As one of the world’s oldest geological formations, the Aravalli Hills range fights for its existence after the Supreme Court redefined its peaks. According to the new definition on the recommendations of the federal government, only peaks or parts of the hills that are 100 metres above the ground level are to be treated as Aravalli hills.
Protests have erupted across northern India, especially the NCR, Haryana and Rajasthan, with citizens worried about the degrading air quality, the effects of which are widely felt, particularly during the winter months. However, earlier this year, sudden dust storms led to an overnight dip in the city’s air quality index (AQI).
While walking across the city during that time, one could feel dust clinging to the skin. Now, dust storms are not a new phenomenon. Delhi has been witnessing them for years, but the frequency of these storms, along with hyper-temperatures and warmer nights, has only been observed largely in the last few years.
Posh areas like South Delhi’s Chhatarpur too remained no exception to it. However, just a few kilometres away, beyond the luxurious farmhouses and wedding resorts, lie the humongous Aravalli ranges – scarred and blasted after years of mining.
Into the wild
As one crosses that area and drives through the Delhi-Faridabad highway, a pit stop while entering the Mangarbani village shows the mined area on the hills. “However, after a ban by the Supreme Court in 2009, mining was stopped in these locations,” said Sunil Hasrana, a local environmental activist who has long been associated with the fight to preserve the Aravallis.
Hasrana pointed out some of the green patches on the hills that surrounded their locality. “After mining was stopped in these areas, the greenery was restored in the following years. If the recent orders from the SC get implemented in the upcoming years, then these hills might go back to ground zero and have a detrimental effect on the villagers and the residents of Delhi NCR,” he added.
According to environmentalists, defining the Aravalli Hills by height risks ecologically critical hills unprotected from mining and construction. “Less than 1% of the Aravallis are actually above 100 metres; this puts the majority of ranges under severe threat of mining activities and real estate projects,” said Chetan Agarwal, an independent environment and forest analyst.
For centuries, the Aravallis performed a role that no modern infrastructure can replicate. Acting as a natural barrier between the Thar Desert and the Indo-Gangetic plains, the range helped arrest dust-laden winds, helped moderate temperatures, absorbed rainwater and, most importantly, recharged aquifers across what are now Delhi, Gurugram and Faridabad.
Speaking to the newspaper, water conservationist and environmentalist Rajendra Singh said, “The Aravalli range contains confined vertical fractures, which are naturally occurring straight, vertical cracks in the rock formations. These fractures are directly connected to aquifers, which are underground layers where water accumulates and is stored.”
“When rainwater enters these fractures, it moves deep underground into the aquifers. Since this water is stored below the surface, it is protected from evaporation by sunlight. This process is why groundwater in the Aravalli region is often sweet (low salinity) and why the range plays a major role in recharging the groundwater system of Delhi–NCR, Haryana, and western India,” said Singh, who is also popularly known as the Waterman of India.
“If the Aravalli ecosystem remains intact, it can continue to support water availability across these regions in the long term,” he added. This is not just a possibility. Many parts of the capital, especially areas in South and East Delhi, already have frequent disruptions in water supply in summer months.
The invisible costs
Satellite imagery over the last three decades shows extensive fragmentation across Haryana and Rajasthan. What was once a continuous ridge is now broken into isolated patches; some has been preserved as token green belts, while others have been swallowed by enormous real estate projects, especially visible in Gurugram and Faridabad.
In areas like Bhatti, Mangar and the outskirts of Faridabad, residents said that the hills once cooled the air and held back dust storms. An elderly villager near the Bhatti mines saidthat earlier the summer evenings were cooler, but ‘nowadays it is unbearable’. Also, vegetation disappeared, and so have wildlife corridors.
Leopards, nilgai and jackals that once moved across the range are straying into human settlements. Three villagers from Mangar said, “Disturbed by the unrest in their habitat, the wild animals frequently attack the domesticated animals and stray dogs. It scares us a lot.”
Capital in fray
Each summer, dust storms from western India sweep into NCR, pushing pollution levels into the “severe” category. Scientists said the loss of vegetated hills has weakened a crucial natural barrier that once filtered and slowed these dust flows. “You can already see how the air quality is degrading in the city. In absence of a planned mining and hills being defined as per the height, the AQI may worsen further,” saids Hasrana, the local activist from Mangarbani.
Heatwaves, too, have grown deadlier. The Aravallis helped moderate temperatures by retaining moisture and supporting tree cover. Their destruction has contributed to the urban heat island effect, especially in rapidly built-up zones like Gurugram and South Delhi. Concrete structures now sit where rocky, forested slopes once absorbed heat during the day and released it slowly at night. The result is a city that no longer cools down after sunset rather there’s a rise in night-time temperatures.
Rajender Singh said, “Although authorities announce pollution-control measures like shutting down mining or industrial activity, on the ground, many mining operations reportedly continue at night. As a result, pollution levels in the Aravalli region have not decreased.”
He further said, “New mining licences continue to be issued in the Aravalli range, which undermines the pollution curbing efforts.” Additionally, even as NCR receives intense rainfall during short monsoon bursts, groundwater levels continue to fall. Without hills to absorb and release water gradually, rain rushes off paved slopes, causing flooding instead of recharge.
A deeply personal loss
Pastoral communities that depended on forest commons have seen grazing lands disappear. As a result of all the destruction, small farmers struggle with falling water tables. Migrant workers live beside abandoned mining pits, which are dangerous.
Meanwhile, luxury developments market “Aravalli views” even as hills behind their boundary walls are levelled to make way for parking lots and banquet halls. The range spans multiple states – Delhi, Haryana, Rajasthan and Gujarat – each with different land laws and political priorities. Court orders banning mining have existed for years, but enforcement has been inconsistent.
Reclassifications, exemptions and weak monitoring allowed destruction to continue even as governments claimed commitment to conservation. Climate discussions in Delhi focus on immediate pollutants but rarely on long-term ecological buffers. Yet, without the Aravallis, pollution control measures resemble temporary fixes on a crumbling foundation.
Recent policy moves to restrict fresh mining in the region signal a recognition, but it is only till the time the new sustainable mining plan is presented by the government to the court. Thereby, there is necessarily no timeline for when this fresh mining ban will be enforceable. Conservationists also caution that banning new leases alone will not restore what has already been lost.
Too vital to lose
The absence of the Aravallis will be felt not as an abstract environmental loss, but as a daily hardship. The hills cannot be rebuilt like roads or flyovers. Once gone, they take centuries to return; that is, if they return at all. The question is no longer whether the Aravallis mattered to Delhi. It is whether the city can afford to lose what remains of them. On Saturday, hundreds of students rallied in JNU in protest against the latest SC decision.
Jawaharlal Nehru University is located in the Aravalli range, Parthasarathi Rock, also known as PSR, the highest natural point in Delhi. The protesting students said that the latest SC order will not only increase temperatures in this region but will also expose it to the threats of desertification, pollution, and other major ecological imbalances across Northern India. Danish Ali, Joint Secretary of JNUSU, expressed solidarity with the ongoing struggle to protect Aravalli.
He said, “This decision, if implemented, will further aggravate Delhi’s pollution.” Rising awareness and demonstrations show that citizens are aware and are raising their voices against moves that can prove to be a climate catastrophe. However, by the time the capital fully reckons with what these ancient hills provided, Aravallis may survive only on maps and a warning etched into the landscape of a warming city.
Down the road
1890s–1940s: British-era surveys described Aravallis as ancient folded hills
1952: No hill-range definition exists in law
May 1992: Restriction on mining and construction in named areas
1995–2001: Multiple petitions before Delhi HC and Supreme Court challenge mining; courts acknowledge absence of precise legal definition for “Aravali”.
2002: M C Mehta vs Union of India: SC recognises Aravallis’ ecological importance
May 2004: SC bans mining in Aravali hills of Haryana
2004–2005: Haryana argues mined areas are “plains”; SC holds topography/ecology override land-records ambiguity
2006 :T N Godavarman jurisprudence expands forest definition
2009: SC reiterates mining ban and warns states against exploiting definitional vagueness to permit quarrying
2010: NGT established; many Aravali enforcement cases begin
2011–13: NGT orders removal of illegal constructions in Gurgaon Aravallis
2014: NGT rejects states’ attempt to narrow definition to hills only; holds Aravali as an ecological system.
2016: Haryana amends acts to exclude large tracts from protection
2018–19: NGT stays dilution attempts
2020: Debate over whether Delhi Ridge is part of Aravallis highlights ongoing definitional disputes in courts.
2021: Draft EIA Notification criticised for enabling potential rewriting of Aravali definition.
2022: Rajasthan mining disputes hinge on whether isolated hillocks form part of the Aravali range.
May 2024: Expert committee formally constituted by the Supreme Court to prepare a uniform, scientific definition of Aravali
June 2024: Technical sub-committees formed
Oct 2025: Expert committee submitted its report
Nov 12, 2025: SCreserved judgment on adopting a uniform definition
Nov 20, 2025: SC accepted uniform definition: Aravali Hill = ≥100 m local relief; Range = clusters of 2+ hills within 500 m; stay on fresh mining leases.
Dec 2025: Review and writ petitions
Dec 27, 2025: Supreme Court takes suo motu cognisance amid controversy and lists matter on 29 Dec 2025.