Irish Water has warned that there is a narrowing gap between supply and demand in the system for the greater Dublin area.
On Wednesday Irish Water and local authorities in the region called on people to conserve water where possible as demand for drinking water reaches record levels over the Christmas period.
The current increase in demand over the last few weeks is higher than any previous year and is 10 million litres a day higher than this time last year.
Irish Water's head of asset operations, Tom Cuddy, told RTÉ radio's Morning Ireland that restrictions in some plants have compounded the issue.
Water production capacity has been reduced as work continues at the Leixlip plant which is currently undergoing upgrades. Further upgrades are ongoing in Stillorgan and Vartry which are due to be completed in 2020.
“We are urging consumers to conserve water where they can. This is a rolling issue, it is an enduring situation that we will have for several months.
“There is a huge amount of work going on all the time reconfiguring supply so we can get the maximum from all the plants,” he added.
Demand traditionally increases in the winter months he explained. The situation at present is stable, but this would change dramatically in the event of a long sharp frost, he warned.
Actions to conserve water that are recommended include turning off the tap when brushing teeth and shaving, and keeping a jug of water in the fridge instead of running the cold tap.