In the third year of California's drought, federal authorities may be forced into a dreaded first-ever, last-resort decision — taking water from east Valley agriculture and sending it to west-side growers.
Nobody knows yet how much water could be shifted, but the stakes are high for those who would lose water on the east side. With San Joaquin River water from Millerton Lake, the farm economy is worth hundreds of millions of dollars annually.
The east siders got the water decades ago through a 1939 federal deal with downstream west-side growers who have historic rights to the San Joaquin River. The west siders made the deal because the U.S. Bureau of Reclamation provided them a steady supply of water from Northern California rivers.
But in cases of extreme drought, like this year — when very little water is available in Northern California — the deal calls for some Millerton Lake water going to the west siders, who own 240,000 farming acres.
The worry would wash away if big storms start pounding the state. For now, it weighs on the east side from southern Merced County to Kern County.
East siders already have been giving up some water for the San Joaquin River restoration project that began in 2009. The restoration project would get no water later this year if the season remains in extreme drought conditions.
Everyone is scrambling for options, said Ron Jacobsma, general manager of the Exeter-based Friant Water Authority, which represents 15,000 growers on 1 million acres of east-side farmland.
"There will be exchanges, transfers and new wells," he said. "Some will call on water that has been banked in ground-water banks. But we could be looking at fallowed land."
Jacobsma and other water leaders daily follow reports showing California's major reservoirs are mostly half empty.
The Sierra snowpack — the major source of water in spring and summer — is 16% of average, including 7% for the usually robust northern section. January weather forecasts have not offered a lot of hope.
Farm leaders estimate 200,000 acres could be left out of production on the west side, where many farmers depend on water coming through canals from Northern California rivers.
Water leaders on both sides of the Valley compare this winter with the historic drought year of 1976-77, the driest year on record in many California locations. The water year is counted from July 1 through June 30.
In 1976-77, the west side farmers with historic San Joaquin River rights had no water supply problem because environmental restrictions were not cutting back supplies, farm leaders said.
But California now spreads a lot of water into environmental efforts, such as the river restoration project and protection for dying fish species in the Sacramento-San Joaquin River Delta.
Westlands Water District, which got a 25% allocation from the Central Valley Project in 1977, fears it will get zero this year. Westlands' contracts don't provide the certainty allowed to the 2,000 landowners who have the San Joaquin River water rights dating back as far as the 1870s.
The landowners are in four areas — the Central California Irrigation District, San Luis Canal Co., Columbia Canal Co. and Firebaugh Canal Water District.
When Friant Dam was built decades ago, they agreed to let federal authorities send their water to the east side. In exchange, they get river water from Northern California, rarely suffering anything more than small cutbacks even in dry years.
But in the worst dry years, federal officials must consider tapping Millerton for the west-side growers. They considered it in 2009, but spring storms helped them avoid it.
At the same time, if the dry weather continues through winter and spring this year, there may not be enough water in Millerton to send downstream to the west side, said Steve Chedester, executive director of the San Joaquin River Water Exchange Authority in Los Banos, representing the four districts.
"We're still in preliminary stages of planning," Chedester said. "We hope it won't come down to an absolute emergency situation. But right now it's blatantly obvious the federal government is not in position to deliver the water from the delta."
Many east siders would be forced to tap ground-water wells that already are down from previous drought years.
Last year, the Tulare Irrigation District in Tulare sold its drought-diminished allotment of Millerton water to neighbors. Farmers in the 65,000-acre district then pumped water from the ground for crops — one-third of which are valuable permanent crops of walnuts, almonds, pistachios and grapes.
"It's a strain on the groundwater resource," district general manager Paul Hendrix said. "We're down to about 150 feet deep now. It's not as bad as some places on the west side, but everyone has become so aware of it."
Deeper water levels translate into higher costs for electricity to pump water up.
On the west side, farmers in Westlands Water District last year pumped more than 500,000 acre-feet of water — enough to fill Millerton Lake. For years, the district's Northern California water allocations have been regularly cut back by drought and environmental regulation.
Anticipating the zero allocation this year, general manager Tom Birmingham said the west Fresno County economy would be affected as thousands of acres slip out of production.
"It is not just the farmers that will suffer," he said. "Farmworkers, communities, businesses and California consumers will feel the full impact."
North of Westlands, the landowners with historic river rights may not be hit so hard, especially if they get water from Millerton Lake.
But they would rather avoid taking the Millerton water, says one landowner, Cannon Michael, president of Bowles Farming Co. in Merced County. He added that this year's shortages underline the need for improvements in managing the state's water system.
Michael, like many farm leaders, says government policies protecting dying fish in the delta last year allowed too much water to flow into the ocean instead of being captured and held in reservoirs for dry times.
"We had an opportunity to put more water away for everyone," he said. "And it was missed."
The reporter can be reached at (559) 441-6316, email@example.com or @markgrossi on Twitter.