Thousands of California farms and cities have been warned that their permission to pump water from rivers and creeks could be cut back if the drought worsens.
Such a warning, mailed to about 7,000 water rights holders on Thursday by the state Water Resources Control Board, has not been issued since 1988 amid the state's last prolonged drought.
The state did not release a list of all cities and farms that will receive the warnings. But state officials said Monday the list includes every city and farm with state water rights in the watersheds of the Sacramento, San Joaquin and Russian rivers as well as the central coast and the Tule Lake region of Lassen County. That would include the city of Sacramento.
The warning is a reminder that a California water right is not absolute. In fact, state regulators have the power to cut off water diversions in the public interest – whether to protect the environment or to stretch a precious natural resource thinned by drought.
"We are giving you fair warning that even if you start the season with water, by the end of the season you may not have water," said Bill Rukeyser, spokesman for the water board. "People would be able to continue to boil their spaghetti, brush their teeth, take showers, drink water. They would not be able to water their lawns."
The state has not actually cut water rights en masse because of drought since 1977, an even more severe drought. And there's no certainty it will do so this year. That depends entirely on weather.
On Monday, there was a glimmer of good news in the latest snow survey by the state Department of Water Resources. It showed the Sierra Nevada snowpack at 80 percent of normal for the season so far.
Thanks to recent storms, that's a big improvement over February, when the snowpack was 61 percent of normal. But it's not enough to recover from two prior drought years.
Rukeyser likened the problem to a Las Vegas gambler who is $6,000 in the hole after two days of bad luck. On the third day, he might win $2,000, but he still leaves town $4,000 poorer.
"With really generous luck, the dice will keep on turning up just right, and eventually we'll break even or maybe pull ahead. But we're a long way away from that now," he said.
Water rights are actually nothing more than a permit to pump or divert water from a naturally flowing source. They are ranked according to seniority, a complex area of state law.
The most senior water rights are called "riparian" rights – typically those attached to land adjacent to a waterway that has a verified historical claim to that water. Many of these rights date back to the period of Spanish settlement, long before California attained statehood.
If diversion rights are cut, the least-senior water rights would be cut first. Affected farmers would have to plant different crops or let fields go fallow, drill deeper wells or find another water supply. Cities would limit water consumption to essential health and safety purposes.
Some of the state's most senior water rights exist in the Sacramento Valley, a region of year-round river flows and a lucrative rice-growing trade.
"Where fallowing crops makes sense, that is certainly something that can be done," said Donn Zea, president of the Northern California Water Association, which represents farmers and water agencies in the valley.
But he said the public must consider long-term solutions.
"This drought situation that we're in will happen again," he said. "This water system of ours, above Sacramento, has not been added to in any major way since before shag carpeting and refrigerators were avocado in color. It's time we fixed it."
The curtailment warning is different from delivery forecasts announced recently by state and federal water agencies. Those affect agencies that buy water under contract.
Instead, the warning affects all other water users in the state who have a permit to divert water at no cost.
The city of Sacramento, for instance, depends on diversion rights in both the American and Sacramento rivers. Some of these rights are considered to have high seniority, but this may not protect the city from cutbacks later this year if the drought worsens.
"It's not a property right," said Ronald Stork, senior policy advocate at Friends of the River.
"Providence has to provide the water. And if she doesn't, your water right is not going to be anything more than a piece of paper."