CHENNAI: The city corporation, with support from the Public Works Department (PWD) and the revenue department, began on Wednesday its drive against encroachments on the Adyar river bed. The sprawling Keerai Thottam, where cultivation of greens was being carried out by a few individuals for more than five decades, was one of the first targets, run over by an earthmover on the first day of the drive.

Mayor M Subramanian, accompanied by several staff members from the Saidapet zone of the corporation, thronged the site near the Alandur causeway in the morning. An earthmover, five trucks and a loader were pressed into service to remove the raised earth where a family, which claimed to possess a valid patta from the revenue department, was cultivating greens.

"That must be a fake patta, which can be challenged in a court of law," mayor Subramanian told TOI, adding, "The work will go on for more than a fortnight. At least 15 colonies will benefit from the exercise." Only a stone's throw away is the corporation's upcoming high-level bridge replacing the age-old causeway. The two-lane bridge, 420 m long and 12 m wide, will soon be thrown open to traffic.

According to Subramanian, the Keerai Thottam, a cultivated area, has been the reason for flooding of areas such as Vinayagapuram, Chetty Thottam, Jyothima Nagar, Jyothi Thottam, Neruppu Medu, Samiyar Thottam, Theedeer Nagar and Kotha Medu near the Maraimalaiadigal bridge. Whenever surplus water is released from the Chembarambakkam reservoir, the rise in water level in the Adyar river inundates the slums in these areas.

When that happens, residents are evacuated with the help of announcements made on the public address system. They are forcibly taken to the Government Model Higher Secondary School on Anna Salai and accomodated there till the water level recedes. The encroachments had also affected the stormwater drain in the nearby areas, sources said.

"It is shocking that encroachers managed to get a patta registered with the local taluk office for a portion of a water body," said R Mohanraj, a resident of Chetty Thottam. "Officials should not have remained silent all these years against the misadventures of a few people. It is good that the local body has taken the initiative to clear the area. It should serve as an example to those who tend to usurp public land or a water body," he added.

"If it's an anti-flood measure, though belated, it is welcome. There are structures in several water bodies and government agencies should give equal treatment to all encroachments; they should be more harsh on structures that block water bodies," said M G Devasahayam, managing trustee, Citizens Alliance for Sustainable Living (SUSTAIN).