Sepulveda Dam, Flood control dam in Los Angeles County, United States.

The Sepulveda Dam is a flood control structure in Los Angeles County that impounds water from the Los Angeles River and protects surrounding neighborhoods from flooding. The dam itself extends across a width of roughly 4500 feet (1370 meters) and forms a large retention basin that collects water during the rainy season and releases it slowly afterward.

The U.S. Army Corps of Engineers completed the Sepulveda Dam in 1941 at a cost of $6,650,561, following the 1938 Los Angeles River flood that killed 144 people. It was the second of the two dams built for the Valley, after Hansen Dam in 1940. Channelization of the river began in 1938, and the engineered 51-mile waterway was finished by 1960.

The basin holds Woodley Park, opened in 1975, with the Leo Magnus Cricket Complex, a dog park and group picnic areas. Lake Balboa Park, also called Anthony C. Beilenson Park, has a 27-acre lake filled with reclaimed water from the Tillman Water Reclamation Plant and rows of 'Pink Cloud' flowering cherry trees. The 6.5-acre Japanese Garden sits on the plant's grounds.

The grounds sit along Burbank Boulevard in Encino and offer daytime access to walking and cycling paths around the basin. Visitors find parking near the sports fields and should note that trails in the basin can be muddy after heavy rain.

During the 2028 Summer Olympics, the area around the dam will host basketball 3x3, BMX racing and freestyle, modern pentathlon and skateboarding. The basin has also become a popular location for filming movies, music videos and car commercials.