The construction is related to a seismic upgrade of the regional Crystal Springs/San Andreas Transmission System. The construction is slated to be completed this fall, SFPUC officials said.
The project is part of a larger $4.6 billion Water System Improvement Program to repair, upgrade and seismically retrofit the Hetch Hetchy regional water system.
The Crystal Springs Reservoir serves as an emergency and supplemental water source within the system for San Francisco and northern San Mateo counties.
