For the first time in nearly 40 years, state regulators are telling more than 100 growers and irrigation districts with some of the oldest water rights in California that they have to stop drawing supplies from drought-starved rivers and streams in the Central Valley.
The curtailment order, issued Friday by the State Water Resources Control Board, has been expected for weeks. Earlier this spring, the board halted diversions under some 8,700 junior rights. With snowmelt reduced to a trickle this year, there simply isn’t enough water flowing in rivers to meet the demand of all those with even older rights predating 1914.
And as flows continue to decline this summer, board officials said, they expect to issue more curtailments, stopping river pumping by more senior diverters.
The effect of the curtailments, which affect water users with rights dating to 1903, will vary. Many have water in storage that they can continue to use. Utilities can keep using flows for hydropower production as long as the water is returned to the rivers. Some growers and ranchers also have groundwater supplies that are unaffected by the order.
A few communities, including Chico and Nevada City, have to stop river withdrawals under the order. But Thomas Howard, the state board’s executive director, said they have alternative supplies. “Each water-right holder has different options available to them,” he added.
Still, the fact that the state is reaching back more than a century in the hierarchy of California water rights highlights the withering hold of a drought that has also led to the state’s first mandatory cuts in urban use.
The last time regulators ordered those with pre-1914 water rights to stop diversions was in the punishing 1976-77 drought. Those curtailments were not as geographically widespread as Friday’s, which applies to the Sacramento and San Joaquin river watersheds as well as the Sacramento-San Joaquin Delta.
Full article: California moves to restrict water pumping by pre-1914 rights holders (LA Times)