CHENNAI: In a bold and unprecedented move, the state government has decided to dismantle a 2.1 km stretch of the four-lane Thoraipakkam–Pallavaram Radial Road on the Pallikaranai marshland. This initiative aims to restore the wetland to its original state to prevent flooding during the monsoon.
Instead, the state highways department will construct a high level bridge from Thoraipakkam to Kamatchi Hospital junction, phasing out the existing road, which is obstructing water flow.
Highways Minister E V Velu announced in the Assembly on Tuesday that Rs. 20 lakhs have been allocated for preparing a Detailed Project Report (DPR) for this flyover.
Compared to the rest of the city, areas such as Pallikaranai, Velachery, Sholinganallur, and Karapakkam, which are situated near the marshland, experienced severe flooding during Cyclone 'Machaung' in November last year. This prompted the government to take decisive action.
According to highway department sources, floodwater from the southern parts of the city, including Pallavaram, Madipakkam, Velachery, Kilkattalai, and Pallikaranai, flows into the marshland and passes through Okkiyam Madu and Kovalam greek before draining into the Buckingham Canal. "After multiple inspections, the government decided to restore the marshland wherever feasible to prevent waterlogging during the monsoon. A DPR will be prepared to build a high level bridge at height of one or two meters from the ground," said a senior official.
Further decisions regarding the road's dismantling will be taken at a later stage. “This is the first time the government has decided to dismantle a road laid on a water body or wetland,” the official added.
The road on the marshland was constructed in 2001-2002 as part of the four-laning of the 10.6 km Pallavaram–Thuraipakkam Radial Road (SH 109), an integral component of the IT corridor project on OMR. This road links Thuraipakkam on Rajiv Gandhi Salai with Pallavaram on GST Road. The widening of the road increased its width from 7-8 meters to the current 18 meters, encroaching on the biologically sensitive wetland.
The Pallikaranai Marshland serves as a natural reservoir, capturing rainwater and slowly releasing it during the monsoon season, thereby mitigating the risk of severe flooding. However, encroachments such as roads, buildings, and other infrastructure have significantly impacted its vital function. Official data indicates that the extent of the marshland has shrunk from 5,500 hectares in 1960 to 580 hectares in 2013.