In 1938, the French colonial authorities in present-day Mali initiated an ambitious infrastructure plan to transform the desert into an agricultural production area. The water was diverted from the Niger River through a system of canals to allow irrigation of over one million hectares of fertile land. Eventually covering over 100,000 hectares, this project is still one of the largest irrigation schemes in Africa.
The Malian project, known as the “Office Du Niger”, has had a profound influence on agricultural water management and planning throughout Africa since the mid-20th century. In the 1960s, African governments saw it as a model for rural development.
With funding from the World Bank, hundreds of dams and large irrigation schemes have been created across Africa. The objectives were to increase food security, reduce poverty and stimulate economic growth. Unfortunately, the reality of many of these irrigation projects has been very different.
Since 2008, in response to rising food prices, governments across Africa have announced plans for a new era of irrigation scheme development. However, it is unclear why previous programs have fallen short of expectations. To answer this question, we evaluated the performance of 79 schemes built in sub-Saharan Africa between the 1940s and 2010.
Our research examined original targets for agricultural production areas, as reported in the project planning documents. These were compared with estimates of how much irrigated land projects currently support. Estimates were derived from high resolution satellite images.
Our results show that these irrigation schemes provide on average only 18% of the irrigated production area they originally proposed. And many schemes are now completely inactive, some only a few years after construction. There seems to be little evidence that system performance has improved in more than 60 years.
Research into individual schemes has blamed a number of factors for the failure of irrigation projects. These include the size of the scheme and the climate. Arguing that larger schemes that experience more variable climates fail more often. This was largely not the case in our analysis of 79 projects.
Instead, we found that the main causes of failure are the political and management structures underlying the development of the irrigation project.
First the politician. For governments, a key motivation for developing the program was to produce more food. This would also reduce dependence on imports while generating exports. But the resulting focus on producing low-value staple crops – such as rice and corn – has often led to poor financial performance.
Low-value crops undermine the financial viability of long-term capital-intensive irrigation projects. This is because these crops do not always generate reliable and substantial profits from the land allotted within the schemes. And this makes it more difficult for farmers to contribute to the upkeep and maintenance of infrastructure.
The result is a cycle of dependence on external investment and subsidies. Once this initial investment is exhausted, many schemes deteriorate rapidly.
Second, donors tend to prefer centrally managed large infrastructure projects. They appear to be less complex technically and logistically than a variety of smaller-scale initiatives. Unfortunately, many centralized government agencies in sub-Saharan Africa are underfunded and understaffed. Many lack the necessary technical and institutional capacity to manage such large-scale projects.
At the same time, donor preferences for scale stimulate the government’s appetite for optimistic plans to leverage financial support. As a result, proposed irrigated areas and scheme yields are often unrealistic. For example, the Office Du Niger only recently reached 10% of the one million hectares projected in 1938. On the other hand, schemes designed to irrigate 127,000 hectares around Lake Chad are now completely inactive.
Planners also underestimate the costs and overestimate the benefits. Our research argues that without changes to the way projects are conceived, implemented and managed, African governments risk repeating the mistakes of 20th century development. This could have detrimental consequences for poverty, food security and economic development.
Ways to move forward
Large-scale irrigation failures in sub-Saharan Africa have been known for several decades. But our research suggests this has had little impact on how planners or governments approach such projects.
Given the actual results achieved, it is questionable that many large-scale irrigation projects have not produced a return on investment. Even those who were initially viable have since devoured funds for maintenance and rehabilitation. Addressing these issues requires greater and more systematic performance monitoring and accounting.
To do this, governments, donors and researchers can use new data sources such as satellite images. Equally important are reforms of planning processes to ensure that investments are contingent on positive and sustainable outcomes for farmers and communities.
In parallel, we also suggest a rethinking of the historical preference for large projects. Are they the best or the only means of increasing food security or farmers’ income?
There is growing recognition that farmers across Africa are highly entrepreneurial. This is evidenced, for example, by the recent increase in attention within the World Bank and other agencies on farmer-led irrigation. Small-scale farmers have developed a wide range of irrigation systems independent of development agencies or governments for many decades and even centuries.
Evidence suggests that these investments can be several orders of magnitude less than large schemes. These can offer better returns in terms of farmers’ income and rural livelihoods.
Investments in large-scale water infrastructure will continue to be an important means of agricultural production. This is all the more true as the availability of water becomes increasingly uneven in many regions due to climate change and the pressures of population growth.
This requires investments in storage infrastructure, both built and natural, to ensure reliable access to water. This in turn provides a basis for encouraging farmers to invest in irrigated agriculture, thereby reducing the risks associated with adopting new technologies or practices.
This also requires new approaches to how irrigation development is financed and implemented in Africa. It is necessary to combine large-scale and small-scale approaches to the development of irrigation to achieve the dual goal of improving food and water security.