A rehabilitation model of traditional
Oasis irrigation and the
use of the foggaras system

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Region North Africa
Capital Algiers
Surface area 2,381,741 km2
Population 33,354,000 inhab.
Population density 14 inhab./km2
Infant mortality rate (per thousand births) 37
Fertility rate (births per woman) 2.5
Population growth rate (per annum) 1.5 %
Life expectancy (female-male) 72 – 70 years
Average temperatures (min./max.) 11.7 / 23.1 ºC
Forest area 1 %


The oases in the Algerian Sahara illustrate effectively how man has succeeded in surviving hostile conditions. Over the centuries, an efficient and sustainable irrigation system has been applied that has allowed the inhabitants of the oasis to live in conditions of extreme aridity while respecting the particular properties of these unstable ecosystems. However, over the course of the past few years, the Saharan oases have come to experience strong demographic growth along with the intensification of agricultural production. In this particularly fragile environment, the inhabitants of the oases tend to forgo traditional knowledge regarding water resources. Also, modern techniques to pump water from underground sources dry up the groundwater reserves in a way that is irreversible. For this reason, the rehabilitation of the foggaras, a system of traditional irrigation, is recommended in the oasis of Touat in south-eastern Algeria.

The Saharan oases

The majority of Saharan oases in southern Algeria are made up of marginal areas where the extremely arid climate and low rainfall, averaging only 50 mm a year, result in areas that are greatly affected by the degradation of water resources and where the level and flow decreases daily. In addition, the population has grown rapidly in the past few years. This strong population growth is accompanied by agricultural intensification. The arid areas, where most of the degradation occurs, are largely the result of the consequences of ill-adapted human practices that jeopardize biological diversity in the Saharan region.

1. The foggaras system distributes water throughout the oasis.
© Pietro Laureano

badCauses and effects of the drying up of the oases

The intensification of irrigated agriculture in this fragile environment contributes to the over-exploitation of natural resources. The inhabitants of the oases have to dig deeper wells and cultivate ever-increasing areas. They have introduced industrial products such as chemical fertilizers while gradually neglecting traditional knowledge.

In fact, the immense agricultural areas are cultivated for the production of cereal for export. The system uses a jet watering system that is ill adapted to desert conditions, the degree ofevaporation is very high while the tube openings are at risk from being obstructed by sand. The level of groundwater reserves decreases to a critically low level due to the vigorous pumping of large quantities of water from great depth.

goodPossible solutions

The Mediterranean Co-operation of the MED Forum, a network of Mediterranean non-governmental organisations (NGOs) for ecology and sustainable development, and the Algerian association Touiza, agreed to set up a programme to protect the oasis ecosystem. Its principal objective is to integrate respectful environmental practices and traditional local customs in the affected areas. The programme covers four representative oases in the Touat region, close to Adrar in the south-eastern part of Algeria (See map). Activities include a programme to restore palm trees and a public awareness campaign that produced a practical guide on the preservation of the oases through the rehabilitation and repair of traditional systems called foggaras.

2. The foggaras drain water from the groundwater
sources to the oases. Vertical wells along the underground
galleries provide aeration and allow for maintenance.
© Concetta Fornaro and Debora Giorgi, Milan 1996

bladThe foggaras

The foggaras are manmade underground galleries that harvest water. They effectively capture water found at depth and transport it to the surface. Underground piping runs almost horizontally and transports the groundwater to the oasis by means of a slight incline of one or two millimetres per metre.
For the system to work, the oasis must be located in a valley or at the foot of a rift, so that it is below the level of the underground source. The Adrar oases are all located below the plateau of Tadmait where the groundwater source flows. The first wells are dug upstream from the oasis. The gradual sloping of the galleries reduces the speed of the flow, thus preventing the water from dragging the soil with it, which would result in the erosion of the galleries. This ingenious method uses gravity to transport water throughout the year.

The materials used for the construction of the foggaras come from the surrounding area. Blocks of stone are cut, clay and straw are combined to make a cementing mix and palm trunks are used to consolidate the underground galleries. The average length of the galleries is 2.5 km and they include vertical wells found every 20 to 30 metres used to aerate and repair the foggaras (picture 2.).

The foggaras allow for the passive transport of water, relying only on the force of gravity. Water is captured underground and flows under the earth, which prevents its evaporation, until it is close to the oasis where it flows into an open-air canal (seguia). A small triangular basin (quasri) collects water that arrives at the oasis by way of the seguia (picture 1. and 3.).
With the help of a stone device in the shape of a comb (kesria), the water continues to irrigate the oasis (picture 4.). The community sets up a ‘water assembly’ where decisions are made on who receives how much water among those who possess water rights in response to variations in water supply. Everyone is free to exercise his or her rights and demands for water. The ‘water deciders’ are then responsible for the distribution of water.

3. The kesria permits water distribution in the oasis.
© Pietro Laureano

The foggaras almost certainly originated in Iran, where they have been known for 3,000 years and are called ghanat or quanat.
They are also used in Morocco, where they are called rhettaras. In Algeria, the work of maintaining the foggaras is considered to be very unrewarding and dangerous and has gradually been abandoned (picture 5.).

In their present state, galleries that have collapsed allow the flow of only a small trickle of water. Moreover, the development of so-called modern agriculture requires that large quantities of water be pumped under high pressure. The water on the same level as the foggaras is thus depleted, and the groundwater levels decline, resulting in the drying up of the foggaras.

4. Water is distributed throughout the oasis according
to a complex system of ownership. Water is tapped into open-air
piping that distributes water to the various fields.
© Concetta Fornaro and Debora Giorgi, Milan 1996

To overcome this crisis situation, local communities dig new wells upstream from the foggaras to improve the flow of water. Meanwhile in the oases that have electricity, wells are dug downstream from the foggara exit and an electric pump is used to draw water from the foggaras to the recuperation basin.
The populations of the four Touat oases that have been chosen, are the direct beneficiaries of the Touiza project. However, other developments in the future are expected. Touiza and the MED Forum intend to pursue their work in the field after completion of the project, by supporting initiatives and projects in which the population continues to participate once projects have been implemented.

Even after local participation has been secured, the population will benefit from workshops on how to save water, combat pollution and desertification and how to preserve palm trees and rehabilitate foggaras. In addition, the know-how acquired during the project will be compiled in a manual to be applied to other oases in Algeria as well as in other countries.


The objectives of the MED Forum and the Touiza Association are to promote sustainable development and the preservation of the oases in the Saharan region of Algeria while ensuring the well being of their populations by simultaneously fighting poverty and desertification. Their specific goal is to guarantee an integrated approach and the participatory management of natural resources and of agricultural ecosystems in the four oases near Adrar.

5. In Algeria, the foggaras had been progressively
abandoned: today they are being restored.
© Pietro Laureano

Activities comprise:

1. Diagnostic

  • Compilation of an inventory of the natural resources being depleted and the traditional techniques that can be used to tackle the problem.

2. Capacity-building

  • Training courses on environmental education for teachers.
  • Workshops for the preservation of palm trees and foggaras.
  • Workshops on water conservation.
  • Workshops on small-scale cattle-rearing.
  • Introduction to project management and development.

3. Participatory management: Pilot projects

  • Organization of volunteers for the rehabilitation of the foggaras.
  • Micro-projects involving raising domestic animals (purchase of 200 goats to distribute to women and youth).
  • Institutional support for communities and local NGOs.
  • Surveys and participatory workshops.

This case study was proposed by Mr Zoubir Sahli
For more information, please contact him at the following address:

Mr Zoubir SAHLI
Agricultural Engineer
Association nationale
de volontariat TOUIZA
18, rue Abdelaziz Mouzaoui
16027 Alger

Tel. (+213) 2 61 81 05
Fax (+213) 2 61 81 05



The teacher explains the foggara irrigation system to the class.


Draw the Saharan desert:
sand dunes and an oasis.
You can paste your picture
to the wall chart.
(See Teacher’s guide).


What do you think of the idea of rehabilitating the foggaras? Do you know of traditional irrigation techniques in your country that are friendlier to the environment than modern techniques and that might be re-utilized? Or have modern techniques improved the water supply? Ask the elders in your village and your grandparents how they acquired water when they were young.
Has it changed today? For the better or for the worse?


Where is Algeria located?
Is your country on the same continent as Algeria? What characterizes the Algerian climate compared to your country? Are the problems of desertification in Algeria the same as those found in your region? What are the differences? What are the similarities?


Imagine a ‘water assembly’ in your school. Some of the pupils can play the role of ‘water deciders’ who decide how the water will be distributed. The others could explain why they need water. They could be farmers, cattle breeders, have large families, etc. They discuss among themselves the best ways to save water so that there is enough water for everyone and that it is distributed intelligently.


Draw a map of an oasis with its system of foggaras, which distributes water across the land (picture. 4).


Tick the correct answers from the following:

In Algeria the foggaras are used to:
• eliminate sewers.
• transport water.
• irrigate the oasis.
• feed the animals.
• transport people.
• prevent the drying up
of groundwater reserves.

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