Lake Elsman is a 6,200-acre-foot (7,600,000 m3)[1] reservoir, created by an earthen dam called Austrian Dam[5] on Los Gatos Creek in the Santa Cruz Mountains of California.[2] At several points it is over 140' deep[6] and its normal surface area is 96 acres.[2] It provides 12% of San Jose Water Works’ total water capacity in some years.[6] The lake and dam is owned by the San Jose Water Company,[6]
In 1988 and 1989, two earthquakes at M=5.3 and 5.4 respectively occurred at Lake Elsman that transferred stress that led to the 1989 M=6.9 1989 Loma Prieta earthquake.[7]
Austrian Dam
Construction of the Austrian Dam was completed in 1950.[2] Beneath the reservoir are the remains of the settlements of Austrian Gulch and Germantown.[8] The dam is more than 900 feet (270 m) long and 180 feet (55 m) high.[6] The dam was damaged in the Loma Prieta quake.[9] The performance of Austrian Dam during that earthquake reinforces concerns about damage to the tops of earth dams by earthquakes.[9]