In many areas, people remained awake past midnight to keep a check in case the rain water entered their houses.
“My neighbours had to keep a night vigil to see whether the rain water enters their home,” R. Vasantha, a resident of Mylapore, told IANS.
Most of the city roads were under knee deep water, forcing people to stay confined to their homes. Schools and colleges were closed in as many as 15 districts of Tamil Nadu.
Weather department officials said whether the depression would intensify into a cyclone could be ascertained only later.
The weathermen have forecast widespread rain over Tamil Nadu and neighbouring Puducherry.
Weather officials said the depression is moving towards Andhra Pradesh and the rain in Tamil Nadu will ease slowly. However, heavy rain is expected in Nagapattinam, Cuddalore, Villupuram, Arakkonam and Chennai and rescue teams have been deployed there.
With the filling up of the Chembarambakkam lake that quenches the thirst of Chennai, surplus water is being released as a precautionary measure.
The Chennai administration has warned people living along the Adaya river to move to safer places.
As the city suburbs remained submerged under water fire service personnel were using boats to take the stranded people to safer places. Fallen trees disrupted traffic in several places in Chennai.
Medical teams were visiting the water-logged areas to monitor the medical situation there.