In a significant reversal of its own earlier stance, the Supreme Court of India in November 2024 accepted a contentious 100-metre definition for the ecologically critical Aravalli range. This decision stands in stark contrast to the court's own directive from 2010, which had explicitly rejected this very benchmark and commissioned a scientific survey to map the hills.
The 2010 Directive: A Scientific Approach
Back on February 19, 2010, the Supreme Court was hearing multiple cases concerning rampant mining in Rajasthan. The court noted with disapproval the state's proposed definition, which stated that only peaks or parts of hills rising 100 metres or more from ground level would be considered Aravalli Hills. Finding this arbitrary definition unacceptable, the bench ordered a comprehensive assessment.
The court tasked the Forest Survey of India (FSI) with conducting a survey using satellite imagery, in cooperation with the court's Central Empowered Committee (CEC) and the Rajasthan government. Crucially, the order specified that this survey "shall not be confined to peaks/parts of hills above 100 metres, from the ground level." The court highlighted the ecological devastation, noting that wanton mining across the 50,000 sq km range in 15 districts had caused severe imbalance and destruction.
The FSI's 3-Degree Slope Norm
Following the court's order, the FSI undertook a detailed scientific analysis. In October 2010, the CEC reported the findings to the Supreme Court. The FSI, after analyzing spatial terrain data, concluded that terrain with slopes of 3 degrees or more is uniquely associated with hills and does not occur in flat land.
This 3-degree slope was established as the threshold for delineating hills in areas at or above 115 metres from Mean Sea Level—the minimum elevation of Aravalli hill districts in Rajasthan. Using this methodology, the FSI identified 40,481 square kilometres across 15 districts as part of the Aravalli range. This area included a uniform 100-metre buffer on the downhill side, as well as flat areas, tabletops, depressions, and valleys within the demarcated zones.
The grim reality of mining's impact was underscored in 2018 when the Supreme Court acknowledged an FSI ground verification report. It revealed a shocking finding: 31 out of 128 sampled hills in Rajasthan had completely disappeared.
The 2024 Reversal and Its Implications
The issue resurfaced in May 2024 when the Supreme Court sought a common definition of the Aravallis for four states: Rajasthan, Haryana, Gujarat, and Delhi. A committee was formed, which included the FSI and CEC. A Technical Sub-Committee led by the FSI was also established in June 2024.
However, the Union Ministry of Environment, Forest and Climate Change relied heavily on consultations with the four states. In October 2024, it informed the court that the states had agreed to the criteria of an elevation of 100 metres and above from local ground level, along with supporting slopes—the same definition Rajasthan used for mining regulation.
On November 20, 2024, despite a formal dissent note from the CEC and detailed arguments from the court-appointed amicus curiae, the Supreme Court bench accepted the ministry's recommendation. This decision effectively rendered over 15 years of judicial monitoring and the scientifically-derived 3-degree slope norm futile.
The court's latest order marks a full circle, endorsing the very 100-metre parameter it had rejected in 2010. This shift has raised serious concerns among environmentalists about the future protection of the fragile Aravalli ecosystem, which acts as a critical green barrier against desertification in North India.
