Crossing a full Brahmaputra from Dibrugarh to Dhemaji North Bank in Assam by ferry takes an hour, but now requires more than double that time as the river takes a meandering path and is heavily silted. People still prefer the ferry because the land route is more than 400 km long. They are waiting for the Bogibeel bridge, which will cut short the travel time to just half an hour.
Also read: Understanding the Brahmaputra and the annual flooding in Assam
The Brahmaputra and its tributaries are known for changing course ever so often, leaving behind a heavily silted river bed. People have adapted to this behaviour of the rivers. They grow paddy and vegetables along their banks when the flood waters recede and move home when the rivers change course. But in recent years, hydroelectric projects built upstream in Arunachal Pradesh have added to the amount of siltation.
Deforestation has not helped either. Neither has the unusually heavy rainfall influenced by climate change resulting in all the tributaries dumping silt. Downstream from Dhemaji, Lakhimpur district has witnessed some serious flooding and siltation. During the monsoon, the Ranganadi hydroelectric dam in Arunachal Pradesh releases large volumes of water from the dam site, inundating large tracts of agricultural land in Lakhimpur. And once the flood waters recede, much of the land is covered by sand rendering it useless for cultivation.
It is in middle Assam that the Brahmaputra dumps the most silt. Here, Morigaon district is severely affected by floods with the river bisecting it. At places, the the river is more than three km wide. Because of siltation, the river is divided into several parts. People now wade through this part of the river, unthinkable in the past years.
Pale shadow: Siltation has shrunk the Brahmaputra near the site of the upcoming Bogibeel bridge in Dibrugarh district.
Abundance of silt: An earthmover removes silt to lay a road near the site of the Bogibeel bridge.
For a few pails: People collect water by digging the bed of the Sesa river at Kolmouguri near Gohpur town of Assam. Heavy siltation from upstream has made the river vanish.
Against the grain: Heavy siltation of the Ranganadi, a tributary of the Brahmaputra, has destroyed crops at Jainpur village in Lakhimpur district of Assam.
Corrosive effect: The bridge across the Jiadhal river on National Highway 52 in Dhemaji district of Assam. The people fear that the silt deposits will damage the bridge when the river flows in full spate during the next rains.
Temperamental river: An erosion-affected village on the banks of the Brahmaputra near Mayong village in Morigaon district of Assam. By frequently shifting its course, the river forces the residents to move their homes ever so often.
No longer mighty: Water is deep enough only for fishermen to wade through the main channel of the Brahmaputra in Morigaon district of Assam. During floods, the water is more than eight metres deep and two kilometres wide.