A simplified model is proposed to predict the performance of a cooling water spray pond. The degree of cooling depends on air properties (temperature and humidity) but primarily on the water dispersion (drop size and velocity). The model follows a drop as it leaves the nozzle and evaluates the heat and mass transfer it undergoes during its transit time in the air. The influence of neighbouring sprays is considered. A series of laboratory experiments with falling water drops was described, together with factory results. The model gives a practical design procedure for factory spray ponds.