Over 5,000 residents in Longford can expect to have their water supplies restored in the coming hours.
Engineers have been working to repair units that power the water pumps at the Lough Forbes Treatment Plant, which were damaged by an electrical surge last night.
The repairs are expected to have been completed by now to allow systems return to production.
Michael Cunniffe, the Irish Water Lead for the Longford area, says the supply in Longford town should return first and it may take some hours and perhaps into the night for full pressure to be restored in all areas.