Someone recently pointed out to me what should have been obvious - the first question in regards to a settlement's location is 'Where go people get water?'. Was all water taken from streams?
If so, does anyone know if this is true for all people in medieval Europe? I've seen some water-transport in a museum in Krawków, Poland, but it only ran through a city and it was pretty primitive. I'm also not sure how old it was - perhaps some centuries, so it wouldn't apply to worlds similar to old Europe.
Was there ever more advanced irrigation? I've heard of Greek-style city irrigation (because apparently the Greeks invented everything), but again, only inside a city - never from a mountain to an area without a stream.
If a well dried up, did the entire associated village/town/city just pack up and fuck off overnight? Where on earth did they go?
Did any civilisation know how to get water through anything else? Bogs, stagnant lakes, the sea, collecting rainwater? I'm primarily interested in medieval Europe, but would love to know if any other civilisations had some tricks which were later lost.
I'm asking as I create fictional, low-technology worlds, and I want to know if every settlement I place on the maps must relate to a water-route, without exception.
Is every route in every country within a day's march of a stream? Did people, even in soggy Britain, ever decline a short path from A to B because there was no water in the middle?
Many thanks for all comments and answers.
Archaeologists often find proximity to watercourses a very useful predicator of where sites (of any period) can be found, because having access to large amounts of water that you don't have to carry very far is always handy. But no, as far as I'm away being near a stream has never been an absolute requirement for people in any period of European history. There are too many other things to consider when choosing a settlement, and you can get water from springs, wells or aqueducts if you don't have ready access to a stream (or carry it with you if you're travelling). I'll give a couple random examples from my own experience to illustrate the point.
Where I'm from, in upland northern England, it's admittedly kind of hard to find anywhere that isn't within a long walk' of some sort of stream (like you said, it's soggy), but there's no particular preference for them in where settlements (most of which date to the early middle ages) are located. Historically our economy was based on sheep herding, so it was more important to be closer to pastureland, i.e. halfway up the sides of hills, than water. The oldest routes between settlements also deliberately avoided water, even when following a stream along the valley floor was the most direct route, because going over hills is more convenient when herding sheep and the marshy valley floors were unhealthy and difficult to traverse. It wasn't until the 18th century that they were drained and people could build roads on them.
Similarly, I once helped excavate a rainwater cistern on a Late Roman/Byzantine fortified settlement in Bulgaria which was situated on a mountaintop and connected to neighbouring sites via herding routes running along mountain ridges. The thing was huge and had been extended multiple times – obviously getting water up there was tricky. But the people who used it were living in tumultuous times, and having a secure place with ready access to pastureland (herding is much more barbarian-proof than arable agriculture) was more important.
Now, the idea that large settlements always had to be near streams might have more to recommend it. You can only provision so many people from a spring or a well, and uplands were never been the most populous areas of Europe. Almost all European capitals are on major rivers, because they provide lots of drinking water for lots of people, and because they're usually lucrative trade routes. Large settlements in Neolithic Europe were also invariably located on river terraces. True, when ancient cities outgrew their water supplies, there was the possibility of engineering a solution using aqueducts or something. But situations like that were the exception. Generally the rule was that a smallish settlement could probably get by just about anywhere, and so transporting water was rarely worth it, but a major one would need access to a large amount of running water.