(This post is part of my Patreon-supported New Worlds series. And many thanks to my faithful patrons, who have funded two years of New Worlds: with this, we embark upon Year Three! Look for the ebook collection of Year Two in early April . . .)
The Tigris and the Euphrates. The Nile. The Yellow River. The Indus.
If you look at the cradles of early civilization, those cradles are river valleys. This is no coincidence: human beings need fresh water to survive, and our settlement patterns are shaped by where we can most easily obtain that water, for ourselves, our livestock, and our crops. One of the ways to kick a savvy reader out of a story is to stick a major city in the middle of a plain, while a perfectly good river flows unused nearby.
But we haven’t just stuck to riverbanks. So let’s take a look at how we’ve managed our water needs over time.
For hunter-gatherers, the need is minor. Their movements will still be dictated in part by the availability of water, but since their bands tend to be small, a spring or a pond can be enough. When you get to agriculture, though, and large sedentary populations, the demand for water escalates pretty fast. Because humans are lazy and pick the low-hanging fruit first, they tend to start with rivers.
These are the preferred place to settle because they flow, which is good for keeping the water fresh instead of stagnant, and also powers waterwheels or facilitates irrigation. Rivers can carry your waste away instead of leaving it floating nearby — which is nice for you, less nice for your neighbors downstream, but we’ll talk about that next week. In the absence of a convenient river, you can use a lake instead. Many of those are fed by rivers anyway, and putting your city at the mouth is extra good.
If there’s no river feeding it, then you’re looking at a spring . . . and in the desert, oases of that kind may be the only way to support a population. As a result, they become highly contested resources in areas without strong centralized leadership. But many oases are small and refill only slowly after being depleted, so while they might be enough to operate as a caravan pit stop, you can’t build a city on top of them.
For that, you put in some work. If there’s an aquifer close enough to the surface, you can dig wells to extract groundwater; this is how many settlements in a wide range of environments take care of their water needs. If there’s one main well for the town, or several scattered throughout a larger city, those often become social hubs, because everybody needs to go there periodically to collect water for their own use — the predecessor to our modern water cooler and its associated gossip.
But what if the area doesn’t have a good aquifer, or wells are insufficient to supply the settlement’s needs? In those cases, you have to bring the water to you. In modern times we lump all of this under the term “aqueduct,” but strictly speaking that applies to the thing the Romans were famous for: the massive bridges built to carry water across valleys and ravines. Other methods include canals (open to the air) and tunnels (not). All of them require quite a bit of engineering, because it isn’t enough simply to have a channel; you need to make sure the water will flow steadily, by managing the gradient of the watercourse, and take steps to keep it from eroding or clogging up. And if you’re using this for irrigation, you need to dam the flow part of the time and release it at others.
There’s actually a theory in anthropology, now discredited, called the “hydraulic hypothesis,” which speculated that early state-level civilizations arose due to the need to coordinate irrigation and other forms of water control. That might not be the One True Explanation for civilization, but it’s undeniably a major concern; if canals aren’t maintained or one farmer takes all the water for his own fields, you very rapidly have problems. In a certain historical novel by Robert Harris, the main character is a Roman aquarius, responsible for maintaining the tunnels and aqueducts that supply settlements; it’s an important job, and when the water level in a city’s cistern drops abruptly, he embarks on an investigation to discover why. (Spoiler: the title of the novel is Pompeii.)
That gets water to a settlement. Getting it to individual locations requires even more work. Piped water goes back at least to the Minoan civilization in the second millennium BCE, and can be done with clay (Minoans), hollowed elm logs (Tudor Britain), or lead (Rome — not as hazardous as you’ve been, er, led to believe). But infrastructure of any kind is expensive and hard to maintain, and so this is a concept we’ve invented and lost a bunch of times. For many people, luxury wasn’t having water piped into your house; it was having your own well, so your trips with a bucket only required you to go to your backyard, instead of the river or the town well. In some cities you could make a living as a water-carrier, hauling enormous casks around with you and selling the contents to housewives.
The exact approach to the problem of water supply depends on the environment. In the Yucatán Peninsula in Mexico, where the limestone geography means there are almost no rivers, Mayan civilization depended on cenotes: natural sinkholes leading to groundwater pools, generally very pure. Around the Mediterranean and in other semi-arid regions, people have for a long time used cisterns to collect rainwater for later use. In places that get snow in the winter, water is all around; you just have to melt it.
And when it comes to individual survival, there are lots of options, from green bamboo to green coconuts to the milk of camels, who can eat and extract water from plants humans find inedible. If you have a plastic sheet, survival guides can tell you how to build a still that will condense water from the air; you can also get condensation from metal, and the U.S. Army Survival Manual tells me that Aboriginal Australians used to tie tufts of fine, dried grass around their ankles and walk through dew-covered grass before sunrise, stopping to wring out their anklets when they got saturated.
But that’s back to the hunter-gatherer level of water supply. For larger groups, you need more water, or people will die very very fast. Since most of us aren’t writing a novel about the days before the eruption of Vesuvius in 79 A.D., the logistics will rarely take center stage, but they can be there in the background: a traveler admiring a beautifully-constructed aqueduct, a farmer disputing with a neighbor over irrigation, a key bit of news acquired while getting water from the town well.