Lessons from Joshimath subsidence

NEW DELHI: Why is Joshimath sinking? Is Joshimath unstable? These questions come to mind when we are faced with anything pertaining to the twon that falls in Uttarakhand’s Chamoli district. 

In January 2023, extensive ground subsidence occurred in the pilgrimage town, causing damage to 65% of houses. 

With various reasons having been attributed to the damage, we explain the whys and hows of the tragedy that has lessons for other Himalayan towns as well as the rest of the states.  

HIGHLY UNSTABLE 

Joshimath area has been described as highly unstable “because it lies on a landslide mass of boulders in the loose matrix of sandy and clayey material”. 

According to a TOI report on January 30, when the natural drainage system is disturbed by unplanned infrastructure, water accumulates underground and erodes the structure/slopes, leading to subsidence.  

The report, quoting a Geological Survey of India (GSI) study, has determined that this event was triggered by unregulated infrastructure development, particularly the construction of high-rise buildings, and disturbance to the natural drainage system in the fragile mountainous region. 

Contrary to earlier speculation, the GSI asserts that the subsidence was not induced by the National Thermal Power Corporation’s (NTPC) hydel project.

The report added that the GSI report echoed findings of several multidisciplinary panels since 1976. 

SEISMIC ZONE V

The Himalayan town lies in seismic zone V (the region most vulnerable to earthquakes) and is prone to landslides and flash floods.

Incidents of land subsidence in Joshimath were reported in the 1970s too.

A panel set up under the chairmanship of Garhwal Commissioner Mahesh Chandra Mishra submitted a report in 1978, stating that major construction works should not be carried out in the city and the Niti and Mana valleys as these areas are situated on moraines, a mass of rocks, sediment, and soil transported and deposited by a glacier.

MULTIPLE AILMENTS

A PTI report on September 27, 2023 quoted a report by government agencies as saying that the land subsidence has affected around 65 per cent of the houses in Joshimath.

Starting January 2, a number of houses and civil structures in an area located near Joshimath-Auli road began to display major cracks due to land subsidence, prompting the relocation of 355 families. 

According to local residents, land subsidence had been noticed over several years but became increasingly severe from January 2 to January 8.

A 35-member team — Post Disaster Needs Assessment  — consisting of professionals from the National Disaster Management Authority, UN agencies, Central Building Research Institute, National Institute of Disaster Management and other agencies said 1,403 of the total 2,152 houses in Joshimath have been affected due to land subsidence and these need immediate attention.

The report said the main causes of damage to buildings in Joshimath include the use of weak building materials, insufficient reinforcement, structural flaws, and the location of buildings on steep slopes.

The agencies urged the state government to completely ban new construction in the town till the end of the monsoon season and allow relaxation only for light-weight structures after post-monsoon reassessment of ground conditions.

The report highlights that although building bylaws exist, they are not mandatory for residential buildings.

Another issue of concern identified in the report is the "lack of town planning and absence of risk-informed land use maps".

PTI quoted the agencies as emphasising the immediate need for the development of a prospective plan with the objective of creating a safe and resilient Joshimath for the next 10-15 years.

BREACH VS TUNNEL

According to the TOI report, “the burst of water was triggered by a breach in a water body perched at shallow depth close to the surface and leakage from drilling of tunnel for NTPC’s 520 MW Tapovan-Vishnugad hydel project had no relation with it, the GSI report has said”. 

Back in 2010, a multi-disciplinary team led by the Chamoli district magistrate found no conclusive evidence linking the tunnel work to instability in the Joshimath area.

It's worth noting that the tunnel in question was successfully completed in 2011.

Despite these findings, residents and activists who opposed hydel projects continued to attribute the subsidence observed between January 2 and January 8 of the previous year to the tunnel, expressing concerns about its impact on the region.

ROAD AHEAD

On November 30, 2023, the Centre on Thursday approved a Rs 1658.17 crore recovery and reconstruction plan for Joshimath.

The decision was taken by a high level committee, headed by Union home minister Amit Shah.

Approximately 20 days after the disaster, the Uttarakhand State Disaster Management Authority (USDMA) declared that 120 families residing in areas deemed unsafe would undergo relocation.

However, in December 2023, almost a year after the disaster, Scroll reported that so far, USDMA has not relocated a single family, with an official citing "some unexpected hurdles", adding: "The relocation process will be long." 

LESSONS FROM JOSHIMATH

While the GSI’s final geological and geotechnical investigation report of the township recommended, among several measures, not allowing new construction in Auli and upper part of slopes, strictly regulating construction work as well as avoiding road widening activities along the Joshimath-Auli axis — as per the TOI report — questions abound as to the lessons for the Himalayan towns as well as rest of the states where governments high on construction seem to have bypassed the climate concerns. 

In the 1960s, there were just 30 shops in the town — that lies on the Rishikesh-Badrinath National Highway (NH 7) — and 400 families used to live here. 

By February 2023, there were more than 4,300 structures on the fragile terrain and the town had a population of more than 25,000.

"Over the years, the burden on the town has grown and it has now caused danger to Joshimath’s very existence,” HT quoted a local in Joshimath as saying.

The report also quoted Garhwal-based geologist SP Sati as saying, “What we are witnessing today in Joshimath is definitely a result of haphazard construction that has been going on in the town. The mushrooming of urban settlements is not a parameter of development but just physical growth. An extensive study should be done on the problem so that it can act as a lesson for other towns in Uttarakhand such as Nainital and Munsiyari.

A Mint report on January 7, 2027 cited several reasons for subsidence: "several new multi-story structures, slope instability gotten worse due to unplanned construction, Helang bypass, mountain streams having altered courses and having extended their channels due to significant rainfall events and obstruction in natural water drainage systems."

"Soil creep, landslides and ground subsidence” have threatened Joshimath as well as many Himalayan towns and cities — Dharamshala, Shimla, Uttarkashi, Mussoorie, Gopeshwar, Nainital, Gangtok, and Darjeeling. Climate change demands rejecting the present "no-holds-barred economic growth model", writes Ravi Chopra, a distinguished environmental researcher. 

"The knowledge and experience of the local people combined with a sound understanding of geology, ecology, and the changing climate are essential for building disaster resilience into Himalayan infrastructure projects. Infrastructure projects can no longer be designed based only on past weather trends and data. They must also incorporate safety factors for future extreme weather events," Chopra says in his essay, "Joshimath: An Avoidable Disaster".

While maintaining that the state and central governments’ response to Joshimath’s current crisis can be characterised as "delayed, halting, misleading, and timid", the IIT alumnus says, this does not mean that there should be no infrastructure development in the mountains. 

"Well-known geophysicist VK Gaur has argued that the region’s perceived weaknesses should be carefully measured and projects designed within the limits defined by the measurements," Chopra adds.