A version of this essay was originally printed in the Sacramento Bee on January 18, 2009.

The governor’s Delta Vision Committee recently announced its recommendations for addressing the decades-old challenges facing California’s water system. Taken all together, the recommendations are comprehensive and thoughtful. The media and public, however, have focused on only one –- the proposal to build a peripheral canal.

Such a canal, costing billions of dollars, would move water more directly from Northern California rivers to Central and Southern California water users, largely bypassing the Sacramento-San Joaquin Delta. An earlier version of the peripheral canal was rejected in a statewide referendum in 1982, and that fight left a bitter taste that lingers to this day.

There is no doubt that the Delta is in crisis and that the lack of action on the part of state and federal water managers, and irresponsible decisions to expand water exports from the Delta over the past decade, have made matters worse. As a result, tensions over water policy have intensified. In turn, this has ratcheted up the pressure on politicians to come up with a big response. And the peripheral canal would be big.

The arguments in favor of such a canal include increased reliability of water deliveries, better control over water quality, and reduced impacts on collapsing fisheries. Arguments against it include its high cost compared to efficiency improvements that could reduce the need for water exports from the Delta, concerns about the impacts on Delta farmers and communities, and ecological concerns from saltwater intrusion into the Delta exacerbated by reduced flows.

Interest groups in California’s water debate are already racing to judgment, both pro and con. While such a massive project may be a good idea, it may also be a bad idea — and the truth is that at present we don’t know what the balance will be because we don’t know what the project will look like, how it will be operated, what it will do, or whether it will really be part of a more comprehensive solution.

Understanding the implications of multibillion-dollar decisions like this can only be done if the details of those decisions are openly debated in a transparent, public process. And they haven’t been.

Given the enormous unknowns about the actual costs, benefits, design, rules for operation and impacts, it is grossly premature to take a position either in favor of, or in opposition to, the peripheral canal. Everyone who struggles with California’s water problems understands that a “portfolio” of solutions is needed — a complex mix of concrete infrastructure and smart management using economic, regulatory, and educational tools. It would be irresponsible at this point for policymakers to fast-track a canal without knowing more, and without also approving the nonstructural recommendations of the Delta Vision Committee.

Some argue that the time for talk is past -_ indeed, there has been plenty of talk about water in California. But when it comes down to decisions to spend billions of dollars of either taxpayer or ratepayer money on a canal, the public has the right to know exactly what we’re getting.

Where is a peripheral canal going to be built and how? Who is going to pay for it? How much water would it move, and at what times of the year? What rules will govern its operation and who will strictly monitor and enforce those rules? What provisions will be put in place to change the operating rules as climate change increasingly alters water conditions and in the event that new science shows new problems or advantages?
What impact will the operations have on the Delta itself — both the humans and the ecosystems that rely on inflows to the region? Provide the answer to these questions, and then we can have a real debate about the pros and cons before shovels go in the ground. Good water policy in California will only come about if it is guided by sound science and transparent, eyes-open analysis.

Peter H. Gleick directs the Pacific Institute in Oakland and has been researching and writing on water problems for 25 years.