Al-Chibayish Marsh (CM)  is considered as the major part of Central Marshes area of this marsh is 1050 Km². The water quality of these marshes is suffering from salt accumulation due to intensive dam construction, limited supply of water from sources,  climate change impacts, and the absence of outlet flow from these marshes, specifically at low flow periods. So, the current research aims to assess and improve these marshes' hydraulic behavior and water quality and define the best location for outlet drains.  Field measurements and laboratory tests were conducted for two periods (November 2020 and February 2021) to define the (TDS) concentrations at nine different locations. Samples were also examined for water's physical and chemical properties as pH, electrical conductivity, water temperature, dissolved oxygen, and turbidity. Simultaneously with the sampling process, the water depths were measured at 50 different locations within the marshes. Moreover, the observations of water quality parameters were analyzed for the previous ten years (2010-2020). Hydrodynamic and water quality simulations were conducted using (SMS-RMA2 and RMA4) software to specify the water depths and velocity variations and define the salt content distribution. The obtained results illustrated 4sediment and TDS and in the Central Marshes area in general and CM in specific. As well, numerical results showed that the use of these outlets would significantly improve water quality. The current outlets do not work, and they link the Euphrates River to the Chabayish Marsh.