The design and construction of concrete water treatment and storage structures in Australia has catered for the existing markets. The next generation of these structures needs a more sophisticated approach. Engineers who analyse and design water treatment plants, or water and liquid storage structures, as well as other complex reinforced and pre-stressed concrete structures, will find this paper of interest. Advanced water treatment plants and water factories for recycling domestic and industrial waste water have introduced new complexities into concrete tank design. Two recently constructed Australian water purifying plants provide examples of the theoretical and practical challenges of designing and constructing the large and complex process vessels required by modern plants to produce large volumes of high-quality water.