Last year was the driest since California began keeping records in 1895. That will be used to try to fast-track the Bay Delta Conservation Plan, whose two massive tunnels would carry water under the Sacramento-San Joaquin River Delta that now provides nearly half of Silicon Valley's water.

The drought instead should raise skepticism about this $25 billion plan, the largest public works project in U.S. history, because it raises a conundrum: The plan says the tunnels will provide not a drop more water than the Delta provides today -- and that is completely out of whack with the interests of agencies and communities lining up to pay billions of dollars to build them.

 In this Feb. 22, 2006 file photo, houses located in the Pocket Area of Sacramento, Calif., are seen along the Sacramento River. (AP Photo/Rich

The explanation may lie in the size of the two 30-mile long, 40-foot high tunnels, vastly larger than needed to maintain the current water flow.

That gives the Central Valley's powerful agriculture industry and Southern California's water contractors reason to believe there will, in fact, be more water pumped out of that ecosystem to fill their needs. Otherwise, why build on such a massive scale? It would be like paying to build an eight-lane highway but arguing that only two lanes would be used.

The only way for Central Valley farmers and Southern Californians to substantially gain from the project without ruining the Delta's ecology would be to build more dams and other forms of storage for water pumped in wet years. But proponents of the Delta plan rarely talk about the costs and political challenges of building dams, which are out of environmental favor.


The Delta plan, as written, places the environmental health of the estuary on a par with providing water for farms and cities. This is largely a Northern California goal.

The Central Valley and Southern regions have been so desperate for water that they have pumped their own groundwater resources to dangerously low levels. Once the tunnels are ready to carry huge amounts of water, it will be harder to resist increasing the flows in drought years.

Yet some of the environmental damage to the largest estuary west of the Mississippi has been caused by the increase of water pumped south: from 3 million acre-feet in 1990 to roughly 5.2 million acre-feet in 2010.

California's water solution has to include more storage; ideas like raising existing dams are a good way to do that. And it has to include more conservation and less wasteful use of water.

A state water plan should encourage those strategies so that less water, not more, will be pumped out of the fragile Delta. Claiming the environmental high ground while building a huge conveyance system simply makes no sense.