A Sewer Runs Through It: Navigating Aging Creek Crossings — Can They Stay or Should They Go?

Presentation Description: The Sacramento Area Sewer District (SacSewer) identified urban sewer crossings for further investigation and rehabilitation during their post-storm and regular crossing checks which are part of their Sanitary Sewer Management Plan to prevent sanitary sewer overflows. SacSewer initiated the Creek Crossing Project to address twelve exposed sewer crossings throughout Sacramento County. These sewer creek crossings included aerial and originally buried gravity sewer lines ranging in size from 4- to 48-inches which were exposed in the creeks. Exposed creek crossings exhibited erosion, loss of pipe and/or pier support, exposed joints, and debris accumulation which puts them at risk of failure.
This case study highlights WSC’s and SacSewer’s integrated approach to delivering custom solutions for each creek crossing including evaluating and designing alternative rehabilitation measures to deliver the right balance of costs and benefits.
The presentation will focus on integrating engineering, structural, environmental, geotechnical, geomorphic, and corrosion protection perspectives to effectively evaluate costs and long-term asset management requirements in addition to the resilience within the creek environment. In addition, you will gain perspective on the range of design alternatives considered for each crossing, including do nothing, protect in place, rerouting, increasing/or decreasing crossing elevation, and engineered solutions such as inverted siphons and pump station installation—all through the lens of the considerations listed above. Case studies from select project sites will be evaluated and discussed as an interactive element in the presentation.