Many wonder if Anderson Dam’s closure will cause water-use restrictions

With February as dry as it's been and as we head into March, many in the South Bay are worried about the announcement that Anderson Dam may be closed for years for seismic repairs. Anderson Dam, Santa Clara County's largest reservoir, holds more water than all of Valley Water's nine dams combined, making it by far, a critical water supply for two million South Bay customers. 

The Federal Dam Safety Division is demanding that the dam be completely emptied by October first, to prevent collapse should an earthquake of 7.2 magnitude or stronger cause its likely failure and devastation to downstream communities. 

The problem is, once dams are built, if there's land in front of them, often times the land is developed. Near the Anderson Dam, construction continues in its shadow, despite years of knowing this. 

For customers, the key question is: Will we have enough water or face severe restrictions? 

"Our groundwater basin, right now, is the healthiest it's been in many years an so, we're ready to respond and provide that water to our community," said Valley Water District Executive Nina Hawk. 

The District also has a massive storage  in Kern County from which it can supply its customers. 

"That's more than we would use in one year. That water is available for us to bring into the county for use for our residents coming into this year," Hawk said.

Because District customers have greatly reduced water use as a matter of habit, the District insists that it has more than enough water to meet normal usage while retrofitting of the massive dam is ongoing. 

 "It's anticipated that this construction could take anywhere from two to potentially five years but it is determined upon the permitting process, the environmental regulations and make sure that we do so in a safe manner and we do so in compliance with the laws and the regulations," said Hawk.

The dam would be partially deconstructed and its infrastructure replaced with far stronger materials and recovered with earth to complete the process. This proecess is said to be a faster and more economic replacement than if earth, steel and concrete were used.

"We have many water supply sources. Currently we have both imported water, ground water and recycled water that's used within the county," said Hawk.

The district is still trying to help environmental agencies solve how to maintain Coyote Creek's critical wildlife and fish habitat while its main source is cutoff.    

Tom Vacar is a reporter for KTVU. Email Tom at and follow him on Twitter @TomVacarKTVU