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Home My WebLink About014_Appendix M - Water Engineering Design ReportEngineering Report Water Main Extension South University District Phase 3 - Block 3 Preliminary Plat Updated May 2026 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) 522-8594 Water Mains 1 5/26/2026 Engineering Report Contents Note: The Engineering Report format follows DEQ-1 organization. Additional information required by the City of Bozeman Design Standards is added where required. Report Narrative 1.1.1 General Information 1.1.2 Extent of water works system 1.1.3 Alternate plans 1.1.4 Site conditions 1.1.5 Water use data 1.1.6 Flow requirements 1.1.7 Sources of water supply 1.1.8 Proposed treatment processes 1.1.9 Sewage system available 1.1.10 Waste disposal 1.1.11 Automation 1.1.12 Project Sites 1.1.13 Financing 1.1.14 Future Extensions Figures and Tables Figure 1. Vicinity Map Figure 2. C2.0 - Water Plan Table 1. SUD Phase 3 Block 3 Estimated Water Design Flows Appendices WaterCAD Analysis Exhibit – To be provided with infrastructure submittal. WaterCAD Fire Flow Table – To be provided with infrastructure submittal. WaterCAD Junction Table – To be provided with infrastructure submittal. WaterCAD Pipe Table – To be provided with infrastructure submittal. Water Mains 2 5/26/2026 1.1.1 General Information The proposed South University District Phase 3 Block 3 Subdivision consists of 17.51 Acres located southeast of the intersection of 19th Avenue and Stucky Road. The Block 3 subdivision will consist of 2 lots with the north lot being approximately 8.84 acres and the south lot being 8.65 acres. The total subdivision area including required offsite improvements is 23.26 acres. This Block 3 Subdivision is designed with the intention of there being 256 residential units between the two lots to create a diversified neighborhood in a growing part of town, adjacent to the Montana State University Campus. The project will be served by extension of City of Bozeman water and sewer mains throughout the project. City of Bozeman water and sewer mains currently exist along the west side of the project site. The developer’s contact information is: RTR Holdings II, LLC Randy Hecht 22 Turtle Rock Court Tiburon, CA 94920 Water supply and wastewater treatment will be provided by the City of Bozeman’s municipal systems. The system owner’s contact information is: City of Bozeman Public Service Department PO Box 1230 Bozeman, MT 59771-1230 Water Mains 3 5/26/2026 The location of the SUD Phase 3 Block 3 development is shown on the Vicinity Map in Figure 1. Figure 1. Vicinity Map, Bozeman, Montana 1.1.2 Extent of Water Works System Water supply to the area is from an existing 24” water main in S 19th Ave, and an existing 12” water main in Stucky Road. There is an existing 8” water main in S 17th Ave that will be extended south from Stucky Road along with new 8” water mains in the proposed Arnold Street and Student Dr. that will be installed as part of the off-site subdivision improvements to service the new development. It is anticipated that future lot development will require on-site main extensions in combined 30-foot-wide water and sewer easements. 8” water main stubs are provided to lot lines for both lots where the on-site main extensions are envisioned. Water Mains 4 5/26/2026 1.1.3 Alternate Plans Due to the project’s location within the City of Bozeman, extension of public mains was the only water supply alternative. Distribution alternatives were explored, and the proposed design was selected to increase looping and minimize dead ends. The use of an on-site well as a source for irrigation usage is not feasible due to the previously allocated water rights in the Phase 2 subdivision park. 1.1.4. Site Conditions The SUD Phase 3 Block 3 site is typical of Bozeman with fine-grained soils overlying gravel deposits. Geotechnical borings have determined the depth to gravel ranges from 2.5 to 6.5 feet. Estimated depth to groundwater obtained from the geotechnical borings is variable from 4 to 9 feet. If mains are installed during periods of high groundwater, dewatering may be required. 1.1.5. Water Use Data The estimated residential water use was based on the City of Bozeman design standards for wastewater generation. The estimated flow was determined based on 2.17 people per unit and an average daily flow rate of 64.4 gpd/person in accordance with the City of Bozeman Design Standards Utility Design Criteria. For the purposes of analysis, Block 3, lot 1 and Block 3, lot 2 were treated as one lot and are both encompassed in this report by being referenced under “Block 3”. Further analysis of each individual lot is to be conducted during their respective site plans. The anticipated Subdivision irrigation is based on previous designs and calculations by the Landscape Architect as show in the landscape plans. Irrigation is the only water demand for the offsite development of the subdivision and is estimated to be an annual use of 194,985 Gallons. This covers the irrigation on the South side of Stucky Road and the East Side of S 19th Avenue. The anticipated site irrigation is also based on previous designs and calculations by the Landscape Architect as show in the landscape plans. The following table displays the combined residential, commercial, and irrigation water design flows. The design max day peak hour flow for the proposed Block 3 is 140.24 gpm. Water Mains 5 5/26/2026 Table 1: SUD Phase 3 Block 3 Estimated Water Design Flows 1.1.6. Flow Requirements As stated previously, the peak hour water demand is estimated to be 140.24 gallons per min (gpm). Fire flows have not been determined yet but will be in accordance with the City of Bozeman adopted Uniform Fire Code. It is anticipated that a fire flow of 1,500 gpm will be required. The fire flow requirement will be the dominant design constraint for system design. As part of the Phase 3 Subdivision process, a hydraulic analysis was completed to determine the available fire flow in this area. According to this analysis, Phase 3 hydrants – including those in Block 3 – will have fire flows ranging from 2,800 gpm to 3,100 gpm, with a system residual pressure of 20 psi. Fire flow requirements are based on the Uniform Fire Code. The required hydrant flow is determined using Table H.5.1 of the Uniform Fire Code. For example, a 48,000 sq ft Type V-A building requires a fire flow of 4,000 gpm. In consideration of the planned use of sprinkler systems in future Phase 3 site developments projects, the fire department is allowing a 75% reduction in required fire flows, reducing the hydrant flow down to the anticipated minimum required fire flow of 1500 gpm. The fire flow required will be determined by the fire department at the time of infrastructure design. The total fire flow available will allow for the use of the hydrant and the sprinkler while maintaining the required 20 psi residual pressure. The Phase 3 Subdivision Engineer’s report is available upon request. Water Mains 6 5/26/2026 1.1.7. Sources of Water Supply This section is not applicable. 1.1.8. Proposed Treatment Process This section is not applicable. 1.1.9 Sewage System Available Sewer service is provided by new City mains extended through the site from the existing sewer main running along Stucky Rd. and 19th Ave. Sewers will be approximately 8.5 feet deep and primarily cross below water mains and services. 1.1.10 Waste Disposal This section is not applicable. 1.1.11 Automation This section is not applicable. 1.1.12 Project Sites This section is not applicable. 1.1.13 Financing This section is not applicable. 1.1.14 Future Extensions The water system layout accommodates future water main extensions as required to complete future system improvements in this area. SSSSSSSSSSSSSSW W W WSSSS SS SS WSDSDSDSDSDSD SDSDSDWWWWWSOUTH 14TH AVESS HC HC HC HC OHE OHE OHE OHE OHE OHE OHE OHE OHE OHE OHE OHE OHE OHESSSSSSSSSS SSSSSSW WSSSSSSSSSSSSOHEOHEOHESDSDSDWWWY3 Y3 Y3 Y3Y3 P3 P3 P3 SDSDSDSDSD SDSDSDSDSDSDSDSDSDSD STUCKY RDSOUTH 14TH AVESTUCKY RD(48' WIDTH - 90' ROW)W W W W W W W W W W W WOHEOHEOHE (48' WIDTH - 90' ROW)**WWWWWWWWWWWWWWWWWWWWWWWSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSWWSSSSSSSTATE ST(35' WIDTH - 60' ROW)SD(47' WIDTH - 70' ROW)SSSS SOUTH 17TH AVE(EXISTING 70' ROW) STUCKY RD(48' WIDTH - 90' ROW) ARNOLD ST(36' WIDTH - 105' ROW) SD SOUTH 14TH AVESOUTH 17TH AVE(47' WIDTH - 70' ROW)S 19TH AVE(ROW WIDTH VARIES)S 19TH AVE(ROW WIDTH VARIES)OHEOHEOHEOHEOHEOHEOHEOHEOHEOHEOHEEXISTINGTRAILS (TYP)SSSSSSSSSSSSSSSSSSWWWWWWWWWWSTORM BASINS T O RM BA S IN (47' WIDTH - 70' ROW)STUDENT DRIVES 19TH AVE(ROW WIDTH VARIES)EXISTINGSTORM BASIN CITY PARK 14.41 ACRESPLAT J-605Tract 3ACOS 2661B CITY PARK 2 9.64 ACRES PLAT J-605 CITY PARK 41.83 ACRESPLAT J-695COMMON OPEN SPACELOT 2, BLOCK 1, 0.07 ACPLAT J-695COMMON OPEN SPACELOT 1, BLOCK 2, 0.07 ACPLAT J-695 COMMON OPEN SPACELOT 2, BLOCK 2, 0.07 ACPLAT J-695 BLOCK 3 , LOT 1A8.840 ACRES(385,071 SF)CITY PARK 3 13.36 ACRES PLAT J-695 LOT 2 "PHASE 1"6.41 ACRESPLAT J-518 BLOCK 3 SUBDIVISIONINFRASTRUCTURE EXTENTSBLOCK 3 SUBDIVISIONINFRASTRUCTUREEXTENTSARNOLD ST STUDENT DRIVE SOUTH 17TH AVES 19TH AVESTUCKY RD YELLOWSTONE THEOLOGICAL INSTITUTE MINOR SUBDIVISION RESTRICTED LOT 4 10.519 ACRES YELLOWSTONE THEOLOGICAL INSTITUTE MINOR SUBDIVISION COMMON OPEN SPACE LOT 2 1.826 ACRES YELLOWSTONE THEOLOGICAL INSTITUTE MINOR SUBDIVISION LOT 3 7.644 ACRES YELLOWSTONE THEOLOGICAL INSTITUTE MINOR SUBDIVISION LOT 1 15.069 ACRES ALLISON SUBDIVISION, PH 4A BLOCK 1, LOT 1 22.50 ACRES W WWW SDBLOCK 3, LOT 1B8.636 ACRES(376,169 SF)WWWWW(36' WIDTH - 62' ROW)SSWWWWWW W SSSSSSSSSSSS SSWW SSSSW WSSSSSDSDSDSDSDSDSDSDSDSDSD SDSDSD SDSDSD SDWW WSDSDSDSDSDSDSDSDSDSDSDSDSDSDSDSDSDSDSDSDSDSDSDSDSDSDSDSDSDSDSDSDSDSDWWWWW WWWWSDSDSDSDSSSS EXISTING TRAILS (TYP) EXISTING TRAILS (TYP)SSSSSSSSLOT 1, BLOCK 2"PHASE 3"8.60 ACRESPLAT J-695 WWSDSDSDSDSDSDSSWWWWSSSSSSSS(27' WIDTH - 70' ROW+29.5' EASE)ARNOLD ST SCALE IN FEETC2.0WATER PLAN1 12/15/2025 PRELIMINARY PLAT ZWL CDP 2 5/26/2026 PRELIMINARY PLAT RC1 JWF CDP PROFESSIONALENGINEERS &SURVEYORSSTAHLYENGINEERING& ASSOCIATESSUD PH. 3 BLOCK 3SUBDIVISION RTR HOLDINGS II, LLC HELENA Phone:(406)442-8594CODY Phone:(307)509-5541851 BRIDGER DR. STE 1BOZEMAN, MT 59715 Phone:(406)522-9526BILLINGS Phone:(406)601-4055GREAT FALLS Phone:(406)604-4644