Traditional irrigation in Mesopotamia

Minimising the effects of salinisation

Irrigation has been practised along the banks of the Euphrates for thousands of years in conditions that are far less favourable than in the valley of the Nile. As Professor Gunter Garbrecht, Professor of Hydraulics and Hydraulic Engineering at the Technical University of Braunschweiz in West Germany, notes:

"First, the floods of the Tigris and Euphrates were very erratic and occurred at the 'wrong time', the period April-June being too late for the summer crops and too early for the winter crops. Secondly, the two rivers carried a much greater amount of sediment than the Nile river. And, finally, the very small incline of the alluvial plain (1:26, 000) and the fine texture of the soil easily gave way to waterlogging and salinisation (lack of natural drainage)." [1]

In spite of this, the local inhabitants practised irrigated basin agriculture as successfully as conditions permitted throughout much of the turbulent history of the area - the principal weapon against salinisation being alternate-year fallowing. Such fallowing allows the water table to fall after harvest, a process encouraged by evapotranspiration from the wild plants that take over once the land is temporarily abandoned. The mechanism is succinctly described by Professor McGuire Gibson of the University of Chicago.

"As a result of irrigation the water table in a field approaching harvest lies about half a metre below the surface. After the harvest the field turns green with Shok (Proserpina stephanis) and Agul (camelthorn, Alhagi maurorum). These wild plants draw moisture from the water table and gradually dry out the subsoil until winter, when they go dormant. In the spring, since the field is not being irrigated, the plants continue to dry out the subsoil to a depth of two metres, thus preventing the water from rising and bringing salt to the surface. Since they are legumes, the plants also replenish the land with nitrogen, and retard wind erosion of the topsoil. In the autumn, when the field is once again to be cultivated, the dryness of the subsoil allows the irrigation water to leach salt from the surface and carry it below, where it is normally 'trapped and harmless'." [2]

It is unlikely that there is a better means of preventing soil salinisation in the area. Indeed, J. C. Russell has described the traditional fallowing system as "a beautiful procedure for living with salinity". What is more, he points out, "the rural villagers understand it, in that they know it works, and they know how to do it and they insist on it". [3] Sadly, the same cannot be said for the modern technological methods of irrigation which are being imposed on the peasants today.

Both Adams and McGuire Gibson - who have made special studies of the history of irrigation in Mesopotamia - seem to agree that fallowing is the best, if not the only way, of combating salinisation in the area. Even then, in the long run, it still does not prevent salty water from being slowly brought up to the surface; as this happens the Shok and Agul roots slowly lose their capacity to 'deep-dry' the land, and, as a result, the top soil becomes increasingly saline.

Such soil can, of course, be removed by the farmers who can then work the deeper layers until they too grow unproductive. Eventually, however, the land must be abandoned - often for periods of between 50 to 100 years or more - as indeed it has been during the long history of vernacular irrigation in Mesopotamia.

The El Shabana

Short-term and long-term fallowing were not the only measures used by traditional agriculturalists, to minimise the effects of salinisation. They were only two elements in a complex cultural behaviour pattern, which was perfectly adapted to local ecological exigencies. Clearly, the details of that cultural pattern have been lost to history.

Nonetheless, we can reconstitute many of its elements from studies of those tribes, which - at least until recently - practised traditional irrigation in the region. In that respect, the work of Robert Fernea, an anthropologist who has studied the social organisation and irrigation system of the El Shabana of Daghara, is particularly relevant. Indeed, Fernea sees the El Shabana's social system as one which must once have been "typical" of all the tribal groups in Southern Iraq. [4]

As in all traditional societies, the technology employed by the El Shabana was very simple. Moreover, their land-tenure system was perfectly adapted to their agricultural practices. Joint ownership of land, for instance, was fairly common, this, Fernea considers, helped prevent having "plots without access to irrigation water". [5]

It also prevented plots becoming too small for half of them to be allowed to go fallow at any given moment. In addition, the El Shabana established a symbiotic relationship with local nomadic groups - through marriage ties, economic interests and agreements to allow animals to pasture on fallow fields. When farming became particularly difficult, the farmers could thus revert to pastoral nomadism. The livestock they kept on their farms was, therefore, not only a source of income "but an ultimate insurance against drought, loss of land, or other crisis". [6]

Two of the tribe's important features were its tradition of hospitality and the existence of mutual obligations between its different members. Together, they not only made it possible to spread the risks of farming but also strengthened the co-operation required to clean and maintain the irrigation canals and to dig new ones. The tribe also had the ability to fragment into its component parts when necessary which, as McGuire Gibson notes, "removes the necessity for sustaining a large number of labourers and for them being forced or tempted to make work for them". [7]

In more general terms it clearly enabled the tribesmen to reduce their impact on their environment to a sustainable level. McGuire Gibson considers the land-tenure system of the El Shabana to have been so well suited to their traditional methods of extensive cultivation that "the two aspects of agriculture must have evolved together in this region". [8]

For his part, Fernea argues that the most adaptive features of the tribe's social organisation was its ability to prevent the concentration of wealth and power. Thus, the society was egalitarian. It was run by the shaykh - or chief - who was regarded as being no more than the first among equals. His main function was to lead his people into battle and to act "as a reservoir of tribal law and an astute judge ... enforcing culturally defined and traditional norms". [9]

Moreover, the shaykh had no real political power: indeed, as Fernea points out, the segmentary lineage structure of the tribe had an almost "decentralising tendency". That tendency was accentuated by the frequent revolutions, which would replace "a shaykh from one lineage with a man from another section of the tribe".

Lastly, the shaykh was not motivated to build up large land-holdings - his prime interest being in acquiring prestige. For that reason, if for no other, shaykhs did not invest in new irrigation schemes for personal gains and aggrandisement. Instead, what wealth they acquired was ploughed back into the social group "in the form of hospitality, help in crisis and the like." [10]

The earliest historical experience in Mesopotamia

Irrigated agriculture in Mesopotamia was carried out as far back as the 4th or 5th millennium BC, by local communities, which were probably very similar to the El Shabana both in their social structure and in their irrigation methods. However, some time during the 3rd millennium, there seems to have been a massive increase in irrigation works in the Euphrates Valley. These do not seem to have been designed to improve the irrigation system of the local tribesmen but rather to satisfy the requirements of a burgeoning urban society. Adamns writes,

"It is noteworthy that the objective of urban supply, rather than irrigation, is stressed in the few early royal inscriptions dealing with watercourse maintenance and that the principal terminological distinction, is between navigable and non-navigable channels rather than between rivers and artificially constructed canals." [11]

Particularly significant, was the building, in Southern Iraq (in the basin of the Lower Diyala River, which occupies about 8,000 square kilometres along the North-Eastern margin of the lower Mesopotamian Plains) of a vast canal by King Entemenak of Girsu around 2400 BC. [12]

The canal was intended to supply water from the Tigris in order to irrigate an area east of Girsu, which formerly had been watered by the Euphrates. The canal, which was so large that it was simply referred to as 'the Tigris' - led to seepage, flooding and over-irrigation and a rise in the groundwater level. [13] Indeed, shortly after the reign of Entemenak, saline land "is attested in records of ancient temple surveyors". [14] It is attested in literary texts. Thus, in The Atrahasis Epic, we read:

"The black fields become white
That broad plain was choked with salt," [14a]

During the same period, we also learn that there was a gradual but marked reduction in the cultivation of salt-sensitive wheat, which was replaced by salt-tolerant barley. Thus, around 3500 BC, it appears that as much wheat as barley was grown in Southern Iraq: by the reign of Entemenak of Girsu (2500 BC), wheat accounted for only one sixth of production: by about 2100 BC it accounted for no more than two percent of crops; and by 1700 BC, no wheat was grown at all.

Soil fertility also declined dramatically - largely as a result of salinity. In 2400 BC the average yield of barley per hectare in Girsu appears to have been 2,537 litres. By 2100 BC, that yield had declined to 1,460 litres; and by 1700 BC, the yield at Larsa nearby, had fallen to an average of 897 litres per hectare. Indeed, the southern part of the alluvial plain "appears never to have recovered fully from the disastrous general decline which accompanied the salinisation process".

As a result, many of the great Sumerian cities "dwindled to villages or were left in ruins". [15] By the 20th century the "former Garden of Eden had become a region of poverty and misery". [16]

Adams and Jacobsen argue that there is probably "no historical event of this magnitude for which a single explanation is adequate". Nevertheless, it seems beyond question, "that growing soil salinity played an important part in the break-up of Sumerian civilization". [17]

Walters - who has made a meticulous study of a large number of cuneiform inscriptions, many of which refer to the administration of irrigation works in South Mesopotamia - does not consider that the spread of salinisation as far as the Larsa area can be explained by the building of Entemenak's canal alone. Instead, he postulates that similar large-scale water projects were undertaken around Larsa itself.

Indeed, in the archives, he found a reference - dated 1881 BC - to a major project involving "the building of a wall above a reservoir at the mouth of the Isin Canal". [18] That wall was big enough "to require an inventory of at least 1.3 million bricks" as well as the despatch of many workers and much material.

The project appears to have been the work of Sumuel, King of Larsa; its object was to divert water for Larsa's own agricultural needs, from a canal serving the territory of the rival city of Isin. A vast bureaucracy was created to administer and maintain the Larsa canal and many of the tablets studied by Walters clearly illustrate the inefficiency and corruption of the bureaucrats involved.

From 1200 to 100 BC to the end of the Assyrian Empire in the late 7th century, the Diyala area was a "disputed borderland", marched over and sacked by armies of rival Empires. [19] A measure of order seems to have been established by Alexander the Great and his heirs, who encouraged urbanisation on the Greek model. As a result, the population increased and agriculture was intensified.

Those trends continued during the Sassanian period (AD 226-637). Thus, in the 6th century - probably during the reign of King Chosroes the First - the giant Nahrawan Canal system was built, its aim being to supplement "the limited and fluctuating supplies of the Diyala River with almost unlimited water from the Tigris". [20]

The construction of the Nahrawan Canal made it necessary "to criss cross formerly unused desert and depression areas, with a complex - and entirely artificial - brachiating system of branch canals". [21] That expansion depended also

"on the construction of a large supplementary feeder canal from the Tigris, which, with technical proficiency that still excites admiration and without apparent regard for cost, brought the indispensable additional water through a hard, conglomerate headland, across two rivers and thence down the wide level left by the Dabban River of antiquity."

Three hundred kilometres of the canal still remain. They illustrate "not only .... the size of the system but also the attention lavished on such ancillary works as thousands of brick sluice gates along its branches". As Jacobsen and Adams point out

" ... we are dealing here with a whole new conception of irrigation which undertook bodily, to reshape the physical environment at a cost which could be met only with the full resources of a powerful and highly centralised state." [22]

From a study of land-tax receipts (which reached a level they have never equalled at any other time) and from our knowledge of the distribution of settlements, it now seems clear that the Nahrawan Canal and its associated works brought the entire surface of the Euphrates plain under cultivation. This led to still more urban growth, indeed

"Ctesiphon, the Sassanian capital, contained a larger urbanised area within its walls alone than the total area of all occupied sites within the 8,000 sq. km composing the lower Diyala basin at the period of the greatest ascendancy of Eshnunna around 2000 BC." [23]

The result was an increased dependence on outside markets, and also the take-over of the irrigation system by the state bureaucracy.

Like other irrigation works of the period, the Nahrawan Canal served, principally, to supply water to the newly founded royal cities, together with the agricultural areas on which they depended for their food. Since the Sassanian Empire, like the British Raj in India, depended for much of its income on an agricultural tax, the canal also served to finance the state bureaucracy and the dynasty's costly imperial policy.

The Canal may also have served to reduce the power of the landed nobility and otherwise to enhance the power of the central government. The Sassanian Empire was, thus, effectively funded by pillaging the alluvial soils of Mesopotamia and by destroying the social and cultural pattern of the communities they sustained.

Indeed, the building of such massive water development schemes caused numerous social and ecological problems. To begin with, there was a steep increase in population - probably as a result of the increased economic activity brought about by the new water works. Adams writes,

"Quite possibly, this led for the first time to a condition of general water shortage rather than local shortages based on uneven distribution." [24]

Social disintegration quickly followed, and with it, the inability to ensure that the irrigation works were properly maintained (which Jacobsen rather superficially attributes to the breakdown of the central administration). The final stage in the drama - to quote Jacobsen and Adams - "assumes in retrospect, a kind of historical inevitability". The area was virtually abandoned.

By the 12th century, "Only a trickle passed through the upper section of the main canal to supply a few dying towns in the now hostile desert". [25] Still more serious was the predictable and dramatic increase in soil salinisation, which led to whole areas being abandoned. Forty percent of the Sassanian settlements were never afterwards re-occupied and major canal branches and their adjoining cultivated districts were permanently abandoned. As a consequence, Islamic tax collections never approached their Sassanian highs, and

"the prosperity of Baghdad as the seat of the Abbasid Caliphate had to rest more on foreign conquests and tribute than on a secure economy in the city's immediate ruralities." [26]

Inevitably, the large-scale, centralised irrigation systems broke down under the strain of social upheaval.

"What replaced it, at catastrophically lower levels of population and economic interchange, was the first, simplest and most resilient of configurations ... which had been antecedent to cities and hence would survive their destruction." [27]

In other words, those small-scale communally-managed, traditional systems which alone were adapted to the social and ecological requirements of the area.

The modern experience

Today, history is repeating itself. Once again, the traditional irrigation system is breaking down under the pressures of centralisation and agricultural intensification. In the modern period, that breakdown first began under Turkish rule and was further exacerbated by the British.

Both Colonial administrations increased the power of the local shaykhs in order to transform them into their own 'agents' within the different tribal areas. The shaykhs were thereby "forced to assume roles that they either did not wish to perform or (which were) carried out to the detriment of their people". [28]

Among other things, their relationship with the other members of their tribe underwent a radical transformation, thus, the shaykhs ceased to be 'first among equals' and became instead landlords - their fellow tribesmen now reduced to mere tenants. Tribal land - which previously had been held communally - thus became private property. As a result, many shaykhs simply sold their land to speculators, while others moved to the cities to become absentee landlords. The story is a familiar one. Ester Boserup, for instance, notes:

"When (large-scale irrigation) regions are left in the uncontrolled possession of a landlord class, which is either of foreign origin or partner in a precarious alliance with a foreign conqueror, rural investments are in danger of being neglected, because the landlords inevitably go for quick profits and liquid assets. In extreme cases, the result is starvation and depopulation." [29]

As we shall see, this seems to be true even if the government of a centralised state is an indigenous one.

The British further increased the power of the landlords. Moreover, as more and more peasants were drawn into the market economy, so they were forced to pay rents, taxes and interest on loans which they found increasingly difficult to meet. Fallow periods were violated and, eventually, only the large land-owners had "sufficient acreage to shift tenants around in order to reduce losses due to poor land fallowing". [30]

The reduction in fallow also meant a reduction in pasturage and hence a decrease in livestock. Moreover, the introduction of the new system of land-tenure together with the gradual disintegration of the tribal system meant that the shaykhs ceased to observe their traditional obligations: instead of acting as custodians of the tribe's land, they acted "increasingly in their own family interests". [31]

Discussing the overall effects of government policy under British and Turkish rule, McGuire Gibson has few good words to say. Thus, he writes:

"By supporting and keeping one family in a position of power, by changing a chief to a landlord; by concentrating wealth while inducing individuals to take up small, fixed plots; by imposing yearly taxes and encouraging rents and debts, the central authority brought about widespread violation of fallow. Eventual selling out by small holders to large landowners did not lead to a reversal of agricultural decline because debt-ridden farmers often did not stay on the land as sharecroppers, but became nomads or fled to the cities." [32]

To alleviate the labour shortage, the landlords were forced to obtain their tenants from elsewhere. Since the latter had no experience of living in the special conditions of the area, they proved to be far less effective than the tribesmen whom they superseded.

Those problems were further compounded by the water development projects initiated by both colonial regimes. Here, the experience of the tribes in the Daghara region - over which the Turks never exerted effective control - is instructive. Thus, in 1870, Midhat Pasha, the progressive Turkish governor, ordered the construction of a dam across the Saqlawiyah canal, at its source on the Euphrates near Felluja.

Its object was to prevent the flooding of Baghdad. Its effect, however, was to impose "a much greater burden of water upon the barrage at Hindiyah" which was "the critical divisor of water allowing a flow to go into the Hilla channel and thence into the Daghara canal". [33] The Saqlawiyah dam eventually gave way; it was repaired but continued to function badly. As a result, "in the last part of the nineteenth century the Daghara area suffered crises of water shortage".

In 1903 the dam collapsed again. H. W. Cadoux, who travelled by stage coach down the middle of the dry Hilla bed, described the effects of the catastrophe. Whole sections of the countryside, he reported, were deserted; the former residents having been forced to move to the area around the Hindiyah channel. Only a few forts, deriving their water from wells sunk in the middle of the canal beds, were still inhabited. All the vegetation, with the exception of palm trees, had withered. [34] The dam was restored in 1914.

Elsewhere, other water projects were initiated. The British administration embarked on a vast scheme to build a major new canal in addition to upstream storage basins and dams designed to store the water throughout the dry season. The effect of those developments was perhaps predictable: soil salinity was increased and agricultural yields fell dramatically. Indeed, McGuire Gibson notes, somewhat sardonically;

"Directly, through engineering that promoted water-logging and salinity, the central government acted to undermine agricultural productivity." [35]

The end of colonial rule brought no improvement to the slow decline of Mesopotamia's irrigation agriculture. In the last 20 years more and more smallholders have sold their land to the shaykhs and have been forced to seek work elsewhere. The waterways are now administered nationally, and the water is supplied by pipe from a government canal. In the meantime waterlogging and salinity have rendered a third to a half of the land of the El Shabana uncultivable. [36]

The lessons of Mesopotamia

For many years, historians of irrigation agriculture in Mesopotamia have explained the rise and fall of state-run irrigation schemes in terms of what has become known as the 'Wittfogel model'. Wittfogel argued that irrigation agriculture is only possible when run by a centralised bureaucracy and, consequently, that the collapse of irrigation agriculture results from the breakdown of that bureaucracy. Jacobsen, a well- known adherent of the Wittfogel thesis, writes,

"When government controls weaken and disturbed conditions come to prevail, the great disastrous abandonments of land take place." [37]

Our brief review of the Mesopotamian experience argues for a very different interpretation. To be sure, a state bureaucracy is undoubtedly necessary in order to administer a vast centralised irrigation system. But the evidence makes it quite clear that the collapse of that system comes about as a result of the inevitable social and ecological destruction it causes.

Small wonder, then, that the great survivors in the history of irrigation agriculture in Mesopotamia are precisely those societies which have escaped being drawn into the orbit of the State. Far from irrigation agriculture falling into decline when bureaucratic controls relax therefore, the opposite is the case: as McGuire Gibson puts it,

"In Mesopotamia, the intervention of state government has tended to weaken and ultimately destroy the agricultural basis of the country." [38]

For his part, Fernea does not regard a tribal society as being the only type of society capable of managing an irrigation system without violating fallow and thus incurring problems of salinisation.

"If a landlord with a large holding were to allow fallowing (as he could afford to do with that much land) and be satisfied with the yield, without pressing his tenants for greater production; if an external government were to refrain from excessive taxing of the tenants, or if the landlord, pressed for taxes by the government, were not to squeeze his tenants; if the landlord with restraint were to re-invest his return only in his land, canals, and the like; if he were, in short, to be a good landlord and act like a shaykh, it would be possible to carry on productive agriculture without violating fallow and causing increased salinisation." [39]

Nonetheless, Fernea is adamant that, historically, irrigation agriculture has been most successful in tribal societies - a phenomenon he explains by "the congruence of fit between tribal methods of cultivation and land tenure and the nature of land, water and climate". This brings us to the crux of the matter. Throughout history, state-run methods of cultivation and land-tenure arrogantly defy "the nature of land, water and climate". [40] Indeed, they are based on the illusion that there are no natural constraints on man's activities. As we have seen, the result has been catastrophic.

Looking towards the future, then, it seems almost inevitable that the pattern of the past will be repeated. Already, the large-scale irrigation schemes of modern Mesopotamia are causing untold ecological and social damage. Catastrophe can undoubtedly be postponed - but it cannot be averted. If the past is anything to go by, we will then see the re-emergence of a traditional irrigation agriculture. As Adams puts it,

"An extensive system, whose cultivated areas and balance with animal husbandry have been continually adjusted as salinity and other conditions make necessary, has repeatedly confirmed its viability over a span of more than six millennia. It would require not an act of judgement but of faith to proclaim, on the basis of the very brief recent experience to date, that this oldest and most flexible of the agricultural configurations that Mesopotamia has known, will shortly disappear without trace." [41]

References