FREMONT -- A big earthquake along the Hayward Fault could rupture the Alameda County Water District's aging pipelines and leave Tri-City area residents without water right at a time they would most need it, the agency's officials say.
That alarming but all-too-plausible scenario has put the district in a race against time to upgrade 15 large pipelines buried along an 8½-mile stretch of fault line in Fremont and Union City.
To avoid such a crisis, the Fremont-based public agency plans to break ground next summer on the pipeline improvement project.
"These projects will help to keep the water flowing and allow us to recover more quickly after an earthquake," said John Weed, the district's board president.
The upgrade work is budgeted between $10 million and $13 million, said Robert Shaver, the district's engineering assistant general manager. The agency, which supplies drinking water to about 331,000 people in Fremont, Newark and Union City, expects to complete the project by December 2014.
"We want to get this work done as quickly as possible, because you don't know when the next earthquake is going to happen," Shaver said.
The Hayward Fault on average has caused a major earthquake about every 140 to 160 years for the past 1,800 years, said David Schwartz, a U.S. Geological Survey geologist. The last time that happened was in 1868 -- 144 years ago -- when a 7.0 quake centered in Hayward killed dozens of people.
"It (an earthquake) might go in five years, or in 40 years, or it might go tomorrow," Schwartz said. "But it will go sometime, that's the only thing we know with certainty."
The fault runs 55 miles through the East Bay, from as far south as Fremont's Warm Springs district to as far north as San Pablo Bay, where Contra Costa, Solano, Sonoma and Marin counties meet, Schwartz said.
The Alameda County Water District's operating expense budget for 2012-13 is $69 million, with an additional $28 million in capital expenditures, Shaver said. The pipeline upgrade is one of several infrastructure improvements funded by a $45 million bond the agency issued earlier this year..
More than half of the district's 15 pipelines are at least 40 years old, with the oldest constructed in 1957, officials said. Those pipes, whose diameter sizes range from 12 to 48 inches, are a high priority because they transport larger amounts of water from the district's major production and storage facilities than other ones, Shaver said.
More than 80 other pipelines -- most of which are six or eight inches in diameter -- are not part of this particular project, but agency officials aim to upgrade them in a separate plan proposed to start in a few years.
"We have prioritized our most important pipelines to be retrofitted first," Shaver said. "We're trying to replace enough of these pipeline segments so we can maximize water service on both sides of the fault after an (earthquake)."
In the project planned to start next summer, crews will replace seven pipes with a grade of steel that should absorb stress and movement generated during a large earthquake, preventing them from rupturing, district officials said. For eight other pipelines, workers will attach special equipment that will allow water to bypass damaged ones and flow across the fault after a natural disaster, Shaver said.
One pipeline site is in Union City and all others are in Fremont. The district plans to hold neighborhood meetings to notify residents of the street closures and traffic disruptions that will occur once construction starts, Shaver said.
Contact Chris De Benedetti at 510-353-7011. Follow him at Twitter.com/cdebenedetti.
The Alameda County Water District is planning to upgrade some of its aging large pipelines in southern Alameda County.