Richard O'Connor was working in the Cave Man snack bar in the gorge during the summer of 1968.
On the morning of the flood he remembers it was a hot and humid day and at about midday it started to rain.
He said: "It was the heaviest rain I have ever seen and within minutes the pavements were overflowing and the road had become a minor river. As the afternoon progressed the water on the road became deeper and stones started to wash down."
The Cave Man faced up the gorge and staff became concerned about rocks bashing the door in.
Richard, who now lives in Ireland, said: "My friend Peter and I decided to place an old door outside to buffer the rocks but, in the attempt, Peter was washed away by a wave. He managed to grab a building further down the road and clamber back over the roofs.
"After that the attempt to barricade the door was abandoned."
Large boulders were hurling down from the gorge and the buildings below were been battered by them. The water was a few feet deep by that point and getting faster.
Richard, who was 18 years old at the time, said: "The Cave Man was bounded by a river on one side and the sheer overhanging cliff and by the road, which was now a raging torrent of mud, boulders and water. We were trapped."
Staff spent the night in darkness apart from the flashes of lightening over the cliffs. The downstairs part of the bar was flooded in several feet of water and the people trapped inside became worried about the rocks crashing down on the roof.
Richard said: "My overriding memory of the night was the noise of the boulders grinding around downstairs, the rocks bouncing off the roof and, of course, the constant thunder."
By morning, the rain had stopped but the underground river in Gough's Cave had overflowed and was pouring out of the cave entrance. Richard and his friends managed to escape by climbing over the entrance to the cave and down to the village by climbing over the hillside.
Richard added: "Later we went back to explore the gorge and the devastation was incredible. Huge boulders blocked the road and massive pieces of road were missing.
"As the Cave Man acted as a buffer for the rest of the village, it sustained the worst damage but the sheer volume of the floods was incredible.
"My motorbike had been caught in the storm and was completely buried under water and rubble. I found it because the wing mirror was sticking up out of a pile.
"When I dug it out, it worked on the second kick. That must say something for Japanese technology of the day."
* One person is thought to have died from the floods. Blackford pensioner Ernest Duckett was told to leave his cottage but didn't. His body was found in the churchyard hours later.
* Cheddar, Blackford and Wedmore were the worst affected areas but the floods raged through Locking, Congresbury, Winscombe and Weston.
* Power supplies were only lost for 6mins in Cheddar.
* 15 residents were forced to leave Blackford, but many residents in Cheddar remained trapped in their own homes.
* Cheddar farmer Anthony Cooper lost 25,000 seven-week chicks that drowned when his coops flooded. The farm suffered about £8,000 worth of damage.
* 19,000 telephone lines were out in the district.
* A 14ft water fall raged down Shute Shelve in Axbridge while Blackford was hit by a 13ft wall of rainwater.
How many inches fell? On July 10 alone, Somerset River Authority recorded:
* 5.17ins at Shipham
* 5ins at Winscombe
* 5.6ins at Blagdon
* 3.44ins at Priddy
* In Cheddar, 5.5ins at Kings of Wessex School and 6ins at Cheddar First School.