What caused the mass fish deaths in the Varuna River?

According to authorities, the deaths were caused by low dissolved oxygen levels in the water, which were exacerbated by the overflow of untreated sewage from malfunctioning interceptors.

How did the Varuna River's pollution levels contribute to the fish deaths?

The absence of a functional sewage treatment plant along the Varuna River has worsened the pollution, leading to the high levels of untreated wastewater and garbage that were observed in the water.

What actions are officials taking to address the issue in the Varuna River?

Authorities have suggested spraying 20-25 tonnes of slaked lime over a one-kilometer stretch of the river to restore oxygen levels and prevent further loss of aquatic life.

Home / Environment / Sewage Overflow Triggers Mass Fish Deaths in Varuna River

Sewage Overflow Triggers Mass Fish Deaths in Varuna River

1 Nov

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Summary

Hundreds of small fish found dead due to low dissolved oxygen levels
Malfunctioning sewage interceptors caused untreated wastewater to flow into the river
Lack of functional sewage treatment plant worsened pollution in the Varuna River

Sewage Overflow Triggers Mass Fish Deaths in Varuna River

On November 1, 2025, a large number of small fish were discovered dead along the banks of the Varuna River, between the Old Bridge and Nakkhi Ghat. According to the regional pollution control officer, Rohit Singh, the incident was caused by critically low dissolved oxygen (DO) levels in the water.

Water samples collected from various points in the river and tested at the Regional Pollution Control Office laboratory revealed alarmingly low DO levels. The results showed readings of just 0.5 mg/L at Nakkhi Ghat, 0.5 mg/L downstream, and 0.4 mg/L near the Old Bridge, far below the healthy range of 6.5 to 8 mg/L.

Investigations further revealed that the interceptors installed on both banks of the Varuna River to collect and transport sewage from nearby drains were non-functional. As a result, untreated wastewater was overflowing directly into the river, severely compromising water quality and leading to the mass fish deaths.