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 Estate subjects is also far from complete. The "imperial quaternions" are, rather, a more or less random selection intended to represent "pars pro toto" the structure of the imperial constitution. Imperial Estate An Imperial State or Imperial Estate (; , plural: ') was a part of the Holy Roman Empire with representation and the right to vote in the Imperial Diet ('). Rulers of these Estates were able to exercise significant rights and privileges and were "immediate", meaning that the only authority above them was the Holy Roman Emperor. They were thus able to rule their territories with a considerable degree