Subscribe
Scientists have warned that diverting the Kheer Ganga river in Uttarakhand’s Dharali could increase the risk of future disasters.
The glacier-fed river changed course after the 5 August 2025 Dharali disaster and has since been flowing westward into the Bhagirathi.
Geologist Naveen Juyal and environmental researcher Hemant Dhyani say forcing the river back into an artificial channel could disturb the geomorphological balance of the area.
Experts say high Himalayan rivers carry large amounts of debris and boulders, making rigid channelisation risky in a region already vulnerable to landslides, flash floods and glacial melt.
The case has revived concerns over construction on active floodplains and the wider policy of trying to control Himalayan rivers in an era of climate change.
The Kheer Ganga river is being diverted in Dharali, Uttarakhand, and scientists have warned that the move could increase the risk of a future disaster.
Experts, citing a photograph taken by British photographer Samuel Bourne in 1866, say that historically the Kheer Ganga flowed to the west of the temple in the area.
The disaster that struck Dharali in Uttarakhand on August 5, 2025 not only swept away homes, hotels and roads, but also raised serious questions about the development policy of “controlling” Himalayan rivers.
After the disaster, the Kheer Ganga changed course, creating a new westward flow path. But the government is now building an artificial channel to redirect it back to its old path. Geologists and environmentalists warn that this is not a solution, but an invitation to another disaster in the future.
The Kheer Ganga, which originates from a Himalayan glacier, is currently flowing westward after the 2025 disaster before joining the Bhagirathi river. Previously, in 2013, it was flowing eastward through an artificial channel.
Preparations are now under way to reroute the river. According to a local newspaper, the Border Roads Organisation has already constructed a 300-metre channel.
Geologist Naveen Juyal and environmental researcher Hemant Dhyani have sent a letter to the National Disaster Management Authority (NDMA), warning that river diversion in the fragile Himalayas could prove disastrous.
In a joint commentary on the paper, Channelizing the Glacially Fed Rivers: Ensuring Safety or Enhancing Vulnerability?, Juyal and Dhyani said that the policy of channelising rivers in the high Himalayan region into artificial channels could further increase the risk of future disasters.
“In high sediment-laden Higher Himalayan rivers, rigid structures are futile because nature appreciates flexible, sustainable river management that can accommodate high sediment load,” the two experts said.
According to the report, the Himalayas are already a highly vulnerable region because of landslides, earthquakes, fragile rocks and rapid erosion. Climate change has made this crisis worse.
Experts say that because of elevation-dependent warming, temperatures in the Himalayas are rising faster than in the Indian plains. This is reflected in the rapid melting of glaciers, the expansion of glacial lakes and the weakening of frozen surfaces in high-altitude areas.
They say this is why avalanches, debris flows, landslides and flash floods have increased in recent years. The Dharali disaster of 2025 is also part of this broader climate crisis, they said.
According to the report, the Kheer Ganga is a glacier-fed stream that flows through a steep gorge approximately 7.5 kilometre long before joining the Bhagirathi river.
On August 5, 2025, a massive debris flow occurred in several consecutive phases from afternoon to evening. It deposited debris up to 10 to 15 metres thick, including boulders, gravel and glacial sediment.
Experts say the debris came down from an unstable moraine ridge above. The India Meteorological Department reported only 8mm to 10mm of rain at the time.
The report speculates that rainfall on snow and glacier surfaces likely broke the ice sheet, releasing saturated sediment and boulders beneath.
According to the report, the debris flow initially entered the artificial channel created after 2013 to divert the Kheer Ganga eastward. However, as the channel filled with debris, the subsequent flow turned westward and began flowing into the Bhagirathi via a tributary.
Since the disaster, the Kheer Ganga has consistently flowed along this western path.
Experts, citing Samuel Bourne’s 1866 photograph, suggest that historically the Kheer Ganga flowed west of the temple. The report says oral memories of local people also confirm this.
According to experts, it is not clear when and how the river was diverted eastwards, but the reinforced cement concrete, or RCC, bund constructed by the Irrigation Department after the 2013 disaster artificially controlled the river.
The report says that after the June 2013 disaster, the Irrigation Department built an RCC wall along the Kheer Ganga to prevent debris from reaching settlements.
However, experts say this wall created a “false sense of security”, leading to the construction of hotels and other structures very close to the river.
They say this construction violates a notification issued on October 7, 2016 by the Union Ministry of Water Resources, River Development and Ganga Rejuvenation.
Section 6.3 of the notification says that no permanent or temporary construction of any kind may be permitted in the Ganga, its tributaries, banks and active floodplains.
According to the report, the government is now attempting to reroute the Kheer Ganga back to its “pre-5 August 2025” path by constructing a new channel approximately 300 metres long.
The stated rationale is that the current course passes through agricultural land. However, Juyal and Dhyani have raised serious questions about the move.
They argue that forcing the river back to its earlier path in debris-flow areas could disrupt the geomorphological balance.
Experts have pointed to several potential hazards. Diverting a river on debris-flow surfaces can cause excessive erosion and heavy sedimentation in some areas. The river can suddenly reroute, posing a threat to new areas.
Channelisation also increases flow speed and pressure, which can lead to landslides and slope instability. Sudden surges in glacier-fed rivers can breach artificial channels. Channelised streams can carry more concentrated debris, increasing the devastation caused by floods.
The report also raises questions about law and environmental regulation.
It says the Uttarakhand Floodplain Zoning Act, 2012, classifies tributary rivers as “rivers” and mandates floodplain demarcation.
Section 2.5 of the Bhagirathi Eco-Sensitive Zone Notification states that any development plan must be based on a “watershed-based approach” and that the natural course of rivers should not be disturbed.
Experts allege that attempts are being made to divert the river without following these rules.
The report concludes that it would have been more appropriate to allow the Kheer Ganga to flow along the new natural course it adopted after the 5 August 2025 event.
Juyal and Dhyani write that the priority in the high Himalayan region should not be to control rivers, but to limit human interference.
They warn that similar channelisation projects are under way in the Kedarnath and Badrinath valleys.
In an era of climate change, when the incidence of glacial lake outburst floods and debris flows is increasing, such projects could increase disaster risk rather than reduce it, they said.
