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The Aravalli Hills occupy a paradoxical position in India’s environmental imagination. Visually sparse in many stretches, often degraded, and long subjected to extractive pressures, they have nevertheless sustained ecological functions of continental importance. Stretching from Gujarat through Rajasthan and Haryana into Delhi, the Aravallis represent one of the oldest geological formations on Earth and form a natural ecological spine for north-western India.
The Aravallis’ importance lies not in dense forests but in less visible services: fractured rocks that store water, ridges that influence wind and rainfall, and slopes that stabilise soil and prevent dust. For the National Capital Region (NCR), these hills are not peripheral—they are natural infrastructure.
It is against this ecological reality that the recent interventions of the Supreme Court of India must be understood. The developments of 2024-2025—culminating first in the Supreme Court’s November judgment endorsing a uniform geomorphological definition, then the detailed Press Information Bureau (PIB) articulation of 21 December 2025, and now the 29 December 2025 suo motu intervention of the Supreme Court keeping those directions in abeyance—reveal the extraordinary complexity of environmental governance in India.
Any serious discussion of Aravalli protection must begin with the jurisprudence emerging from T.N. Godavarman Thirumulpad v. Union of India. In that continuing mandamus, the Supreme Court decisively rejected a narrow, notification-based understanding of “forest” and held that the term must be understood in its dictionary and ecological sense.
This interpretation was neither semantic nor incidental. It flowed from Article 48A (State’s duty to protect the environment), Article 51A(g) (citizens’ duty to protect nature), and the public trust doctrine.
The Court’s intent was unambiguous: ecological function, vulnerability, and continuity—not canopy density or revenue classification—must determine protection. This was particularly relevant to landscapes like the Aravallis, where vegetation is naturally sparse, discontinuous, and adapted to semi-arid conditions.
Haryana’s definition of forest—requiring a canopy density of ≥40 per cent and minimum patch sizes, while excluding plantations and orchards—became controversial precisely because it translated an ecological question into a silvicultural metric.
The canopy density is a reasonable indicator in moist deciduous or evergreen forests. In the Aravallis, however, vegetation is xerophytic and scrub-dominated. The soil depth is shallow; ecological value lies not in biomass alone, but in subsurface hydrology, slope stability, and microclimatic moderation.
By privileging canopy density, large tracts of ecologically vital hills, slopes, and recharge zones risked exclusion from protection—undermining the very logic of the Godavarman doctrine.
Under the EIA Notification, 2006, mining projects beyond specified thresholds require prior environmental clearance, impact assessment, and public consultation. However, in practice, mining in the Aravallis—particularly of stone, quartzite, and minor minerals—has often escaped rigorous scrutiny through lease fragmentation below thresholds, classification of land as “non-forest” using restrictive definitions, weak enforcement, and post facto clearance.
Carrying capacity is central to sustainable mining, especially in fragile hill systems. Yet, prior to the Supreme Court’s 2025 directions, no comprehensive, ridge-wide carrying capacity study guided mining policy in the Aravallis.
The project-specific Environment Impact Assessments, when conducted, typically ignored cumulative dust loading, underestimated groundwater disruption, and treated hills as isolated units rather than integrated systems.
The November 2025 judgment represents a pivotal corrective. Acting on the recommendations of a committee led by the Union Ministry of Environment, Forest and Climate Change, the Court adopted geomorphology as the primary organising principle for protection. The committee has a formally established definition of Aravalli Hills as any landform rising ≥100 m above local relief, including its supporting slopes and enclosed landforms, and that of Aravalli Range as two or more such hills within 500 m of each other, including intervening valleys, slopes, and hillocks.
These definitions matter because they protect entire hill systems up to their base, prevent mining in foothills and slopes (a common loophole), and preserve ecological connectivity. Crucially, the Court clarified that this does not imply that all landforms below 100 metres are open for mining—a misinterpretation sometimes advanced in public discourse.
The PIB statement of 21 December 2025 provides the most authoritative executive articulation of the new regime. Far from diluting protection, it underscores their role in preventing desertification, safeguarding groundwater recharge, maintaining biodiversity corridors, and protecting Delhi-NCR’s “green lungs.”
Groundwater recharge is especially critical. The fractured quartzite and schist formations act as natural aquifers. Mining disrupts groundwater recharge by removing weathered rock, increasing runoff, and lowering infiltration.
Despite degradation, the Aravallis continue to function as wildlife habitat, corridors linking the Delhi Ridge with Sariska, and genetic conduits across fragmented landscapes. Landscape-scale definitions are therefore essential to prevent ecological isolation.
The suo motu intervention of December 29, 2025, marks a critical inflection point. The Supreme Court kept its earlier directions in abeyance and ordered further examination.
The Court asked whether the definition of the ‘Aravalli Hills and Ranges’, restricted exclusively to the 500-metre area between two or more Aravalli Hills, has inversely broadened the scope of ‘non-Aravalli’areas, thereby facilitating the continuation of unregulated mining and other disruptive activities in terrains that are ecologically contiguous but technically excluded by this definition.
The apex court reiterated that until further orders, no permission shall be granted for mining, whether it is for new mining leases or renewal of old mining leases, in the ‘Aravalli Hills and Ranges.’
The SC said that its earlier directions would remain stayed until a new committee is constituted, and in the meantime, the mining activities already in operation would continue in strict compliance with the recommendations made by the Committee. The Court proposed to constitute a High-Powered Expert Committee comprising domain experts to undertake a comprehensive assessment of the Report submitted by the Committee.
That degradation and “dehydration” of the Aravallis contribute to Delhi’s air quality crisis remains scientifically tenable. While Delhi’s pollution has multiple dominant sources, the Aravallis act as a physical barrier to dust-laden winds, a stabilising soil–vegetation system, and a micro-climatic regulator.
Mining-induced dust, exposed slopes, and dehydrated soils increase crustal particulate matter, feed dust plumes during dry westerly winds, and reduce the landscape’s capacity to trap and stabilise dust. Thus, Aravalli degradation functions as a risk amplifier in Delhi’s air pollution matrix. The Aravallis must be understood as part of a regional airshed and hydrological system.
The Aravallis are not inert rock formations but functional ecological infrastructure. The Aravalli debate has moved beyond questions of mining leases and contour lines. It has become a test of whether India can operationalise environmental constitutionalism without succumbing to either bureaucratic reductionism or rhetorical alarmism.
In pausing its own directions, the Court has reaffirmed the central lesson of the Godavarman era: when in doubt, err on the side of ecology.
Ultimately, the future of the Aravallis—and by extension, the ecological security of the NCR—will depend not on how hills are counted, but on whether governance systems can internalise the Aravallis as what they truly are: ancient, fragile, and indispensable national assets for present and future generations.
Ashok Kumar Raghav is engaged in environmental advocacy. He is contesting a PIL in the Supreme Court on the carrying capacity of the ecologically fragile Indian Himalayan Region.
Views expressed are the author’s own and don’t necessarily reflect those of Down To Earth