This chapter examines the Jalangi RiverJalangi rivers transformation and characteristics from both spatial and temporal perspectives. Formerly, the Jalangi RiverJalangi river held significant importance among the ‘Nadia RiversNadia rivers,’ stretching from Char Madhubona in the northeast of Nadia district to Swarupganj opposite NabadwipNabadwip, where it meets the Bhagirathi RiverBhagirathi river. In the past, the river exhibited notable dynamism in its planform geomorphologyPlanform geomorphology, evident in various oxbow lakesOxbow lake and palaeo channels. Despite its current ironic name, historical records highlight its significant hydraulic role. Over time, the river has drastically declined, largely due to the eastward tilt of the Bengal BasinBengal basin, post-Farakka reduced water levels of Padma RiverPadma river and human interventions. This chapter provides a comprehensive analysis of the river, covering hydro-geomorphic changes, declining water qualityWater quality, environmental flowEnvironmental flow dynamics, and socio-economic shifts resulting from fluvial changes. The chapter also aims to foster sustainable management for the local community’s development.