Storms and shifting sands – assessing the ocean’s impact on Start Bay
Researchers from the University have conducted monthly surveys of the South Devon coastline for the past two decades
Start Bay is a closed sediment cell, meaning there’s no sand or gravel coming in from outside and no sediment is leaving the bay. It is subjected to southerly waves from the Atlantic Ocean and easterly waves from across the Channel, which means sediment is regularly pushed from Torcross to Strete, and from Strete to Torcross, respectively.
Professor Gerd Masselink
Professor of Coastal Geomorphology
“I visited Slapton Sands for the first time in 2004, and the beach was almost at the top of the sea wall. Now it is more than 5 metres lower, and the storms we’ve just experienced led to it dropping around 2m in the space of a month. Most years, changes in the wave direction will see that rebalanced, but our research is suggesting that over the past two decades at least, southerly waves have removed more gravel from the beach in front of the seawall, than the easterly waves returned.”
“This increase in storm impacts has come at a time when sea levels are constantly rising having already gone up by around 25cm in the past 110 years. That is not something which is likely to change, and it means communities like Torcross are facing a battle on two fronts. Sea-level rise increases the impact of storms, as it enables storm waves to reach higher up the beach – and as more of the beach erodes, the waves come closer to the shore and cause more damage when they get there.”
The series of storms we had in January has once again shown those defences are extremely vulnerable – and when they fail, they take the road with them. Rebuilding the defences and road every time a storm hits is unlikely to be sustainable in the long term, particularly when you take future sea levels into account. Any decisions made are going to be difficult as there is an important human dimension, but decisions need to take the scientific evidence into account to ensure we’re not repeatedly facing this sort of situation in the years and decades to come.