The conduit, which will run along Polhemus Road in unincorporated San Mateo County, will reinforce a current bypass pipeline that is susceptible to damage in the event of a major earthquake, according to the commission. The pipe provides water to Peninsula residents through the Hetch Hetchy water system.
"This project marks the first of many capital improvement projects that the commission will be asked to approve in the coming fiscal years to seismically reinforce the system, create redundancy to better maintain the system, sustain our pristine water quality, as well as providing our customers an adequate water supply in drought years," said Ed Harrington, the commission's general manager.
Construction of the tunnel is expected to take around two years.
