LAST MONTH, the Supreme Court in In Re: Issues relating to definition of Aravali Hills and Ranges (2025) accepted a definition recommended by a committee spearheaded by the Union Ministry of Environment, Forest and Climate Change (‘MoEFCC’). The Court held that only landforms rising at least 100 metres above the local relief would qualify as Aravalli Hills, and that clusters of such hills located within 500 metres of each other would form an Aravalli Range. The Forest Survey of India has reported that of 12,081 hills mapped across multiple states, only 1,048 (8.7 percent) meet the 100 metres criterion. This has alarmed several experts.
The Aravallis, stretching across Gujarat, Rajasthan, Haryana and Delhi, are a living ecological infrastructure and the oldest hill range in the Indian subcontinent. The range, estimated to be around 670 million years old, acts as a natural barrier slowing the spread of the Thar Desert, stabilising micro-climates, and recharging aquifers.
Why the definition of the Aravallis became a question for the Court
The Supreme Court had been seized of the issue of mining in the Aravalli range through two long-standing environmental matters: M.C. Mehta v. Union of India (1985), within whose mandate the Court was monitoring mining activities in the Aravallis in Haryana, and T.N. Godavarman Thirumalpad v. Union of India (1995), within whose mandate the Court was monitoring mining activities in the Aravallis in Rajasthan. During the hearing of the latter in January 2024, questions arose about whether certain mining operations fell within the Aravalli Hills or beyond them. Different states used different definitions of what constituted the Aravalli Hills and Ranges, and in some cases, such as Haryana, there was no official definition at all.
This accentuated the need for a clear and consistent demarcation, crucial for regulating mining and protecting the environment. The absence of a clear definition led to incertitude over where mining could legally occur which further made enforcement of environmental safeguards difficult and enabled illegal mining activities. To address this, on May 9, 2024, the Supreme Court directed the constitution of a multi-agency committee, including MoEF&CC, State Forest Departments, Forest Survey of India (‘FSI’), Central Empowered Committee and Geological Survey of India to finalise a uniform definition.
Following delays, the Committee submitted its report in October this year where it proposed an elevation-based definition. The definition includes a landform with 100 metres or more elevation above local relief qualifies as an Aravali Hill; and a group of hills within 500 metres of each other constitutes an Aravali Range.
Senior Advocate K. Parameshwar, the amicus curiae, however, opposed the new definition. He argued that the earlier FSI criteria (slope > 3°, 100-m foothill buffer, 500-m valley width) better preserved the ecological integrity of the Aravalis. He warned that the Committee’s 100-metre threshold would exclude smaller hill features, break the continuity of the range, and potentially open new areas to mining. Meanwhile, the MoEFCC defended the new definition as the most practical and scientifically sound rule bringing uniformity across states.
What has the Court allowed now and what has it put on hold?
The Bench, comprising the-then CJI B.R. Gavai and Justices K.V. Chandran and N.V. Anjaria endorsed the new definition. They held that it would guide a comprehensive Management Plan for Sustainable Mining (‘MPSM’), similar to the Court-approved plan used earlier for the Saranda forests.
This means that an ‘Aravalli Hill’ is any landform within Aravali districts that has an elevation of at least 100 metres above the local relief. Local relief is to be measured by reference to the lowest contour line that completely encircles the landform. All land falling within this contour–hilltops, slopes, foothills, supporting terrain–are included.
Drawing on its earlier judgment in State of Bihar v. Pawan Kumar (2022), the Bench observed that complete prohibition often produces perverse outcomes as it pushes mining underground and empowers local mafias. The Ministry was asked to prepare an MPSM to "identify permissible areas for mining, ecologically sensitive, conservation-critical and restoration-priority areas within the Aravali landscape where mining shall be strictly prohibited or permitted only under exceptional and scientifically justified circumstances; incorporate a thorough analysis of cumulative environmental impacts and the ecological carrying 15 capacity of the region; and include detailed post-mining restoration and rehabilitation measures."
In the interim, the Court directed that no new mining leases or renewals shall be granted until the MPSM is finalised and approved, while permitting existing legal mining operations to continue strictly subject to compliance with environmental safeguards and any additional conditions that may be prescribed under the MPSM. It further ordered that comprehensive geographical mapping of the entire Aravalli landscape be undertaken, based on the definition adopted by the Court, to demarcate legally valid hills and ranges. Until such mapping is completed and the MPSM comes into force, the Court clarified that its adopted definition shall remain operative and binding for all regulatory actions, environmental clearances, and judicial proceedings.
How low-elevation hills stand to disappear under the new rule
For decades, there has been emphasis placed on expansive protection for the Aravallis by strict restrictions on mining and construction, and the massive illegality in mining operations. This is reflected in numerous policies including the MoEFCC’s 1992 Aravalli notification and the National Capital Region (‘NCR’) Planning Board’s declaration of Natural Conservation Zones in the Aravallis in 2021. The earlier court orders treated the entire Aravalli system, regardless of elevation, as ecologically sensitive. Experts fear that the 100-metre rule dramatically redefines the Aravalli landscape in a way that weakens protection and defers from previous jurisprudence.
A Supreme Court-appointed committee in 2018 found that in Rajasthan 31 of 128 Aravali hills disappeared in 50 years because of illegal quarrying, and 10-12 large gaps opened up in the Aravalis. The State used the same 100 m criteria which the Court has now accepted as a uniform definition.
According to The State of the Haryana Aravallis: Citizens’ Report- Part 1, submitted by the People for Aravallis collective to the MoEFCC and the Haryana government in May this year, the licensed mining operations have devastated much of the billion year old Aravalli ecosystem in the districts of Charkhi Dadri and Bhiwani. In Gurugram, Nuh and Faridabad, extensive extraction took place before the Supreme Court prohibited mining in these districts in 2009.
Despite the ban, unlawful mining continues openly. Over recent decades, Aravalli destruction across the range has been so widespread that more than a dozen breaches have opened from Ajmer to Jhunjhunu in Rajasthan and into Mahendergarh in south Haryana, enabling desert dust from the Thar to drift into Delhi-NCR, worsening the region’s air pollution.
The forests of the Aravallis play a critical ecological role in enhancing precipitation, preventing drought, and maintaining humidity across Gujarat, Rajasthan, Haryana and Delhi. Their canopy helps regulate wind velocity and stabilise rainfall patterns. The range is also a vital groundwater-recharge zone as its weathered, fissured rock formations allow significant aquifer replenishment, estimated at about two million litres per hectare.The new definition of Aravalli hills, endorsed by the Supreme Court, experts argue, threatens to erase many of these low-elevation hill systems, shrinking habitats and escalating human-wildlife conflict.
At stake is a fragile equilibrium between law and landscape, where a technical definition may determine the fate of an ecosystem that shields millions from heat, dust and water scarcity.
