"‘Ticking time bombs’: Sikkim floods a reminder of why locals opposed dams in the Himalayas for years", 9 October 2023

In the early hours of October 4, a flash flood ravaged North Sikkim. The hurling waters washed away Sikkim’s largest hydropower project, the 1,200-MW Teesta III, escalating the damage downstream in districts of Gangtok, Namchi, and Pakyong. [33] people have died and 105 are missing, according to the latest update...

But local activists and environmental experts point out that the damage caused by the glacial lake outburst flood was compounded by the presence of a string of dams in the Teesta river basin. The flood emanating from the lake destroyed the structures of three dams downstream, unleashing the water stored in their reservoirs, exacerbating flooding and damage.

Activists say they had warned the authorities that building dams in an earthquake-prone region like Sikkim was dangerous. A 2020 report by the National Disaster Management Authority, while comparing potentially critical lakes in the Himalayan region, had noted that the “threat to hydropower is the highest in Sikkim”. Specifically, the government knew the dams built on the Teesta river were under threat from the South Lhonak lake.

Sikkim currently has five existing hydropower projects along the Teesta basin, 15 that are upcoming and 27 more in the pipeline. Of these, at least three suffered damage in the October 4 flooding, said the Union Ministry of Power. The Teesta phase III project, commissioned in 2017, was the first to bear the brunt of the floods and was washed away...

Lepcha of the Affected Citizens of Teesta said that they had raised environmental and cultural concerns – the Teesta river has cultural significance for the Lepcha community – while opposing the dam in the Sikkim High Court. But the court in 2010 dismissed the matter while noting that project authorities had undertaken requisite action such as conducting an environmental impact assessment and obtaining forest clearance.

...The Central Water Commission official confirmed that project developers are well aware of such lakes in their catchment area and it is unlikely that they were caught off guard by events like these.