Traditional water management in arid and semi arid areas:
Case studies of the Gheris oasis and the Figuig oasis, Morocco

L arge scale water works are vital for the population of the oases. Before starting his daily work, every farmer, alone or with his family or his “khemmas” (sharecropper), and the community of a village (qsar) have to unite to ensure water for their community. They need to unblock the springs flow, build basins (Tanoutfi) to increase the water quantity that will flow in the canals to the fields, build and repair dikes or small dams, and expand the khettaras (or foggaras), a succession of wells linked by underground canals going to the fields. The canals should provide enough water for upstream palm groves ensuring enough for those downstream, according to the tradition and the water rights prescribed by ancestral contracts. Artificial lakes are also created to store water for cattle and for years with water shortage.

Operation of the khettara irrigation system

The khettara or foggara represents an ancient sophisticated technique which enables underground water resources to be tapped for irrigation. Actually this method dates back thousands of years and has been adopted over a very large area stretching from China to Spain, throughout Persia and as far as Latin America. Water systems like these are known with different names: khettara or foggara of the Sahara desert qanat or kariz of Persia, falaz of Arabia, and the madrjirat of Andalusia; similar water systems are found also in Peru and Mexico (hoyas) (Laureano, 2005). The first documented inscriptions of the qanat date back to the 7th century BC. In the Mediterranean, the qanatoriginating from the Persians (today’s Iran), has spread over the Middle East and North semi-arid and arid regions, including Morocco.

The khettara system taps the groundwater table by means of a nearly horizontal tunnel which is dug over a long distance (normally 4-8 km but can reach even 15 km in length!). At regular distances (~10m apart), vertical shafts are dug which enable access and maintenance of the main tunnel. The function of the well-like shafts is not to get water out of them, but instead they are used for aeration and condensation of atmospheric water. As the khettara’s main tunnel is constructed to have a lower gradient than the terrain under which it lies, the tunnel becomes gradually shallower until it emerges above the ground at a distance of several km far from the first well, which in certain cases can reach a depth of 150 metres (considering the tunnel is cut under a hill or mountain)! The construction may start also from the settlement site inward, usually following an alluvial cone of a river or fossil wadi.Curetting (scraping) of a vertical shaft in a khettara Aerial view of a series of ketmias

Unlike a feeder canal and the Iranian qanats, the Moroccan foggara do not convey water from springs or underground pools, as their main tunnel does not usually go as deep as groundwater resources (Laureano, 2005). Actually the foggara is fed with water, primarily in the following ways:

  • a. Through microflows of the sands: The sources of these are mountainous areas receiving rainfall that may be thousands of km away from the foggara, and it may take ~ 5.000 years for these microflows to cover this distance!
  • b. Through regular rainfall in the plain above the foggara: In this case the subsoil actually acts like a rocky sponge, draining off the upper part. Even in areas with very low precipitation, because of the enormous size of the basins this water can have a significant contribution to the foggara outflow.
  • c. Through condensation of atmospheric humidity: This is based on the phenomenon of “hidden precipitation” that is of primary importance in the desert ecosystem (due to this process organisms like gazelles, lizards and scarabs ensure drinking water for their survival in the desert). Because of a temperature range that can be up to 60oC between day and night, there is a lot of night condensation that if managed properly can form sizable water reserves. Thanks to heat extraction at night, humidity is released into the sand, and the foggara foster this process acting as pumps that attract vapour. After sunrise the process is reversed with heat the air in the foggara rises through the shafts which are exposed to the burning temperatures of the desert, leaving behind water droplets retained in the soil and in the walls of the tunnel. These droplets are pulled by gravity form the outflow of the main tunnel. It has been calculated that with this process, in the desert, 4cm3 of water can be collected per square meter of surface area in only one night! Humidity water supply to the khettara

The condensed water, relying on gravity, eventually drains through the gently sloping main tunnel. In some cases, the outflow of a khettara is stored in a reservoir, or otherwise directly conducted from the drainage tunnel into a complex system of souguia channels to irrigate the fields. The palm grove of the oasis creates a microclimate suitable for crop production: it provides shade to allow vegetable growth and limits evaporation and transpiration from plants and also attracts and collects moisture.

With proper maintenance, the khettara create a self-sufficient agriculture based on palm trees and olive trees, which then allows the growing of wheat, barley, maize, alfalfa, fruits and vegetables in enclosed gardens (plots or jennas). However, the khettara is more than an irrigation system: It embodies the traditional social structure of a qçar, enabling and regulating the social interactions that are based on the most precious element, freshwater. Thus, to understand the khettara it is necessary to explain also the collective socio-political organization around which the water (and land) is allocated to qçar, families and individuals. Distributor channel (Read more in the Water Works section)


Khettara construction and maintenance

As is the case with river irrigation, the management and maintenance of the khettara is the responsibility of the jmâa. The jmâa is the collective management authority of each community and it is constituted of representatives of every lineage within a qçour, who are chosen according to various criteria (nobility, wisdom, courage and wealth). The sharing of water is organised according to a regulation that differs from qçar to qçar depending on distribution methods, the water flow and the number of tribes and persons entitled to irrigate. The jmâa is the body that chooses also the chief of the tribe (amghar-n-tamazirt or or amghar-n-taqbilte).

Traditionally khettaras are built by a small group of skilled labourers by hand. The critical initial step is the identification of the water resource, usually located at the point where the alluvial fan meets the foothills of mountains (mountains receive more rain). A test well is dug to determine whether the resource and flow is abundant to justify construction of a khettara. If the test is successful the route is laid above ground and the excavation begins, either from the surface (destination) inwards, or vice-versa. The excavation crew is typically composed of 3-4 workers: Usually one person digs the horizontal tunnel with a hoe; another one collects the soil with a shovel in a leather bag, which is then collected from one or two other labourers on the top (ground level) through the vertical shaft. The construction speed depends on the width and height of the tunnel, the nature of the soil and the depth. It can range from 20m of horizontal tunnel per day (in soft earth, small depth) that can drop to only 2m per day (in hard soil and big depth). If the crew hits rocks, the khettara is abandoned!

In general, the jmâadecides on the maintenance and the repairs that need to be carried out of in a khettara, resolves conflicts and approves sales, changes, rentals and sharing of water between owners. Each individual water owner of a khettara has the right to exploit the water-rights as he wishes, and has the right to sell, rent or to mortgage the water to others. Although water is considered the property of co-owners, the entire village has free access to it for domestic use, guaranteed by the main canals (souagui) that cross each qçar. In compensation, all villagers must contribute to the maintenance of the foggaras. Owners must share the expenses of restoration work and extension of the galleries needed periodically.

The collective maintenance works are organised under the authority of the water-chief (sraifi or amghar-n-waman), elected yearly by the jmâa. In Morocco, traditionally, all persons owning water rights are obliged to participate in the collective maintenance of the khettara, regardless of the amount of land and water owned. This maintenance is necessary quite frequently, since sediment accumulations in the khettara’s tunnel quickly lead to a decrease or even block of water flows. Maintenance generally consists of removing sediment from the khettara tunnel and from the main souagui. Also, the vertical shafts may need to be covered to minimise blown in sand, and the horizontal tunnel needs to be periodically inspected for erosion or cave-ins. Typically, each family donates one workman per day during maintenance operations. If the maintenance is done by outsiders, all owners are expected to contribute to their payment.

This water-chief divides the tasks between the workers allocating the heavy tasks to the younger men and the light tasks to the older ones. For example, the older men assume tasks like cutting and removing branches and twigs along the souagui which hinder the free water flow. The younger men assume tasks such as removing accumulated sediments from the canals (souagui). To do this, each seguia is divided into three-metre sections (asfil), and each of them is cleared by two persons. Specific tasks are sometimes performed by specialist workers (mâalmin) in return for payment.

Any person who is not able to participate in collective labour has to pay the worker replacing him or he has to prepare a meal for all the workers. If somebody refuses entirely to contribute, he can be fined by the water-chief or punished by the jemâa with social exclusion.


Day to day management

The distribution of the water is done through permanent rotation, day and night and the palm grove must be divided into fragmented sectors. The distribution of irrigation water is in the hands of a qualified person with a casting vote for water issues, called Sraifi. He is often chosen by the jmaâ after a meeting with the owners and water users for a determined time, usually renewable. The water management is ruled by the common law developed by the population itself. The unit of measurement of water shares (the kharrouba) is 45 minutes of flow from the spring. By using water storage basins and various distributing channels, the Sraifi makes sure every user is served through secondary or tertiary channels going in all directions in the oasis. The Sraifi also oversees the spring water stocked in big basins and distributes it to the persons entitled through specific canalizations according to an irrigation cycle varying between 7 days in the summer and 15 days in the winter.

As the measurement unit adopted, the kharrouba has solved most of the conflicts between owners and users because of the flow variation of the sources and the day/night variations according to the seasons. Water distributing channels Water distributing channels


The water clock… (tighirte)

Regarding the actual water measures, the community has created precise techniques to delimit water ownership. These techniques vary from natural delimitations such as day and night water property to man-made instruments. Such a water clock, the tighirte was particularly useful during the night or in sunless days, when shadow measurement was not possible.

As there were no watches in the old times, in order to measure the Kharrouba (or tanast) the inhabitants used a hemispherical shaped copper tool called the tighirte. It is a graduated container with a tiny hole at the bottom, that can contain more or less 1,5 litres of water. The Sraifi puts the tighirte over a container filled with water, it floats while water enters from the hole, until it sinks. The hemisphere then hits the bottom marking the time corresponding to a Tanast or a Kharrouba. The water clock - Tighirte


The risks of maintenance today

Nowadays, with the weakening of the effective power of the traditional jemâa and the decreasing economic role of agriculture, more and more people are evading their collective obligations. Common law, which used to regulate collective work, is becoming increasingly difficult to enforce. Young people especially, no longer accept to participate in collective maintenance work and no one has the power to oblige them to do so. The declining interest in and motivation for agriculture has also contributed to a decline in the collective maintenance of the khettaras.

Another crucial factor contributing to the decline of the khettaras in Morocco appears to be the installation of numerous motor pumps since the 70s, and the ensuing over-pumping that has caused a lowering of the water tables, therefore rendering the khettaras useless. Both these factors have reinforced each other as, with the lowering of the flow in the khettaras and their subsequent decreased agricultural importance, the motivation to maintain them will continue to decrease, and motor pumping will be further encouraged. In this framework, the future maintenance of the khettaras and the irrigation system is becoming increasingly difficult to guarantee. Structure of the oasis Norias, Big scale water works