Here are the top 10 points in this big story:
"The public should not go out during rainfall. Keep adequate food and water ready. Keep all electronic devices charged for communication. Measures to distribute food and generator sets (for electricity supply), and to meet other infrastructure needs are also ready," Greater Chennai Commissioner Gagandeep Singh Bedi told NDTV.
Mr Singh and his second-in-command, Deputy Commissioner G Sneha, said 53 boats and 507 motor pumps, in addition to 60 heavy-duty pumps, had been deployed in Chennai for rescue efforts and to drain floodwaters. They said only a few low-lying areas were still inundated, but cautioned these will likely get flooded again once rains start.
Concerns over additional floods after water is released from reservoirs near the city were allayed by Mr Bedi, who told NDTV water will be released slowly and that there will be no repeat of 2015. There will be no sudden release of water from Chembarambakkam (as in 2015), he said, adding that 2,000 cusecs is being released.
Overall, 169 relief centres are operational, and floods have been cleared in 216 of around 400 areas. 14 of 16 flooded subways in the city have been cleared, authorities said. Free food will be given at 'Amma canteens' and the Chennai Corporation will distribute food packets to communities in low-lying areas.
Ahead of the expected deluge, the state government has also set up 434 'siren towers' to alert authorities to floods and other emergencies, and is working with telecom networks to ensure mobile connectivity; 50 cellular phone towers (on wheels) are ready for use.
Tamil Nadu has been battered by heavy rains over the past few days, having received 46 per cent excess rain so far, as compared to the historical average. 12 people died, at least 530 houses or huts were damaged and more than 1,700 people are in relief camps.
Chennai was pounded by rains over the weekend - the heaviest since the 2015 floods - leading to widespread flooding in the city and its suburbs of Chengalpattu, Kancheepuram and Tiruvallur. Videos that emerged on social medial showed cars and two-wheelers partially submerged and people wading through knee-deep water in some places to buy essential commodities.
Yesterday the Chennai civic body was pulled up by the Madras High Court, which asked it: "What have you been doing since 2015?". The court took a dim view of floods and droughts faced by the state capital every year. "It is a pity that half the year we long for water and rest of the year we are flooded or die in water," the court observed.
Chief Minister MK Stalin has blamed the erstwhile AIADMK government for waterlogging in the Chennai. "Shoddy work due to corruption under Smart City scheme caused damage to T Nagar (a shopping district in Chennai). Nothing was done by the earlier regime. We have fixed up to 60 per cent. After rains we will complete the rest."
In 2015, when the AIADMK government was in power, Chennai was flooded due to heavy rains and the sudden discharge of excess water from Chembarambakkam, a reservoir near the city, as a result of which around four lakh homes were flooded.
Emergency Numbers:
Tamil Nadu government control room: 1070
District control room: 1077
Chennai control room: 1913
Rajinikanth's House Flooded Amid Heavy Rain In Chennai Rain Continues In Chennai For 2nd Day, Waterlogging Reported In Many Areas Heavy Rain In Chennai, Nearby Areas, Schools And Colleges Shut "Didn't Leave Due To Any Pressure": Kailash Gahlot On Switch From AAP To BJP Gujarat Medical Student, Made To Stand For Hours, Dies. 15 Seniors Blamed "Will Stop Singing Songs On Alcohol If...": Diljit Dosanjh Sets A Condition Nutritionist Explains Why You Should Eat Tofu More Often Developing Countries More Vulnerable To Antimicrobial Resistance: WHO Eknath Khadse Announces Retirement From Electoral Politics Track Latest News Live on NDTV.com and get news updates from India and around the world.