NYC's water system is one of the most complexly simple in the world
The Simple Genius of NYC’s Water Supply System
"New York is a water-scarce city. Despite being surrounded on all sides by waterways and located in one of the rainier regions of America, the landscape upon which it was built lacks a significant supply of fresh water."
To solve that problem, the City has built a system that supplies distant mainland freshwater using unexpected simplicity. "It lets nature do the work of gathering and purifying, then uses just two tunnels and physics to transport it to the City.... New York City had foresight—the ability to recognize that future stability, growth, and success all revolved around the task, simultaneously simple and complex, of getting good water."