Severe flooding in Limerick and Cork has begun to recede tonight and residents in areas affected by last night's deluge began a major clean-up operation.
There was serious localised flooding in Mallow after water levels rose in the River Blackwater.
However, according to a spokesman for Cork County Council, the river flooded its normal floodplain overnight, and the waters, which are now receding, did not threaten any residential buildings or businesses.
He said that the main areas affected in Mallow were Bridge Street, where sandbagging took place during the night, and the low-lying Park Road area. The spokesman added that residents were advised of the flood risk and that council staffed "worked tirelessly" through the night.
There has been no further rain since daybreak, and the River Blackwater's flow peaked earlier this afternoon.
Early this morning, a number of people had to be rescued from their homes in Co Limerick after flash flooding overnight.
Up to 20 houses were affected after the River Arra in Newcastle West burst its banks following heavy rain that put pressure on local streams.
On elderly couple who had abandoned their home were found nearby by the Coast Guard helicopter. The woman had to be winched to safety by a the helicopter. She was taken to the Midwest Regional Hospital to be treated for hypothermia and is reported to be in a stable condition.
According to a Met Éireann spokesman, average rainfall for the last week of July is about 26mm, and he said three times that amount fell between 7pm and midnight last night in Newcastle West.
At one rainfall station in the area, a measurement of 90.1mm was recorded, whereas around 100mm of rain could be expected in a month. The spokesman added that the rainfall was tropical-like in intensity, and that the low-pressure area the brought the rain was slow-moving and very localised.
An emergency operation began at around 2am after local rescue crews called for back-up help, said a Coast Guard spokesman. A helicopter based at Shannon was sent to the scene.
The ESB said that up to 3,000 homes in the Newcastle West area are without electricity. A clean-up operation has begun as the water level starts to recede.
The N21 Limerick - Killarney road was earlier closed by the floods. It has now reopened through Newcastle West, but the (R522) Cork Rd to Drumcolliher is still closed, according to AA Roadwatch.
Around 100 homes in the South Quay area and 50 businesses on Bridge Street and North Quay in the town are facing massive clean-up bills, it was claimed.
Pat O’Donovan, a spokesman for Newcastle West Business Association and owner of a local insurance firm, said he has been inundated with calls from customers.
“People are crying and some people are saying that they’ve no insurance and their stock is ruined,” he said. Mr O'Donovan added that most businesses remained without electricity and phones.
Commenting on the scene in Newcastle West, County Councillor Patrick O’Donovan said: “It was like something out of a horror film. I have never seen so much water floating down a street, there were cars and vans floating down the street.
“The rain was like a monsoon here last night. At one stage it was at my ankles, and as I turned the corner to leave it was at my knees."
He said cost of the damage to homes and businesses would be massive. “At one stage there was about five feet of water, half of the town was under it. The place has been devastated, houses and businesses destroyed.”
It is believed to be the first time the town has been flooded in memory.
According to Met Éireann, showers, mainly across the midlands, will move slowly northwards today, turning heavy in places, while there will be sunny spells and scattered showers elsewhere, with heavy falls possible.
Tomorrow, sunny spells and scattered showers, with the threat of heavy rainfalls, are forecast.
Additional reporting PA