Groundwater
The most important aquifer is that of Zeuss-Koutine. It is situated between the mountains in the southwest, the submerging jurassics of the Tadjeras in the south-east, and the fault of Médenine in the north east, and consists in layers of jurassic age. It is sustained by infiltrating water from the wadis Zigzaou, Zeus, and Oum Zessar and the C.I. (Continental Intercalaire). Renewable resources are estimated to 350 l/s with a salinity ranging from 1.5 to 5 g/l. The depth varies between 170 and 680 m. The second one is that of Grès du Trias, extending from Harboub in the south, the zone of Médenine and Metameur in the east, Wadi Hallouf in the north, and the Dahar fault in the west. Fed by the wadis of the plain of El Ababsa, it dwells in formations of the upper Trias. Salinity ranges from 0.9 g/l at El Megarine and 1.5 at Harboub. Actual exploitation is 128.2 l/s, with the renewable resources estimated at 150 l/s. The average depths is about 150 m. The characteristics of the various deep aquifers in the study were summarized by Labiadh (2003). Except, the Jurassic aquifer of Beni Khédache, the pumping rate of the various aquifers is very important. In addition, the salinity is also high. Shallow aquifers are found in the form of limited resources surface aquifers within less than 50 m depth but with high salinity in most of the cases. They are mostly generated by the subsurface underflow of the big wadis (Labiadh, 2003; Ouessar and Yahyaoui, 2006).
