Large areas of North Dublin will be without water this Sunday morning, 26th February.
Irish Water is facilitating the connection of a new pipeline between Ballycoolin and Swords - a €28 million investment.
The utility says this will "secure the water supply for over 350,000 customers across North County Dublin."
The works will primarily affect customers in Swords, Malahide, Portmarnock and Donabate.
Water supply is scheduled to return at around 12pm.
Head of Asset Operations at Uisce Éireann, Tom Cuddy, says originally 350,000 people in the area were due to be without water, but network rezoning has reduced that number to 100,000.
The body says currently "water supply network serving the North County Dublin Region depends on a single large-diameter, concrete water pipeline that was built in the 1960s, connecting Ballycoolin Reservoir to Swords."