Auburn Ravine Fish Passage Restoration Project
Auburn Ravine is ideally suited for fish, especially fall-run and late fall-run Chinook salmon and steelhead trout. Gravel-bedded stream reaches suitable for spawning of salmonids (fishes of the family Salmonidae which include salmon, trout, whitfish, and char) exists upstream from the City of Lincoln. Barriers, both man-made and natural, have however limited fish mitigation and spawning potential.
Improving salmonid fish passage in Auburn Ravine between Joiner Parkway and Hemphill Dam was identified as a high priority by the Auburn Ravine/Coon Creek Coordinated Resource Management Plan. This is important because The National Marine Fisheries Service, under the provisions of the Endangered Species Act, has classified fall-run Chinook salmon as a federal candidate species.
The Auburn Ravine Fish Passage Improvement project entailed construction of a fish ladder to enhance Chinook salmon and steelhead trout passage over the Nevada Irrigation District's stream gaging structure located in the Lincoln Crossing Nature Preserve, 1000' downstream of Highway 65 in Lincoln. It provides both upstream passage for adult fish to access spawning habitat located above the gaging station and downstream passage for migrating juvenile fishes while maintaining the ability to accurately measure stream flows occurring during the typical irrigation season (April 15 - October 15).
The gaging station was installed in 1981 in order to manage downstream water transfers with South Sutter Water District and provide accurate flow measurements for the City of Lincoln's wastewater dilution requirements.
A design alternative was selected for the gaging station, and the final design was completed in February of 2011. Construction on the $850,000 collaborative effort started in October 2011. Funding partners include the County of Placer, Nevada Irrigation District, CAL-FED, Granite Bay Flycasters and Dry Creek Conservancy.
A "nature-like fishway" consisting of a series of constructed rock chutes and armored step pools in a way that mimics the morphology of a natural channel has been installed. The constructed chutes and pools span the channel downstream of the existing gaging station and are designed to dissipate stream power over the drop from the facility's existing concrete flume to the streambed below while allowing the gaging station to continue accurate measurement of streamflow.