Crystal Springs reservoir is long and narrow because it lies atop the San Andreas Fault . The famous fault runs right through the Crystal Springs Reservoir . Satellite images and maps show the long narrow San Andreas rift continuing north of San Francisco in Tomales Bay , in Point Reyes National Seashore in a straight line . The Crystal Springs Dam survived both the 1906 earthquake and the 1989 Loma Prieta quake with no damage whatsoever , according to the U.S. Geological Survey
1906 earthquake
1906 San Francisco earthquake
Crystal Springs Park, California