INDIAN EXPRESS | MIHIR SHAH | AUGUST 14 2015
Recent scholarship supports the chief minister’s refreshing perspective. It shows that most of the peninsular river basins (the Kaveri, Krishna and Godavari) and the Narmada and Tapti have reached full or partial basin closure, with few possibilities of any further dam construction. In the Ganga plains, the topography is completely flat and storages cannot be located there. The problem further up in the Himalayas is that we confront one of the most fragile ecosystems in the world. The Himalayas are comparatively young mountains with high rates of erosion. Their upper catchments have little vegetation to bind the soil. Deforestation has aggravated the problem. Rivers descending from the Himalayas, therefore, tend to have high sediment loads. The Geological Survey of India records many cases of power turbines becoming dysfunctional following siltation. Climate change is making the predictability of river flows extremely uncertain. Diverting rivers will also create large dry regions, with adverse impact on local livelihoods (fisheries and agriculture). The neo-tectonism of the Brahmaputra valley and its surrounding highlands in the eastern Himalayas means that modifying topography by excavation or creating water and sediment…continue reading