Hundreds more people were being evacuated from their homes in Wales on Sunday in a new flooding alert - just as others were going home after being inundated on Saturday.
North Wales Police evacuated residents from the village of Pennal, near Machynlleth, Powys, following a slight breach in the dam of a local reservoir which caused a small amount of water to escape.
A police spokeswoman said residents were being transported to Machynlleth Leisure Centre.
"Staff from the local councils, representatives from the local water board, North Wales Fire and Rescue Service and officers from North Wales Police are at the scene working to stabilise the situation," she said.
"At this current time it is thought that the breach may have been caused by a landslide."
Superintendent Andy Jenks-Gilbert said the evacuation was taking place as a precautionary measure.
A crack had been found in a stone wall at the reservoir and a small amount of water had escaped, he said.
"Should the wall be completely breached, the contents of the reservoir will go into the river which flows through the village of Pennal, which is around half a mile from the reservoir.
"Police officers are evacuating residents in the area and would ask visitors and locals to avoid the village at this current time."
The drama came as hundreds of people evacuated following flash flooding 20 miles away were returning to their homes and caravans.
Villages in the county of Ceredigion were flooded by up to 5ft (1.5m) of water yesterday.
Some 150 residents and holidaymakers were rescued and evacuated from homes and caravan parks near Aberystwyth after twice as much rain fell in 24 hours as normally falls in the area in the whole of June.
Fire crews were again working around the clock, continuing to pump out water from a number of locations.
Although many roads have reopened, a flood warning remained in place and water had yet to recede fully in some places.
A number of caravans and tents in the Aberystwyth Holiday Park remained cut off from land - with some occupants surveying any possible damage from afar.
Tourist Simon Saunders, originally from the Midlands, was staying in a caravan with friends when told to evacuate the park yesterday.
He said: "It's amazing no-one was seriously hurt when you consider the damage done.
"The caravan parks are popular with families and retired people - so were the evacuation not done so quickly someone could have easily got hurt.
"My mate's camper van looks as if it's stranded and we won't be going home today.
"But everyone has pulled together and helped everyone out."
A flood rescue team, featuring fire, police and lifeboat crews, was immediately mounted, taking pre-emptive action by evacuating people before water levels got too high.
A number of rivers burst their banks as the stormwater flowed downstream.
Among the worst affected areas were Talybont, Dol-y-bont, Llandre, and Penrhyncoch.
The RNLI's flood rescue teams helped people to safety at Aberystwyth Holiday Village and rescues also happened at Riverside Caravan Park in Llandre, near Aberystwyth, Mill House Caravan Park at Dol-y-bont, Sea Rivers caravan park, Ynyslas, and Glanlerry Caravan Park, near Borth.
Residents in 25 properties were evacuated in Talybont, and 10 houses flooded in Penrhyncoch.
RAF teams also winched people to safety.
Although the weather has stayed largely dry since the flooding, agency officials reminded people to stay away from rivers and flooded areas.
But where the water has subsided considerably, those affected have been returning to their homes and caravans.
Many were forced to leave their homes as the rain poured down
Local resident Alun Williams, 64, said: "The general feeling here is one of shock.
"Only a couple of weeks ago we were in the news as the Olympic torch came through Aberystwyth.
"Now the town's in all the papers because of the floods.
"Yes it could have been a lot worse, but I've not heard one person say how lucky they are.
"I just hope it doesn't put people off from coming back."
Some 150 people were rescued and evacuated to rest centres, but police said the overall number who left their homes was nearer 1,000.
Senior politicians, including Prime Minister David Cameron, paid tribute to rescuers who ensured there were no serious casualties.
Dyfed-Powys Police said three people needed treatment for minor injuries.
The First Minister of Wales, Carwyn Jones, spoke of his shock at the extent of the damage and praised the bravery of emergency crews.
"Having spent a number of years living and studying in Aberystwyth, I was deeply shocked to see the extent of the damage caused by the flooding in an area I know so well.
"Yet again, we have witnessed the impressive bravery of our emergency services. Working in truly harrowing conditions, they ensured up to 1,000 people were moved to safety. It is thanks to the professionalism and dedication of both our professional and volunteer emergency crews that no lives have been lost."
The Environment Agency has also urged people to be alert for disruption from possible flooding across parts of northern England later on Sunday and southern England on Sunday night and Monday.
A spokesman said that prolonged and heavy rain is forecast over parts of central-southern and south eastern England overnight and during tomorrow, bringing the possibility of river and surface water flooding.
Because of the complex weather, there is still some uncertainty as to the locations most at risk, but the situation will continue to be closely monitored.
In preparation for this further wet weather, Environment Agency officers are out monitoring river levels, checking defences, and removing any blockages that may increase the risk of flooding.
Care should be taken as driving conditions may be hazardous, and people should listen to traffic reports for advice and for any disruption locally, the spokesman said.