Adapting water supply systems to meet the impacts of climate change

Abstract

Water supply systems are affected in various ways by climate change, in terms of water quality, quantity, and facilities. The effects on water quality include taste and odor problems due to algae growth, increased concentrations of disinfection byproducts due to increased concentrations of their precursors, high turbidity due to flooding, and salt contamination in raw water due to salt water run-ups. In recent years, heavy rainfall and typhoon-related flooding have caused extensive damage to water supply facilities, leading to large-scale water outages. As the water supply systems represent infrastructure lifelines, water cut-offs result in serious damage to the lives and business activities of people. In addition, droughts have also caused water cutoffs every year. A variety of adaptations were applied to meet these effects. General adaptations include the identification of hazards to the water supply systems, risk assessment, and vulnerability assessment (e.g., flood risk maps and drought risk maps). In the case of water quality, although the adaptations that are applied depend upon the specific water quality issues, watershed management at the water source, as well as treatment at the water purification plant were mentioned. For floods and droughts, both intangible adaptations such as the emergency water supply systems and tangible adaptations, such as the installation and renewal of facilities were applied. While these adaptations have been implemented in practice, it is also important to develop a water supply management plan and a water safety plan that properly take the impacts of climate change into account. In order to assess these impacts, it is necessary to continuously monitor target items and work to achieve their enhancement, while utilizing predictive data on climate change.