N° 370March 2011

Ancient Mediterranean water supply networks revived

Scientific news Actualidad cientifica

Actualité scientifique

The ancestral hydraulic heritage which exists all around the Mediterranean Basin is finding renewed life. Over the past five years, the return of water is bringing back the old water supply amenities to their former status. An IRD research team and its partners1 have shown that the local communities are reinvesting these networks, abandoned during several years of drought.The most typical, original and sophisticated examples of this revival are the underground2 infiltration galleries, tunnels known since Antiquity as khettaras in Morocco, qanâts in Iran, foggaras in Algeria. These water mines are the result of an traditional technology, developed on a grand scale from the XIIth Century in North-West Africa to create artificial oases in the Sahara.

High-level technical know-how behind centuries-old schemes The tunnels serve to conduct water from the ground-water body. The principle used for construction testi-fies to considerable knowledge and sophisticated technical mastery. It consists in digging into a hillside to

create an underground conduit, far enough to meet a shallow aquifer (see Figure). Set with a low downstream gradient, the conduit allows water to descend by gravity flow, with almost constant discharge, to emerge at the foot of the hill.Observed from the ground surface, only a line of small characteristic cones of earth over several kilometres tells of the existence of such engineering works beneath our feet. They are the spoil removal shafts which mark the trace of the tunnel, about 30m away, and are used as access points for maintenance.

The example of MoroccoLength of the tunnels can range from 5 to 20 km for a height of 2 to 4m but scarcely 50cm wide. One example is in Tafilalet province of Morocco, in the Meknès area, where the khettaras have been better preserved. The research team focused their investi-gations especially on these. A total of 450 have been counted in this area. These conduits were dug from the end of the XVIIIth or early XIXth Century until 1950

Restoration of Khettaras, or underground water supply galleries, by oasis communities in the Tafilalet Valley, Morocco, illustrate the revival of the ancient water network heritage everywhere around the Mediterranean Rim.

Years of drought had dried up the ancient water supply networks existing around the Mediterranean Rim. However, with rainfall returning over the past 5 years, the hydraulic heritage has come to life again. The names of the tunnels that carry the revived streams -khettaras in Morocco, foggaras in Algeria or qanâts in Iran- evoke the trickling sounds of water. These under-ground infiltration galleries are the most characteristic and original illustration of local communities’ recovery of ancestral schemes. As IRD resear-chers and their partners1 show, these water mines in the middle of the desert, most of which had been abandoned, have now been restored by oasis inhabitants. These communities are now reinvesting in the mainte-nance of khettaras and in agriculture, especially young people returning to rural environments after experiencing unemployment in towns and cities. This is a risk owing to the uncertainties of climate, but fully assumed to revive collective action and to reappropriate the rules governing water-supply access, indeed in antici-pation of possible new shortages in the years to come.

© IR

D /

M-N

Fav

ier

© IR

D /

Thie

rry

Ruf

and enabled a population of about 600.000, 75% of them living mainly from agriculture, to develop in this extensive area at the foot of the Atlas, hemmed in between the mountain and the Sahara.

Tunnel renovationModernization of public water networks during the second half of the past century, notably with dam construction, and the surge in private drilling have left the khettaras weakened. These modern networks have been superimposed on the traditional works, on the means of reinforcement or competi-tion, and a great number of infiltration galleries were taken out of service. Then the periods of severe drought which hit in the 1970s and again from 1995 to 2005 in their turn dried up the khettaras. Five years ago, only a few dozen tunnels were still permanently in operation.However, regular abundant rain has returned, since May 2006. The groundwater resource again feeds the catchment area upstream of some of the galle-ries which were partially or completely abandoned. The local communities then undertook to renovate them. In five years, at Jorf, in the west of Tafilalet, nearly 50 conduits have been put back into working order thanks to community initiatives. The local and regional water and political authorities are now also working towards the same objective and putting forward a rehabilitation scheme for khettaras.

This new boost for the communities’ hydraulic heri-tage gives them the opportunity to reinvest in oasis-based agriculture, in particular involving young people returning from towns and cities mainly due to unem-ployment encountered there. Only recently, many young people started to come back to the oases to take on the restoration and maintenance of khettaras.

Like the communities living in the oases, the popula-tions around the Mediterranean Rim are renovating the old water supply networks, in a similar way to those in the Moroccan High-Atlas, the Alps, Pyrenees or again in the mountains of Lebanon who are again injecting new life into the impressive terraced lands-capes they have sculpted over the past centuries. An uncertainty nevertheless remains: is the return of the water sustainable? A point difficult to ascertain according to the scientists. But this is where these rural societies are putting their stakes. To avoid any further individual groundwater extraction by unveri-fiable pumping, they are relaunching collective action to establish a new level of justice for access to water supplies… with the looming prospect of a possible new water shortage in the coming years.

Copy editor – Gaëlle Courcoux - DIC, IRDTranslation – Nicholas FLAY

The gallery dug from the foot of hill meets up with the underground aquifer; its low-gradient slope allows water to go down by gravity flow to the conduit outlet to feed the irrigation canals in the Tafilalet Valley. The pits seen on the ground surface are access points to the gallery for maintenance.

ContactsThierry Ruf, director of research at the IRDTél. : +33 (0)4 67 63 69 76thierry.ruf@ird.frUMR Gouvernance, risque, environnement, développement – GRED (IRD / Université Montpellier 3)AddressIRD Montpellier 911 avenue AgropolisBP 6450134394 Montpellier cedex 5

Mohammed EL fAÏZ, professor at university Cadi Ayyad, Marrakechamelfaiz@menara.maAddressFaculté des sciences juridiques, économiques et sociales (FSJES)BP 2380 Daoudiate, Marrakech, Maroc

Mhamed MAHDANE, professor at university Agadirmahdane_mhamed@yahoo.frAddressFaculté des Lettres et des Sciences Humaines d’AgadirP 29/S 80000 Agadir -Maroc

References El Faiz M., Ruf Thierry. An introduction to the Khettara in Morocco : two contrasting cases. In : Schneier-Madanes G., Courel M-F. (eds). Water and sustainability in arid regions, bridging the gap between physical and social sciences. Springer, London, 151-163, 2010. Mahdane M., Lanau S., Ruf Thierry, Valony M-J. Gouvernance d’une oasis dont l’eau provient quasi exclusivement de l’exploita-tion traditionnelle des galeries drainantes, les khettaras : le cas de SKOURA au Maroc. Atelier international à Tunis 4-6 novembre 2010. Ruf Thierry. «Dialogues extraordinaires sur l’eau dans le Tafilalet, hommage à Jean Margat et la communauté scientifique marocaine. Film présenté lors de la confé-rence organisée par l’Algérie et l’Unesco à Adrar du 10 au 12 avril 2011.

Key wordsWater, oasis, irrigation, drainage galleries

CoordinationGaëlle CourcouxInformation and Culture Department Tel: +33 (0)4 91 99 94 90Fax: +33 (0)4 91 99 92 28fichesactu@ird.fr

Press officeCristelle DuOSTel: +33 (0)4 91 99 94 87presse@ird.fr

Indigo,IRD photo libraryDaina RECHNERTel: +33 (0)4 91 99 94 81indigo@ird.frOnline access to IRD photos concerning this news sheet from:www.indigo.ird.fr

Graphic design and layoutLaurent CORSINI

Khettara - Illustrative Diagram

Palm GroveReceiving pond Cut cones Surface of

the aquifer

Channels

Underlying galleries of water

Vertical shaftsfor aeration

and maintenance

Outlet for khettara

© IR

D /

Laur

ent C

orsi

ni©

IRD

/ Th

ierr

y R

uf1. These investigations were conducted in partnership with teacher-researchers of the Université Cadi Ayyad in Marrakech and

the Faculty of Letters and Human Sciences at Agadir.

2. An application for inscription of khettaras for listing as material and nonmaterial World Heritage assets was put forward to UNESCO in the context of the “water and culture” day on 9 December 2010.

FoR FuRTHeR INFoRMATIoN

44 boulevard de Dunkerque,CS 9000913572 Marseille Cedex 02France