The circularity of water: the key for living in the desert

The M’Zab valley in the Algerian Sahara

By Mohamed Amine Saidani [1]

 

In the M’Zab oases in the Algerian Sahara, the local communities progressively developed, from the 11th century onwards, an ingenious circular hydraulic system as the only water in the valley comes from the rare flash floods (0 to 2 floods per year). The hydraulic system was designed to capture the floods and recharge the shallow groundwater aquifer through a diversity of hydraulic devices. The water was then made available to the community, for drinking and for irrigation of crops, through shallow wells. The principle of circularity is not limited to water, but was also applied to i) the agro-ecological association of agriculture and animal husbandry with the reciprocal use of by-products (crop residues; manure); ii) the use of animal traction, including for the lifting of water and iii) waste recycling, which increases the efficiency of resource use, thereby reducing the discharge of waste into the environment.

 

However, the promotion of new Saharan agricultural systems, focused on national food security and economic profitability, over the past 50 years, questioned this circular system. These intensive agricultural systems are generally situated in the so-called ‘extensions’, outside of the existing oases, and rely on pumped groundwater from the deeper, little-renewable, aquifers. The environmental impacts of these extensions – mining of the deep groundwater aquifers, the deterioration of the quality of groundwater and soils – are increasingly criticized. Faced with these environmental vulnerabilities, very localized initiatives are beginning to emerge in order to promote more sustainable forms of agriculture in the Sahara.

 

This research is interested in the analysis of the secular circular system and questions the sustainability of the different forms of irrigated Saharan agriculture in the light of the principle of circularity. In this paper I will look at a concrete case of a farm situated in an extension of the palm grove of Bni Isguen, where the farmer has taken multiple initiatives for more sustainable and more integrated agriculture.

Circularity in a farm located in the new extensions

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“On my farm, I collect every drop of water that the good Lord wants to give me, while trying to make the most of it. I apply this same principle at home. I installed water flow reducers on each tap to avoid wastage as much as possible.” It is in these terms that Mohamed* a farmer in the N’tissa irrigation scheme (Bni Isguen) received me. According to him, the harshness of the region in terms of climatic, topographic and geological conditions, coupled with the paucity of flash floods (0 to 2 floods per year), prompted him to collect every drop of water that runs either for immediate irrigation use or to store it in the shallow groundwater table for later use. On his farm, established in 1997, there is an ingenious mix of recharge infrastructure (recharge wells, dikes, basins), inspired by the secular hydraulic system of the M'Zab oases, with more contemporary facilities using new technologies (pumping of flood water, concrete pit to store water in the basement). Initially, Mohamed worked in the plastic industry and did not commit heart and soul to agriculture. He only made a shallow well to provide irrigation water and planted some palm trees and fruit trees. In 2014, at the age of 50, he wanted to change course. He sold his shares in the family-run plastic production company and returned to Ghardaia definitively to devote himself entirely to farming.