The present invention relates to a method and a system for controlling the circulation of water films on the exchange walls of an exchange surface of a cooling tower. It comprises combining a tank and a dispenser lip to ensure that the film has a specific thickness and that it adheres to the exchange wall right from the moment it starts to flow and repeatedly so, on each exchange wall. The exchange walls between air and water are horizontally sloping at a small angle, thereby ensuring that the water flows by force of gravity and, at the same time, limiting the speed increase on the plate to avoid the droplets from being pulled away by the airflow. The water films are recovered in recovery troughs perpendicular to the flow of the water films on the plates. These troughs are tilted horizontally, and enable the recovery of the water films without being crossed by the air flows. The air is blown in by nozzles which are interposed between the water flow plates in such a way that the airflow is in a counter-current flow or, if necessary, in a cross-current flow, relative to the water films thus enabling the evaporation of the water that cools the water flow on the exchange plates without forming liquid aerosols.