Chennai Gets Sixth Water Source: Coastal Reservoir

Chennai just took a giant leap toward water security with a groundbreaking ceremony for India's first coastal freshwater reservoir.

Tamil Nadu Chief Minister M.K. Stalin laid the foundation stone for the Mamallan reservoir, a $41 million project that will store water from 69 upstream tanks and deliver 170 million liters daily to rapidly growing neighborhoods. The 5,161-acre site sits between two major highways along the scenic East Coast Road.

The reservoir honors Pallava ruler Narasimhavarman I, known as Mamallan, who founded the UNESCO World Heritage site of Mamallapuram. The Pallavas built 39 tanks centuries ago that still serve the region today, and this modern reservoir continues that legacy of smart water management.

The project tackles multiple challenges at once. A 34-kilometer protective bund will prevent seawater from contaminating groundwater in neighboring towns like Thiruporur and Mamallapuram. Desilting 69 feeding tanks will clear 3.4 million cubic meters of sediment, improving water flow throughout the system.

The Ripple Effect

This reservoir does more than quench thirst. It transforms problems into opportunities for coastal communities.

Local fishermen will gain new brackish water fishing grounds through a restored 15-kilometer stretch of the historic Buckingham Canal. Authorities plan to issue fishing licenses to nearby residents, creating fresh income sources. Engineers are even studying the feasibility of boat rides along the restored canal.

The project prevents waste by capturing floodwater that currently drains unused into the Bay of Bengal. When filled twice annually, the reservoir reaches 2.25 thousand million cubic feet of storage capacity. That surplus water now serves 1.3 million people in fast-developing areas like Sholinganallur and Pallikaranai instead of washing away.

Anna University's Centre for Water Resources designed the feasibility study and will serve as knowledge partner during the two-year construction. Officials are already examining whether similar coastal reservoirs could work elsewhere along Tamil Nadu's shoreline.

At the ceremony, 15 local organizations received awards for outstanding water conservation work in their communities.

In just two years, Chennai's water future gets brighter with every drop this reservoir catches and every family it serves.