112 страниц. 2013 год. LAP Lambert Academic Publishing In this work, starting from why dams are required, the various impacts that are caused due to series of dams in the same river and how these impacts affect the downstream and the importance of addressing these cumulative impacts have been discussed. The study includes how application of models can simulate some water quality scenarios and how far predicted data by these can be used for mitigation measures. Keywords: Cumulative Impact Assessment (CIA), Environmental Impact Assessment (EIA), Subansiri River, Water quality, Sedimentation, Impacts of hydropower projects, Social impact, environmental impact.