Local authorities in all areas have appealed to householders and businesses to continue to conserve water while supplies return to normal.
Restrictions will apply to water supplies in a number of areas from 7pm this evening until 7pm in the morning.
Fingal County Council said treated water levels had stopped falling but were still at a “critically low level”. It will turn off the water in different areas on a rota basis.
There was a burst watermain in the Lanesborough area and the water supply was cut off for several hours today while repairs were carried out.
The Howth reservoir was still at a critically low level following the power failure at the weekend which affected the pumps at the reservoir, the council said.
Customers in the Howth area will experience low water pressure or no water until the reservoir returns to normal level.
Pressure is also being reduced in the Naul area.
Dublin City Council said all areas would have their water restricted from 7pm tonight until 7am tomorrow. The council appealed to consumers to reduce their water consumption and not to leave taps running.
In Dun Laoghaire/Rathdown, the local authority said water crews had been working continuously to repair bursts that had arisen due to the recent extreme weather conditions.
The council said it was necessary to maintain severe pressure reductions and mains shut-offs in various parts of the county.
Water will be off in a number of areas in Dun Laoghaire/Rathdown this evening and others will suffer a noticeable drop in pressure.
South Dublin County Council also thanked consumers for their cooperation in assisting to restore the water supply to normal service levels.
It said nightly restrictions, combined with the effect of customers reducing their usage levels, had resulted in continued stabilisation of water demand.
The council will continue with the 7pm to 7am restrictions tonight and all areas will suffer either a loss of water or a loss of pressure.
It will take time for the water to make its way through the pipe network while the system recharges following the restrictions, the council said.
Westmeath County Council said it would close the Tyrellspass and Rochfortbridge supplies from midnight tonight to 9am in the morning due to the numerous bursts and leaks caused by the recent weather conditions. Similar restrictions will apply tomorrow night into Wednesday morning.
The Athlone reservoir outlet has also been closed in recent nights and the supply will be interrupted again from midnight tonight until 9am in the morning.
Areas served by the Coosan reservoir to the north of the town and the Batteries reservoir on the western side of the town will not be affected, the council said.
Householders should check external pipes and taps for leakage and repair and ensure that all are lagged sufficiently for further low temperatures.
Farmers should also check troughs and yard taps for burst pipes and insulate against further frost.
Cork County Council, meanwhile, will host an information evening on the Bandon flood early-warning system on Wednesday evening from 4pm to 7pm at Bandon town hall. Property owners and residents are invited to attend at any time during the evening.
The council urged all members of the public affected by the flooding of last November in Bandon to visit the information stands and to discuss the alert system with staff.
Met Éireann said tonight will be frosty with temperatures of between 0 and minus 4 degrees. There will be freezing fog in some areas.
Tomorrow morning will be frosty, with the fog slow to clear. It will be otherwise dry again.