Archive · 22 Aug 2026
Opposition Grows Over Proposed Mamallan Reservoir Near Chennai
Many people near Chennai oppose a plan to build the Mamallan reservoir.
They are worried it could damage wetlands where many birds live.
They also fear it could make flooding worse during heavy rain or seawater flooding.
Fishers and other local workers are concerned about losing their livelihoods.
Residents say they were described as beneficiaries even though many of them object to the project.
They want better studies, public meetings and protection for existing water bodies.
One activist supports the reservoir because Chennai may need more drinking water in the future.
A water resources official said the project should proceed only after technical, environmental and hydrological checks.
More than 50 organisations and over 1,100 residents petitioned Chief Minister C. Joseph Vijay to scrap the proposed Mamallan reservoir.
Opponents say the project could damage the Kovalam-Nemmeli salt marsh, threaten bird habitats and harm local livelihoods.
OMR residents and activists warn that changes to wetland drainage could increase rainfall and seawater flooding in nearby areas.
Critics say the project lacked adequate scientific studies, public consultation and a proper feasibility assessment.
A supporter called the reservoir essential for Chennai’s future drinking-water needs, while officials said environmental and hydrological assessments must be completed.
- Who
- More than 50 organisations, over 1,100 residents, environmental groups, fishers, activists and a state water resources official are involved in the debate.
- What
- Opponents are seeking the cancellation or reassessment of the proposed Mamallan reservoir, while supporters say it could improve Chennai’s future drinking-water security.
- When
- The articles do not specify the project’s date; they refer to a recent March for Marshland rally and the project being initiated under the previous government.
- Where
- The project and its potential impacts concern the Old Mahabalipuram Road corridor and nearby wetlands and catchments around Chennai.
- Why
- Opponents cite possible wetland damage, biodiversity loss, livelihood impacts and greater flood risk; supporters cite Chennai’s future demand for drinking water.
Project Opponents
Project Supporters and Officials
Environmental impact
Project Opponents
Residents and environmental groups say the reservoir could encroach on wetlands, damage biodiversity and affect a habitat supporting more than 200 bird species.
Project Supporters and Officials
The official said concerns about wetlands and ecological impact are important and must be duly considered through environmental assessments.
Flood risk
Project Opponents
Activists say the project could alter the Pallikaranai and Kovalam catchments, increasing rainfall or seawater flooding in surrounding areas.
Project Supporters and Officials
Supporters did not directly address the specific flood claims, while the water resources department said hydrological assessments are necessary.
Water security
Project Opponents
OMR residents say they need reliable piped water and object to a project they believe is environmentally destructive and insufficiently studied.
Project Supporters and Officials
Supporters say Chennai’s water scarcity and future drinking-water demand make the reservoir essential for long-term water security.
- Petitioners
- More than 50 organisations and over 1,100 residents petitioned the chief minister.
- Project
- Proposed Mamallan reservoir.
- Concerned wetland
- The Kovalam-Nemmeli salt marsh, described by opponents as habitat for more than 200 resident and migratory bird species.
- Potentially affected areas
- Sholinganallur, Perumbakkam, Navalur, Siruseri, Thazhambur, Thaiyur and Padur were identified by activists.
- Main risks cited
- Wetland damage, altered drainage, biodiversity loss, livelihood disruption, rainfall flooding and seawater flooding.
- Alternative proposed
- Rooftop rainwater harvesting and restoration and protection of existing water bodies.
- Government position
- A water resources official said technical, environmental and hydrological assessments must be completed before a project of this scale proceeds.