The northeast monsoon accounts for about 48 per cent of Tamil Nadu's annual rainfall (Representational)

The weather office today confirmed that the crucial north-east monsoon has set in across southern India. "The north-east monsoon has set in in Tamil Nadu, Kerala, south Andhra Pradesh areas, Kerala and Karnataka," regional weather office director Balakrishnan said in Chennai.

Chennai city and nearby areas have been receiving rain since Tuesday night. Poonamallee received 11 cm rainfall and Pamaban in Ramanathapuram district received 10 cm rainfall, officials said.

In its forecast, the weather office said isolated heavy rain in Kanniyakumari, Tirunelveli, Tuticorin, Ramanathapuram, Tiruvallur and Kancheepuram are expected in the next 24 hours. Chennai may get moderate rainfall over the next two days, it said.

Chennai and large parts of Tamil Nadu suffered unprecedented drought and drinking water scarcity since May due to inadequate monsoon last year. All four major lakes supplying drinking water to the city had dried up, forcing Chennai Metro Water to cut piped water supply by 40 per cent.

Two trains were deployed to bring 10 million litres of drinking water from Vellore district between July and September.

The city suffered unprecedented floods in 2015.

The Chennai Corporation today also reviewed its preparedness. A statement from the corporation said, "Out of an estimated 3,22,809 cubic metre silt to be removed from 1,636 km-long storm water drains, only 98,000 cubic metre has been removed and that orders have been issued to complete desilting by Friday."

The Local Administration Department has released a six-minute-long film promoting rainwater harvesting, with messages from the Chief Minister, celebrities and residents.