Imperial Reservoir, Reservoir in Imperial County, California, US

Imperial Reservoir is a man-made lake created when the Imperial Diversion Dam was built across the Colorado River. It spans about 11 square miles in the lower Colorado River Valley along the California-Arizona border, storing water diverted from the river for farms, towns, and power generation.

The Imperial Diversion Dam was completed in 1938 as part of the Boulder Canyon Project, impounding the Colorado River to form the reservoir. It sits about 16 miles northeast of Yuma, Arizona, and its water is diverted into the All-American and Gila Gravity Main canals. Senator Wash Dam, built later on the California side, added the Senator Wash Reservoir as extra storage for the canal system.

Several campgrounds operated by the Bureau of Land Management line the shores and tend to be quiet and remote. The desert setting means weather is sunny year-round but becomes very hot during summer months.

The reservoir connects to a larger system of lakes including Lake Havasu and Lake Mead, circulating water across vast distances. This interconnected system shows how different water storage points work together to manage scarcity across the dry Southwest.