FSI’s 3-degree definition covers lower hills of Aravallis that are excluded by the ministry’s 100-metre yardstick
In its October 14 letter reviewed by The Indian Express, the CEC underlined that the definition formulated by the Forest Survey of India (FSI) should be “adopted in order to ensure the protection and conservation of the ecology of the Aravalli Hills and its range.
Supreme Court, the 100-Metre Aravalli Rule & Its Own Panel’s Opposition — A Detailed Explainer
1. Introduction: What Happened?
On 20 November 2025, the Supreme Court of India accepted a uniform definition of the Aravalli hills and ranges based on the government’s proposal:
🔹 A landform must be at least 100 metres above local relief (ground level) to qualify as an Aravalli hill.
🔹 A cluster of two or more such hills within 500 metres constitutes an Aravalli range.
Under this definition, many parts of the broader Aravalli landscape — especially lower hills, ridges and foothills — would not be considered Aravalli for legal protections against mining and other activities. (The Week)
This decision marks a major shift in how India’s oldest mountain range — stretching over hundreds of kilometres across four states — is defined, regulated and protected under environmental laws. (www.ndtv.com)
However, this acceptance came under significant controversy because the Supreme Court’s own environmental panel — the Central Empowered Committee (CEC) — opposed this 100-metre definition, a fact that has alarmed activists, scientists, legal experts and political leaders alike. (Fact Net)
2. Aravallis & Why They Matter
2.1. A Unique and Fragile Landscape
The Aravalli Range is one of the world’s oldest geological formations, spanning from Delhi through Haryana, Rajasthan and into Gujarat. Its ecological functions include:
✔ groundwater recharge
✔ wind and dust control
✔ biodiversity habitat
✔ soil retention and micro-climate stability
✔ natural barrier against desertification
These functions support millions of livelihoods, protect rural and urban water supplies, and influence air quality in the National Capital Region (NCR) and beyond. (The Week)
2.2. Mining & Environmental Stress
For decades, large-scale mining activities — both legal and illegal — have severely damaged parts of the Aravallis, particularly in Rajasthan and Haryana. This has led to water table depletion, landscape degradation, and worsening air quality. Over the years, the courts have been involved in regulating mining to balance economic interests and ecological sustainability. (Business Standard)
3. Legal & Administrative Background
3.1. Past Supreme Court Orders
Historically, the Supreme Court has been a key player in regulating mining in the Aravallis and protecting its ecology. In 2010, the Court had rejected a simplistic “100-metre only” measure and directed the Forest Survey of India (FSI), with technical support from the CEC, to create a comprehensive map of the range that did not focus only on peaks above 100 m. (The Indian Express)
The FSI later produced terrain data based on 3-degree slope mapping, which classified hills based on their natural shape and physiography, including many lower elevation hillocks that are ecologically significant. (The Indian Express)
3.2. 2024 Supreme Court Review
In May 2024, the Supreme Court revisited the issue to standardize the definition of Aravalli hills and ranges across the four states (Rajasthan, Gujarat, Haryana, Delhi) so that mining regulations could be uniformly enforced. The Court instructed the Environment Ministry to form a committee under the Environment Secretary to propose a definition. Both the CEC and the FSI were involved in this committee. (Fact Net)
4. The Government’s 100-Metre Benchmark
4.1. What It Says
The Ministry of Environment, Forest and Climate Change (MoEF&CC) — with inputs from state governments — proposed a definition where:
🔹 Only landforms rising 100 m or more above surrounding relief are counted as Aravalli hills.
🔹 Two or more such hills within 500 m define a range.
🔹 Only these delineated hills and their slopes are automatically protected from mining unless the government categorizes areas differently later. (The Week)
The government claims this measure will provide a uniform, clear and enforceable standard across states and help curb illegal mining. It insists that mining will still be regulated, not broadly permitted. (The Week)
4.2. Government’s Clarifications
The Environment Minister has stated the ministry will perform ground-level mapping to finalize which areas qualify under this rule, and insisted only about 0.19 % of the total Aravalli region is actually subject to mining. (Fact Net)
5. What the Central Empowered Committee (CEC) Said
5.1. CEC’s Opposition
The CEC — a panel created by the Supreme Court in 2002 to advise on forest and environmental compliance — explicitly opposed the government’s 100-metre definition. The committee said the proposal lacked scientific basis and administrative clarity, and should not form the basis for ecologically mapping and protecting the Aravalli range. (Fact Net)
Instead, the CEC recommended the FSI’s methodology, which accounts for terrain slope and includes small foothills and interconnected landscapes that are crucial to the ecosystem. (Fact Net)
5.2. CEC’s Technical Position
According to communications from the CEC:
✔ The 100 m criterion fragments the continuous Aravalli system.
✔ It diminishes the ecological significance of lower elevation features that equally contribute to groundwater recharge and dust control.
✔ It undermines the coherent protection of the landscape. (Fact Net)
The CEC’s viewpoint was presented to the Supreme Court via a PowerPoint submission by the Court’s amicus curiae, who used FSI data to argue against the 100-metre benchmark. However, it appears the Court did not adopt that recommendation. (Fact Net)
6. Supreme Court’s Decision
6.1. Acceptance of the 100-Metre Rule
On 20 November 2025, the Supreme Court accepted the government’s 100-metre definition as a uniform legal benchmark for identifying Aravalli hills and ranges. This was a significant divergence from the CEC’s recommendation, which favoured a slope-based and more inclusive ecological classification. (The Week)
This makes the 100-m rule the legal standard going forward — unless modified by future review petitions. The Court also ordered scientific mapping and instructed authorities to prepare a Management Plan for Sustainable Mining (MPSM) to regulate mining activities. (The Week)
6.2. What the SC Did Not Say
Despite widespread interpretation online, the Court did not give a blanket permission for unlimited mining. Instead, the ruling:
✔ aims to create clarity in an otherwise fragmented regulatory framework.
✔ temporarily restrains the granting of new mining leases until a sustainable management plan is ready. (The Week)
However, critics argue that legal clarity for mining permits could lead to practical loosening of protections in areas excluded by the 100-m rule. (The Times of India)
7. Environmental and Scientific Concerns
7.1. Conservation Experts’ Fears
Environmental scientists and activists have voiced deep concerns:
✔ Many ecologically vital hillocks and ridges are below 100 m yet act as groundwater recharge zones and barriers against desert winds. (The Week)
✔ Internal assessments suggest that over 90 % of the range’s hillocks would not qualify under the 100-metre benchmark, leaving them effectively unclassified. (The Financial Express)
✔ Loss of legal recognition could pave the way for mining, construction or land conversion in areas that historically contributed to air quality and ecological balance. (The Financial Express)
Ecologists warn that diminishing these lower hills can accelerate desertification, raise dust storms, reduce ground water recharge, and disrupt natural wind breaks that protect cities like Delhi, Gurugram and Faridabad. (The Week)
8. Political Controversies & Public Reaction
8.1. Opposition Parties
Political leaders, especially in Rajasthan, have lambasted the Supreme Court’s decision as a weakening of environmental safeguards. The Congress party labelled the government’s enforcement order a “bogus attempt at damage control”, claiming the 100-m definition undermines real protection of the Aravalli ecosystem. (The Times of India)
Ex-Rajasthan CM Ashok Gehlot and other leaders have argued the redefinition reflects collusion with mining interests and noted poor enforcement by BJP governments in the past. (The Times of India)
8.2. Public Protests
Protests have erupted, especially in Udaipur and other parts of Rajasthan, with activists demanding stronger protections for the Aravalli hills and opposing what they see as judicial “backtracking” on ecological safeguards. (The Times of India)
9. Long-Term Implications
9.1. For Mining Regulation
By creating a standard 100-metre benchmark, the legal scope for mining operations may expand to areas previously considered within the geological Aravalli system. This could lead to:
✔ More mining leases once the MPSM is created.
✔ Pressures for real estate or infrastructure development in newly “unclassified” areas.
✔ Increased complexity in environmental compliance across four large states. (The Times of India)
9.2. For Conservation & Ecology
The long-term impact on ecology remains uncertain. Proponents of the rule argue it brings clarity and enforceability to a long-standing regulatory mess. Critics fear it will gradually erode protection for large swathes of ecologically sensitive land, undermining water security, climate regulation and biodiversity connectivity. (The Week)
10. Conclusion
The Supreme Court’s adoption of the 100-metre definition for the Aravalli range — despite its own environmental panel’s opposition — has triggered intense debate across legal, ecological, political and public spheres. What was intended as uniformity in environmental governance now raises questions about environmental justice, ecological science, and the role of expert advice in judicial decisions.
Whether the 100-metre rule ultimately protects or compromises the Aravalli ecosystem will depend on how mapping, management planning, and enforcement unfold, and whether future legal challenges can reshape the narrative. (Fact Net)
FAQs on the 100-Metre Aravalli Rule & Supreme Court Decision
Q1. Why 100 metres?
The government selected 100 m above local relief as a uniform, measurable benchmark to define Aravalli hills across multiple states — ostensibly to end confusion over boundaries. Critics say this benchmark is arbitrary and excludes many crucial ecological landforms. (The Week)
Q2. Did the Supreme Court allow mining everywhere now?
No — the Court did not give blanket permission for mining. It adopted a uniform definition and asked for a Management Plan for Sustainable Mining before new leases are granted. But the definition could legally open up areas not recognized as Aravalli under the 100-m rule. (The Week)
Q3. What did the CEC recommend instead?
The CEC recommended using the FSI’s slope-based methodology, which includes smaller hills, foothills and landscape continuity as part of the Aravalli ecosystem, thus offering broader protection. (Fact Net)
Q4. Will this affect groundwater and air quality?
Experts warn yes — excluding lower hills can reduce groundwater recharge and weaken natural wind breaks, potentially worsening dust and air pollution, especially in NCR regions. (The Week)
Q5. Is this final?
The decision can be challenged — petitions against the 100-m rule are already admitted for hearing by the Supreme Court, arguing it could cause grave ecological consequences. (The Times of India)
