Maintaining the Environmental Flow Requirement’s of a River to sustain It’s Ecological Balance: A Challenge
Lt. Col. Manish Kothari
M.Tech (IInd year), WRD & M Department, IIT, Roorkee, Uttarakhand, India.
Water has been over-exploited by the human society, which has not only drained the vital river resources but has also exhausted of the ancient aquifers that are hard to replenish. The flows of the world’s rivers are increasingly being modified through impoundments such as dams and weirs, abstractions for agriculture and urban water supply, drainage return flows, maintenance of flows for navigation, and structures for flood control. These interventions have caused significant alteration of flow regimes mainly by reducing the total flow and affecting the regime and seasonality of flows. It is estimated that more than 60 % of the world’s rivers are fragmented by hydrological alterations.
Environmental flows describe the quantity, quality and timing of water flows required to sustain riverine ecosystems and the human livelihoods that is dependent on these ecosystems.
It is a great challenge for water manager’s to account for natural differences in flow regime among rivers, understanding the importance of environment flow for the protection of freshwater biodiversity, estuarine ecosystems and maintenance of services that rivers provide. In the absence of detailed information of environmental flow requirements for rivers, it is proposed that a generic approach to be ascertained that incorporates key aspects of natural flow regime for the rivers, which can be validated with empirical biological data and other information. It is assumed that such approach can narrow up the gap between simple hydrological “guidelines” and more comprehensive “environmental flow requirements”.
Keywords: Environmental flow, Riverine ecosystem, Estuarine ecosystem.
