Department of Water Resources Releases Final Environmental Impact Report on The Environmentally Destructive Delta Conveyance Project


December 8, 2023

Contact: Michael Blenner,


Department of Water Resources Releases Final Environmental Impact Report on The Environmentally Destructive Delta Conveyance Project


Sacramento, CA - Today, the Department of Water Resources (DWR) released the Final Environmental Impact Report (FEIR) for the Delta Conveyance project (Delta tunnel). The Delta tunnel would significantly harm the important biodiversity of the Bay-Delta region, at enormous cost to California taxpayers. Sierra Club California staff, volunteers, and supporters submitted comments on the draft of the document last year. These comments highlighted numerous problems in the Draft EIR, including impacts of construction on environmental justice (EJ) communities and Tribes, harm to freshwater flows, and impacts to endangered species. 

DWR received over 7,300 individual comments on the Draft EIR. Each comment and DWR’s responses are included in the FEIR. 

Sierra Club California is strongly opposed to the Delta tunnel and its previous iterations. In 2020, the Department of Water Resources estimated the Delta tunnel would cost $16 billion. Accounting for inflation, the costs are likely to be up to $56 billion, with 47-65% of the tab picked up by Southern Californians living in the Metropolitan Water District. The tunnel will also cause mass environmental destruction for Delta communities and ecosystems during both construction and operation.  

Instead of constructing this environmentally destructive project, which the FEIR claims would add only 500,000 AF/year, Sierra Club California has advocated for a Smart Water Alternatives solution that would increase California’s water supplies by over 10 million AF/year through a combination of conservation, efficiency, groundwater management, water recycling, and stormwater capture measures. 

In response, Erin Woolley, Senior Policy Strategist, issued the following statement:

“The Delta tunnel’s Final Environmental Impact Report shows that the DWR has widely ignored concerns raised by environmentalists, Tribal representatives, and local communities opposing the tunnel’s construction and operation. The project would be a costly environmental disaster, and it’s deeply concerning that after a decade of advocacy, these issues still aren’t being properly recognized by the state.

There are ample alternatives to the Delta tunnel that will fulfill the state’s water needs. Sierra Club California and our allies have consistently recommended the Newsom administration instruct the DWR to prioritize sustainable, local water management efforts instead of the tunnel. This fight isn’t over, and we’re committed to stopping the Delta tunnel and other environmentally destructive projects like Sites Reservoir - wherever they’re proposed.”



Sierra Club California is the legislative and regulatory arm of Sierra Club’s 13 local chapters in California, representing half a million members and supporters.