Jerry Brown, executive director for the Sites Project Authority, said the Sites Reservoir Project reached another major milestone in December with the completion of the draft Environmental Impact Report/Supplemental Draft Environmental Impact Statement public comment period – bringing the project one step closer to fruition.
The project, which has been in the works for more than 60 years, hopes to turn the Sites Valley located 10 miles west of Maxwell where Colusa and Glenn counties meet, into a state-of-the-art off-stream water storage facility that captures and stores stormwater flows in the Sacramento River – after all other water rights and regulatory requirements are met – for release in dry and critical years for environmental use and for communities, farms and businesses statewide to utilize when it is needed.
“Sites is unique because it would not rely on snowpacks like Folsom and Oroville do,” said Brown. “It would also bring a much needed water supply to the west side of the valley.”
According to Brown, the Sites Valley has been identified as an optimal place for a reservoir of this kind because of the “bowl-like” topography of the land as well as the proximity to the Sacramento River and existing conveyance facilities – the Glenn-Colusa Canal and the Tehama-Colusa Canal.
The plan is to block off the valley with two dams – The Golden Gate Dam to the north and the Sites Dam near the community of Sites – while adding a pump station and a series of smaller staddle dams at the most northern point of the valley to turn the existing valley into a water storage facility.
Because there are already two existing conveyance facilities in the vicinity, Brown said the project would only need to build a connecting canal about ten miles long to connect to the existing facilities to pump water in and out of the reservoir – a huge cost saver for the project.
There are also plans to utilize the reservoir for recreational purposes, including boating, fishing and possibly horse trails.
Kevin Spesert, external affairs manager for the Sites Project Authority, said there are about 30 residents in the community of Sites at this time that would be affected.
To begin the process of turning the valley into a reservoir, Spesert said all of the existing trees, structures and debris would have to be removed. Roads in the area, including Maxwell Sites Road, would have to be rerouted as well because they would be underwater should the reservoir get built.
“Maxwell Sites Road is the main road in and out for the residents of Stonyford,” said Spesert. “Students from Stonyford utilize Maxwell High School so shutting down this road for any length of time is not an option.”
To address this issue, Spesert said the project plans to begin with rerouting Maxwell Sites Road to go up and over the hills instead of cutting through them as they do now. A two part bridge will be constructed, said Spesert, to connect the roadway to the other side of the valley via an island created by the reservoir and the roadway would be renamed Maxwell Stonyford Road.
Brown said the biggest concerns that have been voiced about this project are how diversions out of the water will affect aquatic resources, how the Trinity River will be affected and how water quality will be affected when it is returned to the river.
“We are not here to damage the rivers,” said Brown. “No water will be diverted from the Trinity River to fill Sites Reservoir. The unique location of the reservoir means the project is not competing for other water resources, but instead will be complementary to these facilities and enhance the ability to optimize the limited water resources.”
According to Brown, water diverted into Sites Reservoir will come from the streams and creeks that flow into the Sacramento River downstream of the Shasta and Keswick Dams.
There are also highly protective operating conditions that must be in place before diversions into Sites Reservoir can be made that adapt to evolving conditions. Brown said the intakes being used for diverting water into Sites Reservoir include state-of-the-art fish screens that are proven to be highly effective at protecting fish and the project includes more cold water for salmon in drier years.
According to Brown, the reservoir will also be constantly monitored to ensure that quality of water returning into the river is optimal.
“The quality of water returning to the river is probably going to be better than it was,” said Brown.
According to Brown, the Sites Reservoir Project is slated to cost $4 billion dollars. This estimate, said Brown, includes all permitting, preparation, construction and maintenance costs.
Brown said funding for the project is like a pie, with $836 million anticipated from the federal level and $360 million allotted by the state at this time.
“The local agencies would have to handle the rest,” said Brown. “If we received more state or federal funding, the cost for local agencies would go down. We just have to fill in that pie.”
At the end of 2021, the California Water Commission determined that Sites Reservoir will continue to be eligible for funding through the state’s Proposition 1 Water Storage Investment.
According to Brown, the Authority is now working through the public comments received regarding the draft Environmental Impact Report to make any needed adjustments to the draft. In the coming months, Brown said the project will also be working to secure permitting and water rights.
In the coming year, the project is expected to progress with field studies and engineering evaluations to advance the design to a 30 percent design level by mid‐2023, achieve key inter‐agency agreements and develop the final plan of finance.
According to Brown, construction is expected to begin in 2024 and full operations at Sites Reservoir are anticipated to begin by the end of the decade.
The Sites Reservoir Project is led by a Joint Powers Authority made up of irrigation agencies, water districts, cities and counties in the Sacramento Valley area. The Project is being developed on a beneficiary pays principle where the benefits received are paid for by those receiving the benefits and beneficiaries include the federal government, state government, and local public agencies.
For more information, visit www.sitesproject.org.