CM Stalin lays foundation stone for Mamallan reservoir, proposed as Chennais sixth drinking water source

Tamil Nadu Chief Minister M.K. Stalin on Monday (January 19, 2026) laid the foundation stone for the Mamallan reservoir, proposed as Chennai’s sixth drinking water source and the State’s first freshwater reservoir along the coast at Vada Nemmeli, on East Coast Road.

The ₹342.60-crore project in the Kovalam basin, covering the land parcel between Thiruvidanthai and Kokilamedu, would be implemented by the Water Resources Department (WRD) to create the reservoir spread over 5,161.27 acres and with a storage capacity of 1.65 thousand million cubic feet.

The reservoir would have an annual storage capacity of 2.25 tmcft when filled twice and a potential to supply 170 million litres a day (mld) to Chennai. The site would be bound by ECR on one side and Rajiv Gandhi Salai on another.

Highlighting the historical significance of the region, the Chief Minister said the reservoir was named after Pallava ruler, Narasimhavarman I, also known as Mamallan, who founded Mamallapuram. The Pallavas, renowned for their water management system, created nearly 39 tanks, including Uthiramerur and Thenneri, which are still in use.

The proposed structure, which would store surplus water from 69 upstream tanks in the Manamathy tank group, would have a bund extending for about 34 km. It would help prevent seawater intrusion and recharge groundwater in neighbouring localities, including Thiruvidanthai, Thiruporur, and Mamallapuram, apart from providing drinking water to 13 lakh residents of fast-developing areas like Sholinganallur, Medavakkam, and Pallikaranai, he said.

Fishing opportunities

There is a plan to restore the 15-km long Buckingham canal between Thiruvidanthai and Mamallapuram across 311 acres, as part of the project, and this would improve the livelihood of fishermen dependent on brackish water fishing. Fishing licences would also be issued to fishermen in neighbouring localities, said Mr. Stalin.

Refuting claims that the DMK-led government had failed to construct storage structures, Mr. Stalin listed out the names of 43 dams that were built between 1967 and 2011. He also outlined significant initiatives taken by the State government to strengthen water resources management. Noting that Chennai’s landscape has changed significantly over the past five years owing to several schemes implemented under the ‘Dravidian model’ regime, Mr. Stalin said more projects are awaiting inauguration.

Speaking to The Hindu, J. Jayakanthan, WRD Secretary, said fishermen would have new fishing opportunities in the reservoir, which would store excess floodwater draining into the sea. The project would be completed in two years.

The desilting of the Buckingham canal is expected to improve brackish water flow and floodwater, enhancing tidal exchange between the Muttukadu and Kokilamedu estuaries and creating better fishing ground. The feasibility of introducing boat rides in the canal would also be studied. Moreover, nearly 34 lakh cubic metre of silt is planned to be cleared from 69 tanks feeding the reservoir. The feasibility of creating more such reservoirs along the coastline would be examined, Mr. Jayakanthan said.

G. Ravikumar, Director, Centre for Water Resources, Anna University, and principal investigator of the project, said the Centre for Water Resources had prepared the feasibility report to assess the quantum of water to be obtained from upstream catchment areas for storage in the new reservoir.

Anna University would act as the knowledge partner for the project execution, and the WRD has provided ₹2.93 crore to the Centre for its consultancy services. In a few years, groundwater table would undergo changes in the areas filled with inactive salt pans.

Representatives of 15 non-governmental organisations were honoured at the event with awards for best water conservation efforts.

Deputy Chief Minister Udhayanidhi Stalin, Public Works Minister E.V. Velu, MSME Minister T.M. Anbarasan, Chief Secretary N. Muruganandam, elected representatives, and senior officials of the WRD and Chengalpattu district took part in the event.