A Dynamic Coast indeed

By Sam Scriven

There is no doubt about it, this last winter has been the most active for landslides and rock falls along the Jurassic Coast for many years. Here is a rundown of the things we at the Jurassic Coast Trust are aware of, its likely there have been further impacts that we have not heard about.

* Undercutting of previously vegetated cliff base and damage to concessions on the west side of Budleigh Salterton. Vegetation usually indicates periods of stability and places where erosion is slow. The fact that the sea reaches these places this year is causing concern to some residents there.

* There was a big cliff fall near High Cliff, west of Sidmouth at a scale I have not seen in my time working on the World Heritage Site.

* The usual rock falls and mudflows around Charmouth made the papers.

* At least three significant rock falls between West Bay and Hive Beach.

* Storm Ciaran overtopped East Beach at West Bay and wrecked the seafront at Hive Beach. You may have seen local news reports about a local fundraiser seeking support to reinstate the wheelchair accessible picnic benches there after the originals had been smashed to kindling by the waves.

* A rock fall below Sandsfoot Castle, small by comparison to what we’re used to seeing elsewhere on the Jurassic Coast, but again, occurring in a section that has not failed like that for many years and as a consequence was almost totally covered in thick vegetation. No longer!

* A very large landslide occurred at Black Head, near Osmington Mills. This is an area known for large landslides, but nothing this scale has happened there for the best part of two decades.

* A large rock fall at the back of Lulworth Cove was caught on camera by a visitor. Again, this was the largest there for a number of years, perhaps since the 1950s where a similar collapse was reported in just the same spot.

* Perhaps most surprising of all, Chesil Beach was dissected just before Christmas by the outflow of water from a flooded Burton Mere. The assumption is that the flooding was cased mostly by surface water running off the fields with perhaps some water added by the overtopping of the beach by the sea. In itself, not unusual, but the resultant channel that punctured the beach was around five meters deep and apparently formed within a matter of hours. As far as I can tell in talking to our partners who work along the coast, no one has ever seen anything like it on Chesil before.

So what should we make of all this? Taken individually, none of these events is unusual or unexpected. They all occurred in places where we know rock falls, landslides and floods will occur.

The surprising thing is that they all happened over a single season. Anecdotally, the trend seems to be that the frequency of such events is increasing. That is certainly the case for rock falls along the iconic sandstone cliffs between West Bay and hive Beach. What’s causing it? The question we are asked often these days by journalists is whether it is down to climate change. It is impossible to categorically state that one season of cliff failure and flood events is a result of climate change.

Having said that, current climate change is predicted to cause wetter warmer winters and more storms. These are the main drivers for erosion along the coast, so we can at least say that what we are witnessing is exactly what has been forecast. According to the MET office, 2023 / 2024 was the 8^th wettest winter on record in the UK. It might not have felt like that for anyone waiting for what felt like endless rain to stop. The thing that took me off guard was the sheer amount of surface water everywhere. The ground became so saturated that even roads on hillsides became flooded during downpours. No wonder Burton Mere was filled enough to carve right through Chesil Beach. There was nowhere else for the water to go!

In terms of coastal management, there are plans in place to deal with these kinds of eventualities and, if the rapid appearance of new wheelchair accessible benches at Hive beach is anything to go by, a good deal of energy and good will within communities to respond to the challenges a fierce winter can bring. The talk amongst coastal management specialists is of ‘thresholds’ and ‘triggers’; events or changes that herald the need to adapt the ways we manage or, in time, live along our spectacular coastline. You may have seen stories from other parts of the country where communities are having to retreat from the effects of erosion, or where assets have to be let go in order to establish more sustainable ways of living with nature. The National Trust have been pioneers in this approach, but others are not far behind. Adaptation is the key term, and the pace at which we need to adapt will largely be driven by the pace of climate change and its impacts along our coastline. What this winter may begin to show us is something we have known along, that the ‘trigger’ to adapt will not be gradual. All it might take is one or two bad winters...