[1] The primary mission of the dam was to serve as a flood risk management tool to the communities along the San Gabriel River downstream of the Basin.

The recreation amenities constructed during this time period were jointly developed by the corps and county on a cost shared basis.

The outlet works, located at the base of the dam, are fed by sixteen 7 ft (2.1 m) diameter conduits capable of discharging 17,000 cu ft/s (480 m3/s).

The emergency spillway is located to the northwest of the dam and comprises a concrete overflow weir with a capacity of 200,000 cu ft/s (5,700 m3/s).

Excess inflow can be sent to the Peck Road Water Conservation Area and additional spreading grounds along the Rio Hondo.

[9] Most of the spreading grounds are owned and maintained by the Los Angeles County Department of Public Works, reclaiming an average of 110,000 acre⋅ft (140,000,000 m3) of water each year.