The Bagmati River Basin Improvement Project aims to bolster water security and resilience to climate change effects in the Bagmati River Basin (BRB). This initiative will establish a river basin organization to facilitate integrated water resources management, while also investing in upstream water storage, riverbed oxygenating weirs, and community-driven initiatives to enhance the river environment in Kathmandu Valley. These efforts are poised to fortify water security, enhance river health, and improve flood management within the BRB. Notably, this project marks Nepal’s inaugural endeavor to apply integrated water resources management principles since their adoption in 2005. Key objectives include building capacity for participatory river basin management, revitalizing urban riverbank environments, enhancing water availability during dry seasons, implementing flood forecasting and early warning systems, and ensuring effective project management and stakeholder communication. Furthermore, hydrological analyses were conducted to inform dam reservoir design, river environment enhancement, and flood control measures, supported by the utilization of the MIKE 11 flood simulation model.