Civic workers have begun to clear the sand bar that is caused at the mouth of the Adyar river where it enters the sea in Pattinapakkam zone.
The Mylapore MLA visited the spot to oversee the operation.
The clearance is done in preparation for the monsoon season, for free flow of water from the backwaters area.
This operation has to be carried out round the year if fish and other sea creatures are to breed well in the backwaters, say scientists at CIBA, located on the other side of the waters, who study brackishwater sea life.
At one time, the backwaters were rich in fish, prawns and crabs.