By SCOTT SMITH, Associated Press

FRESNO, Calif. (AP) — A group of powerful California farmers pulled their support Tuesday from a pair of massive, $16 billion tunnels that would have re-engineered the state's water system in a decisive move that dealt a major blow to the project pushed by Gov. Jerry Brown.

The board of Westlands Water District, the nation's largest supplier of irrigation water to farms, voted to withdraw its participation from the project after more than an hour of tense discussions and comments from farmers who overwhelmingly concluded it was too expensive.

After the vote, John Laird, secretary of the California Natural Resources Agency, said the aging water infrastructure must be modernized.

"Failing to act puts future water supply reliability at risk," he said in a statement. "This vote, while disappointing, in no way signals the end" of the project known as WaterFix.

Tuesday's vote leaves the project's future in peril, potentially heightening a longstanding feud between typically dry Southern and Northern California, where much of the state's water originates.

Before the 7-1 vote in Fresno, Westlands general manager Thomas Birmingham had urged board members to support the tunnels on the condition that federal officials spread the cost more broadly to make it affordable for the district.

"This thing dies," Birmingham told the board about the decision. "The project will be over."

The vote was the first among several large water districts that have already spent more than $200 million on planning for the tunnels but have not committed to shouldering their share of the hefty construction costs.

Water is a fought-over resource in California, which leads the nation in agricultural production, growing nearly half of its fruits, nuts and vegetables.

Water for irrigation now flows through a complex system of reservoirs and canals managed by state and federal officials that was built decades ago.

The tunnels project calls for building two 35-mile-long (56-kilometer-long) tunnels east of San Francisco to deliver water from the Sacramento River mostly to farms and cities hundreds of miles away in central and Southern California.

Backers say the tunnels will stabilize delta flows, bolster endangered fish and ensure a reliable water supply. Critics say the project will be used to drain Northern California dry and further harm native fish.

William Bourdeau, executive vice president at Harris Farms and a Westlands board member, said the economics of the project didn't pencil out and it came with no guarantee it would produce consistent water supplies years from now.

"We would be obligating hundreds of family farms," Bourdeau said outside the meeting. "That doesn't make economic sense."

Rather than putting the responsibility on the districts that stand to benefit from the tunnels, Bourdeau said the federal government needs to play a leading role as it did decades ago when it built the current complex of dams and canals.

The powerful Westlands agency provides irrigation water to 1,000 square miles (2,590 square kilometers) in the San Joaquin Valley, some of the nation's richest farmland.

Officials in other districts were watching the Westlands vote as they prepare to make their decisions on the project that has been on the drawing board for more than a decade.

Opponents representing delta farmers, who long battled against the tunnels, considered the Westlands vote a good day for California. They'd prefer seeing money spent on capturing Californian's storm runoff and replacing leaky toilets as ways to ease the demand for delta water.

"The sooner we can get Gov. Brown to put an end to pushing California WaterFix, the sooner we can get to solutions for California water," said Barbara Barrigan-Parrilla, executive director for Restore the Delta.

The vote came a day after The Associated Press reported state plans to put dozens more water agencies and millions of families and farmers on the hook for funding the tunnels.

The approach pivots from longstanding state and federal assurances that only water districts that seek to participate would pay, instead shifting responsibility to a broader sweep of districts.

Brown is pressing to secure the project before he leaves office next year. Calls and emails to the governor's press office seeking comment Tuesday were not immediately returned.

Westlands farmers had considered delaying their vote in hopes of securing a better deal from federal officials, but Birmingham told them the terms wouldn't likely change.

"There's just too many unknowns," said farmer and board member, Larry Enos.

"The only guarantee is once we do it, we have to pay the bonds. I can't get comfortable with it today."