Seven Oaks is a dry dam that serves mainly for flood protection to Orange, Riverside and San Bernardino Counties, although it also used to impound water for groundwater recharge.

[6] However, the Mentone Dam site was controversial because it would affect groundwater recharge, was aesthetically unpleasing and lay on unstable sediment deposits directly above the San Andreas Fault.

[8] A system of conveyor belts totaling 3.5 miles (5.6 km), with a capacity of 3,400 short tons (3,080 t) per hour, was built to transport materials to the dam site.

The dam was built in ten alternating zones of dirt, rock and clay that ultimately totaled 38,000,000 cubic yards (29,000,000 m3).

[2] Water releases are controlled by a 1,623-foot (495 m) long tunnel outlet that runs through the base of the structure, and a 500-foot (150 m) wide ungated overflow spillway located just southeast of the dam.

[17] In March 1999, as the dam neared completion, environmental groups filed a lawsuit against the USACE because construction activity at the Seven Oaks site had affected the habitats of two endangered plants, the Santa Ana River woolly star and slender-horned spineflower, and the endangered San Bernardino kangaroo rat.

[1] The Seven Oaks Dam has also damaged the habitat of native fish species including the Santa Ana sucker, which is endemic to a handful of river systems of Southern California.