Free Republic

a debate is emerging between the San Francisco Public Utilities Commission (PUC) and the Bay Area Water Supply and Conservation Agency over the potential disaster if the 89-year-old Mountain Tunnel, which supplies 2.6 million Bay Area homes and businesses with water, collapses. The PUC acknowledges that the tunnel does have a chance of "catastrophic collapse," which would require repairs costing $100 million or total replacement, costing up to $630 million. But the PUC’s 10-year-old 4.6 billion water system improvement program did not include the Mountain Tunnel in its plans. ... The risk right now is that the tunnel lining could...

Mountain Tunnel, a key part of the Hetch Hetchy water system - which supplies 2.6 million Bay Area residences and businesses - is at risk of a "catastrophic collapse" and will cost more than $100 million to repair or up to $630 million to replace, according to the San Francisco Public Utilities Commission. City officials have known for 25 years that significant work is needed on the 19-mile-long tunnel just outside Yosemite National Park in a steep, hard-to-access wilderness area. They considered making it part of the PUC's decade-old, $4.6 billion water system improvement program, which is now more than...