First, let me explain the situation. Post-apocalypse setting, a group of humans (let's say around a hundred of them) have to find safe places to live at, protected from animals, bandits, and other menaces. They decided on a group of tall buildings (as in the picture), between 12 and 18 stories high. They live on top of them, last few floors. It provides safety, overlook of the surroundings.

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Now, the city is ruined so there is no running water in the waterworks, but, there is a strong spring and a well in between the buildings. There is no city wide electrical grid, and they use generators (but rarely due to fuel consumption) and solar panels, but those are usually spent on lights, preparing food, refrigerators, etc.

Idea is that on the top of the building they have greenhouses to grow veggies for their use. But, veggies and greenhouses need water. And I don't think that rainwater is enough, even if collected for that purpose.

So, the question is, how to get the water from the spring or the well to the top of the building, where, for example, could be a big water reservoir? Or is it somehow possible to hook and reconnect the water pipes of the buildings to the spring instead of city waterworks and get it directly to the faucets?

Several members of the population living there have some knowledge in engineering and construction, theoretical and practical, so it can be done if it doesn't include some ultra complicated work that require some special machinery or conditions.

Is it possible at all without electricity and pumps? If not, I am open to all kinds of suggestions!

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    $\begingroup$ You need to research siege tactics. A castle (that's what each of your towers is) with the water supply outside the walls is a serious risk. $\endgroup$ – RonJohn Mar 5 '18 at 20:11
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    $\begingroup$ How will you get all of the soil up there? You're gonna need at least 500 square meters per person to be able to grow enough food to survive, which is at minimum at least 200 metric tons of soil. Aside from the time it would take to move it by hand, that's going to require a huge amount - years worth - of food due to the extra caloric expenditure from carrying it up the stairs. Sure, once you've got it up there, you can compost to create more, but every pound of compostable material you grow is a pound of food you could've grown, so then you'll need even more farmland. $\endgroup$ – AJMansfield Mar 5 '18 at 20:15
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    $\begingroup$ ˇ@AJMansfield This is just a part of their diet, the greenhouse vegetables. Trade, hunting, scavenging and planting in area between the buildings is the rest. Ive done research of the minimum and maximum of yield in greenhouses and so on. At the moment the water is the issue, actually the transport of it, hence the questions. $\endgroup$ – Bora Mar 5 '18 at 20:31
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    $\begingroup$ Wait, are you seriously asking how you can generate mechanical energy next to a strong running spring? $\endgroup$ – Kevin Mar 6 '18 at 4:16
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    $\begingroup$ Just handwave "collecting rainwater" as being sufficient (which it honestly could be depending on the weather) - it wouldn't be the most implausible aspect.Why would anyone live on the top floors? I can see using the roof as gardening space and stationing a lookout up there, but walking up 12 to 18 flights of stairs every time you go in, especially while hauling in whatever materials you've collected that day, just seems extremely burdensome. Why would people walk up an extra 10~15 floors for negligible benefit compared to living on the 3rd floor? Have you considered just how onerous that is? $\endgroup$ – pluckedkiwi Mar 6 '18 at 20:04

31 Answers 31


How about a no-moving-parts solution? Do it like trees do, with capillary action. Trees manage to lift water from the ground all the way to their tops this way. The leaves evaporate the water, which causes a suction pressure which pulls more water from cells below. Trees are a constant elevator of water.

I can imagine a long rope of some hydrophilic material sucking water out of a reservoir and distributing it up the rope through capillary action. At the top, you spread it out fan-like, and dehumidify it. Collect the water, and the now-drier material will begin to pull more from below. Repeat as needed.

The 'rope' could be an engineered material consisting of thousands of tubules or other structure that maximizes the amount of water to be exchanged.


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