[LOTR] How does the plumbing work in an underground Dwarven Kingdom?

Ahh, that's a great question. Ancient Dwarven cities were renouned for their ingenious and efficient plumbing systems in their massive underground cities. They did not have modern plumbing as you or I would today where water is always on demand and our waste is magically whisked away but their cities were designed for utility and nothing went to waste.

Most ancient dwarven cities were built around plentiful supplies of fresh and clean water. Like the City of Erebor you mentioned or in Moria fed by an enormous underground reservoir deep within the mountain. The shape of the city largely mimicked the path of this water throughout the mountain. Cities would generally start at a point of surface water and as they expanded into the deep new "urban" areas were placed near readily accessible water supply because most caves for Dwarven families wouldn't have their own water supply. The true water supply challenge in a Dwarven mine was in how to supply water to cool and feed the mines. Dwarves would place perfectly sized

/r/AskScienceFiction Thread