Kadambrayar River Chokes on Pollution as Oxygen Levels Plummet

As of August 18, 2025, the Kadambrayar river in Ernakulam, Kerala is facing a critical environmental crisis. According to the results of tests conducted last month by the Central Pollution Control Board and the Kerala State Pollution Control Board, the dissolved oxygen levels on the Brahmapuram and Manakkakadavu stretches of the river were alarmingly low, well below the minimum required concentration of 5 mg/l.

The tests revealed that the dissolved oxygen levels were a mere 0.5 mg/l and 0.7 mg/l on these stretches, respectively. This is a significant cause for concern, as the minimum level of 5 mg/l is recommended for optimum fish health and to ensure reasonable freedom from oxygen-consuming organic pollution.

Furthermore, the biological oxygen demand, a proxy for organic pollution, was found to be above the desired maximum level of 3.0 mg/litre on the same stretches. In Brahmapuram, the recorded level was 4 mg/l, while in Manakkakadavu, it was 3.7 mg/l.

A report submitted to the National Green Tribunal (NGT) by the Department of Environment in March 2025 had attributed the pollution in the Kadambrayar to the discharge of domestic effluents from nearby townships and households through drains and creeks leading to the waterbody. The report also noted that leachate discharge, if any, from the Brahmapuram plant and the growth of water hyacinths had further exacerbated the pollution.

The water quality in these stretches of the Kadambrayar did not meet the norms of the National Water Quality Monitoring Programme in the period between January 2024 and December 2024, indicating that the pollution problem has been ongoing for some time.