levels they are flooding to are significantly higher than in past floods.
There have been lots in the past, here are just a couple....
The great flood 1607.
Floods resulted in the drowning of an estimated 2,000 or more people, with houses and villages swept away, an estimated 200 square miles (51,800 ha) of farmland inundated and livestock destroyed,[2] wrecking the local economy along the coasts of the Bristol Channel and Severn Estuary.
https://en.wikipedia.org/wiki/Bristol_Channel_floods,_1607
The coasts of Devon and the Somerset Levels as far inland as Glastonbury Tor, 14 miles (23 km) from the coast, were also affected. The sea wall at Burnham-on-Sea gave way,[3] and the water flowed over the low lying levels and moors.
Lynmouth Flood 1952.
The root cause of the flood was heavy rainfall associated with a low-pressure area that had formed over the Atlantic Ocean some days earlier.[3] As the low passed the British Isles, it manifested as a weather front which caused exceptionally heavy rainfall,
https://en.wikipedia.org/wiki/Lynmouth_Flood