Storm Expected to Test Levees in Delta Area

Residents of the Sacramento River Delta braced Thursday for what some fear could be a wet and destructive weekend as a rare combination of high tides, heavy winds and rising waters converge on the state’s most critical water supply system.

The incoming storm threatens large areas of coastal Northern California, where swollen rivers have already reached near flood stage in Sonoma, Mendocino and Humboldt counties.

“Looks like we’re setting up for a major winter storm, beginning late tonight,” said Rick Canepa, a meteorologist with the National Weather Service for the San Francisco Bay Area and Central Coast.

A high-wind watch was posted for late Friday afternoon through Saturday morning in the Bay Area.

The 738,000-acre Sacramento-San Joaquin Delta is no stranger to flooding. A 1927 deluge destroyed a bridge and much of the community of Rio Vista. In 1972, hundreds of homes were destroyed when a levee broke outside the town of Isleton.

But state and federal flood experts are especially concerned this year because of the deteriorating condition of the delta’s 1,100 miles of levees -- some more than a century old -- in the centerpiece of the state’s most precious water supply, responsible for irrigating farmlands in the Central Valley and slaking the thirst of Southern California.

“We expect the river at Rio Vista to reach about 10.5 feet this weekend and the flood stage there is about 12 feet,” said California Department of Water Resources spokesman Don Strickland. “The concern is that the rain that has already saturated all the levees, combined with strong southwest winds, will put a lot of extra pressure on the levees that are not in the greatest shape to begin with.”

Signs of the weakening levees had already shown up here Thursday as workers along the Georgiana Slough, a waterway about a mile from Isleton, struggled to repair a leak in the levee that flooded adjacent farm fields.

By building a small cofferdam to hold back the leaking water, called a “boil,” the workers successfully stemmed the flow. But Andy Giannini, superintendent of the Brannan-Andrus Levee Maintenance District, said he would continue to patrol the 30 miles of levees under his control, looking for more ruptures until the new storm arrives.

“The insidious thing about a boil is that you can’t always see it until it has done a lot of damage,” Giannini said.

In the calm between two severe storm fronts -- one that finally let up Wednesday and another expected to begin tonight -- homeowners in the Vierra’s Resort compound east of Rio Vista constructed sandbag barriers and moved valuables to higher ground in anticipation of the incoming heavy weather.

“We flooded in 1997 and lost everything. So we are not going to take a chance this year,” said Patty Locicero, 56. By Thursday evening, Locicero and her husband, Joe, 71, had moved two boats and most of their valuables out of their home.

Neighbor Bob Hadden said he had been through six floods in the central delta region 40 miles south of Sacramento.

“You think I’d be smart enough to move,” Hadden grumbled as he lugged his motorcycles up to the second story of his frame home.

Cindy Matthews, a Department of Water Resources hydrologist, said the expected peak of the storm Saturday afternoon will come just as the month’s highest tide reaches the delta communities of Rio Vista, Isleton and Walnut Grove.

“By 3:15 p.m. Saturday,” Matthews said, “the flood levels and the tide will both be at their highest. The winds will be driving waves against the levees.” The result, Matthews said, could be a giant collision as walls of water, the tidal mass rushing into the river and the flood flow straining to get out, meet at Rio Vista.

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Times staff writer Jocelyn Y. Stewart in Los Angeles contributed to this report.