Birthed in part by a long-ago federal effort to create farmland, today the Central Valley Project is one of the largest water and transport systems in the world. In years of normal precipitation, it stores and distributes about 20 percent of the state’s developed water through its massive system of reservoirs and canals.

Water is transported 450 miles from Lake Shasta in Northern California to Bakersfield in the southern San Joaquin Valley.  Along the way, the CVP encompasses 20 dams and reservoirs with a combined storage capacity of 11 million acre-feet, 11 power plants and three fish hatcheries. As part of this, the Delta Mendota Canal and Friant Dam on the San Joaquin River delivers acre-feet to farms in the eastern Central Valley.

More broadly, the CVP’s benefits touch the lives of every American who buys grapes, lettuce, canned tomatoes or a cotton shirt made from Central Valley crops. Because of the CVP and the state-owned State Water Project, the Central Valley has become the richest agricultural region in the nation.

The widespread availability of water and hydroelectric power also has created millions of jobs and yielded untold billions in manufacturing and commerce.

The CVP’s major redistribution of water, however, has not occurred without controversy. Conflicts have long festered over the project’s public costs and private benefits, and its effect on the environment.

Central Valley Project Background

The CVP got its start in 1933 as a state funded project to manage flooding, store water and produce electricity. But the CVP ran into Depression-era financing difficulties. Attempts to obtain federal grants and loans failed, and the state asked the federal government to take over.

Subsequently, dams and reservoirs were constructed for river regulation, navigational improvement and flood control [see also Central Valley Water Tour].

Currently, major CVP projects include:

• Shasta Dam and reservoir on the Sacramento River,
• Trinity Dam and Clair Engle Lake on the Trinity River,
• Folsom Dam and reservoir on the American River,
• Friant Dam and reservoir on the San Joaquin River,
• New Melones Dam and reservoir on the Stanislaus River (which helped galvanize the river-preservation movement in California) and;
• San Luis Reservoir, a joint federal-state storage offstream facility.

The federal government has financed nearly all construction costs on most CVP projects, and state and local agencies are providing reimbursement of costs over several decades.

For instance, San Joaquin Valley farmers and the Westlands Water District have until 2030 to repay $497 million for water projects— dams and canals — built in the 1960s. As of 2008, 15 percent of that debt had been repaid.

In 1992, the changing views and conflicting values coalesced in the form of landmark federal legislation, the Central Valley Project Improvement Act. The Act brought fundamental change to CVP operations and water contracts and allocation, elevating fish and wildlife protection and restoration to a primary project purpose.

Central Valley Project Controversies and Challenges

The CVP has brought with it controversy over how to address the needs of agriculture while providing water for a huge populous and in a way that sustains the environment.

For example, CVP plans initially included a canal to collect irrigation drainage from west side farms, but the drain was never completed.

For years, farmers kept salt from building up in the soil and shallow groundwater by installing underground drainage facilities [see also Agricultural Drainage]. However, the salty drainage water contains selenium, which can reach levels toxic to birds when concentrated in an evaporation pond or other drainage facilities. The water wound up in Kesterson Reservoir, which was meant to be temporary as part of a drain to the ocean, with subsequent  high concentrations of selenium in aquatic plants and insects. Concentrations in some waterfowl food plants were up to 64 times those deemed to be a health hazard to birds. Thousands of birds died or suffered mutations. Kesterson Reservoir was subsequently closed but there was no way to dispose of the drainage water.

Eventually, several farmers in the Westlands Water District sued the federal government for not providing promised drainage. A federal judge ruled in the farmers’ favor in 2000.  And in 2007 the government signed off on a plan to pay $2.6 billion to drain and treat the tainted water. That plan has not been enacted, however.

Due to its role in providing two-thirds of the state’s drinking water, much of the concern is now focused on the Sacramento San Joaquin Delta. The Bay Delta, of course, is the hub of the California’s water system, through which the majority of the water flows to the CVP and SWP.

Adding to the CVP’s many difficult challenges are drought conditions and climate change, which will likely alter water availability and flow patterns as the Sierra Nevada sees less snow and more precipitation during the winter and an earlier snowmelt in the spring.

Fish and the Central Valley Project

Also generating controversy, populations of Chinook salmon in the Sacramento and San Joaquin river basins have significantly declined since the late 1980s. By 1989, when one of four Sacramento River Chinook salmon species—the winter-run— was listed under the state and federal Endangered Species Acts (ESA). In 1998, spring-run Chinook were listed. [See also Anadromous Fish Restoration.]

While mitigation plans and facilities have been a part of the CVP since the early 1940s, these efforts to save the winter-run Chinook salmon, in combination with the CVPIA, brought fundamental change to the CVP.

New, state-of-the-art fish screens were installed on the Sacramento River, and at large diversion canals. In the Delta, gates at the Delta Cross Channel also are closed for several months to reduce fish entrainment at the export pumps. Spawning gravel was replaced along miles of river and a captive winter-run breeding program is underway.

Other fish-protection projects include an $80 million temperature control device installed at Shasta Dam in 1997, and modernization of the Coleman and Nimbus fish hatcheries.

In 2006, an agreement was reached to restore water flows for salmon in the San Joaquin River below Friant Dam near Fresno. The pact provided funding for substantial river channel improvements and water to sustain a salmon fishery upstream from the confluence of the Merced River tributary while providing water supply certainty to water contractors. But it remains controversial and some people are trying to stop the program.

And in 2007, new rules reduced by third the amount of water from pumping stations to federal and state water projects. The changes were enacted to protect the endangered Delta Smelt fish from extinction [see also Wanger Decision].

Central Valley Project Facts and Figures

In a normal year the CVP delivers about 7 million acre-feet of water for agricultural, urban, and wildlife use. It provides about 5 million acre-feet for farms, enough to irrigate about one-third of irrigated farmland in California, and 600,000 acre-feet for municipal and industrial use – enough to supply close to 1 million households with water. The project also provides water to generate 5.6 billion kilowatt hours of electricity to meet the needs of about 2 million people. The CVP also dedicates 800,000 acre-feet per year to fish and wildlife and their habitat and 410,000 acre-feet per year to state and federal wildlife refuges and wetlands.