Tree trunks from the time have been preserved in the marshy conditions that existed at the time and have been revealed as the sea has risen to erode them.

At the end of the last glaciation, 10 000 years ago, the sea level was much lower due to a vast amount of seawater frozen in the ice cap. Submerged tree stumps and bores drilled throught he seabed have shown that the Severn Estuary was a dry river valley. As the ice melted sea levels rose and by 6 000BC much of the present estuary had flooded.

As the rate of sea level rise from meltwater declined it was outpaced by the growth of freshwater peat created in reedswamps. By 3 500BC freshwater wetlands had puched the coastline back at least as far as Brent Knoll and Chedzoy.  

In the Roman period the first sea and river defences were created. Many saltmarsh areas were reclaimed for agriculture and settlement. The coastline was pushed back beyond it's present line just south of Brean. The area south of Brent Knoll remained a saltmarsh where a huge salt making industry was created.

On 30 January 1607 a major flood in the Bristol Channel is believed to have killed around 2,000 people, destroying houses, villages and farmland all along the coast.

Flooding affected Somerset as far inland as Glastonbury, 14 miles from the coast.

Recent research suggests the flood was caused by a tsunami, but other evidence has been put forward to suggest it was caused by a storm surge, with original sources referring to the high spring tide and strong winds from the south west - classic conditions for a storm surge.

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The storm that hit Porlock Weir in 1996 permanently altered the local landscape. Nigel Hester of the National Trust explains in the embedded video on this website the events that led up to the breach of the shingle ridge and the subsequent flooding of the fields behind. The National Trust are the adjascent land owners to Porlock Manor Estate.