Hetch Hetchy water flowing again after tunnel inspection

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The San Francisco Public Utilities Commission is now delivering 80 million gallons daily from the Harry Tracy and Sunol Valley water treatment plants after a 60-day hiatus. The shutdown was part of an inspection of the 19-mile Mountain Tunnel, which snakes through Tuolumne County just outside of Yosemite National Park.

After two months offline, and myriad complaints about the replacement’s funky taste and odor because of an algae byproduct issue at a local reservoir, residents’ beloved Hetch Hetchy tap water is back. The PUC had planned to restore its service March 7, but after a swell in water levels at local reservoirs because of winter storms, the date was pushed back. In the meantime, the PUC drained down local reservoirs..We have so much water locally in our reservoirs that we wanted to drain them down..

Inspection crews found the waterway in better shape than expected, potentially freeing the PUC from having to build a new tunnel. Crews made patch repairs during the inspection, smoothing sections of the tunnel..

The more than 650 cubic feet of water now rushing through Mountain Tunnel every second has also restored power generation at Moccasin Powerhouse and Kirkwood Powerhouse..

The PUC is currently generating 5,400 megawatt hours per day, and the agency expects to surpass its average annual generation of 1.6 billion kilowatt hours because of above-average snowpack, Sheehan said. Record levels of water are rushing through the powerhouses, generating more electricity for Bay Area residents.

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