Despite rains since past couple of days, the BMC has asked citizens to brace up for further water cuts after September 15, if they don't make an effort to save water, a senior civic official from the water department told scribes on Friday.

Wary of inadequate rainfall the civic officials admit, “Lakes are the only steady source of water in Mumbai and thus we will run out options if the water levels continue to deplete due to scarce shower this monsoon.”

The six lakes – Upper Vaitarna, Modak Sagar, Tansa, Bhatsa, Vehar and Tulsi supplies potable water to the city, with Upper Vaitarna and Bhatsa supplying 640 and 2012 million litres of water per day respectively. The newly-constructed Middle Vaitarna also has enough reserve water, assured civic officials.

The officials fear, if there is not sufficient downpour this monsoon; the situation of 1993 would be replicated, where the civic body had to execute a water cut of up to 40 per cent.

The other crucial source of water is wells in the city. But, ironically the civic agency doesn’t have a proper record of the number of the wells in the city. "We have asked all the 24 wards to submit a record of the number of wells in their wards, but only two wards have given us the record so far," the sources in civic agency said.

Desalination has been debated since long as an alternative to the rain-fed lakes and other ground water sources. Due to highly expensive process involved in desalinating sea water to make them potable, the project has been aborted midway. The much touted cloud seeding, too, cannot yield enough water for the lakes.

“Rainwater harvesting is definitely an eco-friendly idea which the civic body should adopt to solve water crisis in a populous city like Mumbai,” said a media person Harigovind Vishwakarma.