Thousands of dead fish were found along the Yamuna near Burari in North Delhi on October 14, prompting concerns over aquatic biodiversity in a stretch upstream of the Wazirabad Barrage where recurring fish deaths have previously been reported.
The fish, including Tilapia and Common Carp, were found floating in shallow water and washed ashore. The New Delhi Nature Society, a nonprofit, shared photographs and videos of the incident on X on October 15. It said the specific cause had not been established.
Bhim Singh Rawat, an expert on the Yamuna and a member of the South Asia Network on Dams, Rivers and People, described the recurrence as concerning. “This latest incident, occurring just after the monsoon season, is particularly unusual and poses a serious threat to the river’s remaining aquatic biodiversity,” he said.
The incident has also drawn attention to wastewater flows entering the Yamuna upstream of Delhi. Several drains in Haryana carry industrial and urban wastewater into the river, including the Dhanaura drain and Drains No. 2 and 8, which receive wastewater from areas including Karnal, Panipat and Sonipat.
Official records submitted to the National Green Tribunal had identified 105 illegal discharge points leading to Drain No. 2 in Panipat. Of these, 48 were reported closed, while action against the remaining 57 was pending, according to the reported records.
In November last year, the CM Flying Squad and the Haryana State Pollution Control Board intercepted 13 tractor-tankers and registered cases against 27 people over alleged illegal dumping of industrial waste in areas including Kurar, Chhajpur and Jalalpur. The reported enforcement action indicates that illegal discharge remains an issue across the wider river system, although no specific source has been linked to the latest fish deaths.
The New Delhi Nature Society said local residents had alleged that chemical waste was being discharged into the river from Haryana through canals. That allegation has not been independently verified. The society also raised, without establishing a connection, whether the deaths could be related to acid rain reported on October 12.
Environmentalists have separately raised concerns about restricted environmental flows in the Yamuna. Rawat said the current flow rate was around 10 cubic metres per second, compared with average hourly inflows of approximately 300 cubic metres per second at the Hathnikund barrage in Haryana. The figures were cited in the report and no independent assessment of the latest incident was provided.
The Burari stretch reported mass fish deaths in May last year as well. Earlier this year, hundreds of fish died at Sanjay Lake in East Delhi during a heatwave and as water levels receded. That incident was linked to a damaged high-density polyethylene pipeline that halted the supply of 10 million gallons per day of treated water from the Delhi Jal Board’s nearby Kondli sewage treatment plant.
The latest Yamuna incident leaves the immediate cause unresolved. Authorities and pollution-control agencies have not, in the supplied report, announced a confirmed contaminant, laboratory finding or formal investigation outcome. The next steps will depend on identifying the source of the mortality and determining whether any discharge or change in river conditions can be linked to the deaths.
