Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Actually it's the other way around Philip ..... they were not for pumping water, but rather for generating electricity in what is called a Hydro-Electric mode of operation, whereby the latent energy of water stored in reservoirs is run through a turbine to spin the generator. I would guess that there are not that many examples of this form of generation common in the UK, but it is very common here in the US, especially in the western US because elevation of source and gravity is the key.

Ah now that does make sense!!

Yes that form of power generation is uncommon over here but there are still a few examples in the UK. I've been very lucky to visit such a facility in Wales at Dinorwig, aptly named the 'Electric Mountain' many years ago.