Several areas of Northern Ireland, including Banbridge, Cookstown and Newcastle are all at risk of facing a hosepipe ban, according to Northern Ireland Water.
Des Nevin from the utility company told the BBC’s Evening Extra programme any hosepipe ban introduced would be localised and only affect domestic customers.
He urged the public to reduce their water usage and said avoiding a ban was in the public’s control.
The warning from NI Water comes as Northern Ireland provisionally recorded a new record temperature of 31.3C in the Co Tyrone village of Castlederg.
The director of customer operations said there was extreme pressure on the Lough Fea water treatment works, which feeds into Cookstown, Magherafelt, Draperstown and Desertmartin.
Also at risk of a hosepipe ban are areas serviced by the Castor Bay water system, which feeds into Banbridge, Newry, Dungannon and also parts of Newcastle and Kilkeel.
“We are asking customers to be very sensible about the water they use, so things like washing cars, leaving sprinklers on... we are really asking customers to refrain from doing that,” he told the programme.
“The demand we are currently experiencing is extreme demand it is a bit like the weather we are experiencing. Whenever we plan and we design systems, we build in a certain level of contingency which is deemed to be reasonable amount of contingency.
“To actually build contingency to deal with extreme events is just not economically feasible to do so, therefore we have to accept that on occasions the systems we have in place will get stretched. This is a situation that is in customers control to deal with.
“If that doesn’t happen, we are in the place where we may have to go down that route of enforcing a hosepipe ban. If and as I say I’m very much emphasising we hope we don’t have to, but if we do it will be localised. It would be domestic only.”
In a release as part of an advertisement being issued to newspapers in Northern Ireland, NI Water urged customers to work with them in order to cut down water usage.
“On Monday July 19, we put 723 million litres of water into our distribution system, this is over 145 million litres more than normal, equivalent to 1.8million baths,” they said.
“We are asking our customers to help us, especially over the next few days when temperatures continue to be high. We know from the increase in our night usage some customers are leaving sprinklers and hoses on overnight, please stop.
“A hose uses more water in one hour than the average family uses in a whole day. “A pressure washer can also be a massive drain, so please think about whether the task is really essential at the moment.”
“While it is tempting, please avoid using swimming or paddling pools. Filling a 12ft swimming pool uses the same amount of water 500 people use for daily handwashing.”
Advice to customers across Northern Ireland includes turning off the tap when brushing your teeth, taking shorter showers and avoiding washing cars.