Residents in Leighton Buzzard have been left without water since Friday evening due to a technical fault.
Anglian Water said the issue has been caused by a damaged valve and is affecting Leighton Linslade and the surrounding area of Bedfordshire, and affected about 11,000 people.
The supplier was hopeful the issue would be resolved by midday on Saturday but problems continued into the afternoon.
Locals sharing complaints about the issue on social media reported water running yellow and cloudy at around 6pm on Friday, before stopping altogether shortly afterwards.
Resident Richard Ayre said: “Anglian Water is rubbish with communication as they are sending everyone to their website, which is crashing.
“The main concern is that they are saying it is one valve that has caused the issue. Surely the town and the villages are not all supplied through one pipe.”
The 29-year-old said he heard the water company was offering bottled water to “people on their priority list”, but he had not been aware there was one beforehand.
“Otherwise we would have signed up as a relative has just been released from hospital and needs to take in a large amount of fluids,” he said.
Twitter user @NinaButterfield posted: “We live in Leighton Buzzard and have a 10-month-old who needs water. When will our supply be back on?”
Complaints about the issue have been so widespread that Leighton Buzzard was trending on Twitter on Saturday morning.
An Anglian Water spokesperson said: "Our engineers have been working to fix a faulty valve in the pipe which supplies water to the area.
"We would like to thank customers for their patience while we carry out this work. We are genuinely sorry for the disruption this has caused, rest assured our teams will continue working to get things back to normal as quickly as possible."
Shortly before 3pm on Saturday, Anglian Water said water "should be coming back on now" for all except those in northern parts of Leighton Buzzard - for whom "the delay might be slightly longer".
Many Twitter users claimed the water had not yet returned as the company said, with user @DuncanHunter11 responding: "This is not true. Most of Leighton Buzzard still has no running water... A total disgrace."
Anglian Water added: "When the water returns it may appear cloudy. This is perfectly normal and is just millions of tiny air bubbles trapped in the pipe.
"If customers leave it to stand in a glass or a jug, it will soon clear and is safe to use as normal."