Aztec Fresh Water System
The Ancient Aztecs lived in the middle of a lake but the water was salty so they had to figure out how to get fresh water to them. The Aztecs Built a twin aqueduct system to transport water from a spring called Chapultepec to the city of Tenochtitlan. The reason they built a twin aqueduct was not to transport more water and faster, but to insure that water flow would not be stopped. They only ran one pipe at a time so that if the pipe broke and needed repairs they could divert the water to the other pipe whilst they fixed the broken one. This just shows how smart and how amazing there Engineering was.