The natural flow regime: A master variable for maintaining river ecosystem health

Abstract River health is sustained by time‐based variation in their flows, and the maintenance of natural flow regime is essential for keeping the rivers healthy. However, the dynamism in natural flow regime now stands altered by changing climate, and the omnipresent regulation of river flows throughout the world has severely impacted the river health. It is well documented that harnessing and altering the flow of the rivers and streams comes at a huge cost. Numerous rivers in the world have stopped supporting socially and economically important native species or sustain vibrant ecosystems that offer valuable goods and services. The alteration of the natural flow regime has led to the collapse of many healthy and resilient river ecosystems throughout the world. Therefore, to ensure appropriate naturalized flow regimes for riverine organisms and a sustainable nexus between energy demand, water requirements and climate, more understanding is required to study the consequences of alteration in natural flow regime triggered by climate change and anthropogenic interventions. Moreover, conservation and management practices must be firmly based on scientific principles to restore the integrity of river ecosystems. The current approaches often fail to take into consideration a basic fundamental principle that the integrity of the river ecosystem is largely determined by the natural dynamic character of their flow regimes. In this synthesis, we try to explain how the maintenance of the natural flow regime is an essential requirement for maintaining river ecosystem health.