The country faces paying out millions of euro in flood damage repairs after Storm Francis dumped near-record amounts of rainfall over towns and villages reeling from Storm Ellen.
Almost 70mm of rainfall fell on mountainous areas of Munster, Connacht and south Leinster overnight - with 9mm of rain falling in a single hour at Valentia in Kerry.
Met Éireann said Valentia received 53mm of rain in a 12-hour period since 6pm on Monday.
Bantry, in west Cork, recorded 25mm of rain in just two hours, as west Cork suffered its third major flood in just 12 days.
Flooding from Storm Francis was reported in Cork, Kerry, Waterford, Kilkenny, Tipperary, Clare and Galway.
Major reviews are under way into how Bantry and Bandon suffered such extensive damage - with Bandon the focus of a €16m flood defence scheme.
While the 110kmph winds generated by Storm Francis weren't anywhere near as destructive as those of Ellen, the rainfall proved as damaging as Met Éireann feared.
While 200,000 homes and businesses were left without power last week in the wake of Storm Ellen, several hundred lost power because of Storm Francis.
Power outages were focused on Cork, Galway, Limerick and Tipperary, but flood damage was very severe in some areas.
Bantry had more than 50 homes and businesses around the town left flood-damaged.
Bantry Business Association official Diarmuid Murphy said the scale of the flooding was overwhelming.
"I couldn't believe it - I have a jeep and when I drove around the corner and came to the top of Bantry Square, I didn't think I would get through it.
"There was a river running through the middle of the town," he said.
Vodafone store operator Ger Egan said the flooding shocked everyone, but locals had rallied to face the challenge.
"Everyone tried to help everyone else - there was great solidarity," he said.
Terence Gibbs of The Cosy Cabin said it was the worst flooding in the town for years.
"It is devastating, to be honest. It couldn't have come at a worse time for traders, residents, the town and west Cork given the way the pandemic has hit the economy," he said.
Such was the water pressure on underground culverts that road surfaces around Bantry 'popped' - leaving the council also facing major road repairs.
Cork County Council blamed torrential rainfall falling onto already sodden ground in Bantry, which sits at the foot of several hills.
"This appears to be as a result of prolonged intense rainfall in an already saturated ground. A number of roads have been damaged and are currently closed pending assessment," a council spokesperson said.
Council crews and Bantry Fire Brigade battled the flood waters throughout the night.
Less severe flooding also hit including Connonagh, Clonakilty, Rosscarbery - for the third time in 10 days - and Dunmanway.
The N71 Cork-Bantry road was left impassable for a time.