Crews from Cornwall Fire and Rescue Service were called to severe flooding in Notter Bridge in Saltash in the early hours this morning (Saturday 19 December).
According to the Environment Agency further flooding could occur today and residents are recommended to take immediate action.
The flooding reached a holiday park where water had got through the flood defence. It comes after red flood warnings were issued across the county.
Approximately fifty caravans were searched to check on the welfare of occupants.
Eighteen people were evacuated and some of the people were rehoused.
The Environment Agency said river levels at Pillaton near Saltash reached the highest level that has been recorded and levels are expected to remain high with a 'red' flood warning alert.
It said: "Heavy and intense rain in the area has caused river levels at Bastreet and Pillaton to rise through Friday 18th December.
"River levels at Pillaton reached the highest on record and are expected to remain high."
The warning read: "High tide, taken from Plymouth at 08:42, may lead to tide locking, where the river will be impeded from discharging into the sea.
"This could cause further flooding. Residents are recommended to take immediate action. Emergency Services are attending site. Remain safe and be aware of your local surroundings.
"The A390 at Notter Bridge may also be at risk. We are monitoring river levels and have staff in the area ready to respond as required."
At 4.24 am, in a statement on their official Twitter account, Bude Community Fire Station said: ''We are currently in attendance at a mass flooding incident at Notter Bridge.
''The incident is being scaled back but we are staying on scene to monitor. ''
Devon and Cornwall Police as well as Dartmoor and Cornwall Search and Rescue, and Saltash Community Fire Station, were also in attendance to the incident.
Cornwall Fire and Rescue Service attended several incidents involving flooding in close by areas. Resources from Saltash, Callington, Liskeard and Launceston, were all deployed to assist due to adverse weather conditions in the area