water

The Massive 5-Million-Gallon Water Tank You Will Never See

The San Diego County Water Authority is constructing a huge underground water tank in Mission Trails Regional Park

NBC Universal, Inc.

San Diego hiking enthusiasts might have to share part of their favorite trail with a cement mixer for the next year. The San Diego County Water Authority is building a massive 5-million-gallon concrete water storage tank, called a flow regulatory structure. You will never see it once it’s completed.

One of the hiking trails in the northwest corner of Mission Trails Regional Park is closed and there are trail detours on other parts.

“It’s very important because we have a lot of big trucks driving in and out. There’s steep hills,” San Diego County Water Authority Senior Engineer Aaron Trimm said.

Construction began in February as the pandemic took over California. It’s expected to take another year to complete. As of Friday, more than a dozen concrete pillars were sticking up out of the ground like a building straight out of Ancient Rome.

“I love my job. I love being out here,” smiled Trimm. “I know it sounds simple with the concrete tank but there’s a lot that goes into this job.”

The structure will be another place for the SDCWA to store water before sending it down the pipeline to its member agencies, and ultimately to homes.

Once completed, it will hold enough water to fill seven Olympic-sized swimming pools. Trimm said they will bury the giant tank and plant California natives to match the surrounding landscape at Mission Trails Regional Park, so when they're finished you will never know it's there.

“Once they grow back in, you won’t even know the tank’s here,” said Trimm.

That’s good for the hikers who are currently being diverted around the construction site.

“We’re excited about getting this done and getting this filled back in and making sure that no one even knows we’re here,” concluded Trimm.

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