The San Francisco Public Utilities Commission is seeking a contractor to replace the 85-year-old Calaveras Dam near Fremont and Sunol in the East Bay for a project estimated to cost $434 million. Photo: Courtesy of SFPUC The Calaveras Dam normally supplies nearly half the water to the Bay Area. Notice went out on Jan. 31, with a pre-bid meeting scheduled for Feb. 15 and contract award at the end of March. Construction, estimated to cost between $250 million to $300 million, is set to start in the summer. Prequalified prime contractors eligible to bid on the project include Dragados USA,
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.