As California basks under sunny skies and its farmers hope for rain, the battle has begun over Gov. Jerry Brown's proposed $14 billion twin-tunnels plan to divert water around the environmentally deteriorating Sacramento-San Joaquin Delta.

Unlike when then-Gov. Arnold Schwarzenegger proposed a tunnel, the federal government -- specifically the U. S. Department of the Interior and the National Marine Fisheries Service -- backs the project.

This stamp of approval is important because the Interior Department oversees the U. S. Fish and Wildlife Service, which is responsible for restoring the delta smelt. The National Marine Fisheries Service also has its finger on the Delta's pulse. It is charged with increasing salmon and sturgeon populations there.

Besides touting a reduction in fish killed by the Delta's massive pumps if the tunnels are built, Brown says the project will protect freshwater diversions from levee collapses and rising sea levels.

"The current plumbing configuration in the Delta serves neither people nor fish and wildlife well," says Mark Cowin, the state's Department of Water Resources director. "To do nothing invites disaster."

But while the state's biggest urban water and irrigation districts support the tunnels, there are farmers and environmentalists vehemently opposed to it. The Southern California Watershed Alliance, for example, has launched a website and commercial campaign saying the project is a boondoggle that will bring higher water rates.

Brown comes to the battle with scars. Voters rejected his Peripheral Canal plan in 1982. But he is plunging ahead and calling the project "another test of whether we can govern ourselves."

We long have supported a solution -- either around or under the Delta -- that helps the environment and delivers water to farmers and 25 million residents. What we would like is a frank and fair public discussion about the project's merits and costs versus potential alternatives. We also are curious about the science underpinning the belief that this plan would help restore the Delta to health.

Cowin is right. To do nothing invites disaster. But to do the wrong thing accelerates disaster and leaves taxpayers all the poorer.