INCREDIBLE VIDEO: Waterfall down stairs as flash flood hits

CARS have been submerged in the car park of a building in the heart of Byron Bay.

Steve Harris manages the Fletcher St building which is home to 11 shops and five apartments.

Mr Harris said all of the shops were impacted by flood water.

Flooding at Fletcher St building: A waterfall of water flows down a staircase at a building in Fletcher St, Byron Bay.
Flooding at Fletcher St building: A waterfall of water flows down a staircase at a building in Fletcher St, Byron Bay.

The underground car park has been severely flooded.

Mr Harris said they'd seen nothing like it in the 20 years the building had been there.

"It's never come this far," he said.

Mr Harris said about 3 or 4am he became concerned and went to grab towels to place under the doorways.

But when he returned with them, there was two inches of water inside.

The stairwell to the basement car park was like a waterfall soon afterwards.

Flooding in a Byron Bay carpark.
Flooding in a Byron Bay carpark. Liana Boss

"It came up so quickly," he said.

"I was like: 'this is serious'.

"I was just trying to lift everything up from the ground.

"It's not like it was a dam bursting; it was just this rise of water that just happened so quickly."

Mr Harris said he was concerned the drains in the town hadn't been properly maintained.

"The drains are a real problem," he said.

Also problematic was motorists driving through the flood waters which have now mostly subsided from the street.

The force of water being displaced by vehicles was enough to force open the doors of one of the shops in his building.

Floodwater in Byron Bay: The CBD is full of water after 250mm of rain fell.
Floodwater in Byron Bay: The CBD is full of water after 250mm of rain fell.

Byron Bay Property Sales co-owner Jeremy Bennett said the flooding was far worse than the inundation brought about by ex-Tropical Cyclone Debbie in 2017.

He said 25cm of water went throughout their Lawson St office, damaging computers, filing cabinets and furniture.

The flood three years ago didn't come close to that level, he said.

"The water was through the whole place, that was about seven o'clock this morning," he said.

Staff were busy this morning removing damaged goods from the office.

Mr Bennett said the water left the building about 10am.

Byron Bay inundated by water after heavy downpour: The centre of Byron Bay has been inundated with floodwater after the region copped heavy rain over the past day.
Byron Bay inundated by water after heavy downpour: The centre of Byron Bay has been inundated with floodwater after the region copped heavy rain over the past day.

Goy Kingkeaw, from Success Thai Food, said they had been preparing to re-open the restaurant after being closed for a holiday when the flood hit.

She said some water and debris had come toward the door of the restaurant, which is across the street from Mr Bennett's real estate office.

Mostly, the building's raised positioning protected it.

But she said cars driving through the flood water had, however, pushed it further up the pavement.

It's understood cars driving through water in the area around Shirley St have been causing, or risking, additional damage to property because of the water displaced through their movements.