Overcoming Complex Terrain—Engineering Fundamentals behind ReWa’s Gravity-Driven Sewer Operations

Infrastructure upgrades in challenging environments require fundamental yet innovative engineering, particularly when constructing large-diameter pipelines. Sewer improvement projects like this face a range of vertical and horizontal constraints—hydraulic, construction, subsurface, and surface—that are intensified in soft soils, floodplains, and areas adjacent to rivers. For this project, Stantec (Engineer) encountered particularly flat pipe slopes, significant pipe buoyancy challenges due to swampy wetland conditions, above-grade pipe segments running adjacent to and across the Reedy River, and under high-voltage power lines. This paper will highlight the history of the Swamp Rabbit Trunk Sewers and focus on some critical design considerations for this extensive upgrade and the significant challenges posed by the environment.