The state has not declared a drought after two dry winters, but farmers and city leaders in the central San Joaquin Valley don't need an official pronouncement.
Everyone looks at the bottom line in the Valley — the groundwater. Big withdrawals have been made this summer from the already sinking underground water table in the Valley.
If this winter is as dry as the previous two, the drought conversation could turn to pumping restrictions, which is a dreaded prospect. Farmers, politicians and many businesses do not want state authority and expense involved in the use of groundwater.
But the underground losses due to pumping here are hard to ignore.
The Kings River Conservation District —1.1 million acres of farms and communities in Fresno, Tulare and Kings counties — estimates 500,000 acre-feet of water have been overdrafted from the underground this year. That's enough to fill Millerton Lake.
In Westlands Water District, the groundwater loss this year will total nearly 600,000 acre-feet — the most desperate time since 1992 at the end of a seven-year drought. Dry weather and controversial environmental pumping restrictions left the district with a 20% allocation of Northern California river water this year.
What happens if the coming winter is dry and Westlands gets a zero allocation?
"The district feels it must explore limits on groundwater extraction," general manager Tom Birmingham said. "The district exercised this limited authority in 2006 when we had 100% of our water allocation. This would be quite a different situation."
In Valley cities, groundwater banking projects store water in big rainfall years so there is enough for dry spells. Still, the water table continues to fall in many places such as Fresno — 100 feet over the last 80 years.
Fresno will build a second water treatment plant to provide more river water for customers and greatly reduce reliance on the city's 270 wells.
"Our combined treatment plants will handle 73% of the total demand," said Martin Querin, assistant director of Fresno's public utilities, water division.
Fresno also has gone from flat-rate billing to metered water rates in the last two years, spurring savings. Fresno's per-capita consumption has dropped from 320 gallons a day to less than 250. City officials would like to see it drop to 200 per day.
But as the population grows and dry spells continue during climate change, groundwater still will be an important part of the water supply for Valley cities and farms, many experts say.
About 70% of California's total groundwater use is in the combined San Joaquin and Sacramento valleys, known as the Central Valley, according to the state Department of Water Resources.
California groundwater pumping is not regulated by the state, as it is in such places as Colorado and Arizona. The idea always has been a political hot potato in Sacramento.
One result: The region has tens of thousands of private wells that are not tracked in a detailed way, unlike river water. People in the water business around the Valley are talking about dozens of private wells going dry this year, but the state has no way of tracking it.
Many farmers say they must drill new, deeper wells now. Older wells are breaking down and going out of service, they say.
Kings County grower Ted Sheely, who has 40 years of farming experience in the Valley, says he spent $10,000 over a few days, coaxing water out of an old well to get a crop through the season.
He needs all of his 25 wells this year because his Westlands water allocation is only 20% for his 7,500-plus acre operation. And the open market for water has been very tight.
Over the years, Sheely has shifted part of his farm to permanent crops — 2,500 acres of pistachios and 300 acres of wine grapes. Using stingy drip irrigation, his wells can supply enough water for those crops in dry years. It has proven to be a wise approach.
"This year is really different," Sheely said. "Even in most drier years, you can buy water from someone if you're coming up short and get it the next day. This year, you might have to wait, and it's a real challenge. When you need water for a crop, you can't wait a week."
The underground aquifers, which run thousands of feet deep in some places, have been more than a backup plan in the past. They were heavily tapped decades ago, making the landscape sink dramatically in some west Valley locations.
Just southwest of Mendota in Fresno County, the U.S. Geological Survey recorded a 28-foot drop between 1925 and 1977. Federal scientists call it the "largest human alteration of the Earth's surface."
Local groups, such as the Kings River Conservation District, bring together water agencies, local governments and environmental groups to find ways of preventing groundwater depletion, such as groundwater banking.
District leaders estimate 90 million acre-feet of water exists down to a depth of 1,000 feet in the district. But the deeper the wells are drilled, the more expensive it is to pump the water up.
And the demand for water is not going away.
"We've seen demand hardened for urban use and permanent crops," said district general manager Dave Orth. "There is a lot less resilience in the groundwater system now. Limits on groundwater may be inevitable at some point. But I think people recognize and support the notion of local control."
The immediate worry is the 2013-14 winter. Will it be wet or dry?
Gary Serrato, longtime water expert and general manager of the Fresno Irrigation District, said this region survived the seven-year drought that ended in the early 1990s. It can survive this dry spell too, he said.
"You have to see it as a 50-50 chance of being above or below average precipitation this winter," he said. "Either way, we will manage, as we have before."
The reporter can be reached at (559) 441-6316, firstname.lastname@example.org or @markgrossi on Twitter.