Water authorities in West Java, Indonesia have difficulties in implementing water improvement\u00a0programs due to lack of tools for prioritisation of water-related issues and their respective programs.\u00a0To facilitate more efficient management of the water resources, the West Java Water Sustainability\u00a0Index (WJWSI) was recently developed. This paper outlines the tasks for developing WJWSI and\u00a0highlights the results of its application in one of West Java catchments, Citarum catchment. The\u00a0results showed that five out of the thirteen indicators and sub-indicators, namely \u2018Water Availability,\u00a0Water Quality, Education, Water Loss and Poverty\u2019, had low sub-indices and thus had poor\u00a0performances. Then, the sub-indices were aggregated using the geometric aggregation method to\u00a0produce the final index. The results of the aggregation indicated that the overall condition of water\u00a0resources in Citarum catchment was considered poor, with a final index value of 20.04. Based on the\u00a0WJWSI application, recommendations are suggested to the relevant authorities in the Citarum\u00a0catchment. It is expected that the implementation of these recommendations will improve the\u00a0performance of these five indicators and sub-indicators from Poor to at least the next higher level of\u00a0Poor\u2013Medium, thus improving the value of the final index from 20.04 to 37.19.<\/p>\n