In a “worst case scenario” Dublin could run out of water in 70 days, according to Irish Water.

Managing director Gerry Grant said water levels in the capital’s reservoirs were still very low and further conservation measures may be needed, despite the recent rainfall.

Revealing the results of monitoring of lake, river and reservoir levels throughout the drought, Mr Grant said “about May 10th or 12th we had 150 days of storage in Poulaphouca [reservoir in Co Wicklow] ”.

But he said some 80 days of storage was used in just 83 days. He warned there were “about 70 days of usable water left for the Greater Dublin Area”.

Reservoir levels

Continuing demand will continue to deplete the reservoir levels unless the rainfall is greater than the demand, Mr Grant said. “We could be 90 days before that lake starts to rise, depending on how dry the autumn is.”

Mr Grant was speaking on Newstalk Radio after which Irish Water issued a statement saying it was “essential” that stored water was conserved “so that the greater Dublin region has sufficient water to last from now until October”.

Currently a State-wide hosepipe ban remains in place with additional restrictions in place in some areas.