Runoff and Sediment Load from the Right Bank Valleys of Mosul Dam Reservoir

Abstract

Mosul Dam is a Multipurpose Project on the River Tigris in Iraq with 11.11 billion m 3 storage capacity. It is used to store the water for irrigation, hydropower generation, and flood control. As in other dams in the world, this dam also have sedimentation problem. Sediment accumulation in its reservoir can effect the dam operation (pumping station, hydropower plants, and bottom outlets) and it will definitely shorten the life span of the dam. In this study, the SWAT (soil and water assessment tool) under GIS (Geographical Information System) was applied to simulate the yearly surface runoff and sediment load for the main three valleys on the right bank of Mosul Dam Reservoir. The simulation considered for the twenty one years begin from the dam operation in 1988 to 2008. The resultant values of the average annual sediment load are 35.6×10 3 , 4.9×10 3 , and 2.2×10 3 ton, while the average values of sediment concentration are 1.73, 1.65, and 2.73 kg/m 3 for the considered valleys one, two and three respectively. This implies that significant sediment load enters the reservoir from these valleys. To minimize the sediment load entering the reservoir, a check dam is to be constructed in suitable sites especially for valley one. The check dam can store the runoff water and trap the sediment load, and then the flow can be released to the reservoir.