Haryana Sets 100m Height Criterion for Aravali Hills

The Haryana government revised the definition of the Aravali hills and ranges in 2025. The new rules set a minimum geological age and height for land to qualify as part of the Aravalis. This move has raised concerns among experts and environmentalists. They fear it may exclude many forested areas, especially in Gurgaon, from protection. The changes could open these lands to development and mining.

Recent Changes in Definition

Haryana now requires hills to be over 100 metres in height above surrounding land. They must also be composed of rocks at least a billion years old. Only rocks from the Aravali supergroup (Paleoproterozoic) and Delhi supergroup (Mesoproterozoic) qualify. Younger Neoproterozoic rocks like Erinpura granite and Malani rhyolite are excluded. This definition was finalised after Geological Survey of India (GSI) flagged earlier drafts.

Comparison with Rajasthan’s Criteria

The 100-metre height rule mirrors Rajasthan’s standard. However, Rajasthan’s classification focuses on mining. Haryana’s is meant for conservation. The Supreme Court rejected Rajasthan’s height rule in 2011-12. Haryana’s new rule narrows the protected Aravali area more than GSI recommended. This could reduce forest and biodiversity protection.

Environmental Concerns

Many forested Aravali areas in Haryana are below 100 metres. These include parts of Gurgaon, Faridabad, and Nuh. Experts argue the focus should be on protecting living landscapes, not just rock age or height. The scrub forests and ridges support groundwater recharge and wildlife. The Aravalis help prevent desertification in the Delhi-NCR region and maintain ecological balance.

Legal and Policy Implications

The new definition affects the 1992 Aravali Notification and court orders that limit mining and construction. Narrowing the definition could remove legal protections from large forest tracts. This may allow real estate and infrastructure projects to expand in these areas. Critics say the change is a policy shift disguised as a technical correction.

Role of Government Departments

The mines and geology department drafted the new definition. Environmentalists question why the forest or environment departments were not involved. They argue that defining Aravalis is primarily an ecological issue. The geology department claims the new criteria offer a measurable and verifiable standard consistent with GSI and Rajasthan.

Geological Background

The Aravali–Delhi fold belt stretches from Gujarat to Delhi. It mainly consists of quartzites, schists, phyllites, dolomites, and marbles. Intrusive granite forms less than 3% of Haryana’s Aravali terrain. The Ajabgarh and Alwar geological groups dominate the landscape. Defining Aravalis uniformly across states was ordered by the Supreme Court in May 2024.