Key Points

A feasibility report of the Chennai Corporation estimates that the city’s requirement will rise to 38.73 tmc from the current 11 tmc. Out of 1,165 suggested projects, the WRD has approved 704 essential works to be executed within the next decade.

The projects span 12 basins, including Chennai and Palar, with a major focus on reviving around 1,150 tanks in suburban areas. These include a chain of 350 tanks, such as Thenneri, Sriperumbudur, Thirunindravur, Manimangalam, and Pillaipakkam, which act as catchments for Chembarambakkam; and another 64 tanks along the OMR stretch, such as Narayanapuram, Thalambur, Semmenchery, and Nanmangalam.

Restoring them as mini catchments is expected to boost storage capacity and make surrounding neighbourhoods less dependent on the city’s reservoirs.

The plan also involves constructing 12 new reservoirs along the upstream stretches of the Cooum, Adyar, and Palar rivers.

Sites have been identified at Thiruverkadu and Poonamallee in the Cooum basin and four villages along the Palar. Each of these reservoirs is expected to add between 0.5 tmc and 1 tmc of storage.

In addition, three major new reservoirs are planned, including one on Salt Lake along the East Coast Road and another on 300 acres of government land near Perumbakkam.

The Perumbakkam reservoir is designed to store up to 2.25 tmc, while the ECR site will add another 2 tmc.

Together, these reservoirs will help retain water for the OMR belt and reduce flooding into Pallikaranai marsh.

To strengthen groundwater reserves, 402 recharge structures will be built along river bunds, while around 200 tanks within industrial hubs such as Irungattukottai, Oragadam, and Pillaipakkam will be revived, reducing dependence on Metrowater by easing 115 MLD of supply.

Inter-basin linking measures are also proposed, including diverting water from Adyar to Palar and channelising flow from Kosasthalaiyar to Cooum.

Experts note that Chennai receives adequate rainfall annually and that restoring tanks, lakes, and aquifers while enforcing rainwater harvesting will be crucial to the plan’s success.

- IANS