Sunny and dry conditions are leading to outages.
Homeowners are being asked to conserve water amid a surge in demand due to the warm weather.
Irish Water says it's dealing with outages in Laois, as well as parts of north Dublin, Donegal and Kerry, according to reports in the Irish Times.
The utility says it's working with local authorities to restore supplies to normal levels.
Tom Cuddy from Irish Water is appealing to people to only use water for what's necessary due to depleted reservoir levels: