Spawning habitat evaluation in the low flow channel of the Feather River

Hydraulic mining, gravel mining, gold dredging, timber harvesting, water diversions, urbanization, and the Oroville dam have played a role in degrading the spawning habitat of the low flow channel of the Feather river. In efforts to restore the spawning habitat, gravel was added to Hatchery Cottonwood Riffle, Upper Auditorium Riffle, and Auditorium Riffle. Monitoring of grain sizes, permeability, dissolved oxygen, upwelling/downwelling conditions, depth and velocity, and temperature took place before the gravel additions, and after construction was complete. The goal of the project was to evaluate the suitability of the spawning habitat as it evolved from the pre-restoration conditions to post-restoration conditions. Based on the measurements taken before and after restoration, the three sites either remained suitable for spawning or improved.