The Koshi river basin extends from the Tibetan plateau through the Himalaya into the Eastern Gangetic Plains (EGP). Home to 300 million people, the EGP is the world’s highest concentration of rural poverty, with strong dependence on agriculture for food security and livelihoods. The work presented here is a contribution to the Koshi Basin Programme, a research-for-development project funded by the Australian Government. CSIRO’s work in the program aims to develop capability in river basin modelling, with aspirations to link that to scenario analysis of how changes in water resource availability may impact on livelihood outcomes, including outcomes for women and girls.