Irish Water has been forced to shut down Ballyragget water treatment plant because of flooding of the River Nore.
A water tanker has been deployed at the Glenvale car park in the town as no water is coming through the taps.
Up to 1,500 people are affected. Householders are asked to bring their own containers to Glenvale and Irish Water have asked people to boil the water before using it.
It will be a number of days before the plant reopens. People with queries can contact the 24 hour help line on 1850278278.