|UNDERGROUND CATCHMENT TUNNELS
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Site: Tafilalet region
Description of the local variant of the technique
The Tafilalet is a historical region located in the southeast of Morocco and since 1997 makes up part of the region Meknès-Tafilalet. The region of Tafilalet is primarily a rocky plain where two rivers, the Ziz and Rheris, can be found. The Ziz valley (oued Ziz) extends on a plateau (or Hemada) south of the Atlas Mountains. At the gates of the desert, the area presents a Saharan climate. Most of the khettara are located on the right bank of the Rheris oued between Fezna and Hannabou at an altitude of 800-850 meters. To the west, this area is bordered by a mountainous area called Jbel Ougnate and to the east by a desert area called Marjha. The khettara draw from the groundwater of the Quaternary Period. Groundwater recharge is accelerated by the river Rheris and lower courses of its chain of Anti Atlas tributaries to the north. Only 24 khettara are productive while 45 khettara are dry, particularly in northern part of the region (in Fezna and El Jorf). It can be assumed that irrigation pumping has accelerated the process of abandonment. Khettara production is concentrated mostly in the sourthern part of the area (Monkara, Krair, Bouya and Hannabou). Each khettara has a name and is owned by the ksar for which it flows. At each ksar, one or more khettara are present and they are managed and maintained by the family of the ksar. The khettara are not simple adductive channels of water from a specific origin, or underground wells at the place of use, but they drain, during their linear development, the permeable layers soaked in the water of the inferior flow, and they produce open water. The water circulation is accomplished by using gravity from the beginning of the khettara, through the village, and up to the crops, by exploiting the slight slopes of the land toward the center of the depression. The slope of the khettara tunnel must be sufficient to allow the water flow but kept to a minimum to limit the erosive action that causes the lowering of the clogging of the underground path. Through the centuries, the technique of khettara has allowed for the sedimentation of a rich and complex habitat system. The underground tunnels are detectable on the surface by digging wells and ventilation.
Technique in danger of disappearance.
Number of Khettara: 69
Khettara with water: 24
Total flow: 127 lit/sec
Average flow: 12.8 lit/sec
Total length: 384,403 meters
Average length: 5,571 meters