More than 100 homes have been evacuated after floods and gale-force winds caused disruption across Cornwall.
People were trapped in their cars and homes by the rising floodwaters, which reached up to 6ft (2m) deep in places.
St Blazey, St Austell, Mevagissey and Lostwithiel were the worst hit areas. The Environment Agency warned further floods were possible overnight.
Prime Minister David Cameron said the government would do all it could to help those affected.
The disruption includes:
- Train services in and out of the county have been affected by landslides
- Schools have been shut while the county's main trunk roads have been closed for several hours
- Twenty-five vehicles have been recovered from floodwater
- Cornwall Council has set up an emergency shelter at Polkyth Leisure Centre in St Austell, where 200 blankets and 200 groundsheets have been donated by the charity ShelterBox
Police said there had been no reports of serious injuries.
The Environment Agency said heavy localised showers were forecast which would bring a risk of further flooding.
There is a flood warning in place on the River Fowey in Cornwall and flood watches on four other rivers in the county.
A spokesman said: "We are monitoring the situation closely.
"Our teams are on the ground clearing debris from rivers and grates, checking flood defences and assisting emergency services."
An old bridge in Lostwithiel remains closed to both traffic and pedestrians as engineers prepare to examine it for damage caused by debris.
They fear a high tide at 0300 GMT on Thursday could cause more debris to be swept into the bridge.
Barry Green, 46, the owner of a bakery in the town, said the flooding had "pretty much destroyed" his shop.
He was working when water spilled into the premises early in the morning.
"It all kicked off at about 5.15am when I heard a bubbling outside in the drains," he said.
"I was up at 3am and everything was fine. I had to quickly get the stock high up off the floor and call the flood lines to let them know we had a problem.
"Within three or four minutes it was knee high.
"One minute it was just lapping at the front door with no problem and I was just lifting a few boxes then I opened the front door and it just came pouring through. The speed of it was very, very surprising."
One woman in Lostwithiel said her car was swept 80ft to 100ft (25m to 30m) away from her home and was left wedged in a pile of rubble down the road.
Another Lostwithiel resident, Derek Baynton, told BBC News: "When I looked out of my window an hour ago I feared a Boscastle-type situation.
"The worst of the rain is over, but the water's still flowing down Quay Street in both directions."
Cornwall-based international aid charity ShelterBox sent blankets to the emergency shelter in Polkyth, the first time it has delivered aid in the county.
Tony Lay, from ShelterBox, said: "Flooding is flooding and it happens all around the world.
"For affected families it is the same, whether you are in Cornwall or in Africa.
"You lose all your personal belongings and it is shocking."
Cornwall Council Leader Alec Robertson said he had spoken to the prime minister on the telephone earlier who had expressed his sympathy and offered government help.
All the county's main trunk roads and travel routes have been affected by the bad weather.
The A30 was closed across Bodmin Moor after a lorry shed its load but has now reopened.
The A38 at Glynn Valley has reopened after being closed in both directions for several hours.
Rail services have also been disrupted.
The mainline track between Penzance and London Paddington was closed for several hours.
The Newquay to Par branch line remains closed due to a storage tanker which has washed down on to the railway track and subsidence under the lines.
Schools around the county did not open.
The Eden Project, which was hit by 3ft (1m) of floodwater in places, said it was expecting to be closed for at least a week.
Chief Executive Tim Smit said: "The heavens opened and, in a period of about 40 minutes, there was a deluge.
"We need to dry everything, we'll need to probably get rid of a lot of stuff and the clean up is going to be horrendous."