This book comprises the proceedings of the 26th International Conference on Hydraulics, Water Resources and Coastal Engineering (HYDRO 2021) focusing on broad spectrum of emerging opportunities and challenges in the field of hydrology and hydrological modelling. It covers a range of topics, including, but not limited to, ground water modelling and management, integrated water resources and watershed management, surface water hydrology, drought assessment and mitigation, risk, reliability and design of hydrologic system, etc. Presenting recent advances in the form of illustrations, tables, and text, it offers readers insights for their own research. In addition, the book addresses fundamental concepts and studies in the field of hydrology and hydrological modelling, making it a valuable resource for both beginners and researchers wanting to further their understanding of hydraulics, water resources and coastal engineering.