Shared Water Resources in Tunisia

Shared surface and groundwater resources

Surface water: Tunisia and Algeria share the waters of several transboundary rivers, notably the Medjerda River, which accounts for 37% of Tunisia’s surface water and 22% of its renewable water resources. In order to improve access to this shared resource, the governments of the two countries have established a joint technical commission for water resources planning and management, exchange of information and data management, including monitoring water use, pollution and environmental conditions.[1]

Groundwater: The major North-Western Sahara Aquifer System covers over 1 million km2, of which 700,000 are in Algeria, 80,000 in Tunisia and 250,000 in Libya. It includes the two main aquifers in the region: the Intercalary Continental and the Terminal Complex. The three countries that share the system have acted jointly to evaluate its water resources and allow for its effective and sustainable management and exploitation. It is worth noting that previous cooperation, involving an international team, made important progress in the development of various components of the aquifer: hydraulic, socio-economic, environmental and information systems. In 2002, the countries signed a formal agreement, one of the main objectives of which was to implement a permanent consultation mechanism to encourage the homogeneous management of this common resource.[2]

Also important is the Djeffara aquifer, which extends under the Djeffara coastal plain between Gabès and Zarzis. It is mainly fed by overspill from the Terminal Complex and recharge from the Matmata Mountains. The Djeffara aquifer is exploited through nearly 200 water points in Gabès and 42 boreholes, including 15 artesian boreholes in Médenine.

Over 40% of all deep groundwater pumped each year comes from these aquifers – 58% from the Terminal Complex, 18% from the Intercalary Continental and 24% from the Djeffara aquifer. Other smaller aquifers are recharged by drainage water in oases and from flooding in small wadis.[3]

Treaties and agreements

Tunisia shares two of the largest aquifers in the world with Libya and Algeria: the Terminal Complex and the Intercalary Continental. These aquifers are deep, extensive and contain fossil water. The three countries recently Established a commission to monitor the aquifers and have agreed to cooperate on their management to minimize cross-border impacts. This is one of only two such agreements in the world.[4]