The enormous Central Valley Project runs nearly 400 miles through California's Central Valley, from the Cascade Mountains near Redding to the "semi-arid but fertile plains along the Kern River in the south," according to the bureau's website.
The Central Valley Project is managed by the Department of the Interior's Bureau of Reclamation.
The dams, reservoirs, power plants, and canals are used for river and flood control, irrigation, municipal drinking water supplies, and protecting and restoring wildlife.
As lead agency under the Central Valley Project Improvement Act (1992), the Bureau of Reclamation must run the giant system in compliance with state and federal laws, including the Endangered Species Act.
The Bureau must issue an environmental impact statement before it can approve the renewal of "existing long-term water service contracts for successive periods of up to 25 years," U.S. District Judge Lawrence O'Neill wrote in a 32-page order.