The residents were furious. Who would insure them now? How could they sell their house? Who would compensate them? How could the cliffs be protected? But who should pay? The residents chose to buy /or build their house there. Is it their liability?
Where
is It? What was it Like? Barton-on-Sea
is about 20 kms east of Bournemouth on the south coast of England - in the
county of Hampshire.
For years Barton-on-Sea was a pretty coastal settlement. Houses and hotels were built on the cliff tops overlooking the beach. Then in the 1970s the beach disappeared. The waves attacked and undercut the cliffs which collapsed. The houses were going to be destroyed.
The people could not get house insurance and who should pay for cliff defences to be built? Coastal defences were built to protect the cliffs but the winter storms smashed these.
What on earth had gone wrong?
On the more detailed map opposite you can see the red star which marks the massive groyne that was built at Hengistbury Head near Bounemouth to stop the process of longshore drift. This was done in the 1930s to make sure the holiday resort of Bournemouth kept a large sandy beach for holiday makers to lie on.
Unfortunately, the groyne ( a wooden fence) at right angles to the beach stopped longshore drift. So pebbles and sand built up at the groyne. They stopped moving along the coast to Barton. Meanwhile th beach at Barton was moving by longshore drift even further east. So gradually Barton lost its beach.
The winter storms whipped up waves that moved in and undercut the soft rock cliffs at Barton. They became unstable.
At Barton the cliffs were soft rocks with sand on top of clays. In heavy rain the clays became waterlogged and tended to give landslips.
When the beach disappeared the waves were able to undercut the base of the cliffs through the processes of hydraulic action and corrasion. Undercutting of the clay made landslips even more frequent. Rapid coastal erosion began.
The sea moved in and smashed the groynes and broke the early sea defences.
Eventually the government agreed to spend a lot of money on coastal defences to try and save expensive cliff top property. Large gabions (metal mesh crates filled with boulders) were dropped along the shore as well as vertical metal poles to hold them in place.
These defences were designed to protect the base of the cliffs so that the undercutting and retreat would stop.
Th lesson learned was that if humans interfere with one part of a coastline there are knock on effects in other places. So the message is to manage whole stretches of coastline as one unit.
Page assembled by Mr. N