In Little Neath River Cave today, on the way through the canal bypass to sump 2, we met an outdoor pursuits group who'd had a look at sump 1 and reported that it was low, with a chance that a light might be visible through it. On our way out we detoured to look at sump 1 and it is indeed low, with 8 to 10m of diving line exposed and air space extending a further 8 to 10m. This is presumably the result of the ten days to two weeks of mostly dry weather we've had.
With the mostly dry weather is set to continue well into next week, it is possible that by next weekend the water level may be even lower. If anyone is intending to visit the Little Neath River Cave or Bridge Cave in the near future, it might be interesting to check the level of sump 1. It would be really interesting if two parties could coordinate a visit to both sides of the sump and see whether a light might be visible through the sump in its present low state.
I'm aware that there have been previous reports of sump 1 being low and I think that an air space has exceptionally been reported. But this is October, not high summer!
Possibly one reason for the level drop might be erosion of the south west side of the downstream bank of stones and gravel which looked to me as though a distinct trench had appeared. But this is on the basis of a few very infrequent visits - so I could well be wrong and the trench is a long term feature.
With the mostly dry weather is set to continue well into next week, it is possible that by next weekend the water level may be even lower. If anyone is intending to visit the Little Neath River Cave or Bridge Cave in the near future, it might be interesting to check the level of sump 1. It would be really interesting if two parties could coordinate a visit to both sides of the sump and see whether a light might be visible through the sump in its present low state.
I'm aware that there have been previous reports of sump 1 being low and I think that an air space has exceptionally been reported. But this is October, not high summer!
Possibly one reason for the level drop might be erosion of the south west side of the downstream bank of stones and gravel which looked to me as though a distinct trench had appeared. But this is on the basis of a few very infrequent visits - so I could well be wrong and the trench is a long term feature.