Sewage sanitation. 00:54:26 Now again, this is not a very fashionable thing to talk about. But in the past, especially when a hurricane hits and devastates a town, if you don't get the ability for people to go to the toilet and wash their hands and sanitation disease starts rippling through the area and cripples everything. And it can corrupt food, it can corrupt water. And so it's a system that allows humans to live in dense population areas together safely 00:54:55 and healthily. Now at the moment we have these systems which are citywide, and they use electrical power to push things along. And the problem here is maintenance. This is talking to the complexity issue. How can we maintain such a complex system in a low energy world where we won't have the ease to go out and maintain such things easily? So we have whole sections of the network breaking down, and they'll be really hard to keep going. 00:55:23 So we're going to go from a big system, to a series of localized systems that can connect to each other if they chose, or disconnect if they need to, while one system goes down for maintenance. And again, we're going to have to use technology that may not necessarily use power. What if we used gravity again to try and push all these systems through? And instead of actually using chemicals to treat the water plant, what if we had these 00:55:50 big ponds that used different plants and animals to process human sewage and the bacteria out? In permaculture, there's a lot of discussion about gray water systems and black water systems. Start thinking in those terms, but on a larger scale.

Cities of the future are going to have to be designed to deal with completely invisible flows