San Francisco water officials were inspecting for earthquake damage Monday at a dam under construction in the South Bay after a small temblor shook the area the night before.
The U.S. Geological Survey reported a 3.4-magnitude quake just after 7 p.m. Sunday about 4 miles beneath the Calaveras Reservoir, which sits east of Milpitas on the rural Santa Clara-Alameda county line. It’s part of San Francisco’s sprawling water supply system.
Officials with the San Francisco Public Utilities Commission said the earthen dam, which is being built to replace an older dam at the reservoir, probably wasn’t affected by the earthquake. But they sent inspectors to check on the structural integrity of the dam as well as a concrete spillway, intake tower and boat ramp as a precaution.