Photos of interest along California State Highway #S 24 Part of the Colorado River, Imperial Dam Irrigation system. The Imperial Dam is the headworks and origin for the All American Canal, which is the main source of water for the Imperial Valley. It is one of a few major structures on the lower Colorado River, such as the Hoover Dam and the Parker Dam, built by the Bureau of Reclamation to control flooding and to supply water for irrigation. Interstate #8 to Arizona US Highway #95