Controversy Over Aravalli Hills’ 100-Meter Rule: Mapping Challenges and Environmental Concerns

New Delhi:
A fresh debate has erupted over the 100-meter definition of the Aravalli Hills, raising concerns about its potential impact on environmental protection. Environmentalists warn that the new rule could open up many ecologically sensitive hill areas to mining, which were previously considered protected.

The controversy stems from the Ministry of Environment, Forest and Climate Change, which recently proposed limiting the definition of Aravalli hills to only those areas that rise 100 meters or more from the lowest surrounding level. According to this definition, hills within a 500-meter radius are considered part of a continuous range. The Ministry has instructed the Survey of India to create maps based on this definition, marking and demarcating areas for administrative and planning purposes.

Background of the Rule

The 100-meter guideline was recommended by a technical committee of the Ministry and subsequently accepted by the Supreme Court on November 20, 2025, specifically for mining regulation purposes. A week later, on December 17, the Ministry issued an office memorandum to enforce this new definition. This follows a meeting chaired by the Environment Secretary on December 8, which aimed to implement the Supreme Court-approved parameters.

The Ministry is also coordinating with the Indian Council of Forestry Research and Education (ICFRE) to prepare a permanent mining management plan (MPSM) for the entire Aravalli region. Until the MPSM is finalized, no new mining leases can be granted, although existing operations can continue under court-appointed oversight.

Expert Concerns

Experts, including retired South Haryana forest conservator M.D. Sinha, have expressed doubts about the rule’s ecological impact. Sinha noted that only a small fraction—potentially less than 10%—of the Aravalli hills would qualify under the 100-meter rule. Environmentalists argue that height alone is an inadequate measure for defining ecologically important areas, as the Aravallis host diverse species and play a critical role in groundwater recharge, regardless of their elevation.

While the Ministry maintains that adopting the 100-meter definition will not weaken mining controls—currently only 0.2% of the Aravalli area is permitted for mining—experts point out contradictions in government affidavits submitted to the Supreme Court, which themselves acknowledge that single metrics like height or slope cannot adequately define such a varied hill range.

Mapping and Environmental Implications

The Survey of India has been tasked with demarcating Aravalli hills on topographic maps based on the 100-meter criterion, assisting state governments in planning and regulatory compliance. However, environmentalists fear that relying on this height-based marker could significantly reduce legally recognized Aravalli areas, undermining long-term conservation efforts.

As the dispute continues, questions remain about the balance between mining regulation and environmental preservation, with potential political and ecological ramifications still unfolding. The debate highlights the broader challenge of protecting one of India’s most vital and ecologically sensitive hill ranges while accommodating developmental pressures.