Qanats

The most important problem in the desert, as we all know, is water. So they had to find a way to bring water to the city, without any kind of modern technology or pumping system.

A passive system "Qanat" is used there. A mother-well was dug in a place far from the city where they could reach to the water table maybe 100 meters underground, they dug other wells to direct water toward the city, with minimum possible gradient. Using the slope of the earth they could bring water close to the surface in the city. It can be seen more clearly in the figure below.

The Quanat's system