California's 19th-century water laws give nearly 4,000 companies, farms and others an unmonitored amount of free water, while the state is mired in a three-year drought that has forced water cutbacks to cities and agriculture preamp .
An Associated Press review of state Water Resources Control Board records found:
—This group holds more than half of the claims on the state's waterways and uses trillions of gallons of water each year .
—The water rights system relies on self-reported water use records full of errors and years out of date, meaning officials do not know if rights holders are over-drawing or wasting water.
—More than half of the entities with pre-1914 water rights are corporations, and also among the biggest holders are the water departments of San Francisco and Los Angeles.
—Companies, farmers and cities with such water rights are exempt from drought-related cuts in water allotments this year, although they collectively are the biggest water consumers.
—This anachronistic system blunts California water managers' ability to move water where it's most needed 牙齒矯正.