Riverine plains are gifted with regular supply of water and silts inevitable for the sustenance of the existing functioning of the ecosystems. Periodic floods sometimes proved beneficial to those ecosystems which human had long adjustments for production activities. The abandoned courses of river play the role of inundation canals with capacity either to carry water to the low lying wetlands or to hold the excess water for a longer time from which water for irrigation during dry spells could be available. These types of inundation canals were made with human efforts in some places both to control flood, irrigate crop fields and pisciculture. These channels may become dry after complete eutrophication as a result of the degradation of the channels with frequent disruption, extension of cultivable lands, diversions, constructions of culverts, bridges and roads. The district of Hugli in West Bengal is a part of the lower Ganga plain, of which 12 mouzas of Polba-Dadpur and Singur CD Blocks have been selected for micro level study on impacts of degradation of water channels on environment and people. The area had experienced the changes in the status of river channels with decreased water holding capacity, shortages in supply of water on the one hand and siltation of water courses, eutrophication of water bodies, extension of agricultural land, wanton diversion of channels, construction of culverts etc. by narrowing the channels on the other. These activities have brought in effects on the ecology and economy of the area. This paper attempts to investigate the factors and processes of channel diversion, to identify the changes in the physical and social environment and to analyze the impacts of those changes with appropriate methodology and information collect from the field.