Technological innovation helps with Tunisia's dry agricultural climate

In recent years Tunisian agriculture has been hampered by the recurring droughts, and with only 80,000 ha of cultivable land under irrigation, cereals and crop production have fluctuated. Yet Tunisia has a volume of water reserves estimated at 5bn cu metres, 55% composed of surface waters and 45% underground. Nearly half of these reserves are situated in the water-rich northern provinces. In a bid to improve access to water, the government has invested to improve supply infrastructure, boost irrigation and develop desert agricultural production.

Water Stress

Over the past 25 years, Tunisia has been living in a water-stress situation, with a water supply of around 430 cu metres per capita per year, below the global average of 1000 cu metres. In 2016 the country experienced a 28% drop in rainwater which has meant a decline in the volume stored in dams – 780m cu metres in mid 2016 compared to an historical average of 1500m cu metres. According to Tunisia’s water utility, Société Nationale d’ Exploitation et de Distribution des Eaux (SONEDE), water shortages could reach 152,000 cu metres per day in 2019, especially in Cap Bon, Sahel and Sfax.

As it absorbs 80% of the national water resources, agriculture has been the sector most hit by water shortages. The Union Tunisienne de l’Agriculture et de la Pêche estimated the lack of water caused a financial loss of TD2bn (€857.8m) for agriculture during the 2016/17 season – 21% of overall output. As an emergency measure, authorities released a TD16m (€6.9m) budget from April to August 2016 to help farmers preserve their herds and dry cultures in the central and southern governorates.

Dam Infrastructure

In an effort to increase water availability, authorities have set out a national water strategy to optimise the management of water resources in the north and their partial transfer to under-served areas in the central and southern regions of the country. As part of the Tunisia 2020 development plans, authorities have projected an increase of the number of dams from 35 to 44, hill dams from 230 to 275, catchment lakes from 894 to 950 and wells from 5400 to 6000 by 2020. In December 2015 authorities inaugurated the El Maleh dam in the Bizerte governorate. At a cost of TD47m (€20.2m), the dam has a design storage capacity of 41m cu metres and is set to boost irrigation and reinforce water reserves in Ichkeul.

Eight additional dams are expected to come on-line in Ettine, Oued Mellegue, Kalaa El Kobra, Saïda, Sarrat, Ed Douamiss, Serrat and El Kebir shortly. The Oued Mellegue dam is expected to start construction in 2017. The dam is estimated to cost TD170m (€72.9m) and will have a capacity of 195m cu metres and protect the governorate of Jendouba from floods. Similarly, the Saïda and Kalaa El Kobra reservoir dams are expected to irrigate new areas in Greater Tunis, Sahel, Cap Bon and Sfax areas, The dams are expected to cost TD600m (€257.3m) and will be partly financed by the Arab Fund.

Network Upgrades

Although the volume of water handled by dams has increased by 90m cu metres between 2010 and 2015, this gain has been offset by losses in the distribution network, estimated at 115m cu metres. This has prompted authorities to launch several projects to fix Tunisia’s conveyance infrastructure.

The authorities are rehabilitating 70 km of drinkable water networks in Greater Tunis, Zghouan and Jebel, and revamping conveyance and distribution networks in the south-east and Sousse, funded by a TD159m (€68.2m) loan from Kuwait. In addition, a TD15m (€6.4m) project has been launched in Mahdia, which will comprise construction of 14 km of canals to ensure sustainable access to drinkable water in the Mahdia and Sfax governorates.

As part of the German-Tunisian cooperation programme, the German development bank, KfW, and the government signed a $100m loan in December 2015 for the development of three water supply projects for water-poor regions in Tunisia. It includes the development of a €52m water supply initiative using surface waters from the Kasseb dam in Béja to supply 32,000 people with water. The funding also covers the modernisation of the Medjerda-Cap Bon canal whose transfer capacities will be significantly increased. The €23.7m project will notably allow increased water supply for the Greater Tunis, Cap Bon, Sfax and Sahel areas as well as the irrigation of 19,000 ha of additional agricultural land. In addition, KfW granted a €15m loan to SONEDE for its national programme of drinkable water quality improvement.

Desalination

In recent years, the authorities have increased investment to boost desalination projects, mostly geared towards the central and southern regions. In 2016 only 8000 ha were irrigated with recycled water. In a bid to increase supply in southern areas, the government launched the development of a desalination plant in Djerba in October 2014. Scheduled to come on-line in 2017, the TD157m (€67.3m) project will have a treatment capacity of 50,000 litres of water per day and provide for the Djerba, Medenine and Tataouine regions until 2035.

A similar project is expected to be launched in Ezarat in the Gabès governorate. The development of an additional desalination plant in Sfax is due to secure the supply of drinking water to the governorates of Sfax, Gabès, Medenine and Tataouine by 2035. It will have a capacity of 156,000 cu metres and is funded by KfW, the Kuwait Development Fund and the Japan International Cooperation Agency.

In a bid to tackle desertification, authorities set out a TD166m (€71.2m) emergency programme in September 2016, consisting of the development of 38 mobile seawater desalination units, including three underground brackish water desalination plants and 35 deep wells as a way to soften pressure on central Tunisia’s water tables. Scheduled for 2017, the new facilities will complement the 10 brackish water desalination plants installed by SONEDE in Kebili, Gabès, Tozeur and Medenine. An investment of TD84m (€36m) will improve the water desalination capacity to 36,000 cu metres daily.

Innovation

Over the past two years, innovative irrigation systems have come on-line to facilitate a better management of water resources. In 2015 Tunisia was among the 12 recipients of the Securing Water and Food scheme, an initiative led by several international development organisations whose goal is to increase water availability and promote efficient water use in agriculture. As such, the Tunisian laboratory, Chahbani Technologies, developed Buried Bellachheb Diffusers, a system based on early injection and water storage in underground layers of tree farms as a way to increase yield of fruit trees and vegetable crops. In June 2016 authorities set up a pilot project for a desalination unit targeting irrigation in Mahdia. The EU-funded project is expected to reduce the quantities of salt from 5.8g per litre to zero for 200 cu metres of water per day. Equipped with a 600-cu-metre water reservoir, the €4.5m project will be used by 60 farmers to irrigate greenhouse crops. The project is capable of irrigating three times more land volume than traditional drip methods.

Sahara Project

To cultivate Tunisia’s considerable desert land – 75% of the country’s territory – another initiative is the Sahara forest project, led by the Norwegian social enterprise Sahara Forest Project (SFP). Funded by the Norwegian Foreign Ministry, this $30m project consists of the construction of a desalination plant to transform 10 ha of desert land back into arable land. Scheduled for 2018, the facility integrates solar power and desalination technology, using seawater to cool and humidify the facility and concentrated solar energy to power the seawater greenhouse, purify the water and pump it.

The desalinated water will be used to irrigate the plants and the extracted salt will be sold. The project is expected to equal the success of a similar pilot in Qatar, which produced vegetables at a comparable rate to European farms. The pilot project, launched in 2009 by SFP to demonstrate the capacities of their technology ahead of work beginning in Tunisia, proved to be a scalable success. In addition, the facility is expected to provide jobs in a vast array of segments, from farmers to high-skilled engineers.

While the new 2014 Tunisian Constitution has established access to drinkable water as a right of every citizen, the country has struggled with water shortages that make it difficult to secure this right. Tunisian authorities have carried out a series of infrastructure developments and innovative projects to boost access to water and support food production in remote areas. The government is currently laying the groundwork for the sustainable management of the country’s water resources, allowing its agriculture sector to gain traction, in spite of the challenging weather conditions expected in the next few years.