SUMMARY
This study examines the water division in the oases of Garta, Sidi Okba, Thouda and Seriana located on the outskirts of Labiod River. For centuries, these oases have been supplied with water by systems of small dams built along the Labiod River. However, at the beginning of the fifties, these four oases were supplied by the great dam of Foum El Gharza. If today, the technique of collecting water by small dams has been replaced by a large dam, however the traditional water distribution network has not been changed. In the absence of the accelerated siltation, the capacity of the dam with an initial volume of 47 million m3 was reduced to less than 30% of the initial volume. To remedy this problem, boreholes were installed in the oases, which caused the water table to drop.