Eco-sensitive zones
Eco-sensitive zones · ESZ around protected areas · ESA
12 min read · Updated 2026-05-25
What is an eco-sensitive zone?
An eco-sensitive zone is a regulated buffer area around a national park or wildlife sanctuary, notified by the environment ministry under Section 3 of the Environment (Protection) Act, 1986. Activities inside it fall into three lists — prohibited, such as commercial mining and polluting industry; regulated; and permitted. A 10-kilometre radius is the default guideline, but each zone's extent is notified case by case.
The story
In September 2022, the Supreme Court issued a single sentence that sent panic through state capitals from Mumbai to Guwahati: "every protected area in the country shall have a mandatory eco-sensitive zone (ESZ) of a minimum 1 km from its demarcated boundary." Mall developers in Gurugram had just broken ground 0.4 km from the Aravalli forest. Eighteen quarries were operating inside the 1-km radius of Bandipur Tiger Reserve. Apartment complexes in Mumbai's Aarey Colony — directly adjacent to Sanjay Gandhi National Park — were already at plinth level.
By April 2023, the same bench partially walked the order back. Pre-existing human settlements, ongoing public projects, and "areas where the ESZ was specifically notified" were exempted. The exemption acknowledged a harder truth: India had 998 protected areas, of which only 341 had ESZ notifications issued, and millions of people lived inside zones that had never been formally drawn on a map. A 1-km blanket would have rendered tens of thousands of homes illegal overnight.
This file is about that uneasy compromise — what an eco-sensitive zone is, how it differs from an Ecologically Sensitive Area (ESA), why the Western Ghats saga set the template, and how the doctrine of the MoEFCC's "shock absorber" is meant to work in theory and falters in practice.
Why this matters for UPSC
ESZ/ESA is a high-frequency topic in both Prelims (legal basis, notification authority, default radius) and Mains (centre-state friction, livelihood vs conservation balance). UPSC has asked at least 4 direct questions on ESZ/ESA in the last 8 years, especially around Western Ghats and the 2022 SC order. Interview boards probe candidates from ESZ-affected states.