Rapid urbanisation, tectonic faultlines: Decoding the reasons behind Joshimath ‘sinking’

The crisis in Joshimath is a tale of reckless human interference with the ecosystem of the mountains disrupting the ecology.

The land of strategic, cultural, and religious importance will most likely now only be recalled in history as significant sites have come under the threat of land subsidence.

However, experts feel the threat to an entire town is not a result of any sudden natural calamity but a slow and ruthless ignorance of urbanisation that looms over the hilly towns of Nainital, Mussoorie, Shimla, and Dharamshala in the coming days.

Joshimath, a key transit point for tourists traveling to Badrinath and Hemkund Sahib, situated at an altitude of 1,890 metres from sea level in the Garhwal Himalayas, has a population of over 20,000. At least 600 residents have been asked to evacuate by authorities in recent days following an incident of subsidence. It is located on the Rishikesh-Badrinath National Highway (NH-7) of Chamoli district which falls in Zone V of the Seismic Zonation map and almost sits on the tectonic fault line of Vaikrita Thrust (VT).

Adding to the peril, two other faultlines fall close to the Vaikrita Thrust on both sides, namely the Main Central Thrust (MCT) and the Pandukeshwar Thrust (Vishnuprayag region). This in turn is further exacerbating the risk of Joshimath sinking mainly due to tectonic activity, as is being claimed by the experts in the field. Tectonic faultlines are planar fractures or discontinuity in a volume of rock across which there has been significant displacement as a result of the displacement of rocks between tectonic plates from megathrust zones.

The hilly town is traversed by running streams of Dhauliganga and the Alaknanda rivers on the south and the north. A number of streams that include Dhaknala, Karmanasa, Patalganga, Belakuchi, and Garurganga flow into the Kunwari Pass in Central Himalayas. The flash floods in Rishiganga and Daulaganga occurred in October 2021, followed by the blockade of these streams due to landslides.

THE 1976 MISHRA COMMITTEE REPORT

The government appointed MC Mishra in 1976, the then collector of Garhwal to form an 18-member committee for reconnaissance of the land subsidence near the Himalayan border. According to the Mishra Committee report, the town is situated in an old landslide zone and is sinking. As per the report, scattered rocks in the area are covered with old landslide debris comprising boulders, gneissic rocks, and loose soil, with a low bearing capacity, highly weathered, and a low cohesive value. “Joshimath is a deposit of sand and stone — it is not the main rock — hence it was not suitable for a township. Vibrations produced by blasting, heavy traffic, etc., will lead to a disequilibrium in natural factors…” the report has stated.

Joshimath has been showing signs of continuous ground subsidence due to the progressing anthropogenic pressure coupled with its topography, being situated in proximity to major tectonic discontinuities. Eco-tectonic and geomorphic factors coupled with meteorological characteristics render Joshimath highly vulnerable to landslide subsidence.

CONSTRUCTION PROJECTS
1. Tapovan Vishnugad Hydro-electric Project

THDC is a joint venture between the government of India and the government of Uttar Pradesh, designed as a 12.1 km long, 444-megawatt, run-of-river hydropower scheme which, when completed, will generate an estimated 1,665 gigawatt-hours of electricity in a year. This is planned to contribute to peaking power consumption in India’s Northern Grid, which faces severe power shortages at high-consumption times. The project is primarily funded by the World Bank and was proposed in 2009, sanctioned in 2011, and is estimated to be completed in June 2023.

However, the project has now been delayed for over a decade due to a series of “mishaps” that experts blame primarily on “inadequate geological assessment.” An independent panel of the World Bank is considering a plea by residents of Haat village, Chamoli district, Uttarakhand to investigate environmental damage. It was severely damaged in February 2021 due to a flash flood caused by a glacier burst at Nanda Devi.

“The tunnel built by NTPC(National Thermal Power Corporation) does not pass under Joshimath town. This tunnel is dug by a tunnel boring machine (TBM) and no blasting is being carried out presently,” NTPC said in a statement. Locals claim that a tunnel was in construction by the NTPC for which a Tunnel Boring Machine(TBM) was deployed to excavate into the mountains. The TBM reportedly got stuck while in construction and later NTPC blasted the area in an attempt to pull out the machine. However, the blast resulted in creating fractures in the slope, and water gushing out of the puncture has added to land subsidence.

2. BRO’s Helang-Marwari bypass project

A 6-km long bypass construction from Helang to Joshimath to Marwari was proposed back in 2019, the construction work started only last year amid opposition from residents. It was planned to reduce the distance to Badrinath by approximately 16 km. Locals opposed the construction citing that commercial activities for businessmen will be doomed if the yatra is cut short. Later the width of the road was reduced from 12m to 5.5m of Marwari bypass to operate as a one-way, highlighting the strategic importance of Joshimath.

The construction work has only been limited to widening the roads as of present which are away from the Joshimath area and there have been no blasting incidents, reported BRO to the Ministry of Road and Transports.

3. Badrinath Highway in Chardham Project

Badrinath Highway is a part of the construction of the Chardham Project – an ambitious project stretching over 900 km road was announced to promote religious tourism connecting all four ‘Dhams’ or religious shrines of India, i.e, Gangotri, Yamunotri, Kedarnath, and Badrinath. The 12000 crore dream project was planned to play a vital role in the travel safety of lakhs of pilgrims and travel enthusiasts.

The project has been on the hit list of environmentalists as the hills of Uttarakhand as not as stable as in Jammu and Kashmir and the region is a “highly sensitive zone with a fragile ecosystem,” as mentioned in the Mishra 1976 report and promises to bring about catastrophic consequences for the mountain ecology.

As of December 9, only 291 km has been constructed out of the proposed 825 km and the construction has been delayed due to court cases and protests in the adjacent regions.

4. Chardham Railway and Tunnel Project

The 125 km Rishikesh-Karnaprayag Railway line in Uttarakhand is another major railway infrastructure project that started in 2019. The project requires the construction of at least 17 tunnels with an escape and main tunnel, ballastless tracks, and 35 bridges.

In the next decade, the Government proposes to build 66 tunnels in the Himalaya region of Uttarakhand and 18 tunnels are already in operation. The company is utilising Sandvik’s DT 821 C and DT 922i advanced automatic jumbo drills to pierce through the rocky Himalayan terrain. These pieces of equipment are penetrating the rocks with bolt-hole drilling and long-hole drilling with the required power for constructing the main railway tunnel and the parallel escape tunnel.

The railways would also rely heavily on electric locomotion which is plausible to generate vibrations during train movements that would keep the mountain ecology eternally unstable and make it vulnerable to slide at the slightest trigger.

URBAN DEVELOPMENTS
The fact that the tourist economy of the region is flourishing being the gateway to Badrinath and Hemkunt Sahib shrines added to the population of Joshimath which has also increased manifold in recent years. The stark difference in settlements can be witnessed in the image in contrast to 1890.

“Natural terrain, Geological instability, deforestation, unplanned urbanization & construction, heavy blasting-drilling for the Tapovan-Vishnugad hydel project, and unscientific hill cutting for Char Dham highway were the causes for the Joshimath crisis,” says a Dehradun based scholar and geologist.

Harsh also noted that the governement should come up with a land use policy before implementing any urban contruction plan. “Why Joshimath has come under tremendous stress is because like most settlements in the Himalayan zone, this town too, is loaded beyond its carrying capacity,” he adds.

He further days that “Govt should consider geological vulnerability, slope stability, spring resources while constructing tunnels, hydel project or roads/buildings etc. Blatant deforestation needs to be stopped which is one of the main factor of soil erosion in hilly slopes/terrains.”

NATURAL CAUSES

Looking back at the 1976 Mishra Committee report, it is found that the undercutting river currents of Alaknanda and Dhauliganga are playing their part in inducing landslides. In February 2021, the flash flooding incident further aggravated the crisis at hand as the soil beneath the city had been eroded by the river currents.

Another factor of paramount concern is the poorly planned drainage system of the burgeoning Himalayan town. Several geologists highlight the crisis point that water could be seeping into the ground, weakening the land slowly but consistently.

Being located at the toe of the hill, household drainage water from Joshimath is supposed to naturally flow downstream into the nine drains that cross the villages and finally flow into the river Dhauliganga and Alakananda. As tourism thrived and more commercial construction took place, the drainage flow streams were obstructed resulting in the wastewater oozing out of far-fetched areas. This water is likely to be seeping into the ground and weakening the already unstable rock sediments on the sub-surface.

Geologists have reported that many seepages occur from streams uphill, which further loosens the soil and leads to mudflow in the rains. Scientists who surveyed the area in 2022 also highlighted similar concerns related to improper drainage management.