Abstract
Climate change may affect the quality and the quantity of water supply systems; however, the likelihood of climate change impacts varies among water utilities. Hence, this research aims to develop the Combined Performance Indicators (CPIs) that integrate the likelihood of climate change impacts and the capacity of water utilities to mitigate such impacts. The CPIs were developed for each process of water supply; namely, intake, treatment and distribution processes. The calculated CPI values were grouped in terms of the service population and the regions of the water utilities, and were plotted on the map of Japan. It was found that the adaptation capacity of water utilities varied depending on their sizes and geographical locations. The adaptation capacity of small-scale water utilities in particular were found to be significantly diversified and some of them are extremely vulnerable to climate change. Furthermore, comprehensive assessment of water utilities' adaptation capacity to climate change was carried out using the management indictors for water utilities that include two additional indicators for finance and pipe age. It was demonstrated that the proposed management indicators for water utilities can be used to develop an adaptation plan for each water utility.
