The dizzying complexity behind the state's plan to divert the Sacramento River into two massive tunnels is now on full display, following the release Wednesday of thousands of pages of new documents.
The documents connected to the Bay Delta Conservation Plan are considered preliminary drafts, released as part of the state's effort to help the public understand the project. It follows the release of a first round of documents about two weeks ago. Final versions will not be released until later this year.
The project proposes to divert a portion of the Sacramento River's flow into two tunnels, 35 miles long, beneath the Sacramento-San Joaquin Delta. The diversions would occur at three massive new intakes, all proposed near Courtland in Sacramento County.
The new plumbing is estimated to cost $14 billion, to be paid by farm and urban water agencies, and their ratepayers, that depend on Delta water from San Jose to San Diego.
The plan also calls for converting many Delta islands into 145,000 acres of restored wildlife habitat. That's about one-fifth of the entire Delta, one of the world's most productive farming regions. This is estimated to cost $4 billion, which the planners expect to be funded by all California taxpayers.
The goal of the plan is to reduce the number of fish killed at water diversion points operated by state and federal agencies near Tracy. Those diversions reverse the natural water flow direction in the estuary, confusing fish like Delta smelt and juvenile winter-run salmon, both endangered species.
Officials involved in the conservation plan, led by the California Department of Water Resources, assert that the new diversions will better protect fish because they will feature modern fish screens, and will pump water only when least harmful to fish.
But the documents released Wednesday shed some light on the real complexity behind those basic goals. Some reviewers will be left wondering if a comprehensive recovery of the Delta's endangered species is really possible.
One such document is the "Effects Analysis," a crucial chapter in the plan that describes how project operations will alter the environment.
The chapter is 656 pages long, not counting 18 appendices. Just one of those appendices -- dealing with effects on fish movement -- is 406 pages long.
Among many other findings, it reveals that the south Delta pumps near Tracy will still be used to divert water in dry years. As a result, Delta smelt will still be killed at a similar rate under those conditions as they are today.
Asked how this kind of result amounts to a conservation plan, officials said reviewers must consider the entire range of effects.
For instance, under other conditions when water diversions occur at the new northern intakes, fewer smelt will be killed. And the thousands of acres of restored habitat are expected to help breed more smelt and more food for them, thereby reducing the significance of each new smelt death.
"We don't expect to have improvement in every time period, every season, every life-history period for each species," said Mark Cowin, director of the Department of Water Resources. "But we do intend to have a net effect that provides for meeting the recovery standard."
Fishery advocates note, among other critiques, that there is a lot of uncertainty about whether the promised habitat conservation will produce sufficient benefits to offset the project's negative effects.
"Proponents of the peripheral tunnels are asking us to just trust them when it comes to keeping our salmon fishery alive," said John McManus, executive director of the Golden Gate Salmon Association. "We're skeptical, to say the least."
The new documents can be found online at http://www.baydeltaconservationplan.com.
Contact The Bee's Matt Weiser at (916) 321-1264. Follow him on Twitter @matt_weiser.