Physical Modeling of Sediment Transport Through In-Channel Fish Resting Pools

The Corte Madera Creek flood control channel, located in Marin County, California, drains a 28 square mile watershed that empties into the San Francisco Bay.  This concrete channel impedes migration of native salmonid species.  To mitigate passage limitations, fish resting pools were installed but the current pool size, 4-ft long by 13-ft wide, is too small to provide sufficient resting area and velocity.  Three alternative pool designs with lengths and widths ranging from 10-to-34 ft and 8-to-10 ft, respectively, and bottom depression depth from the existing channel invert 1.5 to 2 ft, have been proposed (Love et al., 2007). The hydraulic and sediment transport characteristics for these three alternative designs were evaluated using physical models in Humboldt State University’s sediment transport flume. Pool designs with sloping transitions to maximum depth below the existing channel invert stored less sediment but all pool shapes retained some sediment, thus losing effective volume.

Love, M. A.,  Anderson, J. K., and Pryor, B. S. (2007). Corte Madera Creek Flood Control Channel: Fish Passage Assessment and Alternatives Analysis, Michael Love and Associates, Jeff Anderson and Associates. Arcata, CA.