Back in the winter of 2012/13 Cheddar Gorge flooded, damaging the road, and had to be closed for several months, until it dried out and the road could be repaired. In order to help prevent further events like that, cavers from the Charterhouse Caving Company Ltd worked in conjunction with the landowners, Somerset Wildlife Trust (SWT), to reopen Longwood Valley Sink (LVS) and clear out the Longwood Swallet main sink. This work was carried out with financial assistance from the Highways Agency, Sedgemoor District Council and Cheddar Caves and Gorge. The work was successful and for the last three winters the sinks have taken all the water.
In the summer months, a digging team led by Ali Moody have been working to extend LVS and now have something over 65m of cave. Their most recent digging trip was last Saturday, 19th November, and that afternoon the main sink was easily coping with the stream. However, on Saturday night, Storm Angus deposited a vast amount of water on the side of the hill and by Sunday morning both sinks had been completely overwhelmed and water was once again flowing out into the Gorge. Eyewitness accounts indicate that there must have been a particularly large flood pulse during the night, which deposited large amounts of silt, rocks, dead leaves and branches everywhere, blocking the grill on Longwood Valley Sink, which ended up under at least a metre of water. The highest levels recorded over the last two days seem to be significantly higher than those seen four years ago.
Nothing could be safely done about this until the water dropped enough to allow anyone to get close enough to the grill to attempt to clear the blockage, but on Tuesday 22nd, Ali Moody and Neil Watson and James Ozolins of SWT managed to clear most of the debris from the grill and, at the moment, the cave is taking all the water once more.
As can be seen from the photo, a significant amount of debris had collected around the LVS entrance, but fortunately it appears that neither the entrance itself nor the retaining walls around it seem to have been damaged by the surge. Doubtless, when the water has dropped enough, there will be similar amounts to be be removed from the main sink, as well.
Although the original work has allowed the sinks to cope with all but the highest surges – the floods in Chew Valley and South Bristol indicate quite how severe this event was – Autumn storms can be particularly difficult owing to the amount of leaf and wood debris lying around. Work at the sinks, in the valley and in the Gorge will no doubt continue for some time.
Correspondent: Graham Mullan