Authorities in the Tamil Nadu capital have cut water supply by 40 per cent.

Kerala's offer to send 20 lakh litres of water to parched Tamil Nadu has been turned down by the neighbouring state, Kerala Chief Minister Pinarayi Vijayan's office said on Thursday.

"In response to our offer, we have been informed that at present Tamil Nadu have sufficient supply and doesn't require additional assistance from Kerala," Mr Vijayan wrote on Facebook.

Chennai is facing a severe water crisis after its four reservoirs - the main sources for drinking water in the city - turned dry and ground water levels plummeted due to scanty rain.

Leader of Opposition in the Tamil Nadu assembly MK Stalin tweeted asking the state government to work with Kerala for ensuring Mr Vijayan's offer is not ignored. "I wholeheartedly thank Chief Minister of Kerala Pinarayi Vijayan for his timely offer to provide water to Tamil Nadu. Urge the government of Tamil Nadu to work with the government of Kerala to help citizens of our state tide over this unprecedented water crisis," Mr Stalin said.

Tamil Nadu Local Administration Minister SP Velumani said the state government will decide today whether to accept Kerala's offer. "Chennai needs 525 MLD of water/day, Kerala came forward to give 2 MLD, Tamil Nadu officials feel if Kerala could support with 2 MLD of water everyday it would be helpful. Tamil Nadu Chief Minister will announce the decision on accepting Kerala's offer on Friday," Mr Velumani said in a statement on Thursday.

The authorities in Chennai have cut water supply by 40 per cent. The shortage of water has hit information technology firms, five-star hotels and high-rise buildings. Among the dried-up reservoirs is Chembarambakkam lake, Chennai's largest source of drinking water. The lake is bone dry with a parched and cracked bed.

The city needs 800 million litres per day (MLD). But the Chennai Metro Water supplies only 525 million litres.