Assessment of environmental flow requirements of damodar river basins by using flow duration indices method – a case study

Abstract

River systems attain zero flow due to water retaining structure construction, hydropower generating structures and bridge construction. This possesses a tremendous threat to the environment, ecology and aquatic life of the river systems. Therefore, environmental flow assessment is of prime importance to analyze the natural flow regime of the river which is required to be maintained for the sustainability of the ecosystem. In the present study, the environmental flow of the Damodar River Basin has been assessed by using the Flow Duration Curve (FDC). Out of the 41 year of flow data, the 90% exceedence probability of flow was attained in the year of 2009-2010 and corresponding flow was observed to be as 122 cumec approx. This flow will persist for 90% of the time throughout the year.