In an arid climate, the consumptive use of water by a steam power plant may place a constraint on the plant size and location, and may affect the choice of nuclear or fossil fuel. To estimate the water consumption resulting from the use of recirculating evaporative cooling systems, mathematical models of a cooling tower, cooling pond, and cooling pond with a supplemental spray system were developed, based on meteorological phenomena. The monthly and annual evaporation was then computed using climatological data. The use of a spray system to reduce the required cooling pond surface area is found to be feasible and effective in reducing the evaporation resulting from cooling pond operation.