When the tribe built Petra, though, they developed a unique system of conduits, dams and cisterns to harvest, store and distribute rainwater for year-round use.
At certain times of year, the area around the city was prone to flooding. However, the Nabateans were able to effectively control these floods using dams and, therefore, the city’s water supply.
This meant that they could reside in the city even during periods of drought. It also improved the crop yields of Nabatean farmers.