Large Scale Irrigation in Sub Saharan Africa: Good, or Bad?

                               "Where water is the boss there the land must obey" - African proverb 

My investigation this week is based on the potential of large-scale farming in Africa to decrease food insecurity. With the premise of water scarcity as the main variable in this blog, I will look specifically at irrigation methods that have been implemented, and if they have increased crop yield. This week I hope to answer if large scale irrigation (LSI) practices are a worthy candidate to eliminate food scarcity in Africa. 

            To irrigate lands in Sub Saharan Africa (SSA), which will be the focus this week geographically, on paper is a “no brainer”. Here, rainfall is extremely seasonal, lands are arid and socially it is home to some of the greatest poverty in Africa. Yet in SSA only 3-5% of crops are irrigated, while farming taking up the livelihood of 2/3 of the population (Adams, 1991). During my research of LSI, I came across three projects that have been studied extensively, specifically in the SSA region. These are the Bakolori Project, the Sokoto state project and the South Chad Irrigation Project. The irrigation methods adopted in these areas were all based on a large-scale dam, or reservoir, to hold water throughout the year, with canals and pipes to connect to farms. Studies were conducted to monitor the effect of these three projects over the course of 20 years. I will state here that I must critique myself for basing my hypothesis of LSI in SSA only on three projects, is no way holistic of the continent of Africa, and even the region of SSA. But for the purpose of this blog and specific topic, to explore these projects made an interesting case. What I found is a case denying any advantageous qualities of LSI to increase food production. The negative outcomes of LSI were through project development not being followed through and adverse impacts both environmentally and socially. 

Map depicting where the three LSI irrigation projects are (Source)

In the case of project development at these three sites, the amount of land initially set to be irrigated by the LSI systems was never reached because of construction never concluding. In the Bakolori project the aim was to have 300,000 ha irrigated. Eight years later the number dropped to 125,000 ha. Even more drastically, in the following six years and the final year of the project, the number dropped to only 30,706 ha irrigated (Adams, 1991). Similarly, in the Lake Chad project, the construction of a pipe supply canal that would be connected to the Tiga dam was halted due to financial constraints. Subsequently, this caused there to be only 12,000 ha irrigated rather than the initial goal of 82,000 ha (Adams, 1991). In the Sokoto state the same pattern occurred, with less irrigated land due to lack of following the development plans. 

In these three areas, because of the inability to produce irrigated land, crop yield decreased with the under-developed LSI systems in place. This greatly tied into the livelihood of the SSA residents, especially the small family farm workers. To depict this, figure 1 shows the projected crop yield compared to the actual crop yield in the South Chad project, where crops yielded only 17-69 % of what was projected. Additionally, seen on the graph is the concern that a drop in crop yield will elevate the possibility of decreasing crop yield in further seasons. 

Figure 1: Projected vs actual crop yields in South Chad Irrigation System (Source)

Financially this is explained by calculating the failure costs of LSI in SSA compared to non-SSA regions, “The average unit total cost of failed new construction projects in SSA is US$23,200 per ha…. more than twice the average of failed projects in non-SSA” (Inocencio, 2007). In other words, if there is a lower crop yield this impacts the SSA region incomparably to the other developing regions this paper examined. This extends the problem that if LSI is not developed well enough to produce a sustaining crop yield, this will hurt the livelihood of African people in SSA more extremely in future years. 

            In terms of environmental problems associating with socio-economic status, this connects to the dependency of the SSA on the seasonality of rain and flooding for small-scale agriculture practices and fishing. When a dam is set in place this disrupts the natural ecology of the river basin. In Bakolori, the reservoir built forced a natural floodplain to be completely covered. Small family farm crops were lost and precious land that was able to hold nutrients and water moisture throughout the year was erased (Yahaya, 2002). On a broader note; in all three projects due to the construction of large dams, people were displaced from their land. In Bakolori, 13,000 family farms were left without a home or their means of life, farming (Yahaya, 2002). In the Kano River project small-scale farmers had to sell their land and then search for work in the now bigger farm schemes, making an “increased inequality in land and income distributions” (Adams, 1991). Overall, these environmental land changes from the LSI systems brought new socio-economic conflicts to the already, poverty-stricken area of the SSA. 

The Bakolori Dam to show its immense size (Source)

            Regarding my research this week, I find myself asking even more questions than when I first started examining the topic of LSI. Looking at these projects that have been monitored in the SSA, what stood out to me were the predominate facts of failure; crop yield decrease, environmental ecological problems, a wider gap in socio-economic status and to touch on my overall theme, a seemingly greater problem of food scarcity. I have noted that this overarching negative outcome of the three projects was greatly due to the infrastructure planned not being completely built, because of financial and governmental constraints on the project. In theory, the potential of LSI was never fully realized. I conclude with the question of if larger irrigation practices to help food security will only successfully work if there is enough continuous resources and aid from larger organizations, or if the larger systems will fundamentally not work and resources should be given to small scale farmers only?