Large parts of Northern Ireland will endure effective water rationing tonight as engineers battle to fix the huge number of leaks that have hit the system.
In the wake of the thaw that followed arctic weather conditions, burst pipes in the main water supply, plus many in private homes and businesses, have left thousands of people without water.
Northern Ireland Water, (NIW) the company that oversees the service, came under fire for failing to cope with the deluge of calls from the public, though it argued it was doing its best to meet needs.
But with water levels running low in reservoirs, officials said supplies would have to be alternated to different locations as work to repair the damage continued.
Sites opened to hand out free bottled water drew queues of people in need, but as many households endured days without water - and with many also having suffered heating failures - the political fallout over the issues grew.
Northern Ireland deputy first minister Martin McGuinness promised a review of the response to the extreme weather and said the most vulnerable in society would be able to draw-down government funding to ease their plight.
"The recent long spell of sub zero temperatures and snow falls, followed by a quick and dramatic thaw, has resulted in frozen pipes followed by flooding which has affected many people adversely, with some having witnessed considerable damage to their homes," he said.
"I would like to thank public servants for their hard work over the this period of severe weather in seeking to help.
"I will be asking departments for their assessment of the situation and to bring forward proposals on how best to address, and deal with effectively, situations such as this.
"Further to this we will also be examining the Financial Assistance Act, which we have previously utilised, to see how we can address the financial hardship of those who are most in need over this period."
He visited the Shankill estate in Lurgan, Co Armagh, where overflowing sewers flooded houses. Mr McGuinness also travelled to Coalisland, Co Tyrone, where burst pipes had drained the local reservoir.
The deputy first minister repeated calls for key holders to check unoccupied houses and businesses where leaks may have occurred.
There were reports of loss of water supply across Northern Ireland. NIW said the areas set to be hit by alternating water supply covered locations dotted across virtually the entire region.
A spokesman said: "NIW is dealing with interruptions to water supplies across a large number of areas in the province as a result of the severe weather and ongoing thaw.
"Our Major Incident Team has been in operation for the past number of days headed by our Senior Executives.
"As a result of the high water demand being experienced (primarily due to a number of bursts to private supplies), a number of our reservoirs are currently at low water levels and we are trying to rezone and recharge the water network.
"NIW have to alternate supplies from some of our reservoirs, therefore customers will experience a loss of water for a period of time.
"However, it is anticipated that this interruption will only last a number of hours and water will be restored to customers in a timely manner."
SDLP South Belfast MP Alasdair McDonnell was among the senior politicians who said government was failing to handle the problems caused by the severe weather.
"People in South Belfast are at their wit's end having been without water now for several days and many are currently having to cope with the nightmare of sewage in their homes with little help or reassurances from NI Water," he said.
"Businesses in our busy retail area have also been damaged by this water supply nightmare which is proving particularly detrimental at this crucial time of the year for retailers.
"Residents also have the added frustration of not being able to get through to speak to anyone in NI Water or get any information on whether or not their water is being fixed, as the agency's website is down."
NIW said it had been inundated by calls from the public and had dealt with 6,000 in the early part of yesterday alone.
The Housing Executive, which covers social housing and which also came in for criticism when homes were hit by heating problems over the cold snap, said it had received between 2,000-3,000 calls a day about frozen pipes.
Ulster Unionist Sir Reg Empey said: "I make no criticism of the individuals working for the water company and other emergency services, trying to cope with the problems that the public are facing.
"My criticism is for the authorities who fail year after year to produce an emergency plan that works. As a country we seem unable and unprepared to deal with emergencies.
"Recent flooding is the most obvious example."
He added: "But overall, those who are responsible for emergency planning - who have not seemed to have learned from previous emergencies - must up their game significantly, instigate an investigation and put in place planning and provision for the future."