NEW DELHI – Congress MP and former Union Minister Ajay Maken on Monday brought attention to the potential ecological consequences of the newly proposed “100-metre rule” for the Aravalli Hills during the Zero Hour of Parliament’s ongoing Winter Session. Speaking in the Lok Sabha, Maken expressed deep concern over the dilution of the legal definition of the Aravalli range, warning that the move could severely impact North India’s environment and water security.

Maken’s intervention comes in the wake of a Supreme Court decision on November 20, 2025, which accepted a uniform, elevation-based definition of the Aravalli Hills based on the recommendations of a Centre-appointed expert committee. The new guideline stipulates that only slopes rising more than 100 metres from the local ground level will qualify as part of the Aravalli range.

Citing the geological significance of the Aravalli mountains, Maken reminded Parliament that the range is approximately 2.5 billion years old, making it one of the oldest mountain systems in the world. “The Aravalli range has withstood the collision of continents and eons of erosion. Now it faces its greatest threat: an administrative definition that disconnects legal terminology from ecological reality,” he said.

The 100-Metre Rule: A Disconnect from Reality

According to Maken, the so-called “100-metre rule” is fundamentally flawed. The rule proposes that any slope with a height of less than 100 metres above the surrounding ground will no longer be legally recognized as part of the Aravalli Hills. While the definition may seem technical, its implications are far-reaching.

Maken warned that the rule could result in the declassification of 99% of the Aravalli hills in Rajasthan, one of the states where the range is most prominent. “Internal data from the Forest Survey of India indicates that Rajasthan has 1,07,498 Aravalli hills, but only 1,048 of them are more than 100 metres above the local ground level. This means the vast majority of the hills will lose legal protection, putting them at immediate risk of destruction,” he said.

Ecological and Hydrological Consequences

The Aravalli range serves as a critical ecological barrier in North India, often referred to as the “Green Wall” that protects the region from desertification. Maken emphasized that the hills are not only significant from a geological perspective but also play a vital role in groundwater recharge. The unique secondary porosity of the Aravalli rocks allows water to seep through and replenish aquifers, which are essential for the water supply of districts like Gurugram and Faridabad.

“This region has the capacity to recharge approximately 2 million liters of groundwater per hectare per year. Yet, this resource is being plundered through illegal mining, threatening both biodiversity and water security,” Maken said.

He cited a 2018 report by the Supreme Court’s Central Empowered Committee (CEC), which revealed that 25% of the Aravalli range in Rajasthan had been destroyed due to illegal mining since the late 1960s. In Alwar district alone, 31 out of 128 hills have been completely flattened, highlighting the ongoing and cumulative ecological damage.

A Call for Immediate Action

Maken urged the government to reconsider the “local ground level” criterion and withdraw the 100-metre rule to prevent North India from facing an ecological disaster. He warned that the destruction of the majority of Aravalli hills would not only eliminate critical water recharge zones but also accelerate desertification in already water-stressed areas. In mining regions, he noted, the water table has already dropped to depths of 1,000 to 2,000 feet, a situation that could worsen if the new definition is implemented.

“The situation has now reached a critical point. The 100-metre rule will have far-reaching consequences, and the government must act immediately to preserve the Aravalli range,” Maken said.

Supreme Court and Committee Recommendations

The Supreme Court had accepted the expert committee’s recommendations to establish a uniform, elevation-based definition of the Aravalli Hills, aiming to provide clarity on the range’s extent for legal and administrative purposes. The committee, headed by the Union environment secretary, submitted a report proposing that any slope above 100 metres be classified as part of the Aravalli Hills. While the intention was to standardize definitions, critics like Maken argue that the approach is disconnected from ecological realities and risks undermining the very protections the hills need.

The Broader Significance of the Aravalli Range

The Aravalli Hills are not only a geological treasure but also an ecological linchpin for North India. Spanning multiple states, the range moderates regional climate, prevents desertification, and supports diverse flora and fauna. Beyond environmental considerations, the hills are a source of groundwater, sustaining millions of people in urban and rural areas alike.

Maken’s speech highlighted the intersection of legal frameworks, environmental science, and governance. He cautioned that administrative definitions must account for ecological processes, and that a narrow, technical interpretation could have catastrophic consequences.

Illegal Mining: An Ongoing Threat

A central point of Maken’s argument was the ongoing threat of illegal mining. He warned that declassifying the majority of hills under the 100-metre rule would provide legal cover for further exploitation. The destruction of hills for minerals, sand, and other resources has long been a concern, and legal ambiguity could exacerbate the problem.

“Despite the scientific evidence and past Supreme Court directives, mining continues unabated. Legal recognition is our only protection. Removing that protection will accelerate environmental degradation and water scarcity,” he said.

Conclusion

Ajay Maken’s intervention in Parliament underscores the urgent need to balance administrative convenience with ecological preservation. The debate over the 100-metre rule is more than a technical dispute; it is a question of long-term sustainability, water security, and regional environmental health.

As North India faces mounting pressures from urbanization, mining, and climate change, the Aravalli Hills remain a vital natural barrier. Protecting them requires legal clarity that aligns with ecological realities, not just administrative expediency. Maken’s call for immediate withdrawal of the 100-metre criterion reflects a broader concern: ensuring that India’s oldest mountain range continues to safeguard the environment and livelihoods of millions of people in the region.

Without prompt action, experts warn, the declassification of Aravalli hills could trigger widespread ecological disruption, threatening the delicate balance that sustains North India’s forests, water systems, and farmlands. The parliamentary debate on this issue is likely to continue, as legislators and environmentalists alike push for a solution that safeguards both the hills and the communities that depend on them.