Gravel Augmentation

South Bay Clean Creeks Coalition (SBCCC) is excited to announce a new streambed restoration project with the generous support from The Knight Foundation for a section of the Los Gatos Creek. The work is known as gravel augmentation and improves instream habitat for fall Chinook Salmon by adding properly sized gravel to the streambed. The gravel provides a place for the endangered steelhead trout and Chinook salmon to lay their eggs and protects the eggs from changes in water level and currents in the stream.

The first phase of this project will be to assess approximately 800 feet, from below East Campbell Avenue downstream to Highway 17. Natural gravel supply in this channel appears to have incised and coarsened as streamflows have (and continue to) transport available sediment downstream with little or no upstream replenishment. In addition, a concrete grade control structure spans the channel immediately below the East Campbell Avenue Bridge, which functions as a partial / total fish passage barrier. There is also a lot of concrete and other rubble along the banks and in the wetted channel. Collectively, the limited coarse sediment supply and grade control have resulted in degraded endangered steelhead trout and Chinook salmon fish spawning and rearing habitat.

Develop conceptual design drawings

The first phase of this project will be to assess approximately 800 feet, from below East Campbell Avenue downstream to Highway 17. Natural gravel supply in this channel appears to have incised and coarsened as streamflows have (and continue to) transport available sediment downstream with little or no upstream replenishment. In addition, a concrete grade control structure spans the channel immediately below the East Campbell Avenue Bridge, which functions as a partial / total fish passage barrier. There is also a lot of concrete and other rubble along the banks and in the wetted channel. Collectively, the limited coarse sediment supply and grade control have resulted in degraded endangered steelhead trout and Chinook salmon fish spawning and rearing habitat.

Campbell Avenue Barrier’s negative impact to local steelhead and salmon

Concepts and design by Applied River Sciences:

steep riffle image
long flat pool
salmon barrier