Following an easing of restrictions to facilitate New Year's Eve festivities last night, it is expected that most areas of the country will have normal water supplies restored before Monday.
However, in Dublin the restrictions could continue for another ten days.
Meanwhile, an independent inquiry is to be carried out into the water supply crisis in Northern Ireland.
Thousands of households in the North are still without a mains water supply this evening, as the authorities continue to battle to re-connect customers and repair leaks.
The Northern Ireland Water company has warned consumers that supplies may be further curtailed this evening and overnight.
The number of homes across the North without water has fallen to 2,600.
The worst affected areas are Cookstown in Co Tyrone, Hannahstown in Belfast, and Burren and Warrenpoint in Co Down.
Earlier NI Water had announced that thousands of households which had been getting an intermittent water supply would have their full normal service returned.
However, the company now says that supplies will again be curtailed for a limited period between 8pm and 10pm tonight, and 7am and 8am in the morning.
The company has also condemned an incident in Coalisland, Co Tyrone overnight, when vandals released thousands of gallons of water from containers.
NI Water say it has 500 staff on the ground dealing with supply issues and checking for leakage in private and commercial premises.
It is likely to be late next week before supply is back to normal.
The board of directors of Northern Ireland Water is to meet on Tuesday to consider how its response to a similar crisis in the future might be improved.
Stormont Minister Conor Murphy has announced that an independent inquiry into the water chaos is to be held.
The members of the inquiry team and its terms of reference will be revealed next week.