Flood fix

Chennai is implementing sponge parks to mitigate waterlogging. But they may not be the best solution

- PRADEEP KUMAR MISHRA AND SUSHMITA SENGUPTA

THIS MONSOON could be different for Chennai, which has been in the news for its rapidly vanishing waterbodies and waterlogged roads. Estimates show that the capital of Tamil Nadu has lost over 60 per cent to development projects and illegal encroachments of its wetlands in the past four decades. Moreover, in a changing climate, as rainfall becomes erratic with more violent downpours and worsening dry spells, the paved-over city sees devastating flash floods, such as in 2015. But authorities appear to have found a solution to the nagging self-created water problem by converting green spaces in the city into “sponge parks”.

Sponge parks, somewhat similar to rainwater harvesting structures, are essentially green spaces with a system that allows percolation of rainwater or overflowing stormwater, which is channelised to either replenish aquifers or to rejuvenate nearby waterbodies. This way, they help avert waterlogging and ease impact of flash floods.

The Greater Chennai Corporation (GCC) constructed 57 sponge parks across the city in 2023-24, and has planned for 30 more in 2024-25. These constructions came after two Central programmes—the Scheme for Special Assistance to States for Capital Investment (SSASCI), 2022-23 and the Jal Jeevan Mission (Urban), 2021-22—proposed creating sponge parks to reduce urban floods. In its 2025-26 budget, Tamil Nadu allocated ₹88 crore for seven more sponge parks in Chennai, under the purview of the National Disaster Management Authority.