Gov. Jerry Brown wants to build two giant tunnels underneath the Sacramento-San Joaquin River Delta to siphon water from the Sacramento River to the pumps that feed the San Joaquin Valley and Southern California. The California Aqueduct and Delta-Mendota Canal already transport more than 5 million acre-feet a year southward on average. The cost of the project is said to be $25 billion, but the total bill, with interest, will be more like $60 billion.

That's a lot of money to waste on a bad idea.

California's waterworks are out of whack, ecologically, physically and financially, but Brown's titanic tunnels are an expensive fix that does not treat the real problems. I call them the Delta Drains because they will drain the life out of the delta and the money out of our pockets while chiefly benefiting big agribusiness.

The drains are just the notorious Peripheral Canal moved underground. Thirty years ago, California voters rejected the canal and I wrote a key study about its perverse financing that helped stop the project. Unfortunately, Brown refuses to give up on a bad idea.

Despite years of study under the Bay Delta Conservation Plan, no one has been able to square the circle of water exports versus the environment. Someone must lose: either exporters or the people of California.

Proponents make three arguments for the Delta Drains: they will protect the environment, provide water for millions and be virtually self-financing. Alas, none of these is true.

The first bogus argument is that moving water underground will help the delta. Because the massive pumps confuse migrating fish and massacre millions of fry every year, bypassing surface waterways will reduce the carnage. But the drains reduce one environmental problem by making two others worse.

One is that the bay-delta estuary already suffers from too much water diversion, which reduces freshwater flows, nutrients to the ecosystem and flushing effects on pollutants. But the purpose of the siphons is to draw more, not less, water. Meanwhile, the delta is sinking and sea levels are rising, so much of it will become open water when levees fail under the strain, as they have done repeatedly. Yet the drains' real purpose is to assure a steady supply of water southward, regardless - as Brown's point man on water Jerry Meral has admitted. The right way to save the delta is to pump less and only during high spring flows, and to strengthen levees and restore marshlands.

The second false argument in favor of the Delta Drains is that they will assure a steady supply of water to "25 million Californians," mostly south of the Tehachapis. In fact, personal water use is a drop in the bucket. Statewide, domestic consumption is only about 8 percent of the total versus 75 percent for agriculture and 17 percent for business and landscaping. As for water pumped out of the delta, only about one-quarter goes to Southern California, while three-quarters go to agribusiness in the Central Valley.

The principal users of delta diversions are the Westlands Water District on the west side of Fresno County and the Kern County Water Agency at the south end of the San Joaquin Valley. These water wholesalers buy it from the state and federal governments, then sell it to gigantic growers. Water exports are for profits, not people.

The third unwarranted claim for the drains is that the "water users" will pony up most of the cost. Sounds fair, but it's not. The users with the deepest pockets are city-dwellers, who pay 10 times what growers pay for water. Agribusiness gets its water at a discount because cities subsidize growers through electricity purchases, land taxes and the release of "surplus" water by the Metropolitan Water District of Southern California.

Our 1982 study showed that Southern Californians were paying for water going to San Joaquin growers, and it is still true. The people are paying and the growers are still getting a bargain. With the drains, we'll be paying more.

In all this, Westlands is the tail wagging the water dog. The district has the lowest priority water rights and can't get enough water in dry years. The district wants more water diverted from the Sacramento and the North Coast, not less. They don't give a fig for the fish, having sued to stop water releases for salmon in the San Joaquin and Trinity rivers.

I have a better solution. Instead of building the Delta Drains, use the money to buy out Westlands, about $9 billion at current land prices.

This would be cheaper and have the added benefit of saving 1 million acre-feet a year (average) now going to Westlands, leaving that water for other farmers and urban users.

Farming Westlands is a bad bargain for California. The area has too little groundwater and makes too little profit to pay for irrigation water (hence the subsidies). Worse, it has a severe problem of toxic metals in the drain water. Nor are its crops vital foodstuffs, being principally almonds for snacks, flavorings and beauty products. The land should go back to grazing.

In short, the Delta Drains will be Gov. Brown's gift to a few hundred growers, paid for by millions of unsuspecting Californians.

Richard Walker is professor emeritus of geography at UC Berkeley and the author of "The Conquest of Bread: 150 Years of California Agribusiness" (2004) and "The Atlas of California" (2013), among his many writings on the Golden State. To comment, go to