Pacoima Dam is a concrete constant angle arch dam on Pacoima Creek (Pacoima Wash) in the San Gabriel Mountains, in Los Angeles County, U.S. state of California.
The dam is situated in a canyon five miles (8 km) northeast of San Fernando above the San Fernando Valley. The dam is 365 feet (113 m) tall and its reservoir has a capacity of 3,777 acre feet (4,659,000 m3).
The tall dam was built by the Los Angeles County Flood Control District which became part of the Department of Public Works and was completed in 1928. At the time of its construction, it was the tallest arch dam in the U.S. It is also known as Reagan Dam.