From Inception to Completion—Rehabilitation of Large Non-Circular Combined Sewers in Winnipeg, Manitoba

This paper details the rehabilitation of five large non-circular combined sewers in Winnipeg, Manitoba, Canada. The project is part of the City of Winnipeg's annual sewer rehabilitation program and includes egg-shaped sewers ranging in size from 2,060 × 1,625 to 2,950 × 1,950 mm. With multiple rehabilitation technologies on the market, the preliminary design process focused on evaluating applicable rehabilitation methods. Considerations included the existing sewer geometry, liner constructability, construction risk, liner structural performance, and an evolving approach to liner design in the market. The project faced many obstacles during design and construction, including construction on leased City and railway property, construction on busy regional streets, and COVID-19-related shipping delays. This paper takes readers through the entirety of the project from preliminary design to the completion of construction. There is a focus on technology selection, risk reduction, tendering rehabilitation work utilizing the new ASCE MOP 145, and construction. The latter will focus on lessons learned, stakeholder engagement, ongoing risk reduction efforts, and dealing with a volatile post-pandemic global market. The intent is to demonstrate a holistic approach to large-diameter sewer rehabilitation, which is employed from inception to completion.