Canal plan is floated for Delta woes

Most people have heard of the peripheral canal. Now it's time to meet the canal's new stepchild.

Amid a drought year and declining fish populations, California water officials are again sketching lines across the Sacramento-San Joaquin Delta, hoping to move fresh water to people and farms without wiping out endangered species.

The last attempt -- the infamous peripheral canal -- was pilloried by California voters in 1982. It was a relatively simple trench that would have carried a portion of the Sacramento River around the Delta to state and federal export pumps, and then to points south.

A generation ago, critics feared the canal was a south state water grab, though scientists now seem to agree that separating exported fresh water from the Delta's environment may be a good idea.

The new canal on the scene aims for something similar, but without actually taking water out of the Delta.

Instead of a self-contained canal that skirts the Delta, the new proposal diverts a portion of Sacramento River flows into a series of armored levees that wind through the center of the Delta. Most proposals would turn the south fork of the Mokelumne River and Middle River into this proposed canal.

Called "through-Delta conveyance," it also includes gates across some side channels to keep out salt water during high tides. Bolstered levees would be built to withstand earthquakes, floods and a predicted sea-level rise caused by global warming.

Scientists estimate it is likely that multiple Delta islands will flood by 2050 in a natural disaster. This would contaminate fresh water, now drawn from the Delta at large, which serves more than 23 million people and millions of acres of farmland.

That's why Gov. Arnold Schwarzenegger kept some form of Delta canal in his latest water bond proposal, announced Tuesday. But his new plan contains no money for the project. Instead, it directs the Department of Water Resources to work with any other agency that wants to build and pay for a canal.

The plan provides $1.9 billion for Delta ecosystem restoration programs, but only if there's progress on a canal in some form, said Mark Cowin, DWR deputy director. Without conveyance, he said, that $1.9 billion disappears.

"We need a comprehensive approach that addresses both ecosystem improvements and conveyance of water through the Delta. This provides a package to move both of those issues forward together," Cowin said.

This approach may give some breathing room to Delta residents and advocates who fear politicians are outrunning pragmatism on the canal question.

"We are 100 percent against this through-Delta armored conveyance," said Barbara Barrigan-Parrilla, campaign director of Restore the Delta, a Stockton-based coalition of local agencies and environmental groups. "We do not believe that rerouting our last major freshwater source -- the Sacramento River -- is going to restore the Delta. We think it will destroy the Delta."

The proposals outlined so far call for wider, taller levees along the entire route. To ensure that these levees are quake-tolerant, their foundations first must be excavated to remove unstable soils.

"That's going to be a huge undertaking," said Gil Labrie, a Walnut Grove engineer who works with Delta levee districts. "You're talking major engineering."

The plan also would take out potentially hundreds of acres of farmland along the 48-mile route, and may alter existing habitat along the way.

Surrounding areas are slated for massive restoration programs, but parts of the canal route already hold some of the richest habitat in the Delta.

The Mokelumne River's south fork, for instance, runs along the east side of Staten Island, purchased by the Nature Conservancy in 2002.

When asked recently about how a through-Delta canal would affect Staten Island, Dawit Zeleke of the Nature Conservancy said he had no idea.

"I don't know what the plans look like," said Zeleke, the group's regional director. "There are going to be tradeoffs, and we don't know what those are yet."

That was a common response among experts, because various proposals to fix the Delta have lately been emerging.

In addition to a Delta Vision Blue Ribbon Task Force appointed by the governor, the Department of Water Resources is preparing a Delta Risk Management Strategy to assess and prevent various threats to the estuary. Numerous agencies are also working on habitat conservation for the region.

When scientists convened last week to discuss a through-Delta conveyance, they said it's impossible now to know how such a facility would affect fish or water quality. But they said the sorry state of the estuary demands action.

While big changes could be harmful, they suggested that science has learned enough to experiment with small changes in water flows -- as long as policymakers are ready to reverse course if those steps don't work.

"We are a 600-pound gorilla in an egg store," said Bruce Herbold, a fisheries biologist with the U.S. Environmental Protection Agency. "That doesn't mean we can't walk through the egg store safely."

About the writer:

• The Bee's Matt Weiser can be reached at (916) 321-1264 or mweiser@sacbee.com.