Kingsdale bore

[mrodoc]

It is sobering to see the effects of a serious downpour. I was once coming back through Spain and it started to rain. The motorway to France was closed and when we turned to go back a landslide had blocked the road we had driven down (3m of mud and boulders over 100m). We had an unpleasant night in a leaky Landrover and when I clambered out in the morning the previous dry flood channel below (think Los Angeles storm channels) had lorries and gigantic paperbales bouncing down it in 6m deep water. Power out etc etc. Fortunately the way to the motorway was open again so we got out but the town of Bilbao looked like a disaster area.

 

[Pony]

Nidd does have two. Firstly when the Manchester Hole sinks are beyond capacity and then flow on to Goyden, seen it myself. And secondly when Goyden fills and then flows onto New Goyden and beyond. I've not seen that one actually happen but have seen jets of spray, like a whale breathing coming out of the Back Steps entrance area as Goyden filled.
Come to think of it there should be a a third as New Goyden resurges when the surface river isn't flowing. @Goydenman might of seen them.

 

[mikem]

The effect is caused by water at the edges & bottom being slowed down by drag on the ground whilst that in the middle flows over the top of it, thus itself being slowed, so more water catches up from behind (tidal bores like the Severn do the same) - it's just more pronounced in a dry river bed.

[& rapids are faster, the turbulence being caused by a restriction reducing the cross section, so it has to speed up to maintain the same volume per second.]

 

[Fulk]

I loved the 'One in a billion moments captured on camera'; it must happen several times a year.

 

[Goydenman]

Nidd does have two. Firstly when the Manchester Hole sinks are beyond capacity and then flow on to Goyden, seen it myself. And secondly when Goyden fills and then flows onto New Goyden and beyond. I've not seen that one actually happen but have seen jets of spray, like a whale breathing coming out of the Back Steps entrance area as Goyden filled.
Come to think of it there should be a a third as New Goyden resurges when the surface river isn't flowing. @Goydenman might of seen them.

Yes I too have seen the one entering Goyden several times but like you @Pony never seen the one go past Goyden. But I have seen twice the one that goes beyond New Goyden including the huge mushroom of water exiting New Goyden and Thrope entrance

 

[Goydenman]

In Nidderdale there is also the bore caused by the regular dam releases

 

[Pony]

In Nidderdale there is also the bore caused by the regular dam releases

Not forgetting from wind blowing out of the reservoir and also, when the level is down Woogill can form one on it's own.

 

[richardg]

The River Greta up near Bowes in the Northern Dales and the River Aygill near Brough
The famous once or twice in a lifetime Malham, Down Watlows Valley and over the Cove.....

 

[Allan]

In the mid 1980's I saw the Manifold Bore, we had been digging in the stream bed when we heard a "shushing sound", this was the water flowing over the dry riverbed and pushing through the Wild Rhubarb. Even when we still couldn't see the flowing water the river bed was resurging with pressure domes in several places, indicating that the caves were already full. The pressure domes continued even when the river was flowing round them.
It was a sobering experience, there had been no rain in the area we were in.

 

[Emsy]

Quite a few years ago I was lucky enough to witness the Chapel Beck bore at close hand (Chapel le Dale). It arrived without warning (other than the "shushing sound" described above), a split second after my fellow cave-diver submerged to check out the flow in the underwater cave.
The cave water levels were high & silently rising when we arrived, but the beck was still dry. When they re-emerged after a few minutes they got swept downstream for twenty metres or so. Quite alarming at the time.

 

[alexchien]

I surfaced once from Joint Hole directly into the path of a passing Chaple-le-Dale bore. I was worried I may get washed down into Aquaflash Pot, or over Gods Bridge, but managed to drag/float my way to the side of the beck, and grab some turf !
Witnessed by two amused fellow divers.
Yes, it was very wet when I tried to get into Joint, so strong was the flow coming out of the cave, that I couldn't get far.

Ah the previous post has beaten me to this story...........