Sutter levee costs could climb

Sutter County is in what one county supervisor calls a race against time as the state and federal government move to remap the area, including Yuba City, into a floodplain, while costly levee problems mount.

Supervisor Jim Whiteaker warned at a board study session Monday that if the Department of Water Resources maps Sutter County into the flood plain, then no jobs are going to be located in Sutter County, and no houses are going to be built in the floodplain.

“I see it as a race against time for Sutter County,” said Whiteaker, who said it was important that citizens work together.

Whiteaker’s statement came amid a sobering presentation on levee issues by engineer David Peterson, principal with Peterson, Brustad & Pivetti Inc.

Floodplain maps to be released this fall will likely show Yuba City and Live Oak in a proposed flood zone for the first time, while other maps to be released at about the same time will move the remapping of south Sutter County’s proposed flood zones farther along.

The county will have to fix the levees to get off the maps. But core drilling of Sutter County levees that protect Yuba City is uncovering problems that could make a previous $375 million levee repair estimate too low, Peterson told Sutter County supervisors.

While the core drilling data are not expected to become available until late August, the information available is sobering, said Peterson.

The drilling is turning up a layer of boulder and gravel-laden mining debris under the Feather River levee on the Sutter County side that could cause problems with underseepage - a term for water flowing through or underneath the levee that is potentially dangerous if it weakens the structure.

Sutter Bypass levees could also have more underseepage problems than suspected. A trench along the levee, plus sandy soils, could require work along the entire section of bypass.

“It’s sobering because we have to touch more miles of levee than I had thought,” Peterson said in an interview.

Peterson made what he called a “guess-timate” in 2006 that put the repair bill at $375 million to fix roughly a third of the 70 miles of levees that protect Yuba City.

While Sutter County’s levee repairs are not expected to begin until 2010, Federal Emergency Management Agency remapping is already well under way for Sutter County, with two studies aimed at setting new flood insurance rate maps.

Draft map revisions issued last year showed much of Sutter County south of Stewart Road to be in a special flood hazard area. The same area will get updated draft flood insurance rate maps in October, the next step in a lengthy process to remap the area’s flood plain.

Also this Fall, the department will move northward with its flood map efforts, releasing a draft map revision for Sutter County north of Stewart Road that is likely to propose maps that put Yuba City and Live Oak into the floodplain.

Peterson said he suspects that Yuba City will be shown as a special flood hazard area along with Live Oak.

Once the maps are finalized, residents in special flood hazard areas will have to purchase flood insurance if they have federally backed mortgages. The bill could be as high as $2,246 a year for a policy that covers $250,000 in structure damage plus $100,000 in contents, but drops to $1,251 for homeowners who have flood insurance policies in effect when the map changes become final.

The same coverage currently costs $317 for Sutter County residents who get preferred rate policies.