Chamoli disaster: Focus on dams and hydroelectric projects in Uttarakhand

 On February 7, 2021, a snow avalanche at an altitude of 5600 metres, triggered by a landslide, caused a flash flood in the Rishi Ganga river, a tributary of the Alaknanda in Chamoli district of Uttarakhand. It washed away a small hydroelectric project and destroyed the under-construction 520 MW Tapovan Vishnugad project of the NTPC on the Dhauli Ganga river. The death toll from the disaster was 38 and rising. Scores of people including many workers in the two power projects were missing.

The Chamoli disaster has turned the spotlight on several ongoing dam-based hydroelectric projects, rampant road building, tree felling for projects, and also construction practices in the State. Uttarakhand is geologically unique and remains active in terms of deep movement of rock assemblages. The zone has witnessed several earthquakes of varying intensity, including those with magnitudes of 5.0 or more. Hence, several scientists have questioned the wisdom of large dam-building in Uttarakhand. 

There are also concerns about induced seismic effects caused by the repeated filling and emptying of dams, which may be deforming the surrounding area. In addition, the geology of mountains in many parts of Uttarakhand is such that the threat of landslides is high. Rocks here have been weakened by natural processes across time and are vulnerable to intense rainfall as well as human interference, in the form of house-building and road construction. The careless disposal of enormous debris from mining and construction projects has added to the problem by blocking flow paths.

The IPCC “Special Report on the Ocean and Cryosphere in a Changing Climate” found that in the Himalayan ranges, there could be variations in overall water availability, but floods, avalanches and landslides were likely to increase. 

The aberrations in the Indian summer monsoon caused by climate change  could produce great damage, by bringing debris and silt down the river courses, destroying physical structures, reducing dam life, and causing enormous losses. These problems are also aggravated by the erosion of mountain slopes and the instability of glacial lakes in upper elevations. Also, the retreat of glaciers in the high mountains has resulted in a decline in tourism and local agriculture.

Eight hydroelectric projects totalling 2,490 MW are underway in Uttarakhand. The Union government has been offering incentives since March 2019 to make hydropower attractive. These include classification of large hydropower projects as Renewable Energy sources, creating a separate category for hydropower within Non-Solar Renewable Purchase Obligation, tariff rationalisation to bring down tariff, and budgetary support for putting up enabling infrastructure such as roads and bridges. 

The International Renewable Energy Agency estimated that in 2019, the average cost of electricity in India was $0.060 per kWh for small hydropower projects added over the last decade. In comparison, the global cost for solar power was $0.068 per kWh in 2019 for utility-scale projects. In places such as Uttarakhand, the net benefit of big dams is controversial because of the collateral and unquantified damage in terms of loss of lives, livelihoods and destruction of ecology.

(This post is based on a report in The Hindu dated February 14, 2021.)