Sepulveda Dam, at the headwaters of the Los Angeles River, is the western-most of the Corps of Engineers’ dams operated by the Los Angeles District in the Los Angeles County Drainage Area flood control system.
Rainstorms create reservoir impoundment behind Sepulveda Dam.
The project collects local runoff from the uncontrolled drainage areas upstream and reduces the peak discharge into the channelized portion of the Los Angeles River, so the downstream channel has capacity to collect the local inflow from the San Fernando Valley.