SAN MATEO, Calif. (AP) - The $4.6 billion project to overhaul the water system that serves more than 2 million customers in the San Francisco Bay area is celebrating a milestone.

     

San Francisco and San Mateo County officials were on hand on Tuesday at the Lower Crystal Springs Dam in San Mateo County, which was raised as part of the Hetch Hetchy Water System Improvement Program.

     

The program aims to secure the water supply from the Hetch Hetchy Reservoir in Yosemite National Park in case of an earthquake.

     

The project - administered by the San Francisco Public Utilities Commission - has reached the midway point, with roughly half the construction budget spent. Voters approved it nearly ten years ago.

     

It is expected to be completed in 2016.

      

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