Archive · 23 Aug 2026
Mamallan reservoir project faces fisheries clearance dispute in Tamil Nadu
Tamil Nadu is building a large reservoir to provide more drinking water for Chennai.
The project is in the Kovalam sub-basin between East Coast Road and Old Mahabalipuram Road.
About 30 per cent of the work has reportedly been completed.
However, the Fisheries Department says it has not yet given the required permission.
It wants more information about how the project could affect fishing communities.
Around 5,000 fishing families may be affected because the project is near the coast.
The Water Resources Department formally asked for permission on July 21, after construction had already begun.
Officials are now examining whether changes or protections will be needed before the clearance is decided.
Nearly 30 per cent of the Mamallan reservoir project has reportedly been completed.
Construction began before the Water Resources Department obtained a Fisheries Department No Objection Certificate.
The reservoir spans about 5,161 acres in the Kovalam sub-basin near Chennai.
It is designed to store 2.25 thousand million cubic feet annually and support Chennai’s drinking water supply.
Fisheries officials are seeking more information about effects on around 5,000 fishing families before deciding on clearance.
- Who
- Tamil Nadu’s Water Resources Department and Fisheries Department are involved; around 5,000 fishing families could be affected.
- What
- A dispute has emerged because construction of the Mamallan drinking water reservoir progressed before the Fisheries Department issued a required NOC.
- When
- The foundation stone was laid in January, construction continued for nearly six months, and the NOC request was submitted on July 21.
- Where
- The reservoir is being developed in the Kovalam sub-basin of Chengalpattu, between East Coast Road and Old Mahabalipuram Road.
- Why
- The reservoir is intended to augment Chennai’s drinking water supply, while fisheries officials are assessing its environmental and livelihood impacts.
Project implementation
Fisheries clearance and safeguards
Whether construction should have started
Project implementation
The Water Resources Department proceeded with a reservoir intended to increase Chennai’s drinking water supply, and nearly 30 per cent of the work has been completed.
Fisheries clearance and safeguards
A senior government official said the department should have consulted the Fisheries Department and secured approval before beginning construction.
Information required before approval
Project implementation
The Water Resources Department formally sought the Fisheries Department’s NOC on July 21 while construction was continuing.
Fisheries clearance and safeguards
The Fisheries Department says it needs additional project details to assess environmental and livelihood effects and has not received satisfactory responses to repeated requests.
Potential project changes
Project implementation
The reservoir is being developed to augment Chennai’s drinking water supply.
Fisheries clearance and safeguards
Because the project is near the coast and may affect fishing families, the Fisheries Department could impose conditions or require safeguards before issuing clearance.
- Project status
- Nearly 30 per cent of construction has reportedly been completed.
- Project area
- Approximately 5,161 acres.
- Planned storage
- Annual capacity of 2.25 thousand million cubic feet of water.
- Purpose
- To augment Chennai’s drinking water supply.
- NOC status
- The Fisheries Department has not yet issued its clearance.
- Affected communities
- Around 5,000 fishing families may be affected.
- Clearance request
- The Water Resources Department approached the Additional Director of Fisheries and Fishermen Welfare on July 21.