NI Water is currently carrying out repair work in areas around Northern Ireland.
There are also a number of burst water mains.
Customers may experience a loss of water supply or a drop in pressure when the work is being carried out.
NI Water is working to fix the problem as soon as possible.
Belfast, Newtownabbey, Craigavon, Moygashel, Ballynahinch, Lisburn, Maghera and Coleraine are just some of the areas affected.