Massive water-diversion tunnel project in Himachal raises severe environmental fears

By Jag Jivan  

A high-stakes controversy has erupted in the Indian Himalayan Region following the abrupt publication and immediate withdrawal of a major infrastructure tender. The National Hydroelectric Power Corporation (NHPC) issued a public tender notice for the proposed "Chenab-Beas Link Tunnel Project (Link 3)" only to cancel it abruptly just three days later.

The brief window, however, was enough to trigger sharp alarms among environmental scientists, policy experts, and local communities who warn that the project could act as a catalyst for catastrophic disasters in one of the world's most ecologically fragile zones.

​According to a scathing investigative analysis by the South Asia Network on Dams, Rivers and People (SANDRP), the proposed project involves building a 19-meter-high concrete barrage at Koksar village in Himachal Pradesh’s high-altitude Lahaul and Spiti district. From there, an 8.7-kilometer water diversion tunnel would be bored directly through the Pir Panjal mountain range to discharge the high-velocity glacial waters of the Chandra River (a major tributary of the Chenab) into the headwaters of the already flood-prone Beas River basin.

​Despite the rapid retraction of the tender notice, political support for the massive water-diversion scheme remains active. The Governor of Himachal Pradesh, Kavinder Gupta, publically backed the initiative, stating that the link tunnel would allow for "better utilization of water" to meet the primary needs of Punjab, Haryana, and Himachal Pradesh.

​"Sitting on a GLOF": Experts Warn of Multi-Hazard Risks

​Environmental advocates have strongly condemned the revival of the project, pointing out that it lacks essential legal mandates—including environmental, forest, and tribal ministry clearances, as well as mandatory Gram Sabha resolutions from local indigenous communities.

​Parineeta Dandekar, a prominent environmental researcher and coordinator with the advocacy group SANDRP, warns that pushing forward with a project of this scale ignores the stark, immediate realities of climate change in the Western Himalayas. Dandekar notes that the region is a "multi-hazard zone" where risks do not occur in isolation but routinely compound one another.

​"The upstream and immediate downstream of the proposed barrage is an extremely vulnerable region under the shadow of serious GLOF (Glacial Lake Outburst Flood), flash flood, avalanche, and landslide risks," says Dandekar. "There is no operational early warning system, no climate assessment, and no emergency plans for this region so far. The impacts of an additional barrage, blasting, tunneling, and muck disposal here are incomprehensible."

​Dandekar points out that the proposed barrage at Koksar (sitting at an elevation of 10,300 feet) is located directly downstream from volatile, rapidly changing glacial environments:

- ​The Samudra Tapu Glacial Lake: Located 67 km upstream of the project site, data from ISRO’s National Remote Sensing Centre (NRSC) indicates the lake has experienced an alarming 905% expansion in size over recent decades, posing an imminent GLOF risk that could completely inundate Koksar.

- ​The Ghepan Gath Glacial Lake: Situated just 12 km downstream of the barrage site, this lake has expanded by 178% and is deemed one of the most dangerous in India, leading local administrators to warn that local settlements are effectively "sitting on a GLOF."

​- The Bara Shigri Glacier: Himachal’s largest glacier is rapidly retreating upstream, leaving behind over 60 volatile, ice-dammed debris lakes susceptible to sudden bursting.

​Furthermore, climate projections indicate that even under moderate emission scenarios, the Chandra basin is on track to lose 33% of its total ice volume—roughly 17.7 gigatonnes—by the 2050s. This massive loss of glacial ice directly threatens the long-term hydrological viability of transferring water through the tunnel in the first place.

​Structural Threats to the Pir Panjal and Existing Infrastructure

​The physical construction of the 8.7-kilometer tunnel raises severe safety concerns regarding nearby critical infrastructure, most notably the Atal Tunnel at Rohtang Pass—the primary lifeline connecting Lahaul and Spiti to the rest of India.

​The previous drilling of the Atal Tunnel took over a decade due to severe "geological surprises," such as the treacherous Seri Nallah Fault Zone. Dandekar emphasizes that repeating heavy drilling and blasting operations in a highly active seismic zone could severely compromise both the structural integrity of the mountains and the safety of the thousands of tourists and vehicles crossing the Atal Tunnel daily.

​The Problem of Muck and "Water Transfer During Floods"

​A primary environmental grievance highlighted by the advocacy group is the reckless disposal of construction waste. Massive mounds of untreated muck from previous regional road works have already been dumped directly into the Chandra River without retaining walls.

​"There is a realistic possibility that a high-energy flash flood or GLOF will operationalize this muck, devastating the downstream," Dandekar warns. "This muck can block the barrage entirely, creating a reservoir which will eventually break." She compares the threat to the recent infrastructure failures seen during intense monsoon seasons at the Madhopur Barrage on the Ravi River.

​Furthermore, critics question the foundational logic of the inter-linking project. Lahaul is historically a high-altitude desert, but climate change has drastically altered its precipitation profile, triggering heavy summer rainstorms during June, July, and August.

​Because both the Chenab and Beas basins now experience peak flooding simultaneously, transferring high-velocity water into the Beas headwaters during these months would only exacerbate the destructive flash floods that routinely wash away highways and bridges near Manali, Solang, and Palchan. Downstream, key reservoirs in the Beas-Sutlej system like the Pandoh, Pong, and Bhakra dams are already heavily choked with silt, drastically limiting their ability to hold any additional diverted water.

​As local resistance builds, environmental groups are calling on the central government and the NHPC to permanently shelf the Chenab-Beas Link Tunnel, urging a shift in focus toward climate adaptation, early warning systems, and protecting the vulnerable tribal communities who are bearing the disproportionate brunt of Himalayan climate disasters.