Madras HC orders halt to Coimbatore lake works after report shows bird decline
The Madras High Court has directed authorities to stop all further developmental activities at Periyakulam and Valankulam lakes in Coimbatore until a Wetland Management Plan is implemented. The order, issued on August 14 by a Division Bench of Justices N. Sathish Kumar and K. Rajasekar, follows an expert report that flagged a decline in wetland-dependent bird species in the two water bodies.
The court also instructed the authorities to repair the Sewage Treatment Plants (STPs) at the lakes and ensure that untreated wastewater does not flow into them.
The directions were based on a report submitted by the Salim Ali Centre for Ornithology and Natural History, Coimbatore. The Centre had been asked to study whether the lake revitalisation activities undertaken by the Coimbatore Municipal Corporation were harming birds that nest in or use the water bodies.
The Centre noted that eight ecologically and hydrologically interconnected lakes within the Corporation limits are associated with the River Noyyal, and that birds, particularly migratory species, move between these lakes. For the present study, however, it focused on Periyakulam and Valankulam.
According to the report, 183 bird species have been recorded at Periyakulam, including 126 resident and 57 migratory species. Eight of these are globally threatened, including two vulnerable species – the Curlew Sandpiper and River Tern – and six near-threatened species. At Valankulam, 104 species were recorded, with 86 resident and 18 migratory species. Four species are classified as threatened, including the vulnerable River Tern and three near-threatened species.
The expert report said the overall bird composition has shifted towards woodland species, with only a few generalist wetland birds remaining. This change indicates a transformation of the wetland ecosystem into an area “manicured for recreational use,” the report said.
At Periyakulam, several wetland-associated species have shown a moderate to major decline in reporting frequency since September 2018. Nearly 78% of high-priority waterbirds listed in the State of India Birds dataset recorded a reduction in reporting frequency. The report also noted declining trends among threatened species such as the River Tern, Black-tailed Godwit, and Spot-billed Pelican. Several other wetland birds have not been recorded at the lake in recent years.
Similar concerns were raised for Valankulam, where several wetland-associated species showed declining reporting frequencies after the implementation of the lake development scheme.
The Centre also found that the STPs at both lakes were not functioning, allowing untreated wastewater to enter the water bodies. This makes the lakes unhealthy for aquatic life, including birds.
Taking note of these findings, the Bench directed the authorities to immediately repair the STPs and prevent untreated wastewater from entering the lakes. It ordered that all further developmental activities, including ongoing and proposed projects, remain halted until the Wetland Management Plan is implemented.
The case was originally taken up concerning development and commercial activities at the lakes, including the installation of floating solar panels at Periyakulam. The Corporation had earlier told the court that the solar panels occupy only about 0.2 acres, or 0.05% of the total area of Periyakulam, and do not obstruct sunlight reaching aquatic species. It also stated that diesel or mechanised boats were not being operated at Periyakulam, and that rowing and pedal boats are used only for rescue measures.
The matter has been posted for September 18, by which time the Coimbatore Corporation has been directed to file an inspection report.
