Rain is the main water resource in Syria, affecting the availability of all other water resources. The average annual rainwater resource is estimated at 46 billion cubic metres (BCM).

Available water quality data clearly reveal that groundwater and surface water pollution is a common phenomenon across the country.

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.

The Iraqi Marshes are located in the lower Mesopotamian basin, in the vast floodplain wetlands created by the Tigris-Euphrates river system.

The primary source of water in the marshlands is the Tigris and Euphrates rivers, with several major tributaries flowing from Iran towards Tigris and Hawizeh. From the head of the Upper Mesopotamian Plain to the Gulf, the rivers meander slowly.

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

Dams have always played an important role in harnessing precious Iranian water reserves, and the long-term objective of Iran’s water resources development plan is based on the control and regulation of water through dams. In 2015, a total of 647 dams were in operation, of which 352 are considered significant reservoirs, with a total capacity of 48.39BCM.

Internal renewable water resources are estimated at 92BCM, with another 13CM coming in from transboundary resources. Surface run-off represents a total of 97.3km3/year, of which 5.4 km3/year come from draining the aquifers.

Presently, Iraq is contending with two types of water quality issues. One is salinity, the other is the concentration of pollutants in the water related to municipal, industrial and agricultural activities that introduce return flows into freshwater sources.