Stranded motorists have been rescued after a section of the M5 was closed amid “significant flooding”.
National Highways confirmed the motorway has now re-opened, following a full closure between J16 for Aztec West and J14 for Thornbury earlier.
Firefighters were called to the route at about 01:00 BST to help rescue drivers trapped in their cars.
Steven Basterfield from National Highways described Friday’s downpours as “exceptional” and confirmed about 6,000 litres of water per minute had to be removed from the motorway.
A spokesperson from Avon Fire and Rescue Service (AFRS) said eight fire engines, two water rescue teams, a welfare unit and a drone unit were deployed to the scene.
Crews rescued three people who were stranded in their vehicles.
About 20 other cars and two lorries were also affected on the northbound carriageway and had to be directed to safety by police.
One man caught up in Friday’s floods said it looked like a “river flowing” beside his van, and traffic had been at a standstill.
Lewis Spindlove was sleeping in the passenger seat of his colleague’s van as they returned home to Bristol on the M5 southbound, following a late bartending shift.
He awoke at about 02:30 to police moving traffic onto the hard shoulder.
“The deepest that we had to go through was probably about 15-20cm, so not particularly deep, but we were pushed all the way over.
“I wouldn’t say it was scary, but I was absolutely bewildered by how much of the M5 was flooded, I’d never seen it that bad before,” he said.
Diversions were in place and surrounding roads were congested as motorists tried to reach their destinations.
Speaking to BBC Radio Bristol earlier on Friday, Mr Basterfield added: “There’s a lot of work going on at the scene to try and remove this water.
“It’s run off from the fields either side of the motorway and it’s a real multi-agency response.”
High volume pumps were being used at the scene to remove the “extensive flooding”.
Ben Thompson, group manager at Avon Fire and Rescue, said: “We attended a severe flood on the M5 today covering both the north and southbound [carriageways].
“It was a really extensive area, about 400m long and it was up to waist deep and slightly deeper in places, so that made it a real challenge.
“I’m pleased to report however that we successfully rescued three people from their cars and later recovered the stranded vehicles.
“We also dealt with some lorries and other vehicles that had been left stranded, and the police, highways and Environment Agency worked with us to bring the incident to a safe conclusion.”
The Met Office issued a yellow weather warning for rain which covered the south west of England.
It advised that heavy downpours would bring the potential for some flooding and disruption to transport. There was also a chance of power cuts, it said.
The warning was in place until 09:00 on Friday.
BBC Weather is monitoring the prospect of more wet and windy weather arriving later on Sunday and into Monday.