Proposed Delta Conveyance Project

The proposed Delta Conveyance Project would modernize the water transport infrastructure of the State Water Project in the Delta by adding new facilities to divert water and upgrading the current conveyance system to also include a single underground tunnel. The Proposed Delta Conveyance Project includes the following main construction components: North Delta Intakes, tunnels and shafts, a pumping plant and connections to existing facilities in the south delta, and other features to support construction activities.

The proposed Project that the Department of Water Resources (DWR) is analyzing in the forthcoming Draft Environmental Impact Report (EIR) is the Bethany Reservoir Alignment. It consists of a 6,000 cubic feet per second conveyance facility constructed on an eastern alignment roughly parallel to Interstate 5 to a site south of the Byron Highway, adjacent to the existing Bethany Reservoir. The proposed Delta Conveyance Project is very different from the State’s previous proposals. The project has been downsized, refined, rerouted, and redesigned.

If the project is approved following the environmental review process, only one alignment utilizing one tunnel will be selected.  For more detailed information on proposed facility locations, site plans, construction site photos and proposed routes for construction traffic:
DCA Map Book
DCA Bethany Alternative Map Book
DCA Virtual Tour

NOTE: Maps are for discussion purposes only and are subject to change. They do not represent a decision by the DCA or DWR. Final decisions about the project will be made by DWR and will NOT be made until the concluding stages of the California Environmental Quality Act process.


Delta conveyance refers to State Water Project infrastructure in the vast network of waterways comprising the Sacramento-San Joaquin Delta (Delta) that collects and moves fresh affordable water to homes, farms and businesses throughout major regions of the state from the Bay Area to southern California. The Department of Water Resources (DWR) is the owner and operator of the State Water Project and is responsible for all associated upgrades and maintenance, including the proposed Delta Conveyance Project that will modernize State Water Project conveyance.
Visit Delta Conveyance on DWR’s website for more info »


Under the direction of California’s Department of Water Resources (DWR), the Delta Conveyance Design and Construction Authority’s purpose is to design, develop, and, if the project is approved, implement the proposed Delta Conveyance program, an infrastructure project to support the resiliency of California’s fresh water supply via a proposed single tunnel solution.

The Delta Conveyance Design and Construction Authority (DCA) conducts engineering and design work to inform DWR’s environmental review and planning process of a proposed Delta Conveyance Project. For more information about the work of the DCA, see the video here.


The DCA presents information through a variety of channels including social media, public presentations, conferences, and community meetings in order to:

  • Provide clear, concise, accessible and timely information to the public
  • Facilitate public participation in the planning process
  • Improve mutual understanding, encourage dialogue and facilitate constructive public input
  • Build trust through transparency, commitment and follow-through

In 2019, the DCA Board formed a Stakeholder Engagement Committee (SEC) of community members who live and work in the Delta. The goal was to integrate community-focused modifications into the planning and conceptual design of the proposed project. Feedback sought included traffic flow, optimal stockpile locations, uses for recycled tunnel material, tunnel shaft placement, and efficient materials movement.

In 2021, DCA engineers completed preliminary conceptual designs for the California Department of Water Resources to be used in environmental evaluation of the proposed project alternatives, as required by the California Environmental Quality Act (CEQA). Results of SEC feedback included adjustments to facilities locations, the elimination of an intermediate forebay, proposed road improvements to address traffic concerns, and the reduction of the project footprint in several areas.

The SEC was officially sunset in January 2022. The SEC White Paper here summarizes the SEC formation and operation and provides a resource for future advisory or similar committees if Delta Conveyance is approved.

More information on the SEC, including all meeting materials and videos, can be found here: SEC Meetings.

History of the State Water Project

California’s water projects are the product of decades of deliberation and the evolution of California’s twin goals of protecting and securing water resources to meet growing demand while maintaining a healthy environment.

  • 1957-2017

    A construction crew works on the outlet conduit at the Frenchman damsite in southeastern Plumas County, California.

    In the late 1950s, the California Department of Water Resources (DWR) laid the framework for future water development in California and received funding to build the State Water Project (SWP), a “Trans-Delta system” to convey water from the Sacramento and San Joaquin Rivers to south Delta pumps for distribution to millions of residents through the California aqueduct system.  When the SWP was built in the 1960s, planners intended to carry water to the state pumping plants through a 43-mile peripheral canal skirting the eastern edge of the Delta. For cost reasons, the originally proposed peripheral canal was not built and a subsequent statewide referendum was defeated. Over the next few decades, ever more rigorous science was developed to better understand the relationship between water infrastructure, native fisheries, and water quality.

  • May 2018

    Aerial view of floodwaters overtopping the Fremont Weir in Knights Landing, Calif.

    The Delta Conveyance Design and Construction Authority is formed for the design and construction of the California WaterFix project.

  • May 2019

    Interior image of a tunnel

    The Department of Water Resources withdraws the WaterFix permit approvals and initiates planning and permitting to modernize the state’s water system with a proposed single tunnel project, known as the Delta Conveyance program.

  • January 2020

    A juvenile Delta Smelt

    The Department of Water Resources issues a Notice of Preparation for an environmental impact report on the proposed single tunnel conveyance.

  • November 2021

    Aerial view of floodwaters overtopping the Fremont Weir in Knights Landing, Calif.

    The Department of Water Resources amended their Proposed Delta Conveyance Project Section 404 Permit Application with the US Army Corps of Engineers to replace the previously identified Eastern Alternative with the Bethany Reservoir Alignment Alternative for the proposed project.