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The Euphrates River water salinity (expressed as TDS), as it enters Iraq, has more than doubled compared to that of 1973. Downstream of Al Hindiah Barrage located south of Baghdad; the salinity has increased steadily over the last thirty years. The annual average TDS at Al Nassiriah has increased from 1080 ppm in 1979 to more than 4500 ppm in 2001. Water quality of the Euphrates deteriorated due to the decrease in quantity and the increase in salinity of the flow that is entering Iraq, and to flow diversions to the river from the Tharthar Lake and irrigation return-flow within Iraq. The decreased flow from Turkey and Syria is the primary cause of the alteration of water quality. Due to this flow diversion, water from Al Tharthar Lake and from irrigation return flow is being diverted to the Euphrates to compensate. An environmental flow rate of 178 cms (annual minimum flow 5.6 bcm, 1/3 of historic minimum flow) is proposed as the minimum flow that must be released into Iraq to preserve the environment of the Euphrates River in Iraq. A flow of twice this amount would allow more reasonable downstream management with an input average salinity of 760 ppm.