Improvements Made to Fish Passage Section of Auburn Ravine
December 14, 2011
|Water flows in the newly completed fish ladder in Auburn Ravine in the City of Lincoln.|
Water is again flowing in a stretch of Auburn Ravine in the City of Lincoln after completion of a Placer County project to remove an impediment to fish traveling to upstream spawning areas. The project, nearly 10 years in the works, was finished this month.
On Tues., Dec. 13, 2011, the Placer County Board of Supervisors authorized payment of $363,645 to the Nevada Irrigation District (NID) for work on the fish passage project. The funding will come from grant funds through the CalFed Watershed Program, the Granite Bay Flycasters, and the Open Space Trust Fund. No general fund monies will be used for the project.
As early as 2002, the CalFed-funded Auburn Ravine/Coon Creek Ecosystem Restoration Plan recognized fish passage as a limiting factor for Chinook salmon and steelhead
|During construction, a six-foot drop that was impassible to fish was removed and |
replaced with multiple, smaller steps.
trout in Auburn Ravine. The NID Gaging Station in Lincoln was singled out as a priority. In 2006, a California Department of Fish Game study declared that Auburn Ravine is one the of best trout streams in the entire western Sierra region.
Built in 1981, the Gaging Station, created a six-foot drop that prevented salmon and steelhead from accessing the spawning beds in the 12 miles of upstream habitat. A 2004 survey found that
Among western Placer County streams, Auburn Ravine contained more potential spawning habitat than all other surveyed stream reaches combined. The Gaging Station was installed to manage downstream water transfers with South Sutter Water District and to provide accurate flow measurements for the City of Lincoln’s wastewater treatment plant dilution requirements.
Construction of the project to remove the barrier began in October. The fish passage improvements include a new roughened channel with rock chutes and pools. The constructed chute-and-pool feature occupies about 6,392 square feet within the stream channel, covering an area of 34 feet by 188 feet. The area that was disturbed to build the project is almost an acre.
In addition to the contribution by Placer County, funding partners to the $865,645 total project cost include:
- Nevada Irrigation District;
- Granite Bay Flycasters; and
- The Dry Creek Conservancy.
The use of engineered streambed materials will ensure that the rock will remain in place up to the 100-year storm flow. Auburn Ravine has the potential for significant fall-run and late fall-run Chinook salmon and steelhead trout. The gravel-bedded stream reaches above this project are suitable for salmonid spawning.