The Aravalli Range: Ancient Mountains Facing a Modern Threat

 The Aravalli Range: Ancient Mountains Facing a Modern Threat

The Aravalli Range is one of the oldest mountain chains in the world, formed around three billion years ago. These hills are so ancient that they existed long before the Indian subcontinent took its present shape. While the Himalayas are known for their great height, the Aravallis are far older. Scientists often describe them as the “grandfather” of the Himalayas.

The range stretches for about 692 kilometres across Gujarat, Rajasthan, Haryana and Delhi. Nearly 80 per cent of the Aravallis lie in Rajasthan. In Delhi, well-known places such as Jawaharlal Nehru University and Rashtrapati Bhavan are located on Aravalli hills. The highest peak, Guru Shikhar in Rajasthan, rises to 1,722 metres.

Despite their modest height, the Aravallis play a vital role in keeping North India liveable. They act as a natural barrier that slows the spread of the Thar Desert towards Delhi, Haryana and western Uttar Pradesh. Their rocky structure allows rainwater to seep underground, helping to recharge groundwater used by millions of people in the Delhi–NCR region. The range also influences weather patterns by pushing rain-bearing clouds towards the Himalayas, increasing rainfall in North India. In addition, the Aravallis support wildlife and protect important historical sites such as Mehrangarh Fort and the Sariska Tiger Reserve.

Recently, the Aravallis have become the focus of a legal and environmental controversy. The issue arose because there was no clear legal definition of what counts as an “Aravalli hill”. On 20 November 2025, the Supreme Court introduced a new rule stating that only hills measuring 100 metres or more in height would be officially recognised as part of the Aravalli Range and protected under environmental laws.

Environmental experts have expressed serious concern over this decision. Most Aravalli hills are relatively low. In Rajasthan alone, there are more than 107,000 hills, but only about 1,048 are taller than 100 metres. This means that nearly 99 per cent of the hills could lose legal protection and become vulnerable to mining and construction. Unlike forests, which can be replanted, mountains take millions of years to form and cannot be restored once destroyed.

The impact of this damage is already visible. In several places, hills have been flattened, creating gaps through which dust and sand from the desert now travel directly towards Delhi, worsening air pollution. In parts of Haryana, especially Mahendragarh, heavy mining has caused groundwater levels to fall to depths of 1,500 to 2,000 feet. Haryana already has the lowest forest cover in India, at just 3.6 per cent.

The government says it continues to protect key areas such as the Asola Bhatti Wildlife Sanctuary and Sariska, and that mining remains banned in many locations. Environmental activists, however, argue that the 100-metre rule is not based on scientific evidence and risks weakening protection for the entire mountain system.

The Aravallis can be compared to a protective fence. If only the tallest posts are kept and the smaller connecting parts are removed, the fence no longer works. In the same way, even the smaller Aravalli hills are essential. Without them, the range may no longer be able to protect North India from desertification, water shortages and worsening climate conditions.