a curiosity I wonder if anyone else has come across.

Somewhere I'm pushing further and further into. one particular sub level, getting down towards a point where every thing below is flooded, and I am maybe 3/4 of a mile in. The water level can rise and fall quite a bit over a few days. This is over a period where there has been no rainfall at all. half hours drizzle in 10 days is about. Water went from waist deep the neck deep then back down again and then back up again over the course of about 6 days.

I'm baffled

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Build up, something giving way, drain, end of drain causing partial blockage with muck, build up - pressure, pop, drain?

I've seen things like that, but over a much longer period, always with something giving way and then blocking again.

When you say, everything below is flooded, is that just a small amount of working / level or is there loads of workings and levels below the flooded bit, if so the water level can shift dramatically with the water table level fluctuating.

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Long shot..Auto syphon?

Lozz.

The deeper water table may be less influenced by rainfall and more by underground movement through submerged passage - I guess it depends what sort of rock you're in? Main Rising, Bathing Pool and Whirlpool in the Speedwell system in Castleton all fluctuate dramatically with respect to each other, and not always in periods of rainfall.

I was in there last week, and the water-level in the main streamway dropped by a foot in a few hours - there's a lot of pulsing inherent in the system, so it may have been the earlier depth was 'high' and it was settling back. So your case may be caused (like Main Rising) by silt buildup that's eventually released, causing a pulse for a while, and then blocking again. It may be something as daft as an old plank or gate somewhere causing a temporary dam until it swings open, releasing the water - like a giant flopjack.

Deeper voids not directly connected to the flow would also act as overflow reservoirs, so outgoing water might then stop flowing for a while until they've filled up, to continue back along the original level.

it's vast down below. the very bottom (200ft down) level is about 3 miles end to end, levels and stopes and flats from there all the way up to above the water

only thing that has changed, is that I dug out a stope up above that was blocked at one end and waist deep in water/mud, essentially to see if I could progress onwards via the stopes on that horizon.

Obviously the water dissapeared down over and that stope is still dry, but was a fraction of the length of the one that is rising and falling.

before I dug that stope, the water never really changed. Just to confuse matters more, It's flooded throughout from 70 or 80 foot down, but... the main shaft is flooded to the collar. I'm guessing a fall or blockage in the shaft back over is keeping that at bay. I've had all sorts of bonkers ideas about some huge boulder or something getting shoved out of the way by water pressure, then rolling back or something.

There are (according to plans) air doors in various places, and have wondered if they could somehow be magically opening closing?

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I remember years ago visiting the WW1 tunnels at Vimy Ridge; the guide explained to us that because of the chalk geology, that it would rain on surface and then rain again in the tunnels a day or so later!

Mark

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Any industry in the area that could be drawing from the aquifer? (Even farming for irrigation)?

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Any industry in the area that could be drawing from the aquifer? (Even farming for irrigation)?

not a bit. high in the hills, miles from anything apart from sheep

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Maybe it's these keen caver types that are digging sinks and diverting streams in these parts atm :lol:
ask mr Coult where he's been lately.........

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anything's a possibility! but if his spadework has made a connection from over there to over here then thats a very very very long hole

:thumbup:

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OK, so that leaves maybe the possibility of an auto-syphon, the water has got to go somewhere, so are there any fluctuating resurgences (springs, soughs, etc.) in the catchment?
This does not just mean the obvious 'Ebbing and flowing wells', but noticeable variations in flow from other underground water outlets, I think the time issue is significant, maybe look at any water flow data for where the water comes out?.

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Natural caves can have very interesting water fluctuations. Can't find a reference at the moment, but read about Speedwell and Peak cavern and the connecting caves and mines.(I'm assuming that you are in the Great Limestone?).

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yes I am in the great limestone

It's a conundrum. Spotted something this evening on the way home that may be connected. This place runs NE/SW UNDER the village. There's a much older mine that I've seen one plan of that suggests a connection that runs NW/SE. There's a point up stream where old stope collapses in the ancient workings of the other mine are right against the river, and the river occasionally runs in there. Big pile of rocks there at the moment so someone maybe damming/undamming the bit where the river runs in. Potentially could be responsible. Horizon of the old mine is about right below ground.

Still puzzles me where the water is getting back out though. There are references in a few places of a cross cut/trial to red vein from this place which is lower down so that's a maybe.

Gonna wait for a big downpour when I know the river will break into the stope collapses then have a shufty to see if it's gone back up again.

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See the doc I have uploaded into the Boltsburn Mine file. this may help.

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See the doc I have uploaded into the Boltsburn Mine file. this may help.

Thanks pete, Interesting one that, not seen that before. that almost horizontal line above lintzgarth shaft is Mary's Vein. I have a plan of that which shows it worked much further east and west, meeting up with the old west level (and a few really old ones as well), which in turn had shafts to the undercut of the east level which connect boltsburn east and west in one continuous run. East of Lintzgarth Shafts is where there are obvious collapses on Mary's Vein that the river runs into now and again, so potentially it's coming from there to where I am. A completely new adit to either Mary's or Boltsburn Veins (possibly both and predating the railway) revealed itself recently and is getting a little pick and shovel attention too

One full plan I have shows a connection right under the village with red vein and old west level, connecting to workings at stotsfield, which ran as far as thorny brow, so potentially thats what's keeps the water down if its finding its way out all the way down there. There's an ancient and totally run in adit below thorny brow that has become very wet this last few years, which could be whats keeping water down as low as it is in the east end. there's about the right drop in elevation

What's more interesting on that drawing is it shows a couple of spurs off the main east end that aren't on any of the plans I've got (dunhams and beaumonts) and that I've been into and wondered where the hell I was, but also wonder what they based that drawing on.

Sometimes wonder what this village is floating on to keep above ground!

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just uploaded a plan that might make my ramblings above make a little more sense

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Where is this water guys ?

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Where is this water guys ?

Rookhope

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