A sheet of stagnant rainwater on the Ennore Manali Express Highway on Wednesday, December 3, 2025. | Photo credit: B. Jothi Ramalingam
For the third consecutive day, the remnants of Cyclone Ditwah continued to batter parts of northern Tamil Nadu, particularly Chennai and Tiruvallur districts on Wednesday (December 3, 2025). The system is likely to weaken to an area of low pressure by Thursday (December 4, 2025).
As the circulation slowly moves inland, the Regional Meteorological Center (RMC) has issued a yellow alert for Krishnagiri, Dharmapuri and four southern coastal districts, including Thoothukudi and Kanniyakumari, indicating heavy rainfall on Thursday. However, Chennai is likely to experience only light to moderate showers.
Torrential rain
The system brought rain to areas along its path as it drifted inland. Ennore was battered by torrential rain for the third consecutive day, recording 15cm by 6pm on Wednesday (3 December 2025). The site accumulated nearly 56 cm in three days. Various parts of Chennai including Puzhal (5 cm), Villivakkam (4 cm) and Tiruninravur (3 cm) received moderate to heavy rains till 6 pm. However, south Chennai saw relatively lighter showers.
Other districts including Tiruchi and Ramanathapuram also received rain till Wednesday (December 3, 2025) evening.
According to the RMC, the system is likely to move southwest – across the north coast of Tamil Nadu and Puducherry – and weaken into a low pressure area by Thursday (December 4, 2025).
In addition, a trough from the remnant of Cyclone Ditwah over the north coast of Tamil Nadu-Puducherry to the Lakshadweep region passes through north interior Tamil Nadu, north Kerala and south interior Karnataka.
These systems brought sustained rainfall over various districts on Wednesday (December 3, 2025) and are expected to produce isolated heavy rainfall over parts of the state on Thursday (December 4, 2025).
The system moved slowly over the land, dropping rain along its track inland. Rain activity is expected to weaken, said P. Senthamarai Kannan, Director, Area Cyclone Warning Centre.
In the 24 hours ending Wednesday (December 3, 2025) at 8:30 am, Ennore and Hindustan University recorded 15 cm of rainfall each, followed by Chetpet in Tiruvannamalai district (13 cm). Many other places in Chennai and districts like Pudukkottai and Villupuram also received moderate to heavy rainfall.
Sustained rainfall has significantly bridged Chennai’s seasonal deficit to 2%.
Water discharge has increased
For the sixth time since the onset of the Northeast Monsoon, the floodgates of Red Hills Reservoir were opened on Wednesday (December 3, 2025). The water flow was gradually increased to 2,500 cubic feet per second (cusecs) by 5:00 p.m., as the locality received nearly 6.4 cm of rain by evening.
While the release of water from Chembarambakkam and Poondi reservoirs is kept to a minimum level, the sluice gates of the Red Hills reservoir had to be opened wider as 5,000 cusecs were constantly flowing into it to maintain sufficient headroom against the flood. The warehouse in Red Hills has reached 96% of its capacity.
Officials from the water resources department said the five reservoirs together hold nearly 86% of their storage capacity. Controlled discharge is done to maintain a sufficient supply without posing a flood risk to downstream areas.
Meanwhile, Chennai Metrowater treated nearly 962.34 million liters of sewage on Wednesday (December 3, 2025), compared to around 700 billion on non-rainy days.
Published – 04 Dec 2025 08:50 IST
