Hydropower projects fuelling disasters in Himalayas: Experts

New Delhi: Violations of norms during the construction of hydropower projects in the fragile Himalayan region are fuelling disasters in the hilly states, environment experts and activists have warned.

A glacial lake outburst flood in Lhonak Lake in Sikkim last week resulted in severe damage in Mangan, Gangtok, Pakyong, and Namchi districts. The incident also resulted in the breach of the Chungthang dam, also known as Teesta III dam, a crucial component of a mega hydropower project in the state.

These experts and activists emphasised that the series of dams built on the Teesta river fuelled the disaster and demanded the cancellation of the proposed Teesta IV dam.

Several occasions in the last two decades have seen government agencies and research studies warning about potential glacial lake outburst floods (GLOFs) in Sikkim, which can cause massive damage to life and property.

A study conducted by the Central Water Commission in 2015 clearly informed the state government that most of the hydropower projects on the Teesta are highly vulnerable to such events.

Gyatso Lepcha from Affected Citizens of Teesta (ACT), a local advocacy group, said, "The 1,200 MW Teesta III was completely washed away. This dam was built only 30 km away from Lhonak Lake. The state government is blaming the previous government for substandard construction. The previous government is blaming GLOF, but nobody is questioning the construction of the dam in such a fragile area."

"This is not a natural disaster, and we are now demanding accountability plus the cancellation of the proposed Teesta IV dam," he said.

The Himalayas' glacial melt has accelerated due to rising global temperatures. Also, the outburst may have been nudged by a cloudburst and earthquake that struck a day earlier in neighbouring Nepal. The flood's impact and intensity were exacerbated severely by the dams on the Teesta River, triggering a cascading effect downstream.

Tonnes of concrete muck were discharged as the massive Teesta III dam collapsed under the weight of the flood, compounding the flood's ferocity.

The failure to open the spillways of Teesta III dam is being considered a major factor that exacerbated the GLOF's impact.

The ACT has been resisting the proposed dam network in Dzongu and nearby regions for two decades.

However, the authorities have consistently disregarded local opposition and ignored all social and environmental rules. The administration was specifically aware that the South Lhonak Lake posed a threat to the Teesta River dams, Lepcha said.

Dams act as force multipliers in times of disasters. Most casualties occur near them, said Himanshu Thakkar, coordinator of the South Asia Network on Dams, Rivers, and People (SANDRP).

"The authorities at Chungthang were informed by the Indo-Tibetan Border Police (about the rise in water levels), and from 10:40 pm to 11:40 pm, they had an hour to open up the spill gates of the dam. Electronically operated gates take minutes to open. Even hydro-mechanical gates take only about 15 minutes to open," he said.

He said that the Dam Safety Act (2021) only looks at the "structural integrity of the dams; it doesn't talk about the operational integrity of dams. Safety audits need to be a public exercise".

In the case of decades-old dams that have become structurally weak over time, Thakkar said that the DSA 2021 was to include decommissioning of dams but that was later omitted from the law. "There will have to be public pressure to decommission the aged dams which pose a threat," he said.

Violations of environmental rules during the construction of dams and roads, unbridled tourism, and rapid concretization have led to several disastrous events over the years. Prominent incidents this year include the Joshimath land subsidence crisis in January, the Doda land subsidence crisis in February, and the floods in Himachal Pradesh and Uttarakhand.

The Sikkim flood, much like the other disasters that unfolded in the Himalayan region this year, is unquestionably the outcome of a development paradigm that blatantly disregards the geological complexity and the cultural heritage of the Himalayan region, as the environment experts and activists said.

Ebo Mili, an environmental activist from Arunachal Pradesh, said, "We have 1,500 glacial lakes in Arunachal Pradesh, and the number is highest in my district. The attitude of the government and proponents of dams within is despicable. When the dams are constructed, disaster is inevitable.