Executive Summary 

Also known as the Assi River, the Orontes is the only perennial river in Western Asia that flows north from Lebanon to Syria and Turkey and drains west into the Mediterranean Sea. Its flow regime shows typical winter peak flows due to increased precipitation, and summer low flows maintained exclusively by groundwater discharge.

The river is mainly used for irrigation purposes with several agricultural projects planned in the three riparian countries. Water quality at the headwaters is generally good, but deteriorates in the middle and lower reaches of the river due to agricultural, urban and industrial activities.

There is no basin-wide agreement between the three riparians, but there are several bilateral agreements in place on issues such as water allocation (Lebanon-Syria) and the joint construction of infrastructure (Syria-Turkey). Orontes Basin politics are heavily influenced by the status of Turkish-Syrian relations in general, and discussions over the sharing of the Euphrates River in particular.

Main Agreements 

Lebanon - Syria

1994 – Agreement on the Distribution of Orontes River Water Originating in Lebanese Territory, which specifies water allocation between the two countries.

Syria - Turkey

2009 – Memorandum of Understanding concerning the construction of the joint Orontes River Friendship Dam.

Key Concerns 

Water Quantity

The Orontes River is under intensive use in all three riparian countries, mainly for agricultural purposes. The implementation of additional irrigation projects will place further pressure on the resource. While Lebanon and Syria have agreed on water allocation issues, Turkey and Syria have not. There is no agreement between the three riparians.

Water Quality

In its middle and lower reaches, the Orontes is heavily polluted with untreated effluents that are directly discharged into the riverbed. Water quality issues have not been addressed in the cooperation context.


Syria and Turkey have not resolved the question of the disputed coastal province of Hatay (Iskenderun) through which the Orontes exits to the Mediterranean Sea.

  • The Dardara Falls on the Orontes River, Lebanon, 2009. Source: Andreas Renck.
  • The Ghab Valley, Syria, 2009. Source: Adel Samara.
  • Ain Zarqa Spring, the source of the Orontes, Lebanon, 2009. Source: Andreas Renck.
  • Lake Qattineh near Homs, Syria, 2009. Source: Adel Samara.
  • The Orontes in Hama, Syria, 2009. Source: Adel Samara.

Basin Facts 

Riparian Countries Lebanon, Syria, Turkey
Basin Area Shares Lebanon 8%
Syria 67%
Turkey 25%
Basin Area 26,530 km2
River Length 404 km
Mean Annual Flow Volume 1.2 BCM
Dams 9 (max. storage capacity 939 MCM)
Projected Irrigated Area ~300,000 ha
Basin Population 5.86 million