Banning Dam, Gravity dam in California, United States.

Banning Dam is a 37-foot-high, 140-foot-long gravity dam on Eleanor Creek in Thousand Oaks, California. Completed in 1889, it impounds the 8-acre Lake Eleanor within a gorge with sheer cliffs dropping 40–50 feet. It may be the first concrete arched dam built in California.

Work on the dam began in 1881 and was completed in 1889, impounding Eleanor Creek to form Lake Eleanor as a water source for cattle. It may be the first concrete arched dam built in California and is among the oldest still standing in the state. Officials drained the reservoir in 1972, calling it a hazard; hundreds of frogs died and wildlife was moved to Triunfo Creek. COSCA acquired the lake in 1986, and it became Ventura County Historic Landmark No. 120 in May 1988.

The lake takes its name from "Captain" William Banning, who built the dam, and the reservoir is called Lake Eleanor after Eleanor Creek, which it impounds. The site has been Ventura County Historic Landmark No. 120 since May 1988 and City of Thousand Oaks Historical Landmark No. 9. The lake and surrounding open space are fenced off to protect wildlife such as the Great Blue Heron.

The 8-acre lake and its surrounding open space are fenced off to protect wildlife such as the Great Blue Heron, so the water and dam cannot be visited directly. The single developed trail follows the ridge east of Westlake Boulevard, with trailheads at Denver Springs Drive in Westlake Village and Highgate Road in Thousand Oaks; it gains about 500 ft and overlooks Westlake Lake and Las Virgenes Reservoir.

The lake and its surrounding open space are fenced off from the public to protect habitat for species such as the Great Blue Heron. The only developed trail follows the ridge east of Westlake Boulevard, reached from trailheads at Denver Springs Drive and Highgate Road, gaining about 500 ft and offering views of Westlake Lake and Las Virgenes Reservoir.