Karnataka plans size-based buffer zones for waterbodies

Bengaluru: The Karnataka Tank Conservation and Development Authority (KTCDA) has proposed a scientific revision of buffer zone regulations based on the size of waterbodies, becoming the first state in the country take such an approach.

In a press release, KTCDA said, “For the first time in the country, a proposal has been made to scientifically modify buffer zone regulations based on the size of waterbodies/tanks in the state.”

The move follows representations from elected representatives, including the MLA from Kundapura and the Deputy Commissioner of Udupi, who sought changes in the uniform 30-metre buffer zone rule, citing its disproportionate application to both small and large waterbodies.

Based on its recommendations, the KTCDA has proposed a graded buffer system -- zero metre for up to 5 guntas of water body, three metres buffer zone for water bodies between five guntas and one acre, six metres for lakes above one acre to 10 acres, 12 metres for lakes above 10 acres to 25 acres, 24 metres for lakes above 25 acres to 100 acres, and 30 metres buffer zone for lakes above 100 acres.

The release said, “This buffer distance has been framed using a scientific approach, as the buffer zone serves to facilitate the natural inflow of rainwater into lakes… smaller tanks will have smaller buffers, while larger tanks will have larger buffers.”

The proposal also includes revised norms for nala buffers, replacing the existing 30, 15 and 10 metre norms for primary, secondary and tertiary nalas respectively, which were found to be unscientific. As per the revised proposal, the buffer zone will be 15 metres for primary nalas, 10 metres for secondary nalas and 5 metres for tertiary nalas.

KTCDA added, “The modification allows only public utility within buffer zones, without reducing the tank capacity or obstructing water flow… this modification is not intended for real estate development; it aims solely to bring uniformity in buffer zones for different tank sizes.”

Karnataka is the only state to have framed incremental buffer guidelines scientifically linked to tank size, after reviewing practices in other states like Gujarat, Telangana and Tamil Nadu. According to KTCDA, the changes will not increase flood risks, but instead help mitigate them in urban areas, while supporting essential infrastructure like sewage treatment plants, water pipelines, and roads.