Corporation to convert Chennai into ‘sponge city’

CHENNAI: The Greater Chennai Corporation has devised an ambitious plan to convert the entire metropolis as a ‘sponge’ to prevent floods and recharge groundwater. The move comes amid plans to create sponge parks and restoring the Pallikaranai marshland, which is a natural sponge that can hold floodwater thereby reducing flooding in the city during monsoons.

According to a senior Corporation official, Chennai would be made into a ‘sponge city’ by adopting innovative water management strategies to tackle urban flooding. “The concept of sponge city is to make urban areas more permeable, have more open spaces to store rainwater, allow it to percolate to aquifers, and reducing run off,” the official explained.

As part of the plan, the civic body has selected Mathur MMDA Colony pond and Tiruvottiyur North pond for developing them as model Sponge City Parks that can later be replicated and scaled up across Chennai.

In the first step, the civic body would ensure that permeable pavements are used in all the newly constructed parks and the ground level would not be raised to reduce flash runoff into stormwater drains, the official added.

Meanwhile, the civic body is setting up real-time flood forecasting and spatial decision support system under which lake and reservoirs operation guidance system would be developed. Flood control rooms would be established in Chennai, and data from Kancheepuram, Tiruvallur, Chengalpattu and Ranipet districts would be shared with the Corporation.

The civic body has already started creating sponge parks at 14 locations under Singara Chennai 2.0. Sponge parks will have pond-like structures around which walkways, trees and fencing will be provided. The ponds will have recharge wells, and inlet and outlet pipes. During heavy rains, excess water will be diverted to the sponge parks and stored temporarily.

The Chennai Metropolitan Development Authority (CMDA) have also put forth a related proposal to identify suitable open space reserve (OSR) lands to create sponge parks.