A burst water main is affecting water supplies to customers in some parts of Caernarfon.
Dwr Cymru Welsh Water said households in the Pontllyfni, Clynnog Fawr, Gyrn Goch, Capel Uchaf and Bwlch Derwin areas are experiencing low water pressure or no water supply at all.
The utilities firm has a team on site working to repair the damaged main.
All water supplies are expected to return to normal by 10.00 BST on Monday.
A spokesman said: "We are very sorry for the inconvenience this is causing and assure everybody affected that we are doing all we can to restore normal service as quickly as possible.
"As supplies begin to return, some customers may notice a slight discoloration to their tap water.
"This is normal and should clear within a short period of time."
Anyone with concerns about their water supply should call Welsh Water's operational helpline on 0800 052 0130.
A further update will be provided at 10.00 BST.