The California Coastal Conservancy reached agreement in December to bypass an obsolete dam on California�s Carmel River rather than dredging and buttressing the 90-year-old structure. The $84-million reroute and dam removal project will divert the river around the 106-ft high concrete arch San Clemente Dam built in 1921. The basin has since been swamped with 2.5 million cu yds of sediment, thereby reducing storage capacity from 1,425 acre-ft to 125 acre-ft. In 1992, the California Dept. of Water Resources Division of the Safety of Dams issued a safety order because of possible failure from a maximum flood event or an
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.