Irish households are using an additional 24 litres of water per person per day since the Covid-19 crisis began.
Irish Water says the 20% increase since February's significant and needs to be reduced as treatment plants are at max capacity:
The utility says steps like taking a shower instead of a bath and use a watering can instead of a hose can make a difference.
Tom Cuddihy from Irish Water says the increase in domestic demand is worrying for the months ahead.
"As businesses reopen their uses is going to increase, and that's where the real challenge is going to come.
"That's going to be compounded by us moving into the summer, with greater use during the warm weather and so on, and some of our sources in summertime going a bit lower.
"So it's important we get a handle on things now."
