22. What has caused the most recent erosion at East Beach? Do you expect it to return to normal historic rates?
The current period of rapid cliff recession and low beach levels is indicated to have begun in the late 1980s/early 1990s. While this is broadly coincident with construction of the offshore breakwaters and rock groynes on Sidmouth beach, other periods of low beach and rapid cliff loss have occurred previously, with several large cliff failures shown at Pennington Point and along East Cliff in the past.
This evidence suggests that the cause of cliff recession seen in recent years is not related to the breakwaters, and is more likely to be a function of several factors including:
- Low beach levels due to persistent South-Westerly storms
- Particularly wet weather since 2000,
- Erosion along the more vulnerable bedrock joints
- Erosion of a greater thickness of weak sediments capping the cliffs at Pennington Point
- Erosion of a 19th Century railway tunnel excavated along the base of the cliffs, with the entrance believed to have been eroded in the 1990s
Over the longer term, erosion rates are expected to return to the lower historic rate but given the large uncertainties over the geology as well as future storms and climate conditions, it is very difficult to predict when this might be.