The Water Resources Department has started work to dredge the backwaters of Ennore creek, earlier this month, and mitigate pollution.
Layers of fly ash sediments deposited in the backwaters are being removed over the last fortnight. The department is engaged in clearing the fly ash deposits from the 2.5-km stretch between North Chennai Thermal Power Station (NCTPS) and Kamarajar port. The stretch is silted with fly ash for a depth of nearly one metre.
The Ennore creek and its backwaters, the confluence point of Kosasthalaiyar river, North Buckingham canal and the sea, have been destroyed with hotwater discharge and leakage of fly ash slurry, for nearly two decades now. A pipeline from NCTPS carrying fly ash along the creek added layers of silt.
The long-pending work has now been taken up with the Tamil Nadu Generation and Distribution Corporation (Tangedco) depositing ₹28.5 crore based on a directive of National Green Tribunal, southern bench, to remove fly ash.
Though the tender process was completed in March, work was delayed due to the lockdown. Officials of the WRD said nearly 4.30 lakh cubic metre of fly ash deposits was estimated to be cleared from the Ennore creek backwaters and North Buckingham canal.
“We have so far removed nearly 40,000 cubic metre of fly ash and have deposited it on the banks. It is Tangedco’s responsibility to dispose of the sediments cleared as per the NGT order and we have conveyed to them about the progress. As the sludge dries, there is no threat of further pollution,” said an official.
The department would take up similar work on a 2.4-km stretch of the North Buckingham canal flowing parallel to the backwaters at a cost of ₹66.23 lakh.
“We want to clear the fly ash sediments before the onset of the Northeast monsoon in October. This will help improve tidal action in Kosasthalaiyar river and the creek and alleviate flooding. Now, the tidal flow stops near the starting point of the creek because of the heavy sediments,” the official.
Besides reviving the eco-system, including the vanishing mangroves, fishermen who are dependent on the creek and Kosasthalaiyar river would have better livelihood opportunities, once the project is completed, noted the officials.
Meanwhile, environmentalists and fishermen noted that the leak from the NCTPS pipeline continued to pollute the region and the Tangedco must replace the pipeline. Unless the sludge deposited on the banks is disposed of and the leak is plugged, the environmental degradation would continue, they said.
V.Desinghu, executive committee member, Nettukuppam fishermen cooperative society said, “Earlier, we used to get a good catch of crabs and prawns within one km distance. Now, we go up to 6-7 km near Kattupallikuppam in Kosasthalaiyar river. Hotwater discharge from thermal power plants still continues and it affected the fish population. Measures must be taken to stop pollution.”