Irish Water is urging people to conserve water amid a significant increase in demand, although it says there are currently no plans to implement a Water Conservation Order - also known as a hosepipe ban.
Urgent appeals for conservation have been made in a number of areas, including Wexford, Kerry, and Donegal, with night-time restrictions in place in Portlaoise and parts of Longford.
However, the majority of water supplies in the Greater Dublin area are stable despite high levels of demand.
Irish Water's Head of Asset Operations Tom Cuddy said: "With temperatures remaining high we have seen demand for water double in some areas from what would be normal, in particular tourist hotspots in popular coastal regions.
"In the Greater Dublin Area alone we saw an increase from 535 megalitres per day last Sunday to 591 ml/d on Saturday. This increase of 56 million litres per day equates to the average daily use of over 430,000 people."
Speaking on RTÉ's Drivetime, Mr Cuddy said surface water sources, including rivers and lakes, are dropping slowly, but are at normal levels for this time of year.
He said ground water sources, including bore holes, wells and springs which had a number of shocks earlier this year, is where there are challenges.
Mr Cuddy urged people to keep showers short and use a basin in the sink to capture that water so it can be used in the garden. He said he hopes there will not be a need for a hosepipe ban this summer.
Meanwhile, Irish Water is working to restore supply to customers in Drogheda and the surrounding area in Co Louth following a "major burst" in a water main.
To minimise the impact on customers, the network has been reconfigured to allow reservoirs supplying the area to refill.
Burst water mains are also causing supply issues in counties Wexford and Roscommon.