In Wiltshire, Chippenham town centre has been brought to a standstill after the River Avon burst its banks.
Becky Lyons, who runs a pet shop in the town, said she felt “numb” after her premises was left under several feet of water.
“It’s reached my storage area, so all the stock ready for Christmas,” she told the BBC.
“I feel a bit empty and numb. I’ve put everything into this shop.”
Ben Ruddy, whose fish and chip shop was flooded in Lydney, Gloucestershire, said he had seen “never seen anything like this before”.
“The sandbags did not do a lot,” he said. “Within a couple of hours the water was over them.
“It’s awful. Hopefully it’s just a lot of cleaning that is needed.”
In Worcestershire, police are investigating footage of a tractor being driven through the flooded streets which caused bow waves to hit shop windows.
Louise Preston, who owns a pottery shop in Tenbury Wells, said her store’s front window was smashed by the water as the tractor drove past.
She said the bow wave also took out the windows of other shops, describing it as “devastating for the town”.
West Mercia Police said it was “aware of videos circulating on social media” and the force is investigating.
West Midlands Fire Service had warned people against driving through flood water on Sunday.