Due to population growth, industrialization and urbanization, problems arise with drinking water supply, wastewater treatment and overall sanitary conditions. These negative aspects may restrict livelihood and the social and economic growth in the tropical monsoon region. This study was conducted with the goal of building a scientific basis for integrated water resources management for small and medium river basins in the trend of rapid economic growth but uneven distribution of water resources and may suffer adverse effects such as climate change in the future.