Dublin City Council has asked people to think about how they use treated water and to remember what a valuable resource it is.
The local authority is warning against watering your grass, hosing your car or spending 10 minutes in a power shower.
Dubliners use an average of around 148 litres of treated water every day, but only drink two to three litres.
Seamus Lyons from Dublin City Council said the rest is being wasted.
"There's no need to water your lawn - grass recovers very quickly after a hot period," he said.
He also advised chilling water in the fridge, rather than running a tap until the running water turns cold.