Residents claimed planning documents confirmed the 127-acre site was prone to waterlogging | Photo credit: SPECIAL ARRANGEMENT
Residents of Thalambur have expressed concern over the proposed Global Sports City project by the Chennai Metropolitan Development Authority (CMDA).
In their memorandum submitted to Deputy Chief Minister Udhayanidhi Stalin and CMDA officials, the residents pointed out their objections regarding flood risks and hydrological disturbances in the already sensitive wetland ecosystem.
Planning documents confirm the 127-acre site was low-lying and boggy, prone to waterlogging and acting as a natural sink for water runoff, residents noted. This land formed part of the historic Pallikaranai wetland system that once extended to Siruseri and continues to serve as a critical watershed for surrounding areas such as Thalambur and Semmenchery. Converting this floodplain to built infrastructure could force large volumes of water to enter residential areas, exacerbating flooding along key access roads, they added.
Despite mitigation efforts, the site’s natural geography experiences heavy flooding during the monsoons, much like the surrounding area, including the nearby university. The proposed solution of creating a pond, they argue, was neither scientifically robust nor sustainable in the context of swamps, citing examples of artificial reservoirs that require frequent desilting.
Other concerns related to gaps in the wider drainage network. Several interconnected water bodies – including Natham Lake, Karanai Lake and smaller ponds – lacked proper downstream connectivity. The existing stormwater channel carrying runoff from Thalambur was already a bottleneck, with backflow from larger upstream odais causing repeated flooding in areas like Gandhinagar and Mahanagar. Channeling further discharge from Sports City into this system could worsen flooding in both north and south Thalambur, they warned.
The proposal to divert excess water to the Perumbakkam marsh has also drawn criticism. Residents noted that the swamp itself overflows during heavy rain. There are discrepancies in planning maps, including an implied but non-existent connection between Navalur Lake and downstream water bodies, a gap that has already led to seasonal flooding of nearby areas, they alleged.
Other issues flagged included the absence of traffic impact assessments, uncertainty about road infrastructure along drainage channels, and the long-term sustainability of water management sports venues in an area with poor groundwater quality.
Without a comprehensive, science-based hydrologic plan, the project risks increasing vulnerability to flooding, potentially affecting both the proposed facility and surrounding communities during increasingly unpredictable monsoon events, residents said.
Published – 02 Apr 2026 01:03 IST
