Just me n Simon again, so with not enough to dig the Chocolate Ice Cream Dig we were forced to make another plan. We decided on having a go at dropping the Pool Chamber Upstream Sump, hoping it would shed some light on where the large passage has formed from.
During last week's trip we shifted a large boulder out of the passage just downstream of the Sump, in the hope that the next flood would shift the sediment behind and below it. The morning after our trip was a big downpoor, and we were surprised that it had actually made quite a difference, dopping the floor upstream of where the boulder was by about 30cm.
So we set about moving all the big boulders that we could up to a distance of about 15m down from the sump. This gives a potential height drop of over a metre, which would be enough to get into the sump and dig out where necessary. This drop could also be increased to over two metres if we go another 10m down from the sump.
2m would also be sufficient to almost completely dry out Angle Chamber Sump, and our theory is that once dry we'll find an upstream passage on the SW side of the sump heading towards (and beyond) Sheepwash Swallet.
Now we just need some big floods to do most of the work.