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Movement of pebbles at Caswell

The storms last winter resulted in significant beach and foreshore damage across much of Swansea's coastline.

In particular, Caswell suffered significant damage to its main promenade area, which required several thousands of pounds of investment to ensure that the damage was rectified and that Caswell maintained its Blue Flag status.

In order to ensure that the main beach remained accessible and to prevent further damage, the stones that had washed up onto the main promenade and steps at Caswell were cleared and relocated to the western side of the beach.  This is the general area in which the stones were located before the storms occurred and have accumulated over many years.

The storms resulted in a significant increase in the extent of exposed rock and pebbles on all areas of Caswell, but most notably in the western part of the bay in front of the Redcliff Apartments. It is estimated that the amount of material relocated by the Council was approximately 40-50m3, which is a relatively small quantity of material, considering that there is now 1500m3 rock / pebbles exposed on the western side of the bay.

Beach study by Professor Kenneth Pye

As part of the Council's ongoing beach management responsibilities, we commissioned a study to understand what may have caused this change and whether the Council could effectively intervene to aid beach recovery. The studies were carried out by Professor Kenneth Pye, who provides specialist advice on coastal, estuary and marine environments.  

Read the full report from July 2014 here:

PDF Document Caswell Bay study July 2014 (PDF, 2MB)Opens new window

The follow up report from August 2014:

PDF Document Follow up report August 2014 (PDF, 1MB)Opens new window

Sand movement

The studies have indicated that the storms which occurred during the winter and also stormy periods in April and May have resulted in significant beach erosion.  Consequently as there has been progressive movement of sand around the bay and this has resulted in the sand being moved from the relatively higher areas towards the lower parts of the beach. Progressively this has exposed larger areas of rock and gravel on the beach which have been there for many years and the majority of the rock and pebbles now exposed are much larger than the material relocated accross the beach by the Council.

The report determined that the increase in rock and pebble exposure seen since April would have occurred with or without the relocation of material by the Council and our actions have had no significant effect on the general trend of the beach lowering.  The topographical survey shows that beach levels at Caswell are now lower than any time since 1999.

Recommendations

The study concludes that there would be no benefit of removing the pebbles which are now exposed on the Redcliff side of the beach and importantly it is considered that such action would further lower beach levels.  It is likely that such action would result in further pebbles becoming exposed and the pebble beach cusps which have now formed are providing wave protection to the strip of sand on this part of the beach, removal of this would not be beneficial.  

It has been further recommended that if there is further accumulation of stones in front of the main promenade steps resulting in a requirement to remove them, the best place to relocate this material would be the lower to mid cobble storm beach on the Redcliff side of the bay.  If this material was to be removed to landfill, it would become permanently lost from Caswell's sediment system and therefore it should be retained where possible.  Previous studies have shown that there have been periods of similar beach lowering at Caswell Bay and this has been followed by recovery as sand has moved back onshore during periods of constructive swell waves, but this may take some time.

Whilst the topographical changes at Caswell are unfortunate, we must recognise that the beaches are natural environments which are subject to significant changes and are effected by tidal and climatic conditions.  As a Council, we will be monitoring the situation carefully over the next few months, but by utilising expert advice we feel that we have thoroughly investigated and appraised the situation.

The storms January/February 2014 has also affected the beach levels at the adjoining bays at Pwll Du and Langland, with both environments having experienced sand winnowing and exposed gravel lag deposits. This is further evidence that the primary cause of the observed changes was the storm wave climate in this period.

Considering all the facts and following the expert advice we will follow the recommendation not remove any material from the beach and to allow the beach to recover naturally.

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