Nant y gro

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night crawler

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Jan 25, 2009
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North Berkshire.
The Nant-y-Gro dam was a small masonary dam built across the Nant-y-Gro stream during the construction of the dams and reservoirs in the Elan Valley, Wales.
The dam created a million gallon reservoir which was used to provide water to the navvies village below. It also supplied water to storage tanks used by locomotives, steam cranes and other steam driven machinery.

Once the water works were complete, the Nant-y-Gro dam was no longer needed because the Elan village obtained water from the new water works scheme.

So what has this to do with a military site, a big one for it was here Barns Wallis did an experiment.


Soon as I saw some pictures of the place I had to find it and take some photos, so here are what I took.

This is the Nant Y Gro from across the reservoir, you might just be able to make out part of the old dam on the right.

This is the approach to the dam, take the right fork.

Looking down from above at the tank by the dam, the wall to the right is what is left of the dam.

Information board above the tank, have to take the left hand fork to getto it.

Looking across the busted wall of the dam.

Behind the dam

Looking up at the busted front of the dam wall

Another shot of the busted dam wall. I was on a bit of a time limet here as I lesft my wife in the car back at the visitor center for the Elan dams. It was quite an hard walk to get to alon the side of the reservior and up and down a footpath more like a goat track.
I intend to go back again later this year to have a better look around and look for more of the debris from the damage which mucst have been taken down stream after the initioal explosion.
more here.:)
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Veteran Member
Nov 9, 2006
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Severalls Hospital
Great Report NC. The history of the Dam Busters / Bouncing Bomb is epic.

The Elan Valley Dams are amazing too. Have you ever been to see the Dinorwig Power Station -like something out of a James Bond Set!
Thanks for sharing :)


Veteran Member
Jan 13, 2007
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East Devon's Jurassic Park!
That's a fabulous piece of WW2 history there, night crawler. Really interesting to get the background info and see the remains from the experiments of what is such a well-known story. :)
It looks like a great place to visit too. I totally agree, Lb...the Elan Valley is an amazing place. There used to be the remains of slate quarries nearby too and there's fantastic countryside around the whole area. :)


Regular Member
May 9, 2006
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Forest of Dean
Thats a great report mate:)
I rememeber being taken to the cinema with my Dad and Grandpa to see The Dambusters when I was about 9 or 10 I guess.....started a life long fascination with Lancasters for me!.....I often wondered where this little dam was and what was left of it .........and now I know ! Mucho Cheers !!:)

Also that Dambusters site/link http://www.thedambusters.org.uk
............... is brilliant ...some kind a research went into that ! awesome !
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