Paul Rogers, environmental reporter for the San Jose Mercury News and managing editor for KQED Science, says in a story published today that a new analysis of the cost shows it might be as high as $67 billion. That number comes from a presentation last month to the Westlands Water District, which supplies more than 600 farms on about 1,000 square miles of the western San Joaquin. Rogers reports that a presentation from a Westlands staffer and a bond consultant presented three scenarios at a water district workshop last month:

Each [scenario] considered bonds issued for 30 years at 5 percent interest. They pegged the cost to build the tunnels at $18 billion, and overall cost with financing at $42 billion to $58 billion.

When the $9 billion more in wetlands restoration, monitoring and other costs are included, the grand total is $51 billion to $67 billion.

As Rogers points out, those numbers could have a huge impact on the debate over whether to build the tunnels. On one hand, agencies like Westlands and L.A.'s Metropolitan Water District will have to decide whether they and their rate-payers can handle the cost, even when it's not completely certain yet how much water the project will deliver. On the other hand, deficit-wary voters will be asked at some point to approve bonds to help pay for the plan's environmental improvements. Rogers quotes Mark Cowin, chief of the state's Department of Water Resources:

Cowin ... confirmed the estimates are accurate.

"The assumptions they've made are reasonable," he said. "But financing is confusing. There isn't any doubt about it. It's hard to relay information that the public understands. We need to be clear that if you add up the total debt service, that's a different type of calculation than the capital cost estimate. I would hope those two types of estimates aren't confused."

Cowin also poses what amounts to the perennial question in the debate over what to do to restore the Delta, safeguard imperiled fish species like chinook salmon and make sure that valley farmers and cities near and far can get a reliable share of the water that flows through the estuary:

"What are the costs if we don't do it?"

Mark CowinMark Cowin

Coming Face to Face With the Real Cost of the Delta Tunnel Plan