Fiber optic cables were laid between facilities associated with San Francisco’s Hetch Hetchy Reservoir to help reduce communications blackouts.
The belowground cables were installed between the San Francisco Public Utilities Commission-owned town of Moccasin in Tuolumne County and various nearby powerhouses that help harness and transmit hydroelectric power from the dam in Yosemite National Park.
City operations are fueled by the power. San Francisco and the Peninsula take much of their tap water from the reservoir.
The cable was laid because the existing microwave communications system is sometimes knocked offline during powerful storms.
One such storm occurred during installation of the cables and led to three days of work delays that contributed to 15 percent in cost overruns, SFPUC documents show.
Another cause of delays and cost overruns was a decision made to run backup generators for 25 days to allow some electricity operations to be powered down for safety reasons while cables were installed.
The project cost $2.76 million dollars, which will be paid for by the SFPUC. It was originally budgeted to cost $2.4 million.