ELI5 how do water wells work? Why did medieval people know where to build them or why they provided clean drinking water?

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Knowing where isn’t that easy. Throughout history people have dug for water and failed, start over somewhere else. That’s why dowsers made money, that guy with a forked stick who claimed to be able to detect where water was. Either such a person was a complete charlatan, or he was just good at reading the land for water and the stick was his trick to wow the clientele.


You do likely see how rain water will flow on top of the ground and collect in steams and rivers to flow down hill. However some of the water find its way through the grains of dirt instead of just on top of it. Water flows much slower through the dirt then on top of it but it will still flow in a similar way. The water will not be able to flow the same through different layers of dirt and bedrock so the grondwater will often collect in similar streams and rivers under ground. But they tend to be much wider and flow much slower. It can even form huge ground water lakes the size of countries. If you look at a terrain you can often see where the ground water flows. Both based on how the terrain is shaped how the vegitation look like and even the color of the dirt. You would then be able to dig a hole where you expect there to be water and hope to find water there. As for clean drinking water the dirt is usually a very good filter of particles and toxins so the ground water tends to be even cleaner then the surface water.


dig deep enough literally anywhere in the world and you’ll hit water there is water underground in most environments… even the desert… like vast underground lakes. However the best place to dig a well is somewhere where it rains occasionally so that the underground aquifer is replenished by rain water sinking into the ground. If you hit water in a desert and use the well a lot… the aquifer will eventually run dry..


I have water well. In my father back yard. 7 meters deep. I believe they dug it when I was in elementary school. No science in there. You dug a hole deep enough, you found water. Of course the depth will be different in the desert or somewhere with a lot water sources (river, lake, swamp). And the quality of water are different too


Primitive people learned much from observing nature! There are animals that dig for water. We ourselves are animals that have been passing down this type of knowledge.