Development in Very Underdeveloped Areas
Very Basic Water Infrastructure is just three pages. It covers sourcing drinking water to minimize the need for treatment, latrines using wetlands for waste processing and tree urinals.
One of the pages covers using fruit trees as tree urinals. Human urine will not only water the trees but provide some nutrients, so you get more fruit.
You cannot put untreated human urine on crops because it can spread disease, but you can safely eat fruit from fruit trees watered and fertilized with untreated human urine.
In colonial America, recipe books often featured apples as part of dinner. Apples and cabbage were two things you were likely to still have in your cellar at the end of winter, so you would see recipes that contained one or both of them.
You can find recipes online for "apples for dinner," such as this article on allrecipes.com or this piece on insanelygoodrecipes.com. I've written elsewhere about Waldorf Salad and that I once created my own Apple Quiche recipe.
I mention my Apple Quiche recipe because historically in the Roman Empire and Europe, eggs were a primary source of protein and most people ate little meat. Eggs are a more sustainable answer than meat if you have serious privation, so if you can come up with apples from apple trees and eggs, you can develop your own apple-quiche recipe using apples, eggs, some kind of pie shell and whatever other ingredients you can arrange and like including.
I made it for myself regularly for years, so I know you can actually use apples as a staple food in a dish like that. Apples are good for stabilizing blood sugar levels and are generally healthy but they aren't a good source of protein. Dinner dishes featuring apples will need to include ingredients higher in protein, such as eggs, beans, cabbage, nuts, cheese or meat.
It doesn't have to be only fruit trees. It could also be nut trees.
Probably not almonds because they need a lot of water.
But walnuts are in Waldorf Salad and would be a nice addition to apple Quiche and they are the only good vegetarian source of omega three oils that I know of.
Flax is questionable. Greens have them but in tiny amounts.
I will also suggest dates, figs and breadfruit as potential candidates. Ideally, choose local tree varieties that will be sustainable for the area and provide adequate nutrition.
Very basic water infrastructure is critical to improving health. Contaminated water is a source of disease. Modern surgeries have terrible outcomes if you can't keep the wound clean afterwards.
It can also reduce sexual assault associated with open defecation.
R/housingworks has some ideas about what makes for basic, decent housing. Make sure to also check out Adequate Kitchen Facilities, Food Storage and the flair for Yurts.
Round structures are storm resistant AND cost less to build. So one possibility is just build yurts, tree urinals, communal latrines and communal showers and put an unplumbed basin and water vessel in place of a sink.
A basin plus pitcher was standard in American homes before running water was the norm. It's a proven method for having the ability to wash dishes or brush teeth, etc.
In fact, a plumbed sink that LOOKS like a basin sitting atop a dresser is viewed as "an upscale look" because such basins were the norm in upper class homes with servants.
Tree urinals and latrines that use wetlands for waste processing are potentially a means to combat global warming. See Crimson Rose for related info.
We get told we can either save the planet or raise quality of life. I don't believe that's true. I think we can save the planet in part BY raising quality of life for the poorest of the poor.
If you have a village with yards, a few fruit and nut trees per yard is potentially a simple way to determine who owns the food and to provide food security for locals. How many trees and what mix of basic foods would need to be worked out.
Teach locals to dry excess fruit for storage. Come up with recipes using the produce in question as a primary ingredient.
In addition to eggs, you can potentially add other sustainable sources of protein and B vitamins to ensure an adequate diet even without meat. For example snails could add protein and mushrooms can add some of the B vitamins typically gotten from meat.
Eggs do not strictly require refrigeration. They are shelf stable for at least a few days.
Do not store apples with potatoes. It promotes rot.
There are lots of details to be worked out between my general ideas and actual real world application. I think it can work but that doesn't mean it will be easy. Or, you know, it's easy once you figure out the answer. The hard part is figuring it out.
Footnotes
See also Pee on a Tree. You can translate my writing into other languages as long as you cite the source and indicate it's a translation.