Welsh Water says there are around 4,500 customers in Wales currently without water due to burst pipes during the icy thaw in the last 24 hours.
The extreme weather conditions over the past few days have caused the company "unprecedented challenges" it says.
Teams are working around the clock to restore supplies as soon as possible.
Bottled water is being delivered to some areas.
The communities currently affected are:
- Blaenau Ffestiniog (Gwynedd),
- Pencader (Carmarthenshire)
- Synod Inn, Llandysul and Talgarreg (Ceredigion)
- Letterston (Pembrokeshire)
- Abertillery (Blaenau Gwent)
- Clydach Vale (Rhondda Cynon Taff)
One family who run a farm in Tondu in Bridgend County say they have been left without water since Friday and had to resort to the horse shower to get clean.
Welsh Water says it has been "finding and fixing over 200 leaks a day – more than three times the usual amount".
It is asking customers with normal water supplies to help by not leaving taps running and reporting any leaks or bursts out on roads and highways directly to the company.