The Euphrates is the largest river in Syria. Originating in Turkey and flowing through Syria and Iraq, it joins the Tigris in Iraq and becomes the Shatt-al-Arab waterway, which flows into the Arab Gulf. The Euphrates is composed of two main tributaries, the Karasu and Murat, both originating in Eastern Anatolia and having numerous smaller tributaries. Turkey has unilaterally pledged to ensure the flow of 500 CM/s per second to Syria.

What makes this particularly painful for that residents of Khuzestan is that the dams on the Karun are not only used for generating energy and irrigating agricultural land, they are also used to channel water via tunnels to other provinces, notably Isfahan in central Iran, which is politically more power. Many residents in Khuzestan feel that their water is being stolen.

Since the marshes are located at the tail end of the Tigris-Euphrates watershed, water storage and control projects are the main projects impacting on the wetlands.

For many years, negotiations between Turkey and Syria over the Orontes or Asi River were linked to issues concerning the Euphrates and Tigris rivers shared between Turkey, Syria and Iraq, and progress of the former was dependent on progress of the latter

The length of the river is open to discussion. Depending on the source consulted, this ranges from 248km to 556km. Rainfall in the basin is about 644mm annually. The average temperature is around 16°C. The climate is semi-arid to arid in Lebanon, with annual rainfall of about 400mm

The annual amount of water used in Syria is about 15BCM. This comes from the Euphrates (50 per cent) and the Asi River basins (20 per cent). Of the water usage from the Asi River, 2,230MCM are used for irrigation, 320MCM for domestic purposes and 270MCM for industrial purposes. The total amount of water withdrawn from the Asi River is 2,730MCM

In all three riparian countries, the river is used mainly for irrigation, domestic water supply and hydropower. The Asi River is diverted to the Homs-Hama water channels and Ghab-Roudji irrigation systems to meet the needs of Lebanon and Syria. The water is also stored in the Zeita Dam for domestic and irrigation purposes and energy production.

Turkey-Syria Relations were affected throughout the Cold War era and into the 1990s. The water issue became a foreign relations matter once again when both countries began using the waters of the Euphrates-Tigris basin in the 1960s and building irrigation and energy-related projects.

The foundation stone of the dam was laid on 6 February 2011. On completion, the dam is expected to be 22.50 m high, with a capacity of 110MCM. Of that, 40MCM will be used for flood prevention and the rest for energy production, and irrigation (around 9,000 hectares of agricultural land).

The Islamic Republic of Iran covers a total area of 1.75 million km2 and is bordered by Armenia, Azerbaijan, the Caspian Sea and Turkmenistan to the north, Afghanistan and Pakistan to the east, the Gulf of Oman, the Strait of Hormuz and the Persian Gulf to the south, and Iraq and Turkey to the west.