Hansen Flood Control Basin sits in Los Angeles County approximately 17 miles northwest of downtown Los Angeles, bounded by Foothill Boulevard to the north, Glenoaks Boulevard and Montague Street to the south, with its western extent reaching beyond Osborne Street and eastern boundary following Wentworth Street. Managed by the U.S. Army Corps of Engineers and the City of Los Angeles, the basin was authorized under the Flood Control Act of 1936 primarily for flood risk management to protect metropolitan Los Angeles County. The City of Los Angeles leased 1,450 acres within the basin for recreation purposes starting in 1948, with initial recreation development beginning in 1952, including the creation of Holiday Lake. The basin includes water remaining in borrow pits, establishing opportunities for fishing and picnicking activities alongside its primary flood control function.