Cork city council have turned off the water supply to the city centre and suburbs over fears of contamination because of flood damage to a pumping station.
People are being advised to drink bottled water until further notice
Severe flooding has also reported in Tipperary, Kerry, Monaghan, Longford, Kilkenny, Clare, Waterford and Wexford.
The civil defence in Carlow town has been ferrying people out of apartments in boats and tractors.
Thomastown, Graiguenamanagh and Mooncoin in Kilkenny are also flooded.