The committee under Chamoli DM, was set up after people raised concerns over water level sinking in Selong area, had experts from IIT Roorkee, Wadia Institute of Himalayan Geology and National Environmental Engineering Institute as members.
The committee’s conclusion bears out even today, 12 years after the tunnel was completed in this stretch in August 2011. Till date, there is no sign of subsidence around the tunnel alignment at the overground surface. There is also no sign of any damage to surface flora or fauna at the site.
This underlines the fact company engineers have been stressing time and again that drilling/boring through rock formations more than 1 km below the surface does not disturb the structure or surface flora and fauna. The engineers also pointed out that the tunnel is more than 1 km away from the town’s outer perimeter.
The project, which also envisages a concrete barrage 15 km upstream of Joshimath, has been drawing flak from the public for the crisis facing the town due to land subsidence.
Two other panels — one set up in 1976 and the other in August last year — also blamed the geography and water seepage from various sources as the main reason for the subsidence and not the project.
Broadly, the findings by both the committees were similar as they identified geography and habitation as the reasons for the subsidence. Hill wash, natural slope (angle of repose), cultivation, seepage and soil erosion among the probable causes of subsidence. The recommendation was to stop open drain, closing of soaking pits and construction of concrete sewage to stop seepage.
Sources said the findings in the reports have found an echo at recent review meetings at the Centre and its communications to provide perspective to the state.
The first committee to study the reasons of instability of Joshimath was set up Under then Garhwal commissioner M C Mishra by the UP government after instance of subsidence came to light for the first time in 1976. Yet another panel under under DM Chamoli was set up in August 2022 to look into continued subsistence.
The Mishra committee described Joshimath as highly unstable because it lies on an ancient landslide and is “situated on weathered, landslide mass of big unsettled boulders in the loose matrix of fence micaceous sandy and clayey material”.
This August 2022 panel had experts from Uttarakhand Disaster Management Authority, CSIR-CBRT, IIT Roorkee, Geology Survey of India and Wadia Institute of Himalayan Geology as members.
The Mishra committee identified the landslide zone as the area extending upto big nala near Parsari in the east, in the west upto north-west ridge and nala near Gauls, in north upto river bed. Here some in-situ outcrops on the southern bank are there, while northern bank consists of solid in-situ bedrock (Hathi Parbat) and in the South upto and beyond Audi, which may extend upto the high mountain ridge forming the watershed.
