The Santa Fe Dam is a large flood control structure, serving a drainage area of 236 square miles. It is meant to hold back mud and debris flows that sometimes decend from the nearby San Gabriel Mountains, which have wiped out communities in the past. The dam and the sacraficial debris retention basin behind it, is part of a network of similar structures, which include some of the largest dams in the nation. Built by the Army Corps of Engineers, the Santa Fe Dam is over four miles long.
Santa Fe Dam