Imperial Reservoir Imperial Reservoir 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. A component of the Imperial National Wildlife Refuge, the reservoir is northeast of Yuma, 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. Upstream on the Colorado River, the basic feeder watershed to Imperial Reservoir is the Havasu-Mojave Lakes Watershed, of Lake Havasu. Two dry wash watershed
Imperial, Missouri Imperial, Missouri Imperial is a census-designated place (CDP) in Jefferson County, Missouri, United States. The population was 4,709 at the 2010 census, up from 4,373 in 2000. It was originally known as West Kimmswick, and is located south of downtown St. Louis. St. John's Church is a historic parish church located within Imperial. Imperial is located in northeastern Jefferson County at . According to the United States Census Bureau, the CDP has a total area of , of which are land and , or 13.01%, are water. Imperial is bordered to the north by Arnold, to the south by Barnhart,