The Imperial Reservoir is an artificial lake formed by the construction of the Imperial Diversion Dam across the Colorado River in the Lower Colorado River Valley of Imperial County, California, and Yuma County, Arizona.

Dry washes are the major watershed feed systems to Imperial Reservoir.

The next upstream major watershed feeder is the Bill Williams River from western Arizona.

The Senator Wash flows eastward from California into the reservoir.

[2] The Bureau of Land Management operates camping sites on the north and south shores of Senator Wash and at Xanyō Xamshré (a backwater of the river).