Irish Water has said demand for water in the Dublin area remains critically high.
As temperatures reach 30 degrees in parts of the country, the water utility says there is currently "almost no margin of supply over demand".
A number of households in Athlone, Kilkenny, Longford and north Dublin have already experienced outages, while parts of Donegal, Galway, Limerick and Mullingar are at risk of losing supply.
Following recent calls for the public to conserve water, there was a small decrease in water demand over the last day.
Dublin Bus was among the organisations taking action, pledging to wash its fleet once every three days instead of every day.
We believe we can all make a difference to protect our natural resources. We’re enjoying the warm spell but it's having a big impact on water supplies. We will save 100 gallons of water per bus by washing our buses every 3rd night instead of every night #ConserveWater pic.twitter.com/pEuwVVpRsL
— Dublin Bus (@dublinbusnews) June 26, 2018
However, Irish Water says there is still a long way to go - and demand is currently less than 10 million litres below the daily production capacity of 610 million litres.
Irish Water's Corporate Affairs Manager Kate Gannon explained: "If the drought is prolonged, water restrictions would become unavoidable if demand does not continue to drop.
"Irish Water are appealing to the public to be continue to be mindful of their water usage. Every effort someone makes in their home or business impacts their neighbour and community."
As efforts to conserve water continue, people are being urged to take short showers instead of baths, and to avoid using hoses to wash cars or water gardens.