The water outflow from Chembarambakkam and Puzhal reservoirs has been increased after heavy rainfall, which began on Saturday, November 6, continued to lash Chennai, well into Sunday. Water was released from Puzhal, Poondi and Puzhal reservoirs gradually as the water level in the lakes increased steadily. People living along the downstream course of the water flow as well as those in low-lying areas around the lakes were alerted and they have been asked to evacuate.
Chembarambakkam reservoirs were opened at 1.30 pm and while initially 500 cusecs of water were being released, it was increased to 2,000 cusecs of water after some time. Puzhal reservoir was also opened and while initially 500 cusecs of water were being released, it has been ramped up to 2,000 cusecs. Puzhal lake is one of the main sources of drinking water in Chennai and the water capacity, as of 2 pm on Sunday, had reached 19.62 feet. The water outflow was ramped up to 2,000 cubic feet per second at 3 pm due to a continuous increase in water supply due to monsoon rains. Surplus water was released from Poondi reservoir, which was raised in a phased manner up to 3,376 cusecs of water, according to the Tamil Nadu State Disaster Management Authority (TNSDMA).
This is the highest amount of single-day rainfall that Chennai has seen since December 2015. In 2015, Chennai experienced a nightmarish deluge after heavy rainfall and the delayed release of surplus water into the Adyar River from Chembarambakkam reservoir. Hence this time, efforts are being taken to ensure water is being released gradually and proper warnings and precautionary measures are in place.
People living in low-lying downstream areas near the Adyar river have been requested to vacate their homes to safer places. The Greater Chennai Corporation has released a list of functional relief centres to those in need. The list can be accessed here.
After the incessant rainfall overnight, Chennai experienced 20 cm of rain in about 12 hours since Saturday night. According to IMD data, the rainfall ranged between 10 cm and 23 cm in Chennai and its suburbs. The Kamarajar Salai point (DGP Office on the Marina beachfront) near the Tamil Nadu Secretariat recorded the highest of 23 cm and suburban Ennore in north Chennai 10 cm.
Some of the suburban locations, including areas covered in the nearby Tiruvallur district, received between 3 cm (Poondi and RK Pet) and 9 cm (Cholavaram). The IMD has given a 'red' category warning, indicating heavy rains in Tamil Nadu and neighbouring Puducherry on Sunday.
While most parts of the city and suburbs witnessed waterlogging, parts of several neighbourhoods in Saidapet, Velachery, Adambakkam, Madipakkam and West Mambalam experienced inundation up to about two to three feet. Several subways were filled with rainwater up to several feet.
The IMD has predicted heavy to very heavy rain with isolated extremely heavy rain over Cuddalore, Villupuram, Chennai, Kancheepuram, Chengalpattu, Tiruvallur districts and Puducherry. Heavy to very heavy rain is also likely to occur at isolated places over Vellore, Ranipet, Tirupattur, Nagapattinam, Mayiladuthurai, Kallakurichi, Tiruvannamalai and Salem districts of Tamilnadu, Coastal Andhra Pradesh and Rayalaseema. Heavy rain is likely to occur at isolated places over Thanjavur, Tiruvarur, Ariyalur, Perambalur, Tiruchirapalli, Pudukkottai and Ramanathapuram districts of Tamil Nadu, the IMD has said.