SACRAMENTO, Calif. (AP) — Farmers and other landowners who staked the earliest claims to California's water are last to suffer cutbacks at times of drought under the state's water-rights system. Now the dry spell has become so severe that even some of these 4,000 "senior water rights holders" could be ordered to stop pumping from rivers and streams. A brief primer:
WHO ARE THEY?
More than half are corporations, such as power companies that use water for hydroelectric dams. Rural irrigation districts in Modesto and the Sierra Foothills have claims, and water departments in San Francisco and Los Angeles are among the biggest users. A Carmel retirement community has these rights, as does Star Trek actor and ranch owner William Shatner.
HOW DID THEY GET WATER RIGHTS?
Establishing an early right to California water was as simple as going ahead and diverting it. Paperwork came later. San Francisco got the Sierra Nevada water that turned its sand dunes into lush gardens by tacking a handwritten notice to a tree in 1902. The state started requiring applications and monitoring consumption after 1914, but exempted previous claims.
WHO WATCHES THEM?
The State Water Resources Control Board oversees the water rights system and decides when conditions are too dry to meet demand. Every three years, it requires senior water rights holders to report how much water they have diverted, used and conserved. Since regulators lack widespread remote sensors or meters, they depend largely on the honor system to guard against illegal uses.
SO HOW MUCH DO THEY USE?
It amounts to trillions of gallons a year, but no one knows exactly how much. An Associated Press investigation last year found the data riddled with obvious errors. State water officials concede they need better real-time monitoring of flows and diversions. As it is, they generally enforce cutback orders when someone complains.
WHY DO THEY HAVE SPECIAL STATUS?
Much of the parched American West was developed around the principle that water goes to those who claimed the limited resource first. Unused water may be sold or transferred. But California is unusual among western states, in that it doesn't monitor senior rights holders as closely as it does junior rights holders.