Opposition Swells against Mamallan Reservoir

The residents said they were being projected as the beneficiaries of the project, despite having opposed it, drawing parallels with the earlier controversy over the proposed desalination project in the region.

“For over two decades, OMR residents have paid taxes and watched pipelines pass right through our corridor while our own taps remain dry. Now, we are offered the disastrous Mamallan reservoir.

It is a project that will encroach on the Kovalam-Nemmeli salt marsh, destroy a critical habitat for over 200 resident and migratory bird species, rob livelihoods, erode biodiversity and expose local residents to increased flood risk. This is not sustainable water planning. We cannot allow this ecological crime to be committed in our name,” said Bhuvana Raj, an OMR resident

“The reservoir project, which was pushed through towards the end of the previous government’s tenure, has faced opposition from fishers, environmentalists and experts, who have raised concerns over the adequacy of scientific studies on the region’s ecology, local livelihoods and the risks of seawater and rainwater flooding,” he alleged.

With OMR residents, who are projected to be among the beneficiaries, now distancing themselves from the project, activists said its relevance and justification needed to be reconsidered.

“Residential areas in OMR are situated between two critical wetland systems - the Pallikaranai marsh and the Nemmeli wetlands. This reservoir project will heighten flood risk and significantly aggravate our climate vulnerability,” said Harsha Koda, co-founder of the Federation of OMR Residents' Associations (Fomrra).

“We have seen increased water levels in the Buckingham canal, probably because they have blocked the canal to construct the Mamallan reservoir,” he added.

Activists said the project could affect the drainage patterns of the Pallikaranai and Kovalam marshland catchments, which eventually drain into the sea through the Kovalam estuary.

They claimed that areas including Sholinganallur, Perumbakkam, Navalur, Siruseri and Thazhambur, which are drained by the Pallikaranai catchment, could face increased flood risks during intense rainfall. Areas in the Kovalam catchment, including Thaiyur and Padur, could also face greater exposure to seawater flooding, they said.

“The project was initiated without any public consultation and proper feasibility study. Even during the recent March for Marshland rally organised by us at Besant Nagar, many people expressed their opposition to the project through placards and artworks,” said M. Balakrishnan of the Tansi Nagar Welfare Association.

“We are tired of grand, environmentally-reckless announcements that divert water elsewhere while leaving us dependent on private tankers. We don’t need rushed, destructive shortcuts — we demand transparent allocations, ecological accountability and the piped water supply we were promised 20 years ago,” said Koda.

Raju of the Chennai Wetlands Action Collective said the government should, instead, focus on rooftop rainwater harvesting and the restoration and protection of existing water bodies.

The residents and environmental groups have urged the state government to reassess the project’s feasibility through transparent scientific studies and public consultation. They said long-term water security should be pursued without compromising flood resilience, wetlands and the natural drainage systems of the OMR region.

But, Satish Gallay, an activist in OMR, supported the project, saying that the setting up of a reservoir was essential, considering the demand of drinking water in the future. Unlike other cities, Chennai is water-scarce. These kinds of projects will help the government ensure water security of the city in the years to come, he said.

“The Mamallan reservoir project is being examined primarily from the perspective of Chennai’s long-term drinking water security. The concerns raised by residents, environmental groups and other stakeholders regarding wetlands, flood management and ecological impact are important and will have to be duly considered. Any project of this scale should move forward only after all necessary technical, environmental and hydrological assessments are completed,” said an official with the water resources department.