Ganga protection: Centre introduces new flood zones, drops ‘construction-free’ wording

New Delhi: The Centre has revised the definition of the "active floodplain" of the Ganga and its tributaries and introduced new regulatory and warning zones based on different flood return periods.

The Jal Shakti Ministry made the changes through a notification issued on August 7 and published in the Gazette on August 10, amending the River Ganga (Rejuvenation, Protection and Management) Authorities Order, 2016.

One of the key changes is the removal of the phrase "construction free zone" from the provisions concerning the Ganga and its floodplains. The amended order instead states that the banks of the Ganga and its tributaries, along with their floodplains, should be maintained to reduce pollution sources and pressures and preserve their natural groundwater recharge functions through necessary measures.

What is the new definition of Ganga's active floodplain?

The amendment introduces a specific definition of "active floodplain", referring to areas of the Ganga or its tributaries that are inundated during floods corresponding to a one-in-five-year return period.

The revised definition of "floodplain" now covers three categories:

Active floodplain: Areas inundated during a one-in-five-year flood.

Regulatory zone: Areas inundated between one-in-five-year and one-in-25-year floods.

Warning zone: Areas inundated between one-in-25-year and one-in-100-year floods.

The definition also covers areas on either side of the Ganga and its tributaries that are inundated during floods corresponding to their greatest flow or a flood with a frequency of once in 100 years.

What did the 2016 order say about construction?

Under the 2016 order, construction of permanent or temporary structures for residential, commercial, industrial or other purposes was prohibited in the Ganga, its banks, its tributaries and the active floodplain, subject to specified exceptions and permissions.

The 2026 amendment does not amend that specific construction provision. However, it changes the definition of the active floodplain by linking it to a one-in-five-year flood.

Importantly, the latest notification does not itself specify whether construction would be permitted or prohibited in the newly defined regulatory and warning zones.

Ganga floodplains to be maintained for groundwater recharge

The amendment also replaces the earlier provision concerning the maintenance of the river's banks and floodplains.

Under the revised provision, the banks and floodplains are to be maintained to reduce pollution sources and pressures while preserving their natural groundwater recharge functions through necessary measures.

The order, formally titled the River Ganga (Rejuvenation, Protection and Management) Authorities (Second Amendment) Order, 2026, came into force on the date it was published in the official Gazette.

The principal order was notified on October 7, 2016, and was last amended on May 7, 2026, according to the latest notification.