Assam: Subansiri river flow resumes after landslide, but dam safety concerns remain

Guwahati: The flow of the Subansiri River, which was blocked on Saturday due to a landslide at the Lower Subansiri Hydroelectric project at Gerukamukh on the Arunachal Pradesh-Assam border, resumed naturally on Friday evening, officials of NHPC Ltd said.

"The Subansiri River was blocked at 11:30 am on October 27 due to a landslide at the diversion tunnel. As a result, the flow towards the downstream of the Subansiri dam was reduced. The reservoir filled up to the spillway level and the river started flowing naturally again at 10:40 pm on Friday," an NHPC official said.

There is no need for panic among the downstream people, he said.

The Subansiri River suddenly dried up on Friday morning, causing widespread panic among the people of north Assam's Lakhimpur district.

Of the five 9.5-meter diameter diversion tunnels, only tunnel number 1 was in use. It was blocked due to a landslide at around 11:30 am today. The other four tunnels had already been blocked earlier. As a result, the river flow to the downstream was highly reduced," NHPC had said.

As the river dried up suddenly due to the blockade, there was a fear of the diversion tunnel breaching by the blocked water and resulting in a disaster similar to the one that recently occurred in Sikkim.

The SLHEP dam, which is scheduled to become operational from January 2024, has been a cause of concern for the public as repeated landslides have hit its construction work periodically.

These recurring landslides indicate the fragile nature of the terrain where the hydropower dam is being constructed. Though the NHPC claims that the dam is safe, its site on the hills is not.