Water supply was interrupted in large parts of north and central Malta on Saturday morning, with Water Services Corporation attributing the problem to an Enemalta failure.
Enemalta, however, insisted there was no failure and that the outage was planned.
WSC said all of Naxxar, Għargħur, Swieqi, Ibraġġ, Madliena and parts of Mosta, Birkirkara, Iklin and San Ġwann were impacted by the outage.
That means more than 40,000 residents were likely impacted, according to 2021 Census data.
Residents in affected areas who are subscribed to outage notifications received an alert from the company about the service interruption beginning at 9am.
WSC attributed the problem, which it forecast would be resolved by 1pm, to an “Enemalta power failure”.
But Enemalta had a very different reading of the matter.
A company spokesperson told Times of Malta there had been "no failure" and that all the works were planned.
"There's no major issue - these interruptions are very normal," he said, adding some localities were being supplied with power from alternative sources.
The spokesperson said the outages were due to works to underground cables on roads around the country, and stressed that details of the works had been available to view at the company's website in advance.
When asked why WSC was attributing the outage to a power "failure" and not planned works, and why the water company hadn't been notified in advance, the spokesperson said he would need to investigate to provide further details.
A spokesperson for WSC told Times of Malta the company had notified its customers of the issue by SMS, and was "looking into the situation." Many customers would most likely have enough water in their tanks to weather the interruption without issues, he added.
In a joint statement later, WSC and Enemalta said the supply was restored by 1pm. They regretted the inconvenience caused.
Large tracts of Malta are supplied with water through energy-intensive reverse osmosis plants, which draw water from the sea and filter it to make it potable.
The areas suffered similar outages last summer, when massive power cuts led to a reverse osmosis plant in Pembroke being knocked offline.