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More than 50 organisations, including residents’ welfare associations (RWAs) from the Old Mahabalipuram Road (OMR) area, and over 1,100 citizens have petitioned Tamil Nadu Chief Minister C Joseph Vijay seeking the scrapping of the proposed Mamallan Reservoir project.
The reservoir has been proposed as a source of drinking water for the OMR region, which continues to depend on private water tankers to meet part of its water needs.
However, residents have opposed the project, citing concerns over flooding, damage to wetlands and its possible impacts on local livelihoods.
Harsha Koda, co-founder of the Federation of OMR Residents’ Welfare Association (FOMRRA), said OMR’s residential areas are located between two important wetland systems — the Pallikaranai marsh and the Nemmeli wetlands.
“This reservoir project will heighten flood risk and significantly aggravate our climate vulnerability,” he said.
Residents have also raised concerns that the project could alter the drainage patterns of the Pallikaranai and Kovalam marshland catchments, which eventually drain into the sea through the Kovalam estuary.
According to them, areas including Sholinganallur, Perumbakkam, Navalur, Siruseri and Thazhambur, which are drained by the Pallikaranai catchment, could face greater flood risks during intense rainfall.
Thaiyur and Padur, which fall within the Kovalam catchment, could also face seawater flooding, they said. Koda also claimed that water levels in the Buckingham Canal had increased, alleging that the canal had been blocked for construction related to the Mamallan Reservoir.
Residents are also concerned about the Kovalam-Nemmeli salt marsh, which they allege could be affected by the project. According to them, the wetland provides a habitat for more than 200 resident and migratory bird species.
Instead, the residents have urged the government to protect existing water bodies, prevent encroachments and promote rainwater harvesting. They have also sought a transparent water allocation policy and drinking water projects based on scientific assessments that do not compromise wetlands or natural drainage channels.