德拉河
Forty years after these first migrations, Seguia el-Hamra Mehdi Ben Youssef (descendant of Beniabbes of the Beni Hassan tribe) came to Béni Abbès. He lived with Ali Ben Moumen from the Arib tribe, with whom he brought the palm trees of Draa River. They founded the ksar "Oulad Mehdi" in which Mehdi Ben Youssef's sons (Said and Youssef) and Ali Ben Moumen's son (Mohamed) lived. The region was peaceful and prosperous through agriculture and trade, bringing a large number of immigrants.