Enhancing Reservoir Management Through the Use of Mechanical Evaporation Reduction Techniques

Abstract

Large drinking water storage reservoirs are a critical component for the supply of quality water. With a growing population and limited resources water managers are required to seek efficient and effective methods to ensure a secure and adequate water supply. It is certainly evident that it is becoming difficult to secure and develop new dam sites (both on environmental and engineering grounds) and that new sources of fresh water (such as desalination) are costly and not environmentally sensitive. In south east Queensland up to 1/3 of freshwater is lost through evaporation, so it seems sensible to seek solutions to reduce such losses in a sustainable manner. This paper will examine three different evaporation reduction techniques – hard covers (eg. floating barriers), destratification and wind reduction devices (eg. windbreaks). A simple onedimensional model was adapted to investigate the effectiveness of each technique for large storages. It was found that each of the techniques has it limitations for large storages, but that it appears the application of hard covers is the most efficient solution.