Heavy rains have been continuously lashing Chennai and its suburban areas since last night prompting the authorities to sound a preliminary flood alert as two water reservoirs in the city are being opened due to the excess water.

Several parts of the city are already waterlogged, disrupting normal life. 

Chembarambakkam and Puzhal reservoirs, which are the key sources of drinking water for Chennai, will be opened to let out surplus rain water, authorities announced.

Sounding a preliminary flood alert, the state water resources authorities advised district collectors of Kancheepuram and Tiruvallur to evacuate people from low-lying areas and shift them to safe locations.

While Chennai and several suburbs in Kancheepuram and Tiruvallur districts witnessed intermittent rains since Saturday morning, the downpour intensified since last night.