Water supplies in areas of Kiltimagh have been impacted by a lightning strike at the local water treatment plant.
The lightning strike last night during a thunder storm caused low pressure on the water supply scheme, which was followed by a watermain burst this morning.
Irish Water and Mayo Co Co are working to restore the supply to affected areas as quickly as possible.
About 200 homes on the Knock Road and also in the Kilcon areas of Kiltimagh may be impacted by water outages while the repairs are underway.
The supply should be fully restored by evening - once the watermain has been repaired, it may take a number of hours for the water supply to return in full to all impacted properties.
A traffic management plan is in place for the duration of the urgent repair works.