2twLAxr•. � D D l r�N I mD� v: <<:2 'D Z 70 A Z m D\ '� DJ,�Ocn �D ID r D_ co co n O co Z I � � Z Z .N..ry..r+ •wM MADI50N ENGIN7�,EIG GRAN CIELO Si BDIVISI0N A\IAI\CAPAM'Y A\AI,Yl ]3XI11RIftiYi'If.itl\lll llr;Y ill�I) UOZIcH.a�V I:9 ❑Q%F,:H,�R VI'I' C •'' r - .� ��r' - •h�!°- •y- •lyR� `., �:r' Ifs!+ .. _.- �—.r.C- ' �'-• t'' _ •I, �/�._A� t - ,� .t' - Miry' ,y4� 'fit• Ci Y ++ \ `v....-..jh w �'a. 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