Operation of the Iraqi Part of Al-Huweizah Marsh

Al-Huweizah Marsh is considered as the largest in Iraq. This research aims to maintain thesustainability of Al-Huweizah Marsh under all circumstances and within the limits of the available natural resources from the Iraqi side and the absence of feeding from the Iranian sidedue to the recent Iranian separation dike along the international boundaries within the marsh. Twelve scenarios have been suggested as a first step to restore the whole marsh. But the uncontrolled Iranian feeders and exiguity of their discharges recently, it was necessary to studyonly the northern part of the marsh as an alternative case to ensure reasonable amounts of waterfor the purpose of maintaining and restore the marsh. Hydrological routing model was used to calculate the quantities required to restore the whole marsh, as well as the northern part. In thisresearch, the total dissolved solid (TDS) was adopted as the water quality parameter considering,three concentrations of TDS (1500, 1750, and 2000ppm). A two-dimensional flow mathematicalsimulation model was prepared using the SMS package (surface water modeling system) whereRMA-2 and RMA-4 software’s are used to study the flow and water quality patterns, respectively. In order to improve the water quality in the marsh according to the acceptable waterquality determinants and the current conditions, we studied diverting some of Tigris River water,which is one of Shatt-Al-Arab feeders, into the marsh and releasing this amount into Tigris Riverthrough Al-Kassara control structure into Shatt-Al-Arab. A significant water qualityimprovement in the marsh was noticed as a result of mixing 25% or 50% of the Tigris Riverwater which is suppose to go to Shatt Al-Arab. According to the results of this study, it was found that the restoration of the whole marsh cannot be achieved under the current circumstancesbecause of the limited water discharges from Iraqi feeders of the marsh and receding of feeding from Iranian side. The best scenario was that of 3650million cubic meters/year for an area338km2 and water surface elevation of 3m.a.m.s.l. The results also show that Al-Kassara controlstructure is unable to pass the required outflow at low level to improve water quality according to the required standard determinants