Aravalli Hills

What Are the Aravalli Hills?
The Aravalli Hills (Aravalli Range) are one of the oldest mountain ranges in the world (about 2.5 billion years old) and stretch roughly 700 km across northwest India — from Gujarat through Rajasthan and Haryana into Delhi. 
Key ecological and geographical points:
Natural barrier against the Thar Desert’s eastward spread, helping prevent desertification. 
Important for groundwater recharge, as rainwater percolates into underground aquifers. 
Acts as a windbreak and filter, moderating local climate and helping reduce dust and air pollution, especially around Delhi-NCR. 
Home to biodiversity, including forests, scrublands, wildlife habitat and hundreds of species.Contains mineral deposits (e.g., copper, zinc, lead, marble) and supports local economies. 
Historically, protections have been put in place to curb mining and destructive land-use — notably bans on mining in parts of the range since the early 2000s. 
What Is the Current Controversy About?
1. Redefinition of What Counts as “Aravalli Hills”
In late 2025, a major legal and environmental debate erupted over a new definition of the Aravalli Hills that was accepted by the Supreme Court of India:
Under this definition, a landform only qualifies as an “Aravalli hill” if it rises at least 100 m above the surrounding terrain.
Two or more such hills within 500 m of each other are then treated as an “Aravalli range.” 
Why this matters:
Experts and activists say this height-based definition excludes tens of thousands of lower ridges, rock outcrops and ecological features that — despite being less than 100 m tall — still play critical roles in hydrology, soil stability, wildlife connectivity and climate moderation. 
Some reports estimate that under this rule only around 8.7 % of the hills in Rajasthan — the core part of the range — would meet the 100-m criterion, leaving over 90 % outside clear legal protection. 
 2. Environmentalists’ Concerns
Environmental groups, scientists and activists have raised several core objections:
Ecological weakening: Smaller ridges and low-lying features are not “cosmetic” — they help slow desertification, facilitate groundwater recharge, and reduce dust and heat waves, especially in the Delhi-NCR region and surrounding plains. 
Mining risks: If large tracts are excluded from being officially Aravallis, they could become more open to mining and commercial construction, increasing habitat loss, land degradation and water table decline. 
Biodiversity threats: Fragmentation of ecosystems and loss of habitat could harm flora and fauna native to the region. 
Public campaigns like #SaveAravalli have gained traction, with protests and social media activism highlighting fears of ecological degradation. 
3. Political and Government Positions
The debate has also taken on a political dimension:
Opposition parties and regional leaders have criticized the redefinition, arguing it undermines environmental protection and endangers local resources and climate stability. 
Government officials, including Environment Minister Bhupender Yadav, have clarified that protections remain robust and that much of the Aravalli terrain is still under safeguard — countering claims of wholesale deregulation. 
Recent Court Actions (Late Dec 2025)
A major development came on Dec 29, 2025, when the Supreme Court of India stayed (paused) its earlier acceptance of the controversial 100-metre definition due to widespread concern and legal challenges. 
Key points from this stay order:
The previous 100-m rule will not be treated as law for now, preventing immediate exploitation of those newly excluded areas. 
The court criticized misinterpretations of expert inputs and emphasized careful ecological management. 
The next hearing in the case is scheduled for January 21, 2026. 
Environmentalists, conservationists and many political figures celebrated the stay as a temporary victory for ecological protection and grassroots activism.