The transboundary Brahmaputra basin is a significant component of the Asian Water Tower, housing approximately 66 million people in four countries and experiencing intense floods. However, this data‐scarce river has been subject to very few studies related to the long‐term assessment of its water budget. In this study, a multi‐model ensemble Indian Land Data Assimilation System (ILDAS) is set up to study the trends and variabi...