Bay Delta water diversion plan could harm fish temporarily, state analysis says

03/01/2012 12:00 AM

02/29/2012 10:35 PM

A controversial project to alter water diversions in the Sacramento-San Joaquin Delta could initially harm some smelt and salmon species, but state officials say those fish will benefit in the long run.

The Bay Delta Conservation Plan calls for building two giant tunnels, 37 miles long, to divert a portion of the Sacramento River's flow out of the estuary and directly to existing state and federal diversion pumps near Tracy. Those pumps send drinking water to 25 million Californians and more than 1 million acres of farmland.

On Wednesday, the state Natural Resources Agency, which is leading the project, released more than 5,000 pages of new analysis.

The documents reveal, in part, that longfin smelt and winter-run chinook salmon initially could decline in population as a result of diversions into the tunnels and other water management changes. The diversions would occur at five locations between Freeport and Walnut Grove.

But the planners assert that 110,000 acres of new wetland and floodplain habitat, restored over the project's 50-year span, would reverse declines by offering more breeding and feeding area.

The conclusion is explained in a document called the "Effects Analysis," one of many chapters drafted as part of a larger planning document.

"We're satisfied and pleased this analysis is showing there's a plan out there that will work," said Mark Cowin, director of the state Department of Water Resources, which would build and operate the new diversion system.

Some environmental groups, however, said the new analysis is deeply flawed.

Gary Bobker, program director at the Bay Institute, said there is no hard evidence new habitat would offset losses to fish species. The documents released Wednesday acknowledge this uncertainty.

Bobker called the emphasis on new habitat misleading. What smelt and salmon need to thrive, he said, is the right kind of water flows in the estuary and its tributaries.

The longfin smelt is a threatened species under the state Endangered Species Act, while the winter-run chinook is endangered under the federal act.

"There's a high risk of extinction for these species," Bobker said. "It seems pretty irresponsible to put them at further risk by going down the route of degrading flow and relying on wetlands instead."

The Bay Delta Conservation Plan has been in the works for six years. It is one of the largest and most complex habitat conservation plans ever in the United States, involving not just the Delta but most of its watershed.

The plan has two primary goals: improve wildlife populations and habitats; and ensure water deliveries are more reliable and protected from disasters, such as floods, earthquakes and sea level rise.

Cowin emphasized the state is not ready to commit to the size and details of the project. The analysis focuses on the largest alternative, capable of diverting water at 15,000 cubic feet per second.

Other documents released Wednesday include draft chapters for an environmental impact study expected to be completed in July.

The total project is estimated to cost $25 billion when habitat improvements and operating costs are included. Tunnel construction alone is predicted to cost $14 billion. About 30 local water agencies from San Jose to San Diego would benefit from the project. They would pay to build it, likely by increasing the water rates charged to their customers.

The plan must be approved by both state and federal wildlife agencies. If that occurs, the administration of Gov. Jerry Brown asserts it has legal authority to build the project without a public vote.

State officials said the plan is designed to be adaptable as it moves forward. In other words, if evidence shows new habitat is not helping enough, changes to the system would be required.

To view Bay Delta Conservation Plan documents, visit:


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