FLASH floods are causing traffic delays and problems around the county.
Firefighters have been called out to ease the issues, including to Warmdene Avenue in Patcham, Brighton, where they are currently battling the water with two engines.
The Preston Brewery Tap pub in Preston Road was among dozens of businesses hit by flash flooding.
Landlady Sharon Matthews said: "It just came through the doors like it does every time it rains like this.
"It's a nightmare."
Ms Matthews said she got the storm gates out to stop the water gushing in.
But she said the deluge cleared quite quickly after firefighters unblocked nearby storm drains.
"If it happens in the night then you've got no chance," she added.
Pictures show pavements along Preston Road submerged under at least a foot of flood water.
Staff at Mishon Mackay estate agents can be seen blocking the shop doorway with "for sale" signs in a bid to keep the water at bay.
The manager of The Crown and Anchor Pub said: "It literally came in through the door. It was gushing in. It wasn't really extreme but it was quite extreme.
"We locked the front door because when someone came in all the water came in too.
"There wasn't much else we could do really."
Louisa Cockrem was riding on the bus when she noticed firefighters wading knee-deep in water in Preston Road.
She managed to capture pictures of the flooding which show the water lapping against shopfronts.
She said: "I was really shocked. The water was knee-deep.
"There was at least a foot."
She photographed two estate agents trying to keep the water at bay.
Louisa, 37 and from Patcham, said: "Bless them they were really trying but it was getting in."
One motorist reported heavy traffic in Patcham and said a manhole in the area has collapsed.
TRAVEL: #Patcham: SEVERE DELAYS & HAZARDOUS DRIVING CONDITIONS due to flooding on #A23 both ways between Preston Drove & #Pyecombe and a broken down vehicle Northbound plus severe delays due to the weather on the #A27 both ways between #Hollingbury and Patcham
— Sylvie Blackmore (@SylvMelB) August 10, 2018
The roof at Brighton Station is also leaking.
East Sussex Fire and Rescue Service said all their engines that are out on calls at the moment are responding to flooding.
Crews have been in Patcham since 4.19pm.
A spokeswoman for the service said: "There are extremely bad flash floods and the drains are not coping.
"We are extremely busy at the moment."
Portslade has seen torrential rain today.
Wickhurst Rise, off Chalky Road, has seen some of the worst of it, with raw sewage coming up into gardens.
James Henson, who lives in Wickhurst Rise, said: "The road is badly flooded again.
"I live in the council flats and there is raw sewage all over the back garden.
"This happens when ever we get heavy rain."
The fire service spokeswoman said West Sussex is also suffering from the downpour.
Rectory Road in Worthing is one of the areas badly affected.
Rectory Road in Worthing
Flood a23 northbound from mill road #Brighton ! Manual clearance in progress! 😂☔️☔️ flood now clear! pic.twitter.com/pY0wvf90C6
— PC Pete May (@sussexroadscop) August 10, 2018
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