Trump administration approves Sites Reservoir project in Colusa County, clearing path for California’s largest new water storage since 1979
The Trump administration has approved the Sites Reservoir in Colusa County via a Record of Decision, unlocking up to 25% federal cost participation and advancing planning for California’s largest new water storage—about 1.5 million acre-feet—since 1979.
- Federal ROD clears federal review and authorizes up to 25% federal cost participation for the Sites Reservoir.
- Scale and beneficiaries: ~1.5 million acre-feet storage to support ~24 million people and 500,000 acres of farmland.
- Costs and state backing: Estimated $6.2–$6.8 billion with a $1.09 billion Maximum Conditional Eligibility Determination from the state.
- Permits and legal hurdles remain: Clean Water Act, historic-preservation, water-rights approvals and other agreements are still needed.
Project overview: purpose and scale
Planners say Sites Reservoir will function as an off‑stream storage facility that captures high flows from the Sacramento River during wet periods and stores roughly 1.5 million acre-feet for release during droughts. Project proponents list multiple goals: drought resilience for cities and farms, ecosystem improvements, flood management and expanded recreation in the northern Sacramento Valley. If built, Sites would be the largest new reservoir in California since New Melones Lake opened in 1979.
For project materials, see the California Water Commission project page and reporting by E&E News.
Federal sign-off and political framing
The Record of Decision (ROD) was issued by the U.S. Bureau of Reclamation and the Department of the Interior after a multi-year federal environmental review. Interior officials framed the approval as the result of thorough analysis and coordination.
“Reflects years of analysis, public engagement and coordination, and establishes the foundation for construction through sound partnerships that will ultimately result in additional water supplies for California.”
— Andrea Travnicek, assistant secretary, Department of the Interior
See the U.S. Department of the Interior press release for the department’s statement and context.
“Demonstrates how a disciplined, mission-focused approach can expand water reliability for communities, agriculture and the economy.”
— Interior Secretary Doug Burgum
The administration tied the decision to Executive Order 14181, which prioritizes maximizing water supplies under a mission-focused approach. Coverage and analysis appear in E&E News.
Timeline, costs and state backing
The California Water Commission has issued a Maximum Conditional Eligibility Determination (MCED) of $1.09 billion under the Water Storage Investment Program and approved $54.7 million in early funding. Overall project cost estimates range between $6.2 billion and $6.8 billion.
- State-level documents and the Environmental Impact Report were completed in 2023.
- Federal ROD was issued in November 2025, advancing the project toward permitting and contracting.
- Authorities list permit and clearance targets through 2026 for historic preservation, Clean Water Act approvals, water rights and operating agreements.
Refer to the California Water Commission for timeline and funding details.
Environmental review and regulatory hurdles
Although the federal ROD clears the federal environmental review, significant permits and legal clearances remain. Pending approvals include Clean Water Act permits, historic-preservation reviews, water-rights decisions and final operating agreements. Environmental advocates and downstream stakeholders have raised concerns about fishery impacts, river flows and broader effects on the Sacramento‑San Joaquin Delta.
Project documents and the ROD list ecosystem benefits and mitigation measures, but outcomes will depend on final permits and enforceable commitments. See analysis in E&E News and materials on the California Water Commission project page.
Funding and partnerships
The ROD authorizes up to 25% federal cost participation, signaling federal support for construction. The project’s financing plan relies on a mix of federal funds, state grants (including the MCED), local water agency investments and negotiated public-benefit contracts for fisheries, flood reduction and recreation.
Achieving construction requires finalized cost‑sharing agreements and commitments from local agencies and other partners; the state’s early funding demonstrates willingness to invest but does not cover the full multibillion-dollar price tag.
Local voices and concerns
Colusa County leaders and residents emphasize potential local benefits: construction employment, recreation and new revenue. Conversely, farmers, tribal representatives and environmental organizations have questioned whether the project will deliver promised reliability without harming river ecosystems and downstream communities.
Project proponents highlight mitigation plans and public-benefit contracts intended to secure wildlife habitat and recreation, while critics stress that surface storage alone cannot address complex water-supply and habitat challenges.
Coverage and reaction are summarized in E&E News and the DOI press release.
Implications for Sonoma, California
Economic and water-supply effects
Sonoma County is not in Sites’ direct service area but could see indirect benefits if statewide supplies stabilize during dry years. Possible effects include reduced pressure for emergency water purchases, less aggressive regional groundwater pumping, and easier coordination on supply trading or drought relief programs.
Environmental and policy ripple effects
Operational decisions for Sites—such as release schedules, water-right priorities and fish protections—could influence debates in Sonoma about groundwater management, streamflow protections and investments in local resilience. Environmental groups will likely monitor permitting and mitigation terms closely for precedent-setting outcomes.
Economic development and recreation
Construction and recreation opportunities in the northern Sacramento Valley may create contracting and service work that could include Sonoma firms. Local officials and chambers of commerce may consider positioning regional businesses to compete for project contracts.
Policy questions for Sonoma leaders
Key questions for Sonoma planners: Will statewide storage alter local drought contingency plans? Could Sites reduce local groundwater pumping during droughts? Will state and federal contracts tied to Sites reshape water markets that affect Sonoma agriculture and municipal users? These are policy choices that will unfold as permits and funding agreements proceed.
Sources and further reading
Administrative note
Note: The Record of Decision issued by the U.S. Bureau of Reclamation clears a key federal review hurdle and authorizes up to 25% federal cost participation, but construction and operation still depend on securing remaining permits, completing funding agreements and resolving regulatory and stakeholder issues. See the DOI press release and the California Water Commission for official documents and updates.
