California has ordered some of the largest water cuts on record to help ease shortages during the current drought.
The move affects more than 100 senior water rights holders in the state's Delta, San Joaquin and Sacramento regions, including water districts that serve thousands of farmers and others.
The cuts mark the first time since the 1970s that California has curtailed water use to senior water rights holders in the state. The order affects farmers and others whose rights to the water date from more than a century ago.
California has already ordered cuts in water use by cities and towns and by many other farmers.
Farmers who have been told to stop all pumping from the state's watersheds are turning to other sources of water, inducing wells, reservoirs and the open market.
Some farmers are planning to take the state to court, saying they have no backup water supplies.
California water law is built around preserving the rights of senior water rights holders, and some farmers have built their businesses on the belief that they are always guaranteed access to water.