2L cubic metres of fly ash, Kakka Aazhi removed from Kosasthalaiyar
As per the records, the WRD commenced the dredging of the Kosasthalaiyar River backwater area for about 800 m in November 2024.;
CHENNAI: Even as the Water Resources Department (WRD) has commenced the removal of invasive alien Charru Mussels (Kakka Aazhi) from Kosasthalaiyar River based on the directions from the Southern Bench of National Green Tribunal, the exercise has resulted in the removal of a huge amount of fly ash from the river.
Against such a backdrop, the department has submitted a proposal to Tamil Nadu Generation and Distribution Corporation (Tangedco), from whose thermal power plant fly ash entered the river and accumulated, and Tamil Nadu Pollution Control Board (TNPCB) seeking Rs 20.85 crore to continue the removal of fly ash and Kakka Aazhi.
As per the records, the WRD commenced the dredging of the Kosasthalaiyar River backwater area for about 800 m in November 2024. Presently, the department has removed around 2 lakh cubic meters of heterogeneous material, a combination of fly ash and aggregated charru mussels.
“Hence, the scope of WRD is to dredge out fly ash with charru mussels and Tangedco to remove the dredges from the backwater area. Due to the mangrove plantation and the bank, the dredging volume is limited to a phased manner to dispose of fly ash, Kakka Aazhi of the bank immediately,” the department informed the Tamil Nadu State Wetland Authority which is coordinating the removal of charru mussels.
The letter added that as per the NGT directions, Tangedco bears the responsibility for the removal and appropriate disposal of all dredged materials within the 1700 m stretch of the backwater area, including the 800 m that has been covered to date. On the other hand, the ongoing dredging in the 800 m stretch is expected to be completed before May.
The WRD informed the wetland authority that dredging in the remaining portion of the 1700 m stretch in the backwater area will commence upon obtaining approval and allocation of necessary funds from Tangedco and TNPCB.
The department has estimated to dredge about 4.75 lakh cubic metres, of which 8 per cent of volume constitutes charru mussels, based on the systematic sampling.
Meanwhile, the wetland authority has roped in Dr MGR Fisheries College and Research Institute in Ponneri to conduct long-term strategies to prevent the re-occurrence of the invasion in dredged areas as well as to conduct research on the value addition of charru mussels.