China may be denying any construction activity on the river that enters India as Siang and Brahmaputra but the fact remains that China has the advantage to extract more from India with its control over the vast water resource.

"Brahmaputra is a snow fed river and takes its source from about 600 small and large glaciers in the Tibetan region and the remote sensing data indicates that China is engaged in some construction activities on one of the main streams called Yarlang Zambo or Yarlang Tsangpo and at the specific location called Zangmo where the river falls into a deep gorge. Now if these construction activities are of the nature of power generation or storage facilities then the concern downstream as experts say is genuine."

IIT Guwahati has been conducting simulated studies of the effect of big dams on the Brahmaputra.

"If China constructs a dam on the stem that comes to Brahmaputra from Tsangpo, then definitely it's a matter of concern. If they are making a power project then they will want to keep high water level and sudden release can cause floods. And if it's for storage facility to divert water then the lean period proportion will affect the river," says Prof Arup Sharma of Department of Civil Engineering, IIT Guwahati.

But it's not just China. More than 150 dams are proposed to be constructed on the Brahmaputra inside India in Arunachal Pradesh. And the impact of any dam is the same.

"The dams proposed are all power generation dams. But in any dam, if there's flood cushioning then there's scope of absorbing flood spikes," says Byte: professor Sharma.

So while dams may help in mitigating flood misery, if they are not regulated, it can cause devastation. On the other hand, storage facilities almost invariably can cause drought like situations.

There are other solutions but the biggest one in sight is to ensure very close cooperation between the two countries.