R&M Through the Years: Abbott Road Water Transmission Main

May 21, 2019

In celebration of R&M’s 50th anniversary, we are taking a look back at the projects over the last five decades that made R&M into the firm it is today. This month we take a look at the details of a new water transmission line on Abbott Road in Anchorage designed by R&M during the 1980s.

The beginning of the 1980s was a time of growth for Anchorage and Alaska, thanks to North Slope oil revenue flooding the State’s coffers. The population of the City grew by more than 50,000 people during this decade. Due to this growth and expansion of the City to the south to accommodate new residents, additional utility Infrastructure was needed. To address this need, the Anchorage Water & Wastewater Utility (AWWU), the water and wastewater utility serving the Municipality of Anchorage, installed a new water transmission main along Abbott Road.

R&M was involved in Phases 3 and 4 of this project, providing utility design, surveying, geotechnical investigations and permitting.

Phase 3: Water Transmission Main and Valve Vaults

Phase 3 consisted of more than 18,000 LF of 30″, 36″ and 48″ water transmission main and 12 valve vaults, including pressure reducing and distribution turn-out vaults. The project limits included the existing 88th Avenue Transmission Main and Lake Otis and 88th Avenue valve vault.

The water transmission line was designed to follow Spruce Street from 68th Avenue to 88th Avenue and then turn west to Lake Otis Parkway. R&M designed the vertical and horizontal alignment with special consideration for sewer line crossings and an open-cut crossing of Lake Otis Parkway. Special restrained joints design details were used due to pipe diameters and operating pressures. Numerous permits and approvals were also required, including an ADF&G permit for crossing Little Campbell Creek on 88th Avenue.

Phase 4: Water Transmission Line

Phase 4 consisted of the design of two miles of 36″ water transmission line with one highway and one railroad crossing.

The alignment of the water main required a crossing of the New Seward Highway and the Alaska Railroad tracks. The design also incorporated a detailed traffic rerouting plan for the access road and Seward Highway. R&M designed five 36″ valve vaults and a major hydraulic valve vault near Lake Otis Parkway and East 88th Avenue. A detailed geotechnical investigation and surveying/mapping was required for the design.

Next month, we move into the 1990s, during which R&M conducted numerous Native Allotment Cadastral Surveys for the Bureau of Land Management.