An evacuation is taking place near a reservoir in Derbyshire which has been battered by heavy rain.
A wall around Toddbrook Reservoir has been damaged and images appear to show a huge hole in the dam wall.
Derbyshire Police told Whaley Bridge residents to head to a local school amid fears that the wall could collapse.
A spokesman said: "Officers and staff will be at the school to give further direction but at this time we aren't sure how long the evacuation will take.
"Please make alternate arrangements to stay with friends/family, ensure that pets and medication that may be needed for a number of days are taken."
The Environment Agency has issued a severe flood warning, suggesting a danger to life, covering the River Goyt at Whaley Bridge. It states that the river could "rise rapidly" due to water rushing in from the reservoir.
Anna Aspinall, 36, from Whaley Bridge, told PA she and others wanted to help by placing sand bags in the area around the dam but were sent away after structural engineers advised "that the wall is at high risk of failing".
She said: "We have had significant rainfall over the past few days resulting in the overflow of the reservoir, which is very rarely breached, being completely flooded over.
"The result is that the overflow this morning has undermining damage and there is a big risk of the village being flooded out. Residents are currently being evacuated along with businesses."
"We are praying (the dam wall) holds whilst the Canal and River Trust try to drain the water from the reservoir. I live at the top of a hill but am very involved in community life so want to help where I can," she said.
As a helicopter hovered above the village, police officers were going door to door in Whaley Bridge to get everyone out.
Going the other way were teams of council workers and mountain rescue vehicles heading into the village.
Dragging a suitcase of possessions up the deserted high street, local David Holt said: "Police are knocking on, evacuating everyone within risk of that dam wall breaking.
"If it's going to go, it's going to go straight through the village.
"Police are asking you to gather some belongings, leave your house in a secure condition and go to a local school.
"We've taken an elderly neighbour to a friend's house and are heading to the school now."
Severe flooding in South Yorkshire in 2007 sparked the evacuation of roughly 700 people around Ulley Reservoir, near Rotherham, over fears its walls could burst due to unprecedented rain and apparent "areas of weakness".
Flooding due to sustained rain disrupted all lines on the railway between Manchester Airport and Wilmslow early on Thursday, according to train operator Northern.
A major incident was declared late on Wednesday in Poynton, Cheshire, due to "severe flooding" and local groundwork landscaper Adam Wainwright described the aftermath as "complete chaos".
He said: "We had flash flooding and heavy rain.
"There have been houses where the flood has had an effect, and it has just ripped through the houses. The water has just gone through the front door and out the back."
A bridge which partially collapsed due to the flooding in Poynton caused a nearby tree to fall into Simon Howcroft's garden, where a sinkhole also opened up.
Cheshire Fire and Rescue Service (CFRS) said firefighters, emergency services personnel and staff from Highways England were helping those affected, with a rest centre established at Poynton Civic Hall.
CFRS added: "Please bear with us, crews and police officers are working very hard to get to those in need and the most vulnerable in our communities."
Police urged people not to ignore "road closed" signs by driving or walking through water.
"Your car could become submerged and the road underneath could have collapsed, putting you in danger," the Macclesfield North and Poynton Police Twitter account said.
Poynton Fire Station said its crews had handled call-outs to 20 incidents including to help people stranded by flooding.
By the early hours, crews had finished a seven-hour stint involving rescues, salvage operations and incidents involving electrics and floodwater.
Mr Wainwright, 36, a local groundwork landscaper from Poynton, rounded up some friends and got into his digger as the flooding spread.
From about 4pm to 2am, they went to different bridges in the area and cleared away debris to try to help the water flow so people could get to their homes.
He said: "We were stumped by the levels of the water. We pushed the machine to its limits and then we pushed ourselves. We did what we could to try and get it flowing. At the end of the day, we are a community that comes together at a time like this."
Mr Wainwright said the water levels at the bridge near Poynton industrial estate looked like it was about "two metres-plus" high and that he and his small team went "as far as they could go" to clear the debris.
He said: "It was tricky but, at the end of the day, we just got on with it. The thing we look at is safety. We stayed on the footpath and did not go into the river."
He said a bridge had collapsed near Dickens Lane and Waterloo Road, and the area was "knee-deep in thick black sludge with a gaping hole in the road and a gas main suspended in mid-air".
Police in nearby Wilmslow also said officers were "dealing with flooding" and had evacuated affected residents, with Oakenclough Children's Centre open as a rest centre.
The Environment Agency said its teams were out in Cheshire, Derbyshire and Greater Manchester, where intense rainfall had caused flooding and disruption on Thursday.
It urged people to say away from swollen rivers and to avoid driving through flood water.
It issued a series of flood warnings covering central, north-west and north-east England.
The Met Office said it should be a "much drier picture" across England on Thursday.
Forecaster Luke Miall said only sporadic rain was likely in central and western Scotland and northern England, possibly as far south as Yorkshire.
He said: "There may be some showers but they're likely to not be as frequent nor as significant as the last few days."
South-west England and parts of Wales may also see occasional showers, he added.
Cheshire East councillor Jos Saunders said there had been "dreadful problems" with the roads, some of which were "completely" flooded.
She said: "We have got roads where the water was waist-deep, and unfortunately this is the second time in three years it has flooded."
Stockport councillor Steve Gribbon, who is also a watch manager with the Greater Manchester Fire Service, said areas such as Stockport, Bramall and Cheadle Hulme had also been hit.
After going past the swollen River Goyt, he said: "I was amazed by how much has come down. It was about two metres higher than it normally is.
"The river is not normally that wide and it was about twice the width."