Englebright Dam is the upstream limit of anadromous fish migration, inhibiting volitional fish passage to the upper reaches of the Yuba River for both spring and fall run Chinook Salmon and Steelhead trout. New sediment removal techniques for reservoirs and sellable byproducts make dam removal a real possibility for volitional fish passage. And pools are critical component of fish habitat that were overlooked, until now.
Englebright Dam was constructed in 1941 for the specific purpose of holding back debris generated by hydraulic mining. Englebright serves as the afterbay for New Bullards Reservoir hydropower facilities but does not provide any additional benefits, such as water delivery, power generation, or flood control. Since its construction, Englebright Dam has trapped ~23,000,000 cubic yards of mercury contaminated sediment, or roughly 25% of its original storage capacity.
Previous assessment activities concluded that dam alterations or removal for fish passage were cost prohibitive because of the sediment and that there was no habitat for fish in the Yuba. The Sierra Fund is investigating previously unexplored options of sediment removal techniques with multiple benefits, including sellable aggregates. Additionally, TSF is conducting a fish habitat study of pools in the upper reaches of the Yuba River to evaluate the thermal refugia available for salmonids. Data collected from these studies will inform the best ways to restore habitat in the Yuba for threatened and endangered species.
Removal or modification of Englebright Dam to allow volitional upstream passage to previously unreachable habitat for anadromous fish would open up a minimum of 60 additional miles of habitat. In addition, the natural flow regime, natural sediment and nutrient regimes and reduced mercury exposure risks through fish consumption and reduced mercury methylation potential in the reservoir are all benefits of restoring longitudinal connectivity.
The Sierra Fund has been collecting temperature data from “optimal” pools previously by the Department of Water Resources (DWR) but never monitored. The Sierra Fund has also worked with partners to develop a preliminary feasibility study for sediment removal at Englebright which employs the Army Corps of Engineers Environmental Dredging techniques and has off sets from sellable byproducts.
Patagonia, Angler Investor