January 12, 2017 – Governor Brown’s budget proposal, released Tuesday, includes funding for an innovative project underway at the Nevada Irrigation District’s (NID) Combie Reservoir that improves water storage, water quality and fish habitat. The Budget calls for $6.13 million to be invested in the project to “develop facilities to remove and treat mercury laden sediment derived from abandoned gold mines at Combie Reservoir in the Nevada Irrigation District Service area.”1
“We’d like to thank Governor Brown and the Department of Water Resources for this vote of confidence in our project,” notes Rem Scherzinger, General Manager of NID. In the past NID had maintained storage capacity in the Combie Reservoir by removing the sands and gravels, a practice that was stopped when it became apparent that their activities were releasing and mobilizing the elemental and particle-bound mercury left in the sediment from legacy gold mining activities. “This funding will allow us to do the comprehensive pre- and post-project monitoring needed to demonstrate that this process not only recovers operational reservoir storage capacity but actually improves water quality and fish habitat.”
The Sierra Fund has long been a supporter of this innovative pilot project. “We have supported NID’s project by helping with fundraising for the project, conducting community outreach, and ensuring rigorous scientific oversight of the project,” notes Elizabeth “Izzy” Martin, CEO of The Sierra Fund. “This project demonstrates new technology that can be used to increase water storage at reservoirs that are currently choked with mercury contaminated sediment that has come from upstream hydraulic and hard rock mines, by removing the sediment, spinning out the mercury, and returning clean water to the reservoir. The gravel and sand produced in the process can be sold. Talk about multiple benefits!”
A report by the US Geological Survey estimated that half of the storage capacity of the 200 reservoirs in California that they studied had been lost to sedimentation. Identifying economically viable methods for restoring reservoir capacity while improving water quality and fish habitat is an important new approach for California’s ongoing efforts to fight the impacts of drought. The project at Combie Reservoir, if successful, will demonstrate technology that can be deployed at other reservoirs in the state to restore water storage capacity and operation while removing an environmental pollutant, mercury.
The Governor’s budget will begin the long process of working its way through the Legislature immediately. The California constitution requires that the budget be adopted by the Legislature by June 15 of this year.