Scottish Water has said they expect that some customers will lose supply as a result of the problem.
With temperatures having dipped below freezing over several evenings, Scottish Water engineers have been working overnight in challenging conditions to restore and maintain water supplies in North Uist, where the intake to Lochmaddy Water Treatment Works has been affected by the sustained freezing conditions, restricting the flow.
Around 750 homes and businesses on North Uist, Berneray and Grimsay are served by the Water Treatment Works on the hillside above Blathaisbhal, north of Lochmaddy, which draws water from nearby Loch Fada.
Scottish Water’s team has been working through the night to maintain an alternative feed of water from the loch to the water treatment works until the normal intake pipeline and pumps can be cleared of ice and returned to normal operation.
Divers have been deployed twice during the night in an effort to keep the temporary intakes clear of ice which has rapidly built up due to the ambient temperature. Tankers have also been used to supplement stored drinking water as far as possible.
Efforts are continuing, but with stored drinking water in the islands’ water network now running low, some customers are expected to lose water supply or experience lower than normal water pressure this morning.
A spokesperson for Scottish Water said: “We have been working hard at Lochmaddy and a number of our other sites across the Western Isles to maintain a normal service for customers in what can only be described as extremely challenging conditions over recent days.
“At Lochmaddy, our efforts overnight have not yet succeeded in returning the water treatment works to a normal operation and we are therefore now initiating emergency plans to provide alternative water supplies for customers who require it.
“Our team will initially be working to ensure customers who may be vulnerable without drinking water will receive an alternative bottled water supply, drawing upon our Priority Service Register and the support of our partner agencies.
"Additional bottled water is being brought to the island and this will be distributed to all customers from late morning onwards if normal supplies are not restored at that point.
“We would ask customers to please bear with us and to use their water conservatively while we continue working to sustain supplies and restore normal service as quickly as possible.”
Regular updates on the situation will be provided via Scottish Water’s website at: www.scottishwater.co.uk, and if required, distribution of bottled water to all affected customers will begin from late morning today, (Friday, February 12).
How you can help: Be mindful of running water. Don't keep the tap running the entire time you're brushing your teeth or washing your hands; Don’t use the dishwasher or washing machine unless you have to; and take a shorter shower or don’t fill the bath.