DAMS ON ASSAM AND MIZORAM RIVERS WITH SHARED HYDROLOGICAL STRATA IN COMMON WILL CAUSE THE WEAKEnING AND DEPLETION OF UNDERGROUND  WATER RESERVEs, THE MOST BASIC  FOR SUSTENANCE OF LIFE FORMS, Says PRASENJIT BISWAS
The lessons of Uttarakhand should not be lost on the North-east.  For one, most of the region&’s hills and rivers are located on the same Himalayan faults, and to make matters worse, the soil is primarily made of sediments. The Centre&’s plan to construct a mega  dam on every river that flows into the region, by way of huge monetary investments involving private parties, awaits a similar fate.
Recently, the Union ministry of environment and forests gave clearance to the Tipaimukh dam project located in Manipur&’s Churachandpur district. This entails clearing of about nine million trees across 311 square kilometres of pristine forest and is, at best, a man-made disaster waiting to happen. The justifying argument on generation of power and consequent industrial development falls flat in the face of the facts emanating from the Lower Subansiri dam project in Arunachal Pradesh. Out of 2,000 MW that the Subansiri project is supposed to generate, Assam will get less than 200 MW, that, too, at a high price.
 Similarly, from an installed capacity of 1,500 MW at Tipaimukh, it is not clear yet how much the region will get because it has to sell power to Bangladesh and Myanmar as well as part of quid pro quo deals.
The Tipaimukh project is proposed on the confluence of the Barak and Tuivai rivers in Manipur&’s south-western area and there will be an earthen/rock-filled 178-metre high dam.  In case of any breach it has the possibility of not only inundating certain parts of Manipur&’s districts like Senapati, Tamenglong, Churachandpur and Jiribam, but also the whole of the Barak Valley of southern Assam. Silchar town will be under 70 feet of water. Originally conceived to protect the lower regions of the Barak Valley and Sylhet district of Bangladesh, the project is estimated to cost Rs 8,000 crore.
More significantly, the dam will totally alter the flow of water in the river basin on a short- and long-term basis. By containing the flow during the high season and by augmenting it in the lean season, the dam will endanger the hydrology of the river, affecting its entire downstream morphology. Experts believe that it will destroy biodiversity, as the Barak river is home to many rare water species along with the overground flora that will be permanently lost.
On the lower riparian Bangladesh side, daming the river will negatively impact the flow of water in the entire Surma-Kushiyara navigation channel by turning it into a deteriorated sediment deposit. Needless to say that starting from Tipaimukh to downstream Bangladesh via the Barak Valley, the entire agricultural and fishing zones will be reduced to desertification in no time. This will cause climatic  changes and transform itself from a sensitive biodiversity zone to an area of frequent landslides, flood and other disasters.
So far, the Union ministry of environment and forests has not been transparent in conducting mandatory public hearings, or it did not have a downstream environment impact assessment. What has been gathered from unofficial expert reports on the possible impact of the Tipaimukh dam is less than optimistic. Indeed, there is no field survey on the area of submergence, destruction of human and agricultural habitat and, hence, apprehensions galore. Even those who are funding the project are not very clear, as negotiations are on between several private parties and various government agencies. There is  a complete lack of accountability in sensitive matters of protecting fragile ecology and river basin, crucial factors in maintaining a climatic balance in the flow area of the river.
Compounding such an unresolved possibility of disaster, there is a plan to construct mega or medium dams on Mizoram&’s major rivers.
The Tuirial river flows from north to south to finally meet the Barak at Tipaimukh. A dam is also proposed on the Tuirial which flows from the north-western side of Mizoram. And there will be dams on other major rivers such as the Tuivel and Kolodyne. There is a plan to generate 2,500 MW from all the 13 rivers of Mizoram. Needless to say that all these proposed projects hardly meet the requirements of informed public consent with prior environmental impact assessment. Yet the governments are in a great hurry to begin such projects without any guarantee that the projected quantity of power will be owned and distributed by the state concerned and their people.
Building dams on all these rivers in southern Assam and Mizoram, with several shared underground hydrological strata in common, will only cause the weakening and depletion of underground water reserves, the most basic for the sustenance of life forms. Such unwarranted consequences of dam-led development in a geologically and ecologically fragile region needs to be taken into consideration in the aftermath of what happened in Uttarakhand.
The writer is Associate Professor, Dept. of
Philosophy, NEHU, Shillong, and co-edited the Book, Construction of Evil in India&’s Northeast, SAGE, New Delhi, 2012