A hose pipe ban will come into effect this weekend, NI Water has confirmed.
The company has warned that the continued use of water for non-essential purposes is likely to result in supply interruption in many areas.
The wider Armagh area has already suffered problems with its water supply this week.
NI Water CEO Sara Venning said: “We have maximised our water production and need customers help to reduce demand.
“I am appealing to customers to stop non-essential water use – using hoses and sprinklers is causing demand to exceed the capacity to supply.
“I would like to pay tribute to our staff who have been working through the night to ensure water treatment works are running at full capacity and in addition tankers have been deployed to assist with topping up service reservoirs.
“However, we also need the help of the public and businesses to reduce the level of demand.
“In recent days our treatment works have been operating at near maximum levels with over 700 million litres of water being put into the network which is some 25% more than is normal for this time of the year. Despite these steps, demand continues to outstrip supply.
“It would be our intention to introduce a formal hose pipe ban in an effort to protect the public against the increased threat of supply interruptions.
“That process however requires some time to take effect and in the meantime, it is essential that we all work together to reduce the unprecedented levels of demand on our network.
Customers in some areas including parts of Belfast and Armagh as well as other rural hand high lying areas have already experienced loss of pressure and intermittent supply failures.
The ban prohibits watering private gardens; or washing private motor cars and the company have said that its introduction will take effect from the weekend.