Abstract
Rivers are one of the prime sources of freshwater and act as the arteries of the Earth. While the growing pressure of meeting freshwater demands through extensive large and small-scale water infrastructures is indispensable, maintaining the river's natural flow is vital in sustaining the aquatic ecosystem harbored within it. Hence, it is essential to regulate the environmental flow for the sustainability of the rivers and their ecosystem management. This paper focused on analyzing the importance of maintaining the environmental flow by computing the degree of deviation in the river flow regime from the natural flow conditions. It used the Range of Variability Approach (RVA) to calculate the degree of deviation while also lending a special focus on the implications of altered river flow regime on the socio-economic activities especially fishing as a livelihood for the communities residing along the flanks of river Damodar in the downstream region. The daily discharge data measured during pre-and post-dam construction at the Durgapur barrage site of the lower Damodar river basin were used to compute the degree of alteration. It applied the convergent parallel mixed methodology to simultaneously analyse the qualitative responses and the quantitative data to effectively interpret the impact of altered environmental flow on the fishing livelihood of the communities. Thus, the analysis emphasized the importance of maintaining the environmental flow for ensuring the well-being of humans reliant on river systems. This shall also accentuate and contribute to the idea of balancing between development and sustainability.