Tunisia occupies an area of 163.900 km². The average altitude is 700 m, escalating at 1544 m in the Chaambi mountain at the central part of the country. In the northern part, along the coastline, the climate is typical Mediterranean, whereas at the southern part of the country the climate is typically arid, causing a high temporal and spatial variation in water availability. The average rainfall ranges from less than 100 mm/yr in the south to more than 1500 mm/yr in the northern part of the country. The average temperature varies between 11.4°C (December) to 29.3°C (July). The prevailing winds in the northern part are westerly to north-westerly. Wind speed is much lower in the southern part, where the prevailing winds are north-easterly, with Sirocco accompanied by Saharian dust being frequent during the summer months. The annual evapotranspiration is equal to 1200 mm in the northern part of the country, 1400 along the coastline, 1600 mm in the central and raises up to 1800 mm in the southern tip of the country.

Tunisia presents diversified geomorphological characteristics, due to both the influence of climatic conditions, vegetation and the influence of man over land use. There is clear differentiation in the type of soils between the northern and southern parts of the country. In the northern part, characterised by humid or subhumid climate, most soils are clayey, whereas in the south soils are characterised by different types of saline accumulations (calcareous, gyps, slat, etc.).

In 1996 total water demand was estimated at 2.528 million m³ and is expected to follow a tremendous and continuous growth, following the socio-economic development of the country. On the other hand, the total volume of available resources, comprising both natural and non-conventional water resources, presents low variability and ranges between 4.000 and 4.600 million m³. It is estimated that in 2010 exploitable resources will be equal to 4.600 million m³, whereas water demand is projected at 2.689 million m³.

Demand management constitutes an important axis of future water policies, with the overall aim of controlling the consumption of the different sectors, and in particularly that of agriculture which is the largest consumer. Employed measures and tools are mainly based on water conservation, water pricing and rationalization of water use in agriculture.

At the end of 2002, the main water sources comprised 27 large dams, 182 small dams, 650 artificial lakes, 3.176 boreholes, 130.000 wells and 93 natural water springs.

In addition, and in order to assess and monitor water resources and quality, a monitoring network has been established all over the country. This network consists of:

• 95 pluviometric stations 
• 218 flow measurement stations in rivers
• 3.750 points of piezometric measurements and observations 
• 1.200 measurement points of groundwater quality

Inter-basin transfer is performed between northern regions, towards the coast and from the western to the eastern part of the country. Water is primarily used for domestic and irrigation purposes. The conveyance network for inter-basin transfer is approximately equal to 30.000 km.

Although at present the country does not experience extreme water shortage, there is an increasing pressure on available resources due to accentuated droughts, pollution problems, over-exploitation of resources and to risks of abundance limited in space and time, which render difficult the current decision-making processes with regard to water management.

Therefore, there should be a better understanding of these phenomena and promote (a) the use of non-conventional water resources in order to meet potable water demand in deficient regions and (b) the exploitation of additional resources for the development of economic sectors, and especially agriculture.