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A river running dry

The entire basin falls in the seismic zone 4-5, and is highly prone to landslides and land subsidence.

The entire basin falls in the seismic zone 4-5, and is highly prone to landslides and land subsidence.  

The Ganga basin will become more fragile if more and more hydropower projects come up

From aiming for Aviral Dhara (uninterrupted flow) of the Ganga to Nirmal Dhara (unpolluted flow), the government is now simply focussing on a Swachh Ganga (Clean Ganga). While the whole focus of the Clean Ganga project has been on setting up sewage treatments plants and cleaning ghats and banks, the main issue, which is that the river does not have adequate flow of water, has been ignored. With severe pollution destroying the river, and developmental projects critically affecting its flow, the Ganga is in a dire strait.

A fragile region

Today, several hydropower projects are mushrooming at the source of the river, which is the Garhwal range of the Himalayas. Unlike other ranges, the Garhwal is narrow. It is from here that many rivers and tributaries of the Ganga basin emerge. These spring- or glacier-fed rivers join one another at different points to form an intricate riverine ecosystem in the Himalayas. The entire basin falls in the seismic zone 4-5, and is highly prone to landslides and land subsidence.

The understanding that hydropower projects mean development needs to change. To construct a hydropower project, large sections of land are cleared of forests. But what happens when such deforestation takes place in an already fragile mountain area? Many studies have been conducted near the existing dams along the course of the Ganga. The immediate impacts of these projects have been loss of agriculture, drying of water sources, and landslips. As construction in such projects progresses, there is also dumping of muck, which can pose severe threats. Muck dumping during construction of the Alaknanda hydropower project caused devastation downstream in Srinagar in the 2013 flash floods. Such muck is dumped either into the river or in forest areas. After all the massive deforestation, muck dumping, blasting and tunnelling, the hydropower projects thus constructed eventually dry up the river bed as the water is diverted into tunnels. This causes severe distress to aquatic life, and the river bed is no longer even wet in certain stretches. As the Ganga is diverted into long tunnels, de-silted, and directed to powerhouses to churn turbines and generate power, the barren landscape, dried water sources and the obscene muck slopes narrate a story of destruction. This is a far cry from the promise of development.

The irony is that even after all this devastation, electricity is not generated as per the intended capacity. For example, the installed capacity of the Maneri dam is 90 MW but it only works at below 40% of its capacity. This is because there is too much silt during the monsoon and reduced flow of water in winters. As glaciers continue to retreat, the silt in the rivers is only going to increase. As the reason for diminished output is natural and not technical, and therefore cannot be remedied, this is only going to cause more problems for future projects. For example, the flow of debris was stopped by barrages in the Alaknanda hydropower project. This escalated the impact of the 2013 disaster, according to the expert committee of the Supreme Court.

In the case of the Ganga, these projects also prevent sediments from going downstream. This affects the fertility of the delta downstream and also destroys the unique self-purifying properties of the Ganga.

Reports of committees

Twenty government committees and reports warn about the anthropogenic activities in these fragile areas and recommend conservation of these areas for food and water security. When the late G.D. Agarwal, crusader of the Ganga, fasted to invoke the government to act against these projects, the government proposed an e-flow notification for the Upper Ganga River Basin. It specified that during the dry season (November-March), 20% of monthly average flow has to be maintained, and during the monsoon season, 30% has to be maintained. The notification stated that existing hydel projects that do not meet e-flow norms must comply within three years. The 20% recommendation is less than the scientific recommendation of 50% (only for existing projects). If the government intended to rejuvenate the river, it would have specified that e-flows are only for existing projects. Instead it has opened the floodgates for several such projects as long as the compromised e-flows are maintained.

The result of such a relentless push for hydropower projects is that only 80 km of a 2,500 km-long river now remains in the Aviral-Nirmal state. Unless we question these projects now, we will not be able to save the Ganga, the lifeline of millions of people.

Meeta Khilnani is a geophysicist from IIT Roorkee and a member of Ganga Ahvaan, a forum for the conservation of the Ganga in the upper reaches

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Printable version | Feb 24, 2020 11:54:05 PM | https://www.thehindu.com/opinion/op-ed/a-river-running-dry/article25783214.ece

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