The Helix Water District just wrapped up its Tunnel Hills water tank restoration project, ensuring thousands of East County residents' drinking supply.
"Water tanks are an essential part of any potable water system," Tim Ross, Director of Engineering with the Helix Water District said.
The Tunnel Hills water tanks are two of 25 water tanks the Helix Water District manages across San Diego County. They serve about 55,000 customers.
The two tanks hold about 3 million gallons of water combined. The water they hold is not only used for day-to-day purposes, but also for emergencies.
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"If there is a fire event, you know there's enough water to help the fire department fight the fires," Ross said.
Since the Helix Water District is one of the oldest water districts in San Diego, Ross said many of their tanks are approaching their expiration date. He said every five years they conduct inspections to determine if the tank needs to be replaced or restored.
"It could be millions of dollars depending on which option you choose," Ross said.
Two years ago, they began restoring the Tunnel Hills tanks to bring them up to current standards. Both tanks sit at the top of a hill in Lakeside.
The rehab project included new coating, piping, drainage and a new roof on one of the tanks. However, the biggest improvements involved seismic retrofits.
"We've added seismic restraints at the bottom of the tank so that the tank will not fall off its foundation," Ross said.
He said since the tank's diameter is more than 100 feet wide, in the event of an earthquake it could generate a four-foot-tall wave, which could blow off the roof off the top of the tank.
"To offset those potential risks, we actually raised the height of the tank five feet and then we installed a new aluminum dome roof," Ross said.
Ross said full replacement of both tanks would have cost them $10 million, but the restoration project reduced that cost to $3.6 million.
He said the money they use to make the repairs comes directly from the water bills their customers pay.
"We're constantly working on the maintenance so that, you know, when you turn on your tap, what's coming out is safe, clean, reliable water," Ross said.
He said the repairs have extended the lifetime of the tanks by more than 50 years.
