A levee break flooded farm fields with ocean water, forced the evacuation of nearly 300 people and sent authorities scrambling to safeguard drinking water for cities as far away as Los Angeles.
Officials said it was unclear how the break occurred. The waters were being contained in part by an embankment of railroad tracks from the Burlington Northern-Santa Fe railroad.
After the breach, truckers began hauling boulders to slow the flooding and stabilize the levee, officials said. They estimated it could take two days to repair the damage.
The break, which a fisherman noticed Thursday morning, started small and then grew to 300 feet, sending Middle River waters carrying saltwater from the San Francisco Bay pouring into a freshwater delta. Drinking water is channeled from the delta — 738,000 acres of wetlands and waterways — to much of California.
Water deliveries from delta cut
The federal Bureau of Reclamation quickly cut its water exports from the delta by 80 percent and increased flows from the Sacramento River to stabilize the freshwater supply, said spokesman Jeff McCracken.
“Right now we’re just keeping our fingers crossed that we can get this thing stopped as soon as possible,” McCracken said.
Officials with the Metropolitan Water District, which imports water to cities in Southern California, said there was enough water stored at reservoirs for its 18 million customers to weather the break.
The San Francisco Public Utilities Commission said its water supply was not threatened.
Farmers, workers evacuated
Authorities evacuated the area, but there are few homes in the rural farming region. Officials said there could be as many as 300 migrant workers living in camps nearby.
“It was like an ocean. I’ve never seen anything like it,” Giovanni Stagi said after trying to save farm equipment from the rising water.
Besides potentially threatening drinking water for major California cities such as San Jose and Los Angeles, the saltwater also threatened freshwater fish, some of them rare, and farmers’ fields in the San Joaquin Valley.
There appeared to be no immediate danger of a fish kill, and some young fish may benefit from being able to hide in the suddenly submerged crops, said Mike Wintemute of the state Department of Fish and Game.
The marshy delta was largely drained by farmers a century ago, creating a series of artificial islands protected by makeshift levees.