Quantitative Analysis and Efficiency Assessment of Floodwater Harvesting System in Arid Region: Case of Touzouz ephemeral stream—Mzab Valley

Abstract

The Mzab Valley is characterized by an arid climate with limited amounts of rainfall. In the context of water scarcity, the Mzab water management system recovers floodwater for irrigation and shallow aquifer recharge during rainy periods to allow its use during dry periods. The Touzouz wadi is one of the tributaries of the Mzab Valley. A part of the Mzab water management system is designed on this wadi to capture floodwater. This study aims to evaluate The Touzouz floodwater harvesting system (TFHS) in floodwater recovery. The Evaluation is performed by simulating the TFHS response to several floods with variable return periods and for three system functioning modes. Obtained results show that the system delivers better efficiency in floodwater harvesting when the channels and infiltration basin work simultaneously, as designed initially. TFHS reaches the efficiency of 100% for return periods of 2, 5 and 10 years and 85% for 20 years. The study confirms the efficiency of the system on harvesting and regulating floodwater to take advantage from intermittent flows of Touzouz stream for palm grove irrigation and aquifer recharge.