Hydro power projects to harm North East’s sensitive ecology

The massive threat that has been put up before the extremely environmentally sensitive North East in the form of huge development projects by various public and private sector groups has been exposed by none other than a government document itself.

In a counter-affidavit placed before the National Green Tribunal (In appeal No O.A. 91/2013; Bimal Gogoi vs Union of India and others), the Assam government has stated that the 1750-MW Demwe Lower Hydroelectric Power Project on the Lohit River and built in the neighboring state of Arunachal Pradesh, will have adverse impacts on the Dibru-Saikhowa National Park and Biosphere Reserve.

The Demwe project is among the over 200 hydro power projects that are being proposed in the North East and according to researchers working on the subject, these projects will devastate the sensitive ecology of the region.

According to the Assam government reply, the downstream impacts of the project on the Dibru-Saikhowa National Park shall arise out of the changed water regimes, especially in the winter season as there shall be extremes of water fluctuations (35 cubic metres per second during non-generation and 1729 cubic metres per second during peak generation). Such a variation in a short span of time has no natural analogue in fresh water eco-systems. Dolphin ecology and grassland ecology are likely to be affected. But these effects need to be quantified based on available literature and expertise.

The reply further mentions, effects of erosive forces arising out of this wide fluctuation may assume significant proportions in the winter season, too, when erosion is otherwise minimal, said the State government in its affidavit.

In paragraph 6.8 of the affidavit, the State government has admitted that the fluctuations of water flow in Lohit and its contiguous water channels in the river Dibang in the north and river Dibru in the south of the Dibru-Saikhowa National Park will enhance and reduce the flow inside the numerous rivulets inside the National Park.

Interestingly this development comes at a time when both the Assam government and the Arunachal Pradesh government are arguing for mega dams in the region, and has been all along maintaining that power projects are necessary for development.

“We are not against dams in Arunachal Pradesh as we need hydro power, and the centre has assured that interests of the region will be considered while taking any decision,” said Assam chief minister Tarun Gogoi.

Nabam Tuki, Chief Minister of Arunachal Pradesh, where most of these dams are being proposed, have said that he is in favour of dams in the state.

"Dams are being constructed at many places, and Arunachal Pradesh is going to construct dams," said Tuki, and added that, "For the interest of the country, especially for the North East, the dams are being constructed, and there should not be any opposition."

Experts and researchers working on the subject however present a completely different picture, and oppose the government’s stand.

Elaborating on the risk as a result of earthquake, Chandan Mahanta, of the Indian Institute of Technology, Guwahati, said that the North East region being located in the highest seismic zone of the world, there is always a possibility that catastrophic earthquake may occur and in that sense there is always a very high risk.

Besides this, these projects will affect the livelihood options to a great extent as these will alter the water flow of the rivers on which these are being built to a great extent, and this will affect the livelihood options of the people and also the sensitive ecology.

Citing an example of the 2000 MW Lower Subansiri hydro project along the state of Assam and Arunachal Pradesh, Neeraj Vagholikar of the environment action group, Kalpavriksh, who has done research on this issue, said that after commissioning of the project, in the winter, the flow will fluctuate from drastically on a daily basis from 6 cumecs for around 20 hours(when water is being stored in the dam) to 2560 cumecs for around 4 hours when the water is released for power generation at the time of peak power demand in the evening hours. He adds that, as a result of this the river will be starved for 20 hours and then flooded for 4 hours with flows fluctuating between 2 per cent and 600 per cent of normal flows on a daily basis, and the flow during peak load water releases in the Subansiri river in winter will be equivalent to average monsoon flows and could cause a lot of destruction.

“This means that the livelihood option of growing crops and grazing cattle will be seriously impacted, thus stopping a farming culture that people have practiced for centuries. Livelihoods such as fisheries and navigation will also be impacted in the downstream,” said Vagholikar.

According to activists these dams will also impact neighboring Bangladesh severely as the latter is in the downstream.