Chennai is set to get a new ₹342.6 crore Mamallan drinking water reservoir to add 170 million litres per day to the city’s supply. Chief Minister M.K. Stalin laid its foundation stone on January 19. The reservoir, to be built near Mamallapuram in Chengalpattu district, will serve about 13 lakh people. It is expected to be ready in two years. However, fishermen and local residents have raised strong protests. They say the project will "disrupt their livelihood and permanently alter" the delicate brackish-water ecosystem. Villagers from Kanathur Reddikuppam to Kokkilimedu warn the reservoir could destroy their traditional fishing grounds and violate Coastal Regulation Zone rules. Residents of Kovalam Kuppam have sought intervention from the Union Ministry of Ports, Shipping and Waterways, claiming the reservoir would block the Buckingham Canal's natural flow. Petitions and objections were made during Gram Sabhas on Republic Day, but officials reportedly rejected some petitions opposing the project. Officials defend the reservoir, highlighting its flood control benefits and the critical need to meet rising water demands. Chennai currently relies heavily on Krishna river water and supplies average 700 to 800 MLD, below the 1,100 MLD demand that is expected to double in ten years. The reservoir is planned with a 1.65 TMC capacity and will also remove silt from Buckingham Canal, improving water flow and fishing conditions. Despite protests, officials emphasize that sustainable development can balance growth and community interests. This reservoir honors the legacy of Pallava king Narasimhavarman I, known as Mamallan, famous for ancient water management.