Finally putting to rest months of speculation, the Geological Survey of India (GSI) has concluded in its final investigation report that the widespread ground subsidence in Joshimath last year was primarily caused by "unregulated infrastructure development" in the form of high-rise buildings and disruption to the natural drainage system.
The January 2023 incident, which damaged 65% of houses in the pilgrimage town, was triggered by unregulated infrastructure development in the form of high-rise buildings and disturbance to the natural drainage system in the fragile mountain environment, TOI reported.
No Role for NTPC Project:
The report categorically rejects claims that NTPC's Tapovan-Vishnugad hydel project played any role in the subsidence. Concerns about the project's tunnel boring activities were addressed by the GSI, stating that they did not contribute to the breach of a water body near Marwari, which is identified as the key factor behind the ground fissures. Notably, a 2010 investigation by the Chamoli district magistrate also found no evidence of the tunnel impacting Joshimath's stability.
The GSI report aligns with findings from several multidisciplinary panels since 1976, highlighting the inherent instability of the Joshimath area due to its location on a landslide mass. The report emphasizes that human interventions, particularly unplanned infrastructure development, exacerbate this vulnerability by disrupting natural drainage and causing water accumulation and erosion.
Key Findings:
- High-rise construction and drainage disruption blamed: The report identifies "unregulated infrastructure development in the form of high-rise buildings" and "disturbance to the natural drainage system" as the main triggers for the ground subsidence.
- NTPC tunnel exonerated: Contrary to popular claims, the GSI found no link between the sinking and the tunnel construction for NTPC's Tapovan-Vishnugad hydro project.
- Sudden water burst identified: The report cites a burst of silt-laden water from Jaypee colony as a specific event leading to cracks and fissures in several areas. This outburst, it explains, was caused by a shallow water body breaching, not by the tunnel project.
- Multidisciplinary assessments confirm findings: The GSI's conclusions align with multiple previous studies, including a 1976 report by the Mishra Committee, which highlighted the unstable nature of Joshimath's landslide-prone terrain.