The Ecologically Sensitive Area (ESA) is a legally protected geographic zone (concept/provision) established under the Environment (Protection) Act, 1986. The concept originated from the need to regulate development in ecologically fragile regions, with the Ministry of Environment, Forest and Climate Change (MoEFCC) first notifying ESAs in 1989. The Act's Section 3(2)(v) empowers the Central Government to restrict industries or processes in specific areas to protect the environment.
An ESA features a customized management regime to protect biologically rich ecosystems from industrial degradation while allowing sustainable development for pre-existing human settlements. The mechanism works by outlining prohibited, regulated, and permissible activities in the area. For instance, in the proposed Western Ghats ESA, the key provision is a complete ban on new mining, quarrying, thermal power plants, and heavily polluting "red-category" industries.
The ESA concept is closely connected to the term Eco-Sensitive Zone (ESZ), also known as Ecologically Fragile Area (EFA). While an ESZ typically acts as a buffer zone around a Protected Area (like a National Park or Wildlife Sanctuary), an ESA can encompass a larger, contiguous landscape with unique ecological features, such as the entire Western Ghats. The Supreme Court of India, in T. N. Godavarman Thirumulpad vs. Union of India & Ors., directed in June 2022 that every protected forest must have a mandatory ESZ of a minimum of 1 km from its boundary. This was later modified in April 2023 to allow flexibility for areas already covered by MoEFCC's draft ESZ notifications. The most significant recent change is the phased, state-wise finalization of the Western Ghats ESA, based on the K. Kasturirangan Working Group report of 2013, which proposed notifying approximately 60,000 sq km of natural landscape.