Lake Henshaw, Lake in San Diego County, California, United States

Lake Henshaw is a freshwater reservoir in San Diego County, California, at the southeastern foot of Palomar Mountain. It covers about 1,140 acres and holds up to 55,000 acre-feet when full, with a drainage area of 207 square miles at the source of the San Luis Rey River.

The reservoir was created in 1923 with the completion of Henshaw Dam, a 123-foot-high earthfill dam that is 650 feet long. It is owned by the Vista Irrigation District and has long been used for agricultural irrigation.

The lake is a local spot for fishing, especially for catfish and carp, and hosts the Carp Throwdown fly fishing tournament organized by The Fly Stop. Anglers gather here to cast lines and share tips, making it a familiar meeting place for the fishing community.

Visitors can reach the lake by car via State Route 76 and find parking near the shore. The area is open for day use and overnight stays, with boat and cabin rentals available for those who want to spend more time on the water.

The lake's capacity is limited to 55,000 acre-feet for seismic safety, leaving room for groundwater storage in the local basin. This dual role makes it both a surface reservoir and a key part of the area's water management.