For centuries, the Aravalli hills have stood quietly along the edge of Delhi–NCR — older than the Himalayas, lower in height, but immense in importance.
A recent Supreme Court judgment classifies only hills equal to or above 100 meters as part of the Aravalli range.
Earlier, the 2010 Forest Survey of India (FSI) classified Aravalli hills as landforms 3 meters or higher, based on geological and ecological characteristics.This ensured protection of the hills as a continuous ecosystem, not just isolated peaks.
In 2024, Supremecourt increased this height to 40 m, leaving 60% of Aravalis open to exploitation
Now in 2025, the new classification replaces this with a height-only threshold of 100 meters, ignoring the nature and function of the ecosystem. As a result, vast stretches of the Aravallis—especially in Haryana and Delhi–NCR—stand excluded from protection.
Since most Aravalli formations consist of low-height ancient hills, this redefinition effectively removes legal protection from nearly 90–91% of the Aravallis, making them vulnerable to mining, construction, and irreversible degradation.
This post explains why the 100-meter criterion is scientifically unsound, environmentally dangerous, and contrary to established conservation principles.
The ecological value of the Aravallis lies not in their height but in their:
Geological continuity
Ability to block desert dust and hot winds
Role in groundwater recharge
Support of native biodiversity
The Aravallis are ancient, eroded hills. Judging them by modern mountain standards disregards their unique geological identity and ecological role.
Air Quality
The Aravallis act as a natural dust barrier against desertification from Rajasthan. Weakening their protection will:
Increase particulate matter (PM10 and PM2.5)
Worsen smog conditions in Delhi–NCR. Currently where we are facing AQI of 500, after this change it may rise up to 1200 leaving this area unlivable.
Increase respiratory and cardiovascular diseases
Water Security
These hills are critical groundwater recharge zones.
Their destruction will lead to:
Reduced aquifer replenishment
Increased water scarcity
Higher urban flooding during monsoons
Climate Resilience
The Aravallis moderate temperature extremes and support micro-climates. Their degradation will:
Intensify heatwaves
Reduce climate resilience of urban regions
Biodiversity
The Aravallis support diverse flora and fauna and act as wildlife corridors. Fragmentation will cause:
Irreversible biodiversity loss
Increased human–wildlife conflict
Indian environmental jurisprudence recognizes:
Article 21 – Right to Life, which includes the right to a healthy environment
The precautionary principle
Inter-generational equity
Diluting ecosystem protection through arbitrary thresholds undermines these principles and risks irreversible damage to natural heritage.
We respectfully urge the Hon’ble Supreme Court of India to:
Reconsider the 100-meter hill classification
Restore and uphold the 2010 Forest Survey of India definition, recognizing
Ensure continued protection of this critical ecosystem in the interest of:
Public health
Environmental sustainability
The constitutional Right to Life
Once destroyed, the Aravallis cannot be restored.
This is not only an environmental issue but a question of livability, health, water security, and the future of Delhi–NCR.
Protecting the Aravallis today safeguards future generations.
This document supports a citizen-led petition seeking reconsideration of the recent reclassification of the Aravalli hills. We invite concerned citizens, environmental experts, urban planners, healthcare professionals, and policymakers to review this background and support the effort to preserve this vital ecosystem.