San Francisco will have to do without Hetch Hetchy water for the next 2 months

SAN FRANCISCO (KTVU) - The main water supply for San Francisco and other Bay Area cities will be cut off for the next two months starting today due to safety inspections.

Officials have drained Mountain Tunnel and are now ready to survey and make necessary repairs to the 100-year old artery. It connects Bay Area faucets to the Hetch Hetchy Reservoir in Yosemite National Park, which provides San Francisco and the Northern Peninsula with 85 percent of its water. The 19 mile artery is at risk of collapsing.

Typically San Francisco receives 15 percent of its water from local reservoirs, including the San Andreas and Crystal Springs Reservoirs. KTVU's Tara Moriarty visited the Harry Tracy

Water Treatment Plant in San Bruno where normally the facility treats and cranks out 40 million gallons of water but today, it was producing twice that amount.

"This is where the 80 million gallons is coming in right now," said Betsy Lauppe Rhodes, a spokesperson for the SF Public Utilities Commission, as she pointed to an underground mini Niagara Falls of sorts. The plant has been preparing for months for the Mountain Tunnel closure by upgrading its filter systems.

"We've got plenty of water in our local reservoirs and so customers are going to turn on their tap and they're really not going to notice a difference," explained Charles Sheehan of the SFPUC. "We're going to be conducting an assessment [of the Mountain Tunnel] to see if we need to build a new tunnel in the future or if we need to periodic shutdowns each year to do repairs and upgrades,"

The inspection to the Mountain Tunnel is critical as a collapse in the system could take $270 days and cost more than $100 million to repair. To replace the artery entirely, it would cost $620 million.

The pipeline normally closes for maintenance for one month each year, but the last time it closed for two months was in 1980. That time the shutdown was also due to an inspection and things went smoothly.

For now, SFPUC officials say treatment plants in San Bruno, Sunol and Half Moon Bay will pump out 150 million gallons of clean water each day to compensate for the loss of Hetch Hetchy's stores.

There are fish and other wildlife that inhabit the local reservoirs but added filters to the treatment plants should alleviate any discernable differences in the quality or taste of the water.