Delta Conveyance

Delta Conveyance

Delta Conveyance

Delta conveyance refers to State Water Project (SWP) infrastructure in the vast network of waterways comprising the Sacramento-San Joaquin Delta (Delta) that collects and moves high-quality, clean, safe and 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 SWP and is responsible for all associated upgrades and maintenance, including the proposed Delta Conveyance Project that will modernize this water transport infrastructure in the Delta.

View this Story Map for more information on several key aspects of the Delta Conveyance Project. 


About the Project

The proposed Delta Conveyance Project would modernize the state’s water infrastructure in the Delta to help protect the reliability of this important water supply for 27 million Californians and 750,000 acres of farmland from earthquakes and climate-driven weather extremes. DWR has prepared new informational materials about the need for the proposed project related to the risks to State Water Project water supplies from climate change and seismic activity.


​​​​Animation: Climate Change Vulnerabilities

This animation explains how the proposed Delta Conveyance Project will help California adapt to a hotter future with more unpredictable precipitation and seasonal flow patterns due to climate change. Modernizing the State Water Project infrastructure in Delta will allow us to capture, move and store water during extreme rain events for use when it is needed most, providing flexibility to better manage California’s changing weather patterns. Watch the animation here.

Video: Seismic Quick Question

The next installment in the Quick Questions video series examines why Delta levees are vulnerable to failure during an earthquake and how the proposed project would protect continued operation of the State Water Project in the event of major seismic activity. The recent earthquakes in the Delta underscore this real and serious threat and potentially devastating impact on statewide water supplies. Watch the video here.


A Missed Opportunity

If the Delta Conveyance Project was operational during the high rain events of winter 2021-2022, January 2023 and January 1 through April 11, 2024, a significant amount of water could have been moved. The graphic below shows how much rain could have been captured and how many people and households it could have supplied.

Click on the image above to open the PDF. 

Project Documents

The Department of Water Resources released the Final Environmental Impact Report (EIR) for the proposed Delta Conveyance Project, advancing an essential piece of the state’s strategy to protect water access for millions of Californians. It was redesigned following public input and Governor Newsom’s pledge of rightsizing the project to one tunnel to better support both environmental and water supply needs.

By 2040, California is expected to lose 10% of its water supply due to hotter temperatures. During January’s atmospheric rivers, the Delta Conveyance Project could’ve captured enough water for 2.3 million peoples’ yearly usage. Until this year, the state faced its three driest years on record. Extreme weather whiplash will result in more intense swings between droughts and floods. California’s 60-year-old State Water Project infrastructure is not built for these climate effects.


Final EIR

The Final EIR was prepared by DWR as the lead agency to comply with the requirements of the California Environmental Quality Act (CEQA). The Final EIR is presented in two volumes: 1) the contents of the entire Draft EIR, as revised, and 2) all comments received on the Draft EIR and responses to substantive comments.