Officials have linked the issues to discharge from Bengaluru’s Bellandur, Agara and Varthur lakes, which continue to release untreated waste into feeder streams.
Published Jul 16, 2025 | 2:05 PM ⚊ Updated Jul 16, 2025 | 2:05 PM
Foam formation in Thenpennai river.
Synopsis: The Tamil Nadu government told the National Green Tribunal that the Thenpennai river, one of the four major east‑flowing rivers of the state, is being choked with untreated sewage and industrial effluents flowing in from Karnataka.
The Tamil Nadu government said that the Thenpennai river, one of the four major east‑flowing rivers of the state, is being choked with untreated sewage and industrial effluents flowing in from Karnataka.
On Tuesday, 15 July, Water Resources Department (WRD) Secretary J Jayakanthan submitted a report to the Southern Bench of the National Green Tribunal (NGT).
The river, which stretches for 320 kilometres within Tamil Nadu, is a key source for irrigation and drinking water. Pollution along its course has already impacted about 9,000 acres of farmland, affecting both soil quality and crop output.
The report placed before the NGT documented the condition of the Thenpennai river as it enters Tamil Nadu. The report stated, “The water entering Tamil Nadu was blackish with a sewage‑like odour. Foam and foul smell were observed at Kalaiparam Dam with no signs of aquatic life.”
Officials have linked the issues to discharge from Bengaluru’s Bellandur, Agara and Varthur lakes, which continue to release untreated waste into feeder streams.
Tamil Nadu has flagged that earlier communications to Karnataka have yielded little improvement. Even though Karnataka outlined plans for additional sewage treatment plants, no interim measures have been established.
It noted that there is no immediate mechanism in Karnataka to prevent the discharge, leaving Tamil Nadu’s Kelavarapalli reservoir and downstream areas exposed.
The submission stressed that unless interim measures are introduced, contamination will continue to spread, threatening agriculture, drinking water and the ecological balance.
The tribunal registered a suo motu case on the basis of a media report. The next hearing is scheduled for 21 August, with Tamil Nadu pressing for urgent action to protect the river and the livelihoods it supports.
(Edited by Muhammed Fazil with inputs from Subash Chandra Bose.)
