Olmsted Flowline Seismic Retrofit

The Central Utah Water Conservancy District is a water wholesaler providing high-quality culinary and secondary water throughout their eight-county jurisdiction. The 7.24 km (4.5 mile) long Olmsted Flowline conveys water from the Provo River to the Alpine and Jordan Aqueducts to approximately 1.2 million customers, forming one of the largest municipal and industrial water conveyance arteries in Utah. This pipeline system includes reinforced concrete and welded steel pipe sections varying in diameter from 120- to 102-inches. A seismic risk analysis of the Olmsted Flowline conducted by the district in 2016 identified a 400-foot-long section of 102-inch-diameter, unrestrained, welded steel pipe located within a steel pipe arch tunnel under U.S. Highway 189 as a potential point of failure. To replace the system, a 3-month maximum shutdown window was provided that was timed to be simultaneous with other construction projects on the system. This paper will present the background and design approach for the replacement of this segment of pipeline. A review of the construction manager/general contractor delivery approach will be presented and the benefits that it provided for this project.