Sebbas Creek Off-Channel Project

This implementation project will construct CDFW-approved 100% designs for improving off-channel habitat in Sebbas Creek at an abandoned oxbow. Specifically, the project will reconfigure the geometry of an existing partially abandoned oxbow along the mainstem channel to allow for more frequent and longer duration flooding during annual flow events. This project will create approximately 20,000 sq. ft. of off-channel habitat, depending on the stream flow conditions and will also significantly increase channel complexity and fish habitat in the mainstem adjacent to the oxbow. The water inundation at the oxbow upstream end will be controlled by 3 engineered deflector jams designed to shunt water into the inlet. Water inundation at the downstream end will be controlled by grading and the installation of several engineered roughness element log features. Additionally, there will be 2 grade control log structures, one at the inlet of the oxbow and one near the center.

Sebbas Creek currently exhibits relatively simplified fluvial-geomorphic land-forms and lacks complex off-channel habitat for juvenile salmonid rearing. These conditions are a result of historically unrestricted logging. This project, if implemented, will provide meaningful increases in available off-channel habitat for coho salmon as well a provide for associated complex ecosystem development.