CHENNAI: Residents along the Old Mahabalipuram Road (OMR) have raised an alarm over Chennai Metro Rail Limited and its contractors relaying the road, alleging that blacktopping was getting carried out without milling the existing surface, potentially aggravating flooding during the monsoon. They alleged that the road height was increased by nearly six inches.
Federation of OMR Residents Associations (FOMRRA) co-founder Harsha Koda said the addition of a thick tar layer without removing the old surface would alter the road profile and divert large volumes of stormwater into service lanes and side roads that are not designed to handle such flows.
Relaying a 200-foot-wide stretch over more than 20 km could displace 60 to 70 lakh litres of rainwater, worsening waterlogging in low-lying neighbourhoods and IT parks along the corridor.
The OMR (Rajiv Gandhi Salai), a key IT corridor, has a history of inundation even during moderate rainfall, with roads turning into channels that strand commuters and disrupt operations in offices and residential complexes.
Harsha Koda said the ongoing works could further impede natural drainage towards major outfalls such as the Buckingham Canal, forcing runoff into narrow internal roads and basements.
Referring to earlier instances where Metro Rail works disrupted drainage patterns on OMR, he said repeated interventions on the carriageway, coupled with inadequately designed and poorly maintained stormwater drains, had created floodprone hotspots.
He alleged that the current blacktopping is being undertaken without commensurate upgrades to side drains, culverts or outfalls. However, the CMRL officials were not available for comment.
Citing a 2021 High Court order, Harsha Koda recalled that the then Chief Secretary V Irai Anbu had directed the Highways Department to ensure that roads were relaid only after milling the existing surface. The directive noted that adding fresh layers raises the road level and adversely affects footpaths and stormwater drains, and that roads with dense bituminous macadam layers need not be overlaid without milling.
He called for public disclosure of design drawings, hydrology studies and capacity assessments for the affected stretches, an independent flood-risk audit, and pre-monsoon desilting with additional culverts and pumps to prevent inundation.