Sepulveda Dam is a flood risk reduction project located in the south-central portion of the San Fernando Valley, just northwest of the junction of the Ventura Freeway (U.S. Highway 101) and the San Diego Freeway (Interstate Highway 405). It lies across the Los Angeles River, 43 miles above the mouth of the river, and six miles above the confluence of Tujunga Wash and the Los Angeles River.