California wants to build biggest reservoir in 50 years. There may not be enough water to fill it
The Sites Reservoir project, intended to be California's largest new reservoir in half a century, faces a significant operational threat. Despite securing a draft water right to draw from the Sacramento River, project officials warn that state-imposed restrictions on water diversions could cut the reservoir's expected yield by up to 50 percent. This reduction creates a major hurdle for the $6 billion infrastructure plan, as the diminished water supply may fail to justify the substantial investment required from participating water agencies.
Sites Project Authority Executive Director Jerry Brown emphasizes that the project's financial feasibility hinges on these diversion terms. With the state water board preparing to finalize the water right later this year, the authority is pushing for less restrictive conditions. They argue that new modeling demonstrates more water availability than the state's current draft suggests. A supplemental hearing is scheduled for this Friday to review this data, a move that environmental groups have vocally opposed.
Government support remains strong, with Governor Gavin Newsom and Senator Alex Padilla advocating for a path forward that balances fish and wildlife protection with water supply needs. The reservoir aims to serve as a critical storage solution for cities and farms across the state, from the Bay Area to Southern California. However, environmental organizations and indigenous groups argue that increasing diversions from the Sacramento River system poses unacceptable risks to salmon populations and landscape integrity.
As the state water board prepares for a final vote in November, the project stands at a critical juncture. Water agencies, including the Metropolitan Water District of Southern California, must soon commit to the full cost of construction. If the final water right terms remain too restrictive, the financial backing necessary to break ground may evaporate, potentially ending the state's most ambitious water infrastructure goal.