From the Department of Water Resources:
Twenty-seven million Californians, including seven million in disadvantaged communities, rely on the State Water Project (SWP) for clean, affordable and safe water. Today, those supplies are increasingly at risk due to climate change, sea level rise and earthquakes. That’s why the Department of Water Resources (DWR) is moving forward with the Delta Conveyance Project to provide real water supply benefits for millions of Californians served by the SWP.
Economic Source of Water
For more than 60 years, California’s now $2.3 trillion economy has benefitted from the clean, affordable, and reliable water supplies provided by the SWP—a foundational source that is one of the most affordable options and less expensive than alternatives such desalination, recycling and stormwater capture according to a 2024 economic analysis. While these projects are an important component of local water supply portfolios, they can’t entirely make up anticipated future losses and many rely on the SWP as an original source of water supplies.
Benefits Outweigh the Costs
A 2024 benefit-cost analysis for the Delta Conveyance Project found that for every $1 spent on the project, $2.20 in benefits would be generated. Most importantly, the report shows that the Delta Conveyance Project enables ongoing demands to be satisfied and protect SWP supplies, preventing both water shortages and water rationing, and allowing more water to be saved during wet years. Breaking down the benefits:
- Urban Water Supply Reliability: More SWP deliveries under wetter periods allow agencies to:
- Fill storage more frequently
- Enter drought periods with higher reserves
- Impose fewer periods of mandatory rationing
- Reduce severity and frequency of shortages
- Water Quality: Lower salinity improves water quality, which is beneficial for urban and agricultural agencies.
- Earthquake Disruption: Avoiding potentially significant disruption to statewide water supply caused by earthquakes saves time, saves money and protects water quality.
Increased Water Supply
Four years of data show the Delta Conveyance Project provides water supply benefits regardless of the water year type by adding system flexibility to improve water management and adapt to changing weather patterns and sea level rise. This is especially important given that every water year is unique, with some being dry and others wet. California’s climate has always been highly variable, and as the climate changes, precipitation patterns are becoming even more unpredictable, wildly swinging from extreme drought to intense precipitation and flooding.
Cost of Doing Nothing Now and in the Future
Failing to implement the Delta Conveyance Project has real financial consequences resulting from climate change, sea level rise and seismic events. Failing to act with urgency in this moment also has long-term financial consequences, including continued declining supplies, water shortages, mandatory water use restrictions, and potential land fallowing and job loss, which all impact our state and local economies.
Resources & Additional Information
- Benefit Cost Analysis
- Analysis: Benefits of the Delta Conveyance Project Far Exceed Costs
- Cost Estimate
- Facts About the Economic Value of the Delta Conveyance Project
- FAQ: Understanding Costs, Benefits, Funding and Financing for the Delta Conveyance Project
- Economic Analysis of the State Water Project
- DCP In Practice Fact Sheet
