From CORDIS:

Objective: Foggaras are traditional systems of water catchment and distribution typical of arid and semiarid areas. They are made up of horizontal underground shafts, which drain water and convey it by gravity to areas where it is needed. The drain age tunnels catch only the quantity of water that can autonomously reproduce and represent a harmonious system of maintaining watertables, which are thus fed through the catchment of humidity and hidden precipitation. As a matter of fact they are considered as real structures of water production. They have been widespread since the 1st millennium B.C. With different names: qanat, khettara, falaj, madjrat or minas. Foggaras are also traditional technologies belonging to the cultural heritage of peoples who safeguard this ancient and clever know-how in any situations. Closely related to the building of mausolea and settlements, they characterize landscapes, which their constructions made fertile.