The Environment Agency has issued a flood warning for the Washford River from Exmoor to the coast at Watchet and warned families most at risk to move to safety.
It says river levels have risen quickly due to Saturday's heavy rain and warns of possible flooding on Sunday morning.
The warning says riverside properties in Roadwater and roads in Kingsbridge on Exmoor could be affected as the rain continues during the day.
Agency staff are working to check defences and clear waterways of obstructions.
The alert says: "River levels have risen rapidly as a result of heavy rainfall on 07/01/23. Consequently, flooding could occur between 07:30, 08/01/23 and 12 noon on 08/01/23. We expect flooding to affect properties in Roadwater and roads in Kingsbridge.
"Further showery and at times persistent rainfall is forecast over the next 24 hours. We expect river levels to remain high until 12 noon on Monday 09/01/23. We are closely monitoring the situation.
"Our incident response staff are checking defences and clearing weed screens. Please move family, pets and cars to safety and avoid contact with floodwater.
"Please avoid using low lying footpaths near local watercourses and refer to local authority website for local road closures."
The Met Office is forecasting showers through Sunday and heavier rain overnight into Monday.
The Washford River rises at Luxborough in the Brendon Hills and joins the Bristol Channel at Watchet.
More information is available on the Government's website.
We will bring you updates as we get them in our live blog below