Spending $250 million on anything raises eyebrows.
But since it means San Franciscans will be able to drink water after a massive earthquake, it is money well spent, according to the San Francisco Public Utilities Commission.
The agency recently approved construction of a 3.5-mile-long water delivery tunnel that is seismically superior to an existing 78-year-old tunnel. Like the aging tunnel, the new tunnel will deliver water from the Hetch Hetchy Water System to 2.5 million Bay Area customers.
The existing tunnel is called The Irvington Tunnel.
The new tunnel, appropriately, will be called The New Irvington Tunnel.
The new tunnel will be placed parallel to the existing tunnel, “between the Sunol Valley south of Highway I-680 and Fremont,” the agency said.
“The new tunnel will provide an additional seismically-designed connection between water supplies from the Sierra Nevada Mountains and the Alameda Watershed to Bay Area water distribution systems,” the agency said in a statement.
The new tunnel will also allow the SFPUC to shut down the existing tunnel for much-needed maintenance and repairs, the agency said.
The tunnel will be excavated using conventional mining methods, including a road header and, in sections of hard rock, controlled detonations, the agency said.
The finished tunnel will be horseshoe shaped and have an internal diameter of approximately 8.5-to-10.5 feet, it said.
The SFPUC expects to select a contractor by early January. Construction is scheduled to begin in April 2010 with completion in early 2014, it said.