Abstract: A combined space-cooling and irrigation system and method of operation. The system is operated by an automated control unit specifically programmed to manage cooling and irrigation needs as follows. When irrigation water is needed, the system pumps cool water from a municipal water supply, a well, or a deep pond, through a heat exchanger on the way to a reservoir. The water pumped through the heat exchanger cools fluid in a separate closed circuit. The cooled fluid in the closed circuit is then used for cooling purposes, for example, to cool the air circulated through a house or building using a commercially available fan coil unit. The reservoir releases collected water for irrigation purposes at appropriate times.