FRESNO — California water officials said Wednesday that a $14 billion twin-tunnel plan for the Sacramento-San Joaquin Delta would restore the ecosystem and reduce deaths of threatened fish, although during dry years the delta smelt would be killed at the same rate as today.
During water-scarce years, the existing pumps in the south portion of the delta would continue to divert most of the water, cause reverse flows and kill the fish that get caught in the machinery, according to an analysis in new draft chapters released by the California Resources Agency.
Officials said the plan does provide a cumulative net gain in fish populations over time. There would be significant improvements for the smelt during wet years, they said, because water would be diverted from the north portion of the delta, where fish would not be sucked into deadly pumps.
In addition, the creation of thousands of acres of tidal wetlands would increase smelt habitat and food for the species.
"We don't intend to have improvements in every season," said Mark Cowin, director of the California Department of Water Resources. "We do hope to have a net effect that provides for fish recovery."
But environmentalists said the plan continues to rely on taking too much water out of the delta, and habitat restoration would not be enough to offset the impact of the tunnels on fish.
"It's clear we need to reduce diversions from the delta, and the plan does not contemplate reduced diversions, which seems really problematic," said Doug Obegi, an attorney with the Natural Resources Defense Council. "There's very little evidence that restored habitat will help fish."
The twin tunnels, Obegi said, could also create new hotspots where predator fish would congregate to eat the smelt.
Promoted as a way to deliver water while protecting the environment, the Bay Delta Conservation Plan is a federal and state initiative that includes a proposal unveiled by Gov. Jerry Brown in July.
The 35-mile twin tunnel project would carry water south to vast farmlands and thirsty cities. It would have a total capacity of 9,000 cubic feet per second and its three proposed intakes would be located along the Sacramento River between Freeport and Courtland.
Construction and operation costs of almost $20 billion would be covered by water contractors.
The plan also calls for creation of more than 100,000 acres of new habitat — floodplains, tidal marshes and grasslands — at a cost of $3.2 billion, to be paid by taxpayers. About 47 square miles of that habitat would be created in the next 15 years.
Existing water projects pump water from the delta to 25 million people and 3 million acres of farmland. But in recent years, as fish populations continued to plummet, federal management plans have limited the amount of water that can be pumped, in order to protect fish species.
Without the new plan, officials say, the ecosystem will continue to decline, as will water deliveries.
"The premise of the status quo is unsustainable from the environmental and economic perspective," said Michael Connor, the commissioner of the U.S. Bureau of Reclamation, which runs the federal water project in California.