Major clean-up operations were launched today across Cork city and county after heavy overnight rain caused serious flooding.
Douglas, Glanmire and Clonakilty were the worst affected.
The ESB has said power has being restored to most customers.
Cork County Manager Martin Riordan said the local authority was "as ready as it could be" but it had responded accordingly to the flash flooding.
Speaking on RTÉ's Six One News, Mr Riordan said that the council had received a rainfall warning and had responded accordingly.
He said, however, it was difficult to be prepared for what he described as the "huge impact" of the rain over such a short period of time.
The ESB is operating an emergency helpline for people experiencing problems with electricity - 1850-372999.
The National Co-ordinating Group of Emergency Management this afternoon said that the rainfall has eased in Cork and river levels are being monitored by the ESB and the Office of Public Works.
The group said there were no reports of severe flooding in any other part of the country.
The group's chairman, Sean Hogan, said it met to monitor the situation and to support the local efforts in Cork.
However, he said the clean-up phase has already begun and the authorities in Cork have not asked for any national assistance.
Mr Hogan described the situation that had arisen for householders and businesses in Cork as terrible.
Another 20mm of rainfall is forecast for the next 24 hours, which may result in some localised flooding in the south and east of the country.
The impact of the overnight rainfall was intensified by the rainfall in June, which has been the wettest June on record.
Eoin Sherlock of Met Éireann said that nearly 50mm of rain fell within six hours last night.
Normally, he said, 76mm of rain falls in Cork during June, this month over 200mm fell.
(Send your pictures of today's flooding to email@example.com)
Northern Ireland also experienced heavy rain. Homes in Belfast were flooded and motorists were forced to abandon their cars.
The fire and rescue service was at one stage dealing with an emergency call every 20 seconds.
Flood waters in Belfast have since subsided and a clean-up is under way.
Northern Ireland's Finance Minister Sammy Wilson has approved emergency funding of up to £1,000 for those affected by the flooding in Belfast.