Chennai: Nandanam, T Nagar, and Teynampet face serious flood threats this monsoon, as the 1.6 km Nandanam Canal remains clogged and sewage-laden.
This canal, a bypass from the Mambalam Canal, starts behind Raintree Hotel, crosses under Anna Salai and Nandanam Metro, and then beneath Chamiers Road before draining into the Adyar River at Lotus Colony. These areas are now in danger.
Encroachments and uncleared shrubs have slashed the canal's capacity from 37.5 cusecs to 18.7 cusecs.
The original 2.5-metre width is now reduced to 1.5 metres in spots, especially near Lotus Colony.
TOI observed sewage pouring into the canal at Lotus Colony, with encroachers dumping garbage. Water hyacinth, debris, and solid waste have further narrowed the canal. Although the Greater Chennai Corporation (GCC) cleared parts of the canal with bobcat vehicles, one of the machines has been abandoned there for weeks.
The canal once carried road runoff from Sathyamurthy Nagar, T Nagar, and Anna Salai. However, the Nandanam Metro Station project closed off an open section, leaving the canal underground and its road inlets blocked, causing road water stagnation.
GCC's Teynampet zone executive engineer, Muthiah, said the canal's width at the station is just 1.5 metres. "Since it is closed by the metro station, we can't remove debris underneath, and the flow is affected. We'll deploy bobcat vehicles again for the open sections," he said.
The canal also lacks gates at Lotus Colony and has no boundary walls to prevent breaches. With the Mambalam Canal blocked, GCC now plans to use additional motors to redirect drains through Chamiers Road and into the Nandanam Canal. K Sivanandam, a resident of Lotus Colony, said during Cyclone Michaung, the canal breached and water stagnated for four days. "They have not fixed the gates and walls till date. Ground floor houses had hip-deep water," he recalled.