Algeria

Algeria comprises the largest part of the SASS basin with about 700 000 km² over a total surface area of about 1 million km². Algeria is also the first user of this resource in order to cover the water needs of all the socioeconomic sectors with more than 85% reserved for agriculture and 15% for drinking water, industry and tourism.

Located in a region characterized mostly by a desert and sub-desert and partly an arid bio-climate with a largely negative climatic water balance (CWB) (difference between the annual rainfall rate and the potential annual evapotranspiration rate), agriculture in Algeria is exclusively irrigated. Restricted initially to the classical and traditional oases and structured socially, culturally and economically around the SASS water resources, the Algerian agriculture has developed thanks to the use of new production systems based on a single-crop farming system of date palm in the modern oases and on a variety of other crops outside the oases mainly vegetable crops and cereals farming.

The diverse farming systems in the region attest to an attempt on the part of farmers to adapt their production systems to current socio-economic and technological changes. It is within this perspective that some of unreliable farming systems gradually perished, others changed, while others developed with more or less success. However, most of the farming systems in the region generally suffer structural economic, social, and soil-related constraints. Moreover, most of the irrigated agricultural systems in Algeria (the same case in Tunisia and Libya) do not give due value to the quality of water used for irrigation, which resulted in harmful environmental impacts on the SASS water resources and irrigated lands.

Consequently, the sustainability of irrigated agriculture in the SASS region is threatened and continuously faces multiple and highly complex challenges where the technical dimensions are often imbricated and related to social and economic constraints.

For the SASS III project, the Algerian National Water Resources Agency (ANRH) has proposed two oasis systems, namely:

• the oasis system in the Touat-Gourara-Tidikelt region, using the SASS’s “foggaras” in irrigation;
• the oasis system of Oued Righ Great Valley, one of the largest regions specialized in date palm cultivation (“deglet Nour”).

Libya

Libya represents the poorest Maghreb country in terms of water resources. It contains mainly underground water resources, the largest part of which is derived from the SASS or its related water tables. These resources are often mobilized and overused in order to cover the needs for water of the different socio-economic sectors in Libya. Given the increasing gap between water supply and water demand, recourse to the techniques of seawater desalination (despite its relatively high cost) became the only solution to fulfil a portion of the increasing demand for potable water.

A mathematical model was built, based on the data collected and analysed by experts from the two neighbour countries sharing the same water resource in the plains of Jeffera (i.e. Tunisia and Libya), in order to simulate the current behaviour of the north western Sahara aquifer system and conclude some projections for its potential behaviour in the medium-term (in 50 years). The simulations conducted led to the following conclusions as far as Libya is concerned:

• If water withdrawal will continue with the same current pace until 2050, it will inherently lead to an important lowering of the water tables and hence more sea water intrusion into the region of Tripoli. This potential scenario would inevitably lead to the disappearance of a part of the water resources in the central zone of Libyan Jeffera either due to a drying up of the aquifer or to an excessive degradation of water quality (an increase in water salinity).
• An additional inconceivable increase in water withdrawal in the zone of Jeffera.
• The proposal of establishing a policy that aims to decrease water withdrawal (politically difficult to implement) would have positive impacts on the water resources in the region, but cannot put an end to the decrease of the piezometric level and sea water intrusion.

Given the situation of water scarcity, agriculture in this region is highly affected and suffers degradation. The decrease of the piezometric level and increase of water salinity caused by seawater intrusion pushed local farmers to abandon irrigation which led to a degradation of the hydraulic infrastructure and irrigation networks in the western part of the Libyan Jeffera.

Besides, the central zone of the SASS region (Oueds Merdou, Zemzem …) contains considerable but lowly valued geothermal water resources.

Everywhere and in all cases, irrigation efficiency is extremely low and irrigated agriculture in the SASS region is unable to endure even in the zones endowed with considerable water resources. The productivity of one meter cube of water is very low and its economic profitability is not ensured due to competition.

Irrigated agriculture is equally threatened to disappear, a potential risk proven by a number of facts namely wells drying up, an important lowering of the piozemetric level, excessive salinization of irrigation water and extreme pollution… the Libyan Water Authority identified two of the mentioned problems to treat them within its “demonstration pilot” component. They are the following:

• Irrigation water scarcity in the entire Libyan Jeffera plain, a shortage caused by a decrease of the underground water level and salinity caused by seawater intrusion.
• Unvalued geothermal water resources for intensive irrigation in the central region of the country.

Tunisia

The water issue in the Tunisian SASS region is particularly crucial for the following reasons:

It stretches along the “chott” (salt lakes), a region that suffers a high dewatering of the two water tables (IC) and (TC) and a degradation of water quality.

Human pressure on the SASS resources is increasing in order to meet the urgent demands for water of all development sectors.

However, this problem is manifested differently depending on the natural and socio-economic contexts. Concerning irrigation water, three major problems were mainly identified:

• a shortage in good quality water that threatens the future and sustainability of the local agriculture that is  based mainly on irrigation;
• a degradation in the quality of the available water resources, which led to a severe decrease of the farmers’ income and agricultural yield;
• miss management and unequal distribution of water resources which violate the rights of farmers and contradict the ethics of solidarity and equity on which is based the traditional agriculture in the SASS region.

It should be noted that the three main problems mentioned above are only major threats among multiple other problems that made of the water issue in the three neighbour countries an intricate matter in need for an urgent sustainable development process.

The first cause of water shortage is structural since Tunisia is the least user of the SASS region. Other factors include the inappropriate modalities of water use in irrigation (surface expansion, water wastage, inefficient technological and economic tools) and the inefficiency of institutional and legal bodies.

The DGRE and DGGREE identified two major local problems at the level of the SASS region. They are:

• land degradation caused by hydromorphy (water stagnation) and salinization caused by the use of poor quality water in irrigation. This problem is particularly acute in the oases of chott El Jerid (El Jerid and Nefzaoua Oases);
• overuse of water resources combined with an increase of water salinization at the level of the Jeffera plain in Tunisia.

The two problems identified by the DGRE and DGGREE were validated and endorsed after consultation with regional and local authorities and two demonstration pilots were dedicated to analyse and treat them.