BENGALURU: Cauvery river, one of the prime sources of water for southern parts of Karnataka, is extremely polluted. Also called Dakshina Pinakini, the river water was ranked under E category, indicating high levels of pollution, in most parts of Bengaluru.
As per the Central Pollution Control Board (CPCB), E category refers to the quality of water which can be used only for irrigation, industrial cooling and controlled waste disposal.
The Karnataka State Pollution Control Board (KSPCB) Water Quality Classification of Polluted River Stretches in Karnataka for August 2026 stated that Cauvery water fell under E category in Sarjapur and Mahadevapura. In Chamarajanagar, Mandya and Ramanagara, it is under C and D categories, respectively.
As per CPCB, if the water quality is C, it can be used for drinking with conventional treatment followed by disinfection and if listed under D, it can be used for propagation of wildlife and fisheries.
The KSPCB report for April-July 2026 too showed water quality of Cauvery to be poor. The river samples at five locations in Kodagu showed it to be in the B Category, which is fit for outdoor bathing (organised).
‘Most water bodies are D category in K’taka’
A senior KSPCB official, seeking anonymity, said, “Nearly all water bodies (lakes and rivers) in Karnataka fall under D category. That is water not fit for consumption without proper treatment. It is a sad state of affairs. If all the installed sewage treatment plants at all water bodies work at full capacity and if the polluting sources are shut down, even then, it will take a long time to revive and fully improve their water quality.”
The KSPCB April-August reports assessed the water quality of Tungabhadra, Cauvery, Kabini, Krishna, Bhima, Ghataprabha, Malaprabha, Bhadra, Hemavathi, Kali, Karanja, Yagachi, Netravathi, Kumudavathi, Kumara Dhara, Krishna, Asanganalla, Kagina, Lakshman Tirtha, Arkavathy and Shimsha rivers. The water quality was also tested at Almatti, Vanivilasa Sagara, Rakkasakoppa, Sumavathi and Gundal reservoirs at different locations.
The August report showed Arkavathi river at Rajarajeshwari Nagar in Bengaluru Urban and in Ramanagara ranked E. It was also listed as the worst polluted. In the reports, the quality of water of all sources at all locations was C category or below.
None was listed under A category, which is fit for consumption directly from the source. Taking note of the pollution levels and the ongoing hearing before the National Green Tribunal, based on a petition filed by the Tamil Nadu government on the poor quality of Cauvery river, Forest, Environment and Ecology Minister Ramalinga Reddy said he has sought detailed reports from KSPCB, Bangalore Water Supply and Sewerage Board and water resources department, but so far nothing has been submitted.
He admitted that the water quality is poor and stringent action should be taken against officials and polluters.
Rating water
Class of Water & best designated use
A: Drinking water source without conventional treatment but after disinfection
B: Outdoor bathing (organised)
C: Drinking water source with conventional treatment
D: Propagation of wildlife & fisheries
E: Irrigation, industrial cooling and controlled waste disposal