Water restrictions are to remain in place over the next few days across the country.
Dublin City Council today said the water supply situation worsened last night due to the extreme change in temperature which had led to flooding and burst pipes.
Temperatures have changed by almost 25 degrees over three days causing chaos across Ireland and leaving tens of thousands of householders with little or no water.
Dublin City Council said it has mobilised crews to both identify leaks and to deal with burst pipes around the capital
It said water storage levels at Stillorgan were effectively at "rock bottom."
"If we combine the impact of the last two days there has been a loss of 130MLd. This is unprecedented and the worst two-day event on record," it said in a statement.
Water tankers have been sent out to areas affected by limited water supplies.
In Dublin the cuts and restrictions to supply, which were imposed between 7pm and 7am before Christmas, are being extended to cover a period from 6pm to 9am. Large parts of Kildare and Wicklow, which are also supplied by the greater Dublin reservoirs, will also be subject to the shutdown. Cork city and county, Limerick, Sligo, Kilkenny, Laois, Kerry and Westmeath have also been badly affected.
Burst water mains and dry reservoirs have left thousands of homes in Northern Ireland without access to mains water.
Northern Ireland Water has brought in extra staff to try and cope with the "unprecedented" demands. In the past week its emergency line received 16,000 calls, with 9,000 of those coming since Christmas Day when the thaw was beginning.
A number of reservoirs are reported to have run dry because pipes supplying them were damaged.
Meanwhile, Aer Lingus said today it hoped to operate a full schedule to the US today following disruptions yesterday.
Aer Lingus flights bound for New York and Boston did take off from Dublin yesterday afternoon. However, airports in New York, Boston and Philadelphia have now re-opened.