The Mekong River Basin is undergoing a period of dramatic change with hydropower emerging as one of the predominant drivers. In a region where electricity demand growth rates average 5.5-11.6%, hydropower development is almost exclusively intended for electricity generation. Over the next 20 years, some 90 hydropower projects will be in place, under construction or under firm planning for the Mekong River Basin, with the potential to store 80 billion cubic metres of water. The Sesan a tributary of the Mekong which rises in Vietnam and flows through Cambodia will comprise a potential cascade of 12 major hydroelectric projects with a combined active storage of 6 billion cubic metres. This poster outlines the rapid scoping approach for identifying the multiple uses of new and existing hydropower schemes, with a focus on optimizing the sustainable use of catchment resources at the local, provincial, and national level.