The National Green Tribunal (NGT) has issued a notice to the Sikkim government, Sikkim Urja Limited and the NHPC Limited on a hearing related to the breach of the Sikkim Urja Teesta Stage-III dam at Chungthang during the recent flash flood.

The notice has been issued by the principal bench of the NGT. A hearing — physical, with a hybrid option — has been scheduled on October 20.

The bench has taken up the issue suo motu and asked the three parties to attend the hearing failing which the application will be heard and determined in their absence.

“Take further notice that in default of your appearance on the date of above mentioned, the said Application will be heard and determined in your absence,” the notice issued by Arvind Kumar, deputy registrar, NGT (principal bench), has stated.

The 1200mw hydel project in Chungthang was Sikkim’s biggest hydel project, which sources said was washed away within 10 minutes following the glacial lake outburst flood (GLOP) from South Lhonak Lake on the intervening night of October 3 and 4.

The Sikkim government has a 60 per cent stake in the project which is managed by Sikkim Urja Teesta Limited. The NHPC also operates hydel projects in Sikkim.

Soon after the incident, Sikkim chief minister Prem Singh Tamang (Golay) had said: “South Lhonak Lake did burst but major destruction downstream is also because the Teesta-III dam gave away. This is because of sub-standard work. This was done in the previous government.” His government would start an inquiry, he said.

The dam was commissioned in 2017, when the Sikkim Democratic Front (SDF), led by former Sikkim chief minister Pawan Kumar Chamling, was in power.

Chamling’s party, however, has countered Golay’s allegation.

“The collapse of the Teesta-III dam must be forensically investigated. There should also be an investigation on whether enough was done to prevent glacier lake outburst flood (GLOP),” P.D. Rai, senior vice-president of the SDF, countered, adding that the SDF government had worked on lowering the water level at the lake.

The SDF wondered why the Teesta III dam was not decommissioned when Golay came to power in 2019 if he thought the dam was faulty.

BJP MP from Gangtok Y.T. Lepcha also filed a complaint against Chamling.

“The prime cause of all these devastation is traceable and we can pin-point it on the greed of the ex-C.M. Sri P.K. Chamling who worked against public opinion…” the BJP legislator wrote in his complaint.

Environmentalists have been opposing dams in Sikkim. The Affected Citizens of Teesta (ACT) had sat on a 915-day dharna from June 22, 2007, to September 27, 2009, against hydel projects in Sikkim. Many believe that four hydel projects were scrapped in the Teesta basin due to the campaign by ACT.

The NGT hearing also comes at a time when the state government is preparing grounds to set up 520mw Teesta stage IV hydel project.

Sources said that the process to acquire land had started a few days before the October flash flood.

“The Teesta stage IV hydel project must be scrapped as all previous studies and clearance for this project are irrelevant with the topography changing after the recent catastrophe,” said Gyatso Lepcha, the general secretary of ACT.