This is the beginning of the river Subansiri's journey into the plains flowing down from the hills of Arunachal Pradesh which is damming the river for a hydel power project.

Its course holds timber— the equivalent of gold here. Everything from mere twigs to massive logs of wood, float down from the vast forests upstream and are trapped in the sand. The community of Sunapur only has to shake the wood loose from the river bed and tow it to the banks.

Typically five men work to load each lorry load and women and children chip in to cut and stack the wood.

But what was once a healthy harvest of wood has dropped. "You can say for every one rupee of wood we used to get, we get 10 paise worth now," the workers say. They blame the massive 2,000-Mw Subansiri Lower hydroelectric project under construction a few kilometres upstream in Arunachal Pradesh.

Activists allege the downstream issues were never taken into consideration before its sanction. "You tell us how will the livelihoods of these communities be compensated? Their agriculture is not very viable because of the sandy soil, thus they supplement their income by harvesting from the river – wood, fish and boulders," say Keshav ‘Bhai' Krishna and Rajan of the People's Movement for Subansiri Brahmaputra Valley.

They allege that the Assam government has been a "mute spectator" to this dam and others being planned upstream in the Brahmaputra basin. They point out that the environmental and economic impact on Assam's communities due to the dams has not been studied.

They say the only instance that got the Assam government's ear was when the National Hydro Power Corporation (NHPC) asked for a sum of money because the dam would "provide flood mitigation benefits downstream".

The Assam government for its part has not signed an MoU with the NHPC, even though half the dam is in its territory, for two principal reasons – negligible free power from and a border dispute with Arunachal Pradesh. But it cannot deny the existence of micro-economies that depend on the river as a few kilometres upstream on the Brahmaputra, where the mega bridge at Bogabil is being built with thousands of tonnes of stone harvested from the riverbed.