Brief History and Defining Irrigation

The Concept of Irrigation Modernization

The Changing Role of Irrigated Agriculture

References

Irrigation is summarily defined as the application of water for crop growth. Thus, it is easy to conceive that irrigation practices go way back to the early recorded civilizations, when the use of a basket or bucket-type of device allowed "spreading" water over a few plants grown close to the homestead. The origin of irrigation has been traced back as early as 8000 years ago (Sixth millennium before Christ) to the Zagros Mountains between Iran and Iraq. Later on, the Sumerians in Mesopotamia (Fifth millennium before Christ) who farmed the Delta of the Tigris and Euphrates Rivers build canals, perhaps laid in stone, which allowed them to direct the water to different areas and for different purposes. Those canals were refined into aqueducts to provide potable water to the cities, increasing the power and visibility of their influence. While beyond the scope of this note, it is suffice to say, that irrigation has been closely associated with and sometimes the causal effect of the rise and fall of subsequent civilizations, and continues to plays an important role in the development of vast areas, around the world.

A more structured definition for irrigation is given by ICID (1998, Multi-lingual Technical Dictionary in Irrigation and Drainage) as "Water application confined in time and space, enabling to meet the water requirements of a crop at a given time of its vegetative cycle or to bring the soil to the desired moisture level within the vegetative cycle. The irrigation of a field includes one or more watering per season." This now conveys the idea of a more complex operation requiring both technical and managerial skills, implying the existence of a certain infrastructure or setup through which the application of water can be accomplished. Through time, man has gradually improved and facilitated this task, giving origin to an array of irrigation techniques and systems. The sizes of the systems are somehow related to the development of the society. Small scale and often mountainous systems are within the scope of small communities while large systems constructed in the river plains have been built by strong state or power. However, the ever changing technologies and managerial approaches makes it necessary, from time to time, to review and adjust or change those existing conditions, giving way to the idea of modernization of the irrigation systems. It is worth noting from the outset that the concept of irrigation is intrinsically tied to the concept of drainage, or removal of excess water. Thus, irrigation modernization refers to both irrigation and drainage related actions.

There are currently, approximately, 273 Million ha under irrigation worldwide, equivalent to 20% of the total area cultivated. In Figure 1, information on irrigated area development for the period 1961 to 2001 is shown. Very notorious is the flat curve for Africa, Latin America and the Developed Countries whose needs for irrigation development would be perceived as diametrically different, with the former likely to derive higher benefits from irrigation expansion. Lately, the rate of irrigation public investments --particularly reflected by droppings in total lending amounts by the World Bank-- have slowed down, as compared to the early 80's and 90's. Annual lending amounts have dropped from their US$ 1100 million peak in 1993 to US$ 400 million today (IPTRID, 2003). Nevertheless, irrigation expansion appears to continue, as seen for both developing (includes Asia, Africa and Latin America) and worldwide levels; although a flat trend appears in the making during the past three or four years. However, and very recently, the World Bank appears to be reorienting its strategy with a come-back to irrigation infrastructures financing, including dams. These 'high-risk/high-reward' projects are again being considered priority projects.

Today, irrigation contributions to global agricultural production, food and fiber, is still of the order of 40 %. The new millennium has brought renewed efforts to reduce drastically, if not totally eliminate, before the end of the 21st century, the twin menaces of humankind today: food insecurity and poverty. Irrigated agriculture will need to play an important role within that alleviation strategy. In order to do so, innovative approaches will be required to assure that irrigated agriculture becomes more productive by unit of water, unit of labor or unit of investment, or combinations thereof; while conserving the environment, and assuring the sustainability of the water resources. To accomplish this goal, a significant shift in today's performance of irrigation systems ought to take place, and their modernization must be at the forefront of the improvement effort.

Figure: Irrigated area development, World and Regions, 1961 to 2001.

Like beauty, modernization is in the "eye of the beholder". Most likely, a definition would be heavily biased by the discipline and background of the definer. For a hydraulics engineer, modernization might imply a "jump" in technology, for example the replacement of sliding gates for a remote-controlled automated system or the transformation of an open channel distributary canal into a buried pressurized pipe. On the other hand, an institutional specialist would see modernization as a re-organization of the irrigation sector seeking a more efficient and dynamic arrangement of water-related institutions; or a sociologist that sees the need to improve on the participatory nature of water users in the managerial set-up of a particular irrigation system. In this context, a group of experts on the subject, gathered at FAO in Rome in 1997, and proposed the definition below, which has been formally adopted by the Organization.

Modernization of irrigation system is a process of technical and managerial upgrading (as oppose to mere rehabilitation) of irrigation schemes combined with institutional reforms, if required, with the objective to improve resource utilization (labour, water economics, environment) and water delivery service to farms. (FAO, 1997, p: 3)

The previous definition was generated by and conveys the results of a multidisciplinary task force assembled to capture the nature and scope of the work required for a true irrigation modernization process. A key element of these efforts relates to the acceptance that the process goes beyond a pure technical input and recognizes the need to give importance also to institutional- and organizational-related matters. Modernization implies changes that may occur at all operational levels of irrigation schemes from capturing of the water supply, to its conveyance and to the final distribution at the farm level. This "integrated" definition is a major step forward and a departure from previous modernization approaches based or executed along disciplinary lines of actions, with disregard of other and much needed complementary actors. Thus, unless irrigation modernization is perceived and executed under such a multi-disciplinary umbrella approach it is bound to fail. Conspicuously missing from this definition is the concept of drainage, but as said earlier, it is an integral component of irrigation. The Irrigation Modernization Survey activity undertaken by IPTRID and FAO was conceived under such an understanding.

To better understand the role that irrigated agriculture will be brought to play over the next decades, it is pertinent first to summarize the trends of three key elements that have a direct bearing on the demand for food and its accompanying nutrition conditions, translating into food security and malnourishment. These parameters are: population, income and poverty. The latest assessment in population indicates that there is a slowdown in world demographic growth; from 6.0 billion today, to 7.2 billion by 2015 and a projected 8.3 billion by 2030. The growth rate which has peaked in the late 60s at 2.04 percent p.a. has fallen to 1.35 percent p.a. by the mid-90s and is projected to fall further to 1.1 percent by 2015 and to 0.8 percent in 2030 (UN, 2003). Despite the drastic fall, 79 million persons are currently added to world population every year. Even by 2030 the annual addition will still be 67 million. Practically, all the increases will come from the developing countries.

With respect to income, the outlook is mixed. The latest assessment by the World Bank for the period 2000 to 2015 foresees higher growth rates in per capita Gross Domestic Product (GDP) than in the 1990s for all regions and countries with the exception of East Asia, which remains unchanged. However, the study cautions that for certain countries "the economic growth rates that may be achieved are likely to fall short of what would be required for significant poverty reductions." The situation in sub-Saharan countries is singled out as income growth may be very limited and far from sufficient to offset growing poverty and food insecurity.

Concurrently, the World Bank has made assessments on the incidence of poverty, defined as the percentage of the population and numbers of persons falling below the US $ 1/day poverty line threshold. The Bank concludes that "the proportion (not the absolute numbers) of population living in poverty in the developing countries as a whole may fall from the 32 percent it was in 1990 to 13.2 percent by 2015." This projection, if met, would undoubtedly represent a positive development. However, the absolute numbers in poverty in the developing countries are projected to decline only from 1.27 billion today to 0.75 billion, during the same period. That such a large number of people may still live under such dreadful conditions remains a challenge for the world community.

Population, income and poverty trends thus lead into the concept of food security, defined by FAO as "A situation where all families [of a nation or a region] have both the physical and economic access to an adequate amount of food for all its members and where these families do not run the risk of loosing that access". The basis for rural development is food security, which can be obtained by a combination of the following factors: an adequate food production at the local level, secured imports to compensate for any deficits, and an effective food distribution system. Today, a determinant factor for food security is the purchasing power of the individual or family unit.

Finally, parallel to food security runs the opportunity to an adequate nutrition that will guarantee the population's health. The three main sources of human food are agriculture (77.5 %), livestock (15.9 %) and fisheries (6.6 %). Per capita food consumption, expressed in kcal/person/year, is used as the indicator of food intake. A threshold of 2 700 kcal is taken as an indicator of the level of satisfaction of food security requirements. The latest FAO figures (1999-2001) indicate that there are 842 million persons undernourished today, worldwide. This number includes 10 m from industrialized countries, 34 m in countries in transition (ex-USSR, Baltic States and Eastern Europe) and 798 m from developing countries. While a few countries have seen their own numbers decrease, the disturbing news is that food insecurity seems to be again on the rise, when compared to the 1996 World Food Summit reference.

The preceding discussion sets the stage for the role of irrigated agriculture in the near future. Water is the vital resource for life and food security. Due to insufficiencies in water management and the growing increases of the demand, the world could be about to face a water crisis concerning its availability in terms of both quantity and quality. Competition for the resource increases day by day in all sectors: Potable and sanitation, agriculture, industry and manufacturing, mining, navigation, recreation and, nowadays more and more, for environmental purposes.

Although specifically referring to increases in water productivity, the role that irrigated agriculture is to play is well summarized by Cosgrove and Rijsberman (2000): "The more food we produce with the same amount of water, the less the need for infrastructure development, the less the competition for water, the greater the local food security, and the more water remains for household and industrial uses. And the more that remains in nature." Clearly, it is possible to produce more food while securing water resources sustainability if we introduce new technologies and approaches to both water and irrigation management. This includes, among others, a more efficient water reuse, improved water delivery in quantity, quality and timing, supplementary irrigation costs reductions, and development of new water sources at lower economical, social and environmental costs. All these pointing towards the need for a significant improvement in the way we view and handle irrigated agriculture.

It needs to be kept in mind, that agriculture is by far the largest user of water resources. As it is shown in the figure, it accounts for about 71 percent of all withdrawals worldwide, with domestic use amounting to about 9 percent and industry using the remaining 20 percent (FAO, 2003).

Figure: Water withdrawals by sector, World.

In the following figure water withdrawals by region and sector can be seen. Other water sectors have demands that while not consumptive per se place limitations and condition withdrawals. Such is the case, for example, of required water levels in a reservoir for hydropower generation, recreation or esthetic purposes; or minimum flow in a river to sustain aquatic systems or navigation.

Figure:Water withdrawals by region and by sector.

Also, and until now, it has been customary to ignore the environmental demands represented by various ecosystems, including wetlands and mangroves. This is no longer the case as pressure on the benefits of undisturbed habitats gains momentum. As competition for the resource increases, the major consumer will necessarily have to reduce its share. A conservative and optimistic projection indicates that water withdrawals for irrigation in developing countries will need to increase by an aggregated 14 percent until 2030 in order to meet their perceived irrigation expansion needs. Again, the need for increased irrigated agriculture water use efficiencies is clear, where, among others, improved conjunctive surface-ground water relationships are to play a role.

Irrigation's importance lies in its risk averting nature, it constitutes a powerful tool to deal with the vagaries of rainfall. Its availability allows a higher level of planning, both diversification and intensification of land use and makes it economically feasible to invest on other agricultural inputs -fertilizer, pesticides, better quality seeds, and the like. The end result of well managed irrigation should translate into higher yields that can range between two and three times from those of rain fed crops, depending on particular physical and managerial circumstances. As mentioned earlier, by closing of the century, irrigated land made up about one-fifth of the total arable land in the developing countries but contributed two-fifths of all crops and three-fifths of cereal production. Thus, irrigation has a multiplier effect that can make the difference between poverty and being able to meet household's basic food requirements.

The preceding paragraphs suggest the need for reforming irrigation, to cover not only technical aspects but, likewise important, rearranging the sector's institutional setup, with policies and legal aspects included. This again leads to the realm of irrigation empowerment and modernization. The former has already resulted in a worldwide reaching effort in the transfer of responsibilities for operation and maintenance of irrigation systems to water users associations; initially established for that specific purpose and now branching far beyond. However, empowerment alone may not be sufficient to achieve the required adjustments. Irrigation modernization must come into play, as earlier defined: involving institutional, organizational and technological changes, resulting in a process of change from supply-oriented irrigation to service-oriented irrigation.

It is against this broad background that the survey on irrigation modernization originated. The various elements required within an irrigation modernization process need also to be addressed. This discussion is also found in this webpage.

Cosgrove, W.J. and F. R. Rijsberman. 2000. World Water Vision: Making Water Everybody's Business. The Hague, Netherlands: World Water Council.

FAO [Food and Agriculture Organization of the United Nations]. 2003. Unlocking the Water Potential of Agriculture. Rome, Italy. Pp: 62

FAO. 1997. Modernization of Irrigation Schemes: Past Experiences and Future Options. Water Reports: 12. Rome, Italy. Pp: 258 [Wolters, H. W., and C.M. Burt. 1997. Concepts of Modernization. In Modernization of Irrigation Schemes: Past Experiences and Future Options. FAO. Water Report 12, Rome, Italy.]

IPTRID [International Program for International Research in Irrigation and Drainage]. 2003. The Irrigation Challenge: Increasing Irrigation Contribution to Food Security Through Higher Water Productivity from Canal Irrigation Systems. Issue Paper 4. FAO. Rome, Italy. Pp 20

United Nations. 2003. Water for People, Water for Life. World Water Development Report. UNESCO-WWAP. New York, N.Y. Pp: 576

Contact: water-management@fao.org