People are being urged to conserve water where possible, as demand is exceeding supply in some areas.
Night time water restrictions are being introduced in some parts of the country, including Kerry, Portlaoise and parts of north county Dublin.
People in these areas could see reductions in pressure at night.
Irish Water, working in partnership with @LaoisCouncil , wishes to advise customers in Portlaoise of night time restrictions due to increased demand and depleted reservoir levels. The restrictions are essential for adequate supply during the daytime. https://t.co/n1Elv7wUui
— Irish Water (@IrishWater) July 18, 2021
Tom Cuddy is head of operations at Irish Water.
He told Newstalk Breakfast a number of factors, including staycations, are contributing to the demand.
"With the hot weather demand is up, and we've reports from several areas of exceptional demands and it's really exceeding supply capacity in some areas.
"This is an annual pattern through the summer with sources dropping, but also some particular issues just now.
"We have staycations, holiday resorts where populations have doubled and trebled.
"We also have agricultural areas - at this time of year crops and livestock watering has a very high demand.
"And of course then we have some businesses re-opening, with the COVID restrictions lifting, so for that reason we have to make some interventions.
"So far they've been relatively modest - Irish Water and the local authorities, we're monitoring the ongoing situation.
"If we can conserve our water and avoid excessive use, then we'd be able to manage in a controlled way".
Mr Cuddy says people should hold off on non-essentials.
"We would like people to be mindful of water conservation and their indoor and outdoor use.
"Avoid extended showers and having taps running when they're brushing their teeth or when they're rinsing vegetables and so.
"Watering of lawns - really, we feel it's no harm to let the lawn get a tan at this time of year - the grass will recover very quickly.
"And things like cleaning patios and that, that can wait till other times of the year - it's really not necessary at this time of the year".
It comes as the hot weather looks set to continue, with a High Temperature alert in place across the country.
The rare advisory will remain in place until Friday afternoon.
Both Friday and Saturday saw the highest temperatures of the year recorded to date.
Irish Water has issued the following advice:
- Take a shorter shower and save up to 10 litres of water per minute
- Fix dripping taps or leaking toilets in your home
- When brushing your teeth or shaving, turn off the tap and save up to six litres of water per minute
- Save and reuse water collected from baths, showers, and hand basins in the garden
- Avoid using paddling pools
- In the garden use a rose head watering can instead of a hose and aim for the roots
- If you need to wash your car, use a bucket and sponge instead of a hose
- Report any leaks to Irish Water at 1800-278-278
