Sewer Crossing Bank Stabilization and Toe Stabilization Design

As part of the Sacramento Area Sewer District’s Creek Protection Project, cbec teamed with Brown & Caldwell to conduct a geomorphic reconnaissance at 40 stream sewer crossings in Sacramento County.

This evaluation was part of a multi-specialty assessment to ascertain the existing stability and integrity of select stream sewer crossings on numerous creeks in the Sacramento region. All work performed was in accordance with the project specifications set forth by the United States Army Corps of Engineers, Sacramento County Department of Water Resources, and the State Water Resources Control Board.

cbec conducted geomorphic reconnaissance as part of a multi-specialty team that also included civil and geotechnical engineers. The method of reconnaissance was undertaken to assess local field conditions at each crossing relating to bank and bed stability. cbec used state-of-the-art data logging techniques using GPS and bespoke data libraries to record observations. cbec produced multiple hydrodynamic models in combination with the results of the reconnaissance to identify eight priority sites. cbec designed alternatives for these sites featuring biotechnical bank stabilization and erosion control measures comprised of rock, soil, and live vegetation (shrubs or trees such as willow posts or poles) in various combinations. These methods employ natural processes to provide erosion control and bank protection. Biotechnical measures provide bank stability, and ultimately provide visibly superior site aesthetics, and often added riparian and ecological habitat value. At two sites specifically, complex channel geometry required the development and application of a 2D hydraulic model (SRH-2D). cbec also developed engineering design drawings and cost estimates for each of the alternatives. Deliverables consisted of technical memos that provided relevant design assumptions, criteria, and analysis used to support the design.


Waterbody / Watershed

Cripple Creek, Arcade Creek, American River