A major water storage project for California moved ahead this month with the approval of additional funding to offset added costs.
The Sites Reservoir project received a funding increase of nearly $219 million from the California Water Commission to balance expected cost increases due to inflation and resulting higher construction costs.
Sites Reservoir is a proposed off-stream water storage facility in the Sacramento Valley. It has a planned storage capacity of about 1.5 million acre-feet — enough to supply more than 4.5 million homes for a year. Sites is one of the largest new water storage projects in California in decades.
The reservoir would use a mix of new and existing infrastructure to divert water from the Sacramento River during high-flow periods — after all other water rights and regulatory requirements are met — into a large basin for storage.
Funding Commitments
The Governor’s office reports that the additional funding approved by the water commission makes Sites eligible for $1.094 billion in Proposition 1 funding. The total project cost is estimated to be up to $6.8 billion, with about $780 million being financed through the federal government.
A significant portion of the project funding comes from conditional commitments by 30 local water agencies from across the state, representing millions of Californians and thousands of acres of food-producing farmland.
The region of the state where Sites Reservoir would be located receives the majority of California’s rainfall. So locating a new reservoir here means that Sites can collect excess winter storm flows from uncontrolled streams below the existing reservoirs in the Sacramento Valley and store that water for use during dry periods.
By operating in conjunction with other California reservoirs, Sites Reservoir will substantially increase water supply flexibility, reliability and resiliency in drier years. In addition, a portion of this water supply will be dedicated to support native fish, migratory birds and their habitats.
As an off-stream reservoir, Sites would avoid many of the negative environmental impacts associated with on-stream dams. Capturing only excess flows during extreme storm events leaves water in the Sacramento River to support fish and wildlife. Sites will also contribute to the increased freshwater flow into the Delta during drier periods to assist with salinity management.
Construction on Sites Reservoir is scheduled to begin in 2026 and the reservoir is expected to begin full operations in 2032.
CalChamber Position
The California Chamber of Commerce will continue to support construction of Sites Reservoir and legislation that seeks to streamline the permitting process for water supply and flood risk reduction projects. Addressing unnecessary delays in the permitting process for critical infrastructure projects will reduce costs borne by ratepayers and better ensure California builds at the pace and scale needed to address climate change.
