Water grabs are an age-old California tradition practiced by some of the state’s most revered politicians and landholders. But Central Valley Rep. Devin Nunes’ Big Gulp may top them all in its audacity.

His legislation pending in the House must be killed before the water war to end all water wars erupts in California.

Nunes’ bill has the strong support of Central Valley farmers and House Republicans, including Majority Whip Kevin McCarthy, of Bakersfield. But it demonstrates a total disregard for the health of the fragile Sacramento-San Joaquin River Delta ecosystem — and for the century-old deal giving the state authority to govern Delta water rights.

Practically every House Democrat in Northern California stands in opposition to this reach for 1.4 million acre-feet of Delta water to irrigate Big Ag’s fields, a move that could destroy the largest estuary west of the Mississippi. But the best chance of stopping it is in the Senate, where California’s Dianne Feinstein and Barbara Boxer have vowed to kill the bill.

Silicon Valley receives half of its water from the Delta’s limited supply. Its leaders should be on the line with Feinstein and Boxer urging them on.

At stake is decades of work to preserve the Delta ecosystem. If it collapses, California’s water supplies will be in chaos.

Nunes, R-Visalia, could care less about the Delta’s health. He said he plans to attack Feinstein and Boxer at every turn, telling reporters, “Now they’ve got to fight for their environmental wacko friends.”

Let’s be clear about what constitutes environmental wackos in Nunes’ world.

His legislation would toss out the state’s authority, in place for nearly a century, to balance water supplies between the environment and competing water users. It would overturn widely supported federal protections of endangered species. And it would override the 2006 court-approved settlement — a decade in the making — between Delta water users and ecologists to restore the San Joaquin River.

Water districts throughout the state are on high alert, and lawsuits are certain if Nunes succeeds in reordering the distribution of Delta water.

There would be no need for the continued water struggles if Californians, including farmers, did a better job of conserving the Delta’s limited water flow.

Farmers have improved their water conservation in the past decade, but they still gulp down 80 percent of the water used in California. If they conserved 10 percent of their current usage, there would be plenty of water for everyone.

More than anything, Nunes’ bill points to the need for California to agree on a comprehensive plan to repair the Delta’s levees, restore its health and provide enough water for current and future Californians.

Rep. John Garamendi, D-Walnut Grove, called Nunes’ Big Gulp “one of the worst bills that I’ve seen in a long, long time, and I’ve seen some real turkeys over the years.”

The House Republican majority should remember its commitment to states’ rights and kill Nunes’ legislation before it further splits California. Barring that, Feinstein and Boxer need to stop it in the Senate.