The Delta Conveyance Project is Key to Modernizing the State Water Project and Delivering Water to Millions of Californians

By Karla Nemeth, DWR Director

When two of every three Californians pay their water bills each month, they pay for reservoirs and aqueducts that were designed for them a half century ago. The State Water Project was conceived in the mid-1950s, when California’s population had doubled in the previous 15 years. Floods had recently ravaged Northern California towns. The concept was as simple as it was bold – bring water from the wetter parts of the state to the cities and agricultural operations that were outgrowing water supplies in the Bay Area, San Joaquin Valley, and Southern California.

Fast-forward decades, and the State Water Project has helped resolve groundwater problems in the Santa Clara Valley, South Coast, and elsewhere. In the San Joaquin Valley farm belt, groundwater overdraft persists, but by law irrigation districts must bring aquifers into sustainable conditions by 2040.  The 27 million Californians who pay for the State Water Project have become a $2.3 trillion economic engine, the equivalent of the eighth-largest economy in the world.

Now the State Water Project is aging. Major San Joaquin Valley canals damaged by sinking land tied to the over-pumping of groundwater must be repaired. Meanwhile the world is warming, pushing saltwater deeper into the Sacramento-San Joaquin Delta, parching landscapes, and intensifying both storms and drought. Over the next 20 years, California could lose 10 percent of its water supply to hotter, drier conditions.

Today California water policy is far more complex than it was in the 1950s. Californians value environmental protection and want to ensure access to safe and affordable water supplies for all communities. There is no one-dimensional way to address this complexity. But among the multitude of actions needed to safeguard and integrate the next generation of water supplies, revitalizing the State Water Project would put California closer to water resilience than any other single action.

State Water Project supplies support other investments by public water agencies from San Jose to San Diego. To conserve or recycle water, you must first have water, and the State Water Project delivers it. The large scale of the project makes the water it delivers relatively affordable. State Water Project supplies are more cost-effective than desalination and most water recycling programs and competitive with conservation and stormwater capture – all of which generate relatively small volumes of water. It would be difficult to replace a significant share of State Water Project deliveries, and some alternatives would require construction of new delivery systems.

Modernizing the State Water Project depends primarily on two actions. First is maintaining existing infrastructure -- including repairing subsidence-damaged canals. Second is constructing the Delta Conveyance Project. New intakes on the Sacramento River and a 45-mile-long tunnel under the east side of the Delta would give the State Water Project flexibility to capture storm runoff that now flows to the ocean. This will be especially valuable in a world of more extreme drought and flood, and it will reduce conflicts with endangered fish protections. The Delta Conveyance Project also would safeguard water deliveries even if levees collapse in the low-lying, flood-prone Delta. (In 2005, the non-partisan Public Policy Institute of California put the probability at roughly two-in-three that during the next 50 years either a large flood or seismic event would affect the Delta.)

Recognizing the need for urgency, Governor Gavin Newsom has crafted a legislative package to trim some of the Delta Conveyance Project permitting processes underway, without compromising public review. The Governor’s proposed legislation would get us to construction faster, saving the ratepayers of local water districts hundreds of millions of dollars.

The Governor has called the Delta Conveyance Project one of the most important climate adaptation projects in the country. A recently released strategic adaptation plan by the State Water Project backs that up. It highlights five key actions to show how they would be expected to change future water delivery reliability. On its own, the Delta Conveyance Project is the single most effective strategy and amplifies the others.

California needs the State Water Project to function into the future. Without it, we strand 70 years of investment and the infrastructure that catalyzed its modern economy.

Karla Nemeth is the Director of the California Department of Water Resources. She was appointed director by former Governor Jerry Brown in 2018 and again by Governor Gavin Newsom in 2019.