Small-scale Groundwater Irrigation - Potential and Promise

When you read around the topic of groundwater irrigation in Africa, there seems to be growing popularity (both academic and practical) around the use of what is referred to as “small-scale irrigation” fed by groundwater. This small-scale irrigation (SSI) is seen to be making a significant contribution to food production in developing countries all across the world, and, although groundwater has been somewhat snubbed by African countries up till now (see my previous blog post where we investigate Giordano’s(2006) report into agricultural groundwater use), it is very much growing in importance in many regions such as Sub-Saharan Africa (Villholth 2013).

Before we investigate the extent of SSI across Sub-Saharan Africa (SSA), it is important to define what we mean by “small-scale irrigation”. Generally, SSI refers to irrigation on small plots, using a level of technology which farmers can operate and maintain with a high degree of efficiently and where farmers have autonomy over their practices and lands. Also falling under the definition of SSI is smallholder irrigation; likewise these are small-scale farms, however are privately or publicly owned (but still feature farmer control).

According to Villholth (2013), a current “true” estimate of the extent of SSI across Sub-Saharan Africa is around 1,248,800ha (similar to that provided by Giordano (2006)). Although official statistics regarding groundwater use are imperfect, assumptions can still be made; for example Villholth suggests that the fact that 800,000 motor pumps were imported into Ethiopia between 2004 and 2010 imply a growth in groundwater irrigation of around 100,000ha (assuming one in four of pumps were used for groundwater irrigation and irrigated plots were on average 0.5ha in area).

Small-scale Irrigation in Action

One might ask why such a practice is slowly gathering momentum as a popular farming technique. Both Villholth (2013) and Carter andHowsam (1994) agree that groundwater irrigation paints itself as a highly effective vehicle for bringing development and the benefits that come with it directly to the poor of SSA. This is largely because of the nature of groundwater; the resource itself is relatively communal, and is easily accessed by those who hold a patch of land in a suitable area. There is no need for water to be bought or disseminated at great expense, and the infrastructure required is relatively affordable. In many cases, groundwater provides the opportunity for the poor to support themselves literally "from the ground up".

Groundwater also holds promise as in many cases it is the only perennial water source for a region or area. It is essentially always available, and in many cases offers autonomy of control. This leads to vastly reduced risk for other inputs (for example, seeds, fertilizer and energy) as a consistent supply of water can be assured. This can in turn lead to an intensification of farming (reduced risk means farmers can be more assured in their investments paying off), diversification into cash crops and ultimately higher and more stable outputs that can either provide ample food or generate reliable revenues for an individual or community (Villholth 2013).

Many studies back-up the prowess of small-scale groundwater irrigation as a highly suitable technique. Dittoh et al. (2013) for example found that farmers in the Upper East region of Ghana that were using irrigation saw 20% higher net revenues relative to farmers using surface water. In terms of income, Ajayi and Nwalieji (2010) found  that the number of farmers in a high income bracket increased dramatically in Nigeria following the push for fadamas (irrigated land) since 1993 – an observation shared by the World Bank (2015) who have seen “increase in yield per hectare, quality products, availability of ready markets with good pricing guaranteed”. In fact, Namara et al. (2011) argue that groundwater irrigation makes communities far more secure, noting that rural communities are stabilized due to less distress migration, stemming from increased livelihoods and greater employment opportunities generated.

There seems to be a consensus then that groundwater-fed SSI may be a way forward for not only meeting food needs, but also providing a sustainable and reliable platform on which rural communities can begin to develop. But what is the true potential for SSI? Like most activities, it obviously has its limits, but what are these? While it is VERY tough to estimate groundwater availability, especially so in Africa where data collection is temperamental at best, Pavelic et al. (2013) have reached a rough figure. Through the creation of a simple catchment water-balance based method, which was applied at a national scale for 13 countries in the region, they estimated an area suitable for expansion of around 13 million hectares, which could potentially serve 26 million small farms or households.

This seems like the dream solution. The rural poor of Africa can seemingly build quite literally from “the ground up”, in a way that guarantees their security and autonomy, as well as a bright future. But is it really that easy? In reality, there are a huge variety of prerequisites that would need to be met before Africa could really take off on a “groundwater revolution”. Although promising, then, this solution also represents a huge challenge. This is something I will be discussing more next week.

Until next time.