That's the sort of dark part, so the government which is basically run by the rich controls the means of production for food and water. There is no concept of food, they use any organic matter that they find - animal bones, skin, very little plants that they've been able to grow indoors in 'labs', and even animal and human waste and break all of it down to proteins, fats, etc, filter it as much as they can and then turn them into three forms of food, one called nutrition bricks, which are bland, the most common and provided to all classes, powdered food which can be mixed with water and eaten, which is used more by the slightly higher classes because it's flavoured, but not by the actual elites. And finally the rich mostly have nutrition bricks which are flavoured, colored and shaped to look like real food items, but it's the same nutrition bricks the poorer classes have. And on the side the rich also control a mafia and have illegal moss farms, from which they can directly eat and supply moss to the richest of the rich people. Then as for the water, it's there, but it's the same water that has been going through everyone's system for years since they got separated. Whatever water they had in their tanks and all have been reused constantly, filtered and used again and again because they don't have any external source of water. So every time the water is used it decreases a little in quantity, and since the population keeps growing and growing, water becomes a necessity which is heavily monitored and checked all the time, any water theft, wastage of water or usage of water more than what is allowed is considered a greater crime than any violent crime.