Dhemaji district administration sources said that the swollen Brahmaputra River breached more than 100 metres of the Matmara dyke at Bengtola at 7 AM affecting 1000 villages and rendering at least 50 families homeless.
More than 100 families were still stranded in the floods and the district administration was trying to rescue them.
The affected villages have alleged that the weak Matmara dyke as well those in Machkhowa and Sisi were being threatened but no maintenance and repair work was undertaken.
Chief Minister Tarun Gogoi had last year announced a Rs 100 crore package to repair the weak embankments in the district but the project was still not implemented.
With today's flood damage, nearly three lakh people of the district got affected, sources said.
The situation was worse in Dhokuana sub division of neighbouring Lakhimpur district with Lali River inundating 20 villages today.
Flood waters have also affected people of Narayanpur subdivision of the district.