The Water Resources Department (WRD) has sought Coastal Regulation Zone (CRZ) clearance from the Tamil Nadu Coastal Zone Management Authority (TNCZMA) to build a major drinking water reservoir in the Kovalam sub-basin between ECR and OMR.

Announced in the 2025–26 state budget, the project will convert 4,375 acres of coastal wetlands into Chennai’s sixth major reservoir, designed to store 1.655 tmcft and supply 170 MLD of water to southern and peri-urban areas. The proposal was first reviewed by the State Environmental Appraisal Committee (SEAC) on June 3, which ruled that prior environmental clearance was unnecessary but mandated CRZ clearance since the site falls under CRZ-I, II, III (NDZ) and IVB. SEAC also advised exploring SBR-UF or MBBR-UF treatment technologies to prevent long-term water quality decline. IIT-Madras later confirmed technical feasibility.

Phase I spans 1,770.5 hectares, involving bund excavation, foreshore embankments, peripheral drains, and creation of a 17.71 sq. km freshwater lake, at an estimated cost of Rs 471 crore.