My NaNo this year is a sequel; the primary action takes place within a city set into a huge waterfall. Thus most of it is perpetually wet (and noisy). The 'road' surfaces are grated to allow the water through, 'houses' are built with noise reducing materials, and there is an elaborate amount of ductwork designed to reclaim the water, to filter the air of moisture, to recycle all waste into energy or usable materials.
In book one, there was extremely limited contact with the outside world, only enough to allow in the hemp grown and harvested by the outsiders, which is in turn used to make plastics, textiles, and an array of other things. For food, fish are caught and raised at the bottom level of the city, artificial protein is lab grown, algae is harvested for food and other uses, and small greenhouses are used to grow other sorts of edibles.
Energy is produced through the burning of waste, solar panels on the top level of the city, and hydro electric from the falling water.
It took a lot of brain cells to put it all together ;)