Method and apparatus for conserving water in a car washing apparatus

High pressure spray type car wash apparatus comprising a motor driven pump having an inlet and an outlet, a reservoir having an inlet and an outlet, a first supply conduit for conducting water from a tap, a second supply conduit for conducting liquid from the reservoir, said first and second supply conduits being in communication with the pump inlet, the pump outlet being in communication with two discharge conduits, a first discharge conduit in communication with the reservoir, a second discharge conduit in communication with a high pressure dispenser, a first valve means for regulating flow of wash water from the pump outlet to the reservoir, means for injecting cleaning agents into the system, and second valve means for automatically shutting off the flow of liquid from the reservoir to the pump inlet when tap water is entering the system.