By Kainat Aziz & Adeela Hameed
The historic town of Joshimath in Uttarakhand will be lost if an under-construction National Thermal Power Corporation (NTPC) project, the Tapovan-Vishnugad hydropower project, near it is not completely stopped. In addition, a 6 km long Helang-Marwari bypass road is being built by the Border Roads Organisation (BRO). It falls under the controversial 825 km Char Dham road expansion project in Uttarakhand. This is yet another project believed to have exacerbated the problem. Around 678 houses in Joshimath have so far developed major and minor cracks on their ceilings, walls, or floors. Even the foundations of several houses are impacted as the land, on which the town is set, continues to sink.
The woes of Joshimath are far-reaching
Subsidence is defined as the downward vertical movement of the Earth’s surface. It can be caused both by natural processes and human activities and involves little to no horizontal movement.
The problem of land subsidence in Joshimath is neither new nor is it sudden. It had emerged decades ago. A committee – the MC Mishra Committee – was formed to assess the reasons behind it. The Mishra Committee report of 1976, the oldest report that explores land subsidence in Joshimath, warned against removing boulders by digging, excavating the slopes, or using explosives.
The town is built on slopes that have deposits from an old landslide. The deposits might have stabilized over time, however, uncontrolled construction, particularly of projects like roads and dams, that extensively employ explosives, drills, and excavations, have weakened the slopes. The construction of buildings has further added to the problem. To make matters worse, the Seismic Zonation Map of India places Joshimath in Zone V (highest risk zone).
Experts have warned that Joshimath is not the only town in Uttarakhand facing subsidence. There are many others on the brink, including towns and valleys in other geographically sensitive Himalayan regions. But authorities have time and again turned a deaf ear to independent scientists.
Resident locals including Atul Sati, convener of the Joshimath Bachao Sangharsh Samiti, had issued warnings on this, years ago, protesting the construction of NTPC’s 520 MW Tapovan-Vishnugad hydropower project since 2004.
However, the company responsible for the hydropower project has claimed that its 12.1-kilometer tunnel had nothing to do with the latest land subsidence. Yet, reports note that the company has a history of breaches and listed incidents where such digressions occurred.
Land subsidence is a silent disaster taking hold of the Himalayan towns across the country. Similar fissures and sinking complaints have come from Karnaprayag, some 80 kilometers from Joshimath.
Chenab Valley under threat
Around 300 people have been shifted to temporary and make-shift accommodations in a village of district Doda in the Union territory of Jammu and Kashmir after some houses collapsed and others developed cracks recently. The village, Nai Basti, is located 35 km from the city of Doda, on the Kishtwar-Batote National Highway.
The incidents started to occur on February 1, 2023, when six houses were affected in Nai Basti village in Thathri. Some houses fell while others developed cracks. The situation was worsened by a landslide, with the number of constructions damaged reaching 21. The authorities declared a mosque and a religious school for girls unsafe after a thorough investigation. While some people shifted to temporary shelters set up by the district administration, many families have returned to their ancestral homes.
Experts are of the opinion that undue human encroachment in geographically sensitive areas is the main cause of land subsidence. It has been well known that human expansion has resulted in streams and springs, which serve as natural discharge channels, being blocked. Haphazard construction that has been going on without keeping a region’s geo-morphology in mind is another reason for increased land subsidence in the Himalayan valleys.
However, locals, including the Sub-Divisional Magistrate (Thathri), Athar Amin Zargar, have claimed that the incident in Nai Basti was not like Joshimath. Land subsidence is frequent around Thathri and other places in the Chenab Valley.
It is said that Nai Basti and Thathri was subsidence-prone zone before 1988. Those who live there now settled at the height of the Kashmir insurgency. Thathri is situated on a steep slope along the Chenab. No expansion is possible within the town so, it has been expanding upwards, which is why this village has grown higher up on the hill.
A thorough study of land subsidence in Nai Basti conducted by the Geological Survey of India is underway. Around 117 members of 19 families of policemen, ex-servicemen, defense personnel, and laborers have, till then, been relocated.
Duksar village
A land sinking incident was also reported from Duksar village of Gool tehsil of Ramban district. About 10 houses collapsed while deep cracks, of several meters, were observed in the connecting road. The presence of Murree and Sangaldan Thrust along with steep slopes makes the area susceptible to sliding. In addition to that, major construction projects underway in the surrounding regions, including the Sangaldan railway tunnel, slope cutting for the extension of an adjacent road in the neighborhood, and blasting for the extraction of minerals like limestone and gypsum altogether may have aggravated the situation causing subsidence.
Is geology at ‘fault’?
In the Himalayan arc, land subsidence may occur due to the reawakening of a geographic fault where the Indian Plate has slid underneath the Eurasian Plate, all along the Himalayas, in the form of slow sinking known as the ‘creep moment’. Doda had seen a few minor earthquakes prior to February along with the neighboring Chamba district of Himachal Pradesh. This may have triggered a shift in the fault line resulting in the development of deep cracks in the area. However, experts also suggest that subsidence at Nai Basti may have been caused, in part, by the constant seepage of domestic water into the soil.
Hydropower projects in the Chenab Valley a looming disaster
The country has planned a number of hydropower projects on the Chenab river apart from the existing projects such as Baghlihar I and II and Dul Hasti. These projects are Sawalkote (1,856 MW), Pakal Dul (1,000 MW), Kiru (624 MW), Kirthai I (390 MW), Kirthai II (930 MW), Kwar (540 MW), and Bursar (800 MW).
The Indian Ministry of Environment and Forests (MoEFF) gave a nod to the 800 MW Bursar Hydroelectric Project in 2018 without fulfilling some basic environmental norms according to reports. The proposed project rests in the Pakal village on the Marusudar, one of the major tributaries of the Chenab river.
According to the National Hydroelectric Power Corporation (NHPC), which is the project executing agency, the Bursar HEP is a storage project in which the flow of water can be regulated not just to the benefit of this project, but all downstream ones. This would enhance the power generation potential of all projects during the lean flow months. The hydroelectric projects include Pakal Dul, Dul Hasti, Rattle, Baglihar, Sawalkot, and Salal.
According to their EIA report, a total of 18 hamlets would be affected, directly or indirectly, due to various project activities. The total population of affected villages was estimated at around 16,943, distributed among 3,193 households.
However, environmental experts have questioned the authenticity of these EIA reports while also raising concerns over the fact that whether the construction of a series of big hydropower projects on a single river basin – the Chenab – is such a good idea or a disaster in the making.
Chenab valley is situated along a fault line and is categorized under Zone V (highest risk zone) of the Seismic Zonation Map of India, similar to Joshimath. Increased seismic activity has indeed been reported over the last couple of years, yet what makes matters worse is the erosion and loosening of soil around the region. And with land subsidence happening in Doda recently, skepticism regarding the advantages of these hydropower projects is increasing among the local residents as well as people living downstream.
Recommendations
Considering its numerous potential causes, subsidence sometimes has several sources in a given area, both natural and anthropogenic. The difference between natural and human-induced subsidence is essential for policy-making. This demonstrates that it is desirable to apply mitigation measures to prevent human-induced subsidence whereas for natural subsidence only adaptation measures may be utilized.
Some of the following may be considered as well.
- Policy interventions: Required construction work in mountainous regions to avoid a repeat of Joshimath in other vulnerable Himalayan valleys like Chenab.
- Sensitive areas: To be marked out in a master plan. All construction work is to be attempted/pioneered in these regions on the basis of this master plan.
- Thorough research: Needed to know how a new project will add to the existing impacts of ongoing works and human-based activities in a certain area. Thus, a cumulative EIA is to be done. The manner EIAs are carried out at the moment has to change.
Successful instances of cities with an active policy on subsidence are rare, but they do exist. Shanghai, China has a strong operational monitoring system and a successful subsidence mitigation technique. Due to excessive groundwater extraction for both home and industrial usage, the city had undergone considerable land subsidence. As as far back as 1921, reports surfaced about land in Shanghai subsiding. Several responses were undertaken in the 1960s, including a resolution limiting groundwater usage, the introduction of artificial recharge of groundwater, and the diversion of certain groundwater removal to deeper aquifers. Subsidence rates in Shanghai’s metropolitan region dropped as a consequence.
References
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https://thewire.in/government/joshimath-updates-ntpc-land-subsidence-cracks
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https://www.researchgate.net/publication/238413571_Ground_subsidence_A_silent_disaster_in_Himalaya
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https://thewire.in/rights/uttarakhand-temple-collapses-in-joshimath-cracks-seen-in-karnaprayag-too
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https://www.thethirdpole.net/en/energy/jk-hydro-project-cleared-without-site-visit/
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