Too many #fantasy settings don't put enough thought into the infrastructure of mining. If you have some really big mines - which are popular with fantasy settings for good reasons! - then you need something to power the pulleys, lifts, and (most importantly) the pumps if the mines are in a region with significant amounts of groundwater. Because these mines will be wet by default.
Of course, you could go Steampunk or even Magitech, and use steam power or magical enchantments to power all this infrastructure. But a real world alternative which has been used in the Harz Mountains for centuries is - water power! Yes, that's right, you use water to pump more water out of the mines!
But the thing is, this is going to leave massive marks on the landscape. The Upper Harz has a vast system of ditches and reservoirs created over the centuries which ensured that there was always enough water available to power the mines, and the water always went where it needed to go (and parts of it are still used for electricity generation to this day).
So... if there are some dwarven, goblin, kobold or whatever mines in some nearby mountains, the first clue towards their existence might be some artificial barrier lakes and ditches that channel the flow of water to the mines - and some outflows from the mines as well, carrying the (no doubt toxic) waste with them.
What will be the effect on the human or elven communities downriver? Well, they might not be happy about it - though perhaps the ability to trade with the mines is more important for the local rulers. And such conflicting interests are, of course, great story material...
#ttrpg #dnd
https://en.wikipedia.org/wiki/Upper_Harz_Water_Regale
This is a good #WorldBuilding idea.