COIMBATORE: Environmentalists have raised concerns over non-technical river rejuvenation work that has allegedly caused erosion of the riverbanks near the Puthukkadu check dam across the Noyyal river. They warned that the check dam could be at risk of damage during the next spell of heavy rainfall.A video documenting the condition of the site showed severely eroded banks and trees on the verge of collapsing into the river. A similar situation was reportedly observed at the Kurichi check dam after an NGO carried out desilting and river rejuvenation work at both locations.R Manikandan, founder of Kovai Kulangal Padhukaappu Amaippu, flagged the issue, calling for urgent attention to river rejuvenation projects. He said, “Excessive and unscientific excavation has been carried out on the riverbed. Steep bunds have been made on either side of the river without any technical understanding of the dynamics of the river flow. Deep excavation has been carried out on the riverbed without adequate technical planning of appropriate hydraulic slopes and surface drainage provisions along the bunds.”He added that the surface runoff and drainage from areas outside the bunds have not been provided with adequate drainage outlets. “So, when there is heavy concentration at a single point, it has compromised the stability of the adjoining soil, posing a serious risk to the retaining and wing walls of the structure,” he said.Highlighting a similar situation at the Kurichi check dam, Manikandan said, “The condition of the Kurichi check dam banks is relatively better and might still be able to survive the monsoon. Because of the intensity of erosion, the Puthukkadu check dam will not withstand any further heavy rain. The major impact is on the structure and the trees along the bunds, which are over five decades old.”Following a representation made to the district administration, officials from the water resources department inspected the Puthukkadu check dam. Commenting on the issue, a senior official from the department said, “The desilting has happened very close to the anicut, within a 5-10 meters distance, which is technically wrong. They should have left at least a 50-metre gap. We are taking steps to rectify erosion and stabilise the retaining wall.”
