The impact of the Tropical Water Project on the operation of Darbandikhan dam

In addition to global warming and population growth, the Turkish and Iranian water projects have negatively affected the water resources in Iraq. Recently, Iran has implemented its largest water project (The Tropical Water Project – TWP). This project aims to store the flowing water in the Sirwan and Zmkan rivers (i.e., tributaries of the Diyala River) to provide irrigation, domestic, and industrial water for areas inside and outside the Diyala River Basin. The Darbandikhan dam and Halabja water supply project are located on the Diyala River. In this study, the impact of the TWP on the operation of the Darbandikhan dam and Halabja water supply project was investigated. The monthly inflow data of the Darbandikhan dam from September 1991 to December 2017 were used to simulate the operation of the dam using the HEC-ResSim 3.1 package. Two scenarios were adopted for the operation of the Darbandikhan dam. In the first scenario, the Darbandikhan dam operation was simulated without considering the effects of the TWP project.

In contrast, in the second scenario, the full operation of the TWP project was considered. The results revealed that about 48.4% of the power generation capacity would be lost, and the water surface elevation in the reservoir would be affected significantly due to the TWP project. The water surface elevation would be at or below 443 m for long periods, which will affect the operation of the Halabja water supply project.