and utilize the limited water resources against climate change. One of the most efficient
methods is integrated water resources management (IWRM), which requires the use of a
Decision Support System (DSS). K-water and its domestic and international partners
under the support of Asian Development Basin (ADB) has been working to help realize
(IWRM) in the Citarum River Basin (CRB). As a first step, K-water has developed a
core database for enhanced data management and rainfall runoff forecasting system for
predicting rainfall condition, which will be utilized as input data for establishing water
and environmental management practices.1 to be conducted in the second phase. This
paper describes the results of the first phase development.