waking a sleeping giant: realizing the potential of groundwater in … · 2019-07-12 · waking a...

World Development 122 (2019) 597–613

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World Development

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Waking a sleeping giant: Realizing the potential of groundwaterin Sub-Saharan Africa

https://doi.org/10.1016/j.worlddev.2019.06.0240305-750X/� 2019 Elsevier Ltd. All rights reserved.

⇑ Corresponding author at: PO Box 77000, Port Elizabeth 6031, South Africa.E-mail addresses: [email protected] (J. Cobbing), [email protected]

(B. Hiller).1 We largely adopt the World Bank definition of SSA, comprising 48 countries,

extending from Mauritania, Mali, Niger, Chad and Sudan in the north, to South Africain the south.

2 Almost half of the SSA population lives below the international poverty line.

3 The United Nations Office for the Coordination of Humanitarian(UNOCHA). December 2016 (2016) regarded a drought in 2016 as the woyears, with 38 million people at risk across eastern and southern Africa. Furtvon Uexkull (2014) and Couttenier and Soubeyran (2014) find at least a weaklink between drought and civil conflict/war.

4 Including urbanization, population growth, increasing per capita consrates, increasing average temperatures, reduced rainfall in dry months, and ifrequency and magnitude of extreme events.

Jude Cobbing a,⇑, Bradley Hiller baAfrica Earth Observatory Network (AEON), Nelson Mandela University, South AfricabGlobal Sustainability Institute, Anglia Ruskin University, UK

a r t i c l e i n f o a b s t r a c t

Article history:Accepted 19 June 2019

Keywords:GroundwaterSub Saharan AfricaPolitical economy factorsIrrigationUrban and rural water securityResilience

Unlike many global regions, Sub-Saharan Africa (SSA) has yet to undergo a groundwater revolution. Inthis paper we confirm that for most SSA countries current groundwater use remains under 5% of nationalsustainable yield. This is likely to be a constraint on wider economic development and on addressing vul-nerabilities to climate change and other shocks. Groundwater use has supported the process of economicstructural change in other global regions; hence we derive an empirical model for groundwater use tosupport economic development, comprising trigger, boom and maturation phases. We identify that thetrigger phase depends on political and economic (‘secondary’) factors, in addition to resource character-istics. The boom phase is described as ‘semi anarchic’, while the maturation phase is characterized byslowing abstractions but continued economic benefits. In SSA, we posit that the predominance of limitingsecondary factors, coupled with a discourse of caution and focus on the maturation phase (more appro-priate for other regions), is constraining the use of groundwater for economic development. We suggestthat groundwater has the potential to be a foundational resource to support irrigated agriculture, urbanand rural water security, and drought resilience across the region, as it has in many other global regions.We argue that overcoming the current barriers and costs to groundwater development can be offset bythe benefits of regional socioeconomic development and increased resilience. In the context of enduringpoverty and recurrent humanitarian crises in SSA, this new synthesis of information suggests that such anunderutilization of sustainable groundwater is unjustifiable. Stakeholders active in the region should pri-oritize groundwater development to help facilitate a transition to higher value-added activities andgreater regional prosperity and resilience, and ensure that measures are put in place for this to be donesustainably. We conclude with some ideas to help trigger such development in SSA.

� 2019 Elsevier Ltd. All rights reserved.

1. Introduction

Sub-Saharan Africa (SSA)1 (Fig. 1) suffers chronic developmentchallenges2, some of which are related to the availability of, andaccess to, water resources. Economic and/or absolute water scarcityin SSA manifests in 315 million people remaining without access toimproved drinking water (UNDESA, 2015), endemic food insecurityand low levels of irrigated agriculture (Siebert et al., 2010; Pavelicet al., 2012) and recurrent drought events (Besada & Werner,

2015; Baro & Deubel, 2006), all of which can contribute to humani-tarian crises, environmental migration and civil instability3. Further-more, major climate and non-climate drivers4 are predicted to placeincreasing pressure on regional water resources (Thompson,Berrang-Ford, & Ford, 2010; UNDP, 2012, Gizaw & Gan, 2017).

To remedy current scarcities and meet future demands, waterresource development in SSA should diversify away from a pre-dominant investment focus on surface waters (Foster, Hirata, &Howard, 2011) towards an integrated range of alternatives,

Affairsrst in 35hermore,positive

umptionncreased

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Fig. 1. Sub-Saharan Africa, with drylands highlighted (after Ward et al., 2016).

598 J. Cobbing, B. Hiller /World Development 122 (2019) 597–613

including groundwater5. Conditions in SSA are suitable for potentialgroundwater contribution: rainfall volatility is the highest of anyregion globally (Calow & MacDonald, 2009), much of the region’spopulation lives distant from a perennial surface water source(Kummu et al., 2011), and 40% of the region is classified as drylands6

(Fig. 1) (Ward, Torquebiau, & Xie, 2016). Groundwater may also offerflexibility, timeliness and resilience of use and the potential to avoidsome of the centralized technical and institutional burdens associ-ated with surface water development (Pahuja et al., 2010). However,despite such inherent potential benefits in many parts of SSA7,groundwater remains a poor sibling of surface water, due to – atleast in part – its hidden nature, both physically and institutionally(Wijnen et al., 2012; Braune & Xu, 2010).

The record of groundwater development in SSA to date is one ofnuance and contrast. On one hand, accessible and often shallowgroundwater resources are utilized by millions of private wellowners and communities who apply low technology and tradi-tional methods (such as hand dug wells) for local drinking/live-stock water and small-scale irrigation. Abstraction of suchaccessible groundwater resources has doubled in the last two dec-ades across much of SSA (Pavelic et al., 2012) and an estimated 50%(Carter & Parker, 2009) to 75% (Goulden et al., 2009) of the regionalpopulous now relies on these resources. In short, such resourcesare used widely, but often not intensively, at a regional scale. How-ever, they can be prone to local mismanagement (including over-exploitation and pollution), their seasonal fluctuations can bevulnerable to drought events and their utilization is often not opti-mized. On the other hand, less accessible and often deeper ground-water resources remain poorly understood and largely unutilizedat scale. Such resources require greater technology and financingto access and pump despite being typically more resilient, reliable

5 Groundwater is water contained in interconnected pores in the saturated sub-surface, accessible via wells and boreholes and which can emerge naturally at thesurface as springs, baseflow to rivers, and other discharges.

6 Defined based on the Aridity Index (Trabucco & Zomer, 2014) and including arid,semi-arid and dry sub-humid areas. Climate change is expected to exacerbate thearidity of drylands in SSA (Haensler, Hagemann, & Jacob, 2011).

7 Including large storage volumes, lower development costs, lower treatmentrequirements, lower evaporation losses, greater resilience (buffer) to climate varia-tions / change and extreme events, protection from pollution, local availability andincremental development potential.

and able to support greater yields. As an example, few large urbanwater utilities in the region favor groundwater as a permanentsource of supply (Foster, Hirata, Misra, & Garduno, 2010).

The relative absence of strategic and large-scale formal invest-ment in SSA’s groundwater, and of formal policy and institutionalsupport (Braune & Xu, 2010), lies in contrast to many globalregions (such as South Asia, People’s Republic of China (PRC), Mid-dle East and west coast USA), where groundwater has underpinnedimpressive development outcomes (Ward et al., 2016).

We believe that multiple demand- and supply-side factors areconverging to make now the right time to address increasinglyurgent humanitarian, socioeconomic and climate imperatives viaan exploration of sustainable groundwater development potential.Up until now, there has been limited, and at times contradictory,information on the potential and accessibility of groundwaterresources across SSA. For example, warnings about SSA’s limitedgroundwater potential (e.g. Edmunds, 2012) contrast with reportsof ‘megawatersheds’ and substantial underexplored resources (e.g.Bisson & Lehr, 2004). There has also been little research into factorsresponsible for the current levels of under-development. We aimto understand some of the conditions which could help promptgreater groundwater utilization at scale, beginning with an explo-ration of the availability and accessibility of SSA groundwaterresources as a basis before moving forward.

2. The groundwater resources of Sub-Saharan Africa

2.1. Assessment

The groundwater resources of SSA are among the least under-stood globally (Tuinhof et al., 2011; Villholth, 2013), with a fewwell-studied aquifers contrasted with large areas where detailedknowledge of local conditions remains poor. The sheer scale ofSSA presents both opportunity and challenge: on one hand it is agrowing regional economy with a diverse population of approxi-mately one billion; on the other, the SSA drylands alone areroughly the size of Europe and India combined, which increasesthe complexity of assessing and utilizing regional groundwaterresources. Yet, SSA contains a small fraction of Europe and India’sborehole records and hydrogeological studies for characterizingits groundwater resources8. Continental scale assessments ofgroundwater resources exist but rely on remotely sensed data com-bined with global model outputs (e.g. Döll & Flörke, 2005; Siebertet al., 2010). Likewise, contemporary (post-1980) hydrogeologicalmaps are often available at national or regional scale (using geolog-ical data of similar scale and supplemented by hydrogeological dataif available, e.g. MacDonald, Bonsor, Dochartaigh, & Taylor, 2012;SADC, 2009).

However, groundwater is a resource that depends on local geol-ogy, topography and climate, and its potential is spatially highlyvariable. Local hydrogeological investigation is vital to confirmparameters such as sustainable yield, water quality and currentusers.

Within the region, there is also high variability in the availabil-ity of hydrogeological data (and data products such as maps andanalyses). For example, in some countries (such as the DemocraticRepublic of Congo) routine monitoring of groundwater levels and

8 Limited knowledge and poor data coverage sometimes mean Africa’s geology(and groundwater resources) is over-simplified. A recent book on world groundwaterstates: ‘‘Sub-Saharan Africa’s geology consists of four basic rock types: Precambrianbasement rocks, consolidated sedimentary rocks, unconsolidated sediments, andvolcanic rocks” (Alley & Alley, 2016:72). Foster et al. (2012) classify Africangroundwater into three simple categories. Such assessments can provide a usefuloverview but may also obscure the fact that Africa’s geology and groundwaterresources are at least as diverse and complex as those of other continents.

J. Cobbing, B. Hiller /World Development 122 (2019) 597–613 599

quality is rare, and in some others (such as Zimbabwe), it is indecline (Robins, Davies, Hankin, & Sauer, 2002). Where data isavailable, it can be difficult to access (Cobbing & Davies, 2011). Avicious cycle often exists: poor groundwater data contributes tolow levels of groundwater development, which in turn produceslittle data (Robins et al., 2002).

Recent water resources studies (both surface water and ground-water) show that, on average, the region withdraws about 121 bil-lion cubic meters (BCM) per annum9, which corresponds to lessthan a quarter of the region’s total internally renewable waterresources10. This is about 170 m3 per capita, less than a third ofthe world average of 600 m3 per capita (Ward et al., 2016). In com-parison, India currently withdraws approximately 761 BCM of water,or about 60 times more per unit area (FAO, 2016). Whilst total with-drawals in SSA for agriculture doubled between 1960 and 2008, theregional population has more than tripled during the same time(from about 229 million people to 830 million people, according toWorld Bank data) and neither (irrigated) food production nor watersupply and sanitation services are keeping up with populationgrowth. However, the constraint is not an absolute lack of water.

The total volume of groundwater in storage in Africa (includingnon-renewable groundwater) has been estimated at 0.66 mil-lion km3 (i.e. 660,000 BCM) with a range in uncertainty of between0.36 and 1.75 million km3 (MacDonald et al., 2012). This is not thesame as the total renewable or practically accessible volume, but itmeans that groundwater is by far the largest stock of fresh wateron the continent. In contrast, freshwater storage in African lakesis estimated at about 0.03 million km3 (MacDonald et al., 2012).Despite this, international organizations sometimes imply thatgroundwater is considerably smaller in volume compared withsurface water. For example, a report on African water resourcesby the United Nations Economic Commission on Africa (UNECA,2004:2) states: ‘‘The continent has large rivers, big lakes, vastwater lands and limited, but widespread, ground waterresources”11.

The total volume of theoretically renewable groundwater in SSAis calculated to be about 1400 cubic kilometers per year (km3/yr)(FAO, 2016; Margat & van der Gun, 2013). Of this volume, it is esti-mated that only about 20 km3/yr (±0.14%) is being abstracted. Thecomparable figures for India are about 432 km3/yr total (Frenken,2011), with about 251 km3/yr of this groundwater being with-drawn (±58%)12. In SSA, average per capita annual abstraction ofgroundwater is 28 m3/yr, compared to 208 m3/yr for India. WithinSSA, per-capita volume withdrawn in the drylands is higher thanthe regional average, but still well below sustainable levels and thefigure for India (Fig. 2).

9 Approximately 87% (105 BCM) of total SSA water withdrawal is used foragriculture, with the remainder used for domestic (10%) and industrial (3%) uses(Ward et al., 2016). Worldwide, agriculture accounts for approximately 70% for waterresource consumption.10 Internal renewable water resources is that part of the water resource (surfacewater and groundwater) generated from endogenous precipitation. We distinguishbetween ‘renewable’ and ‘non-renewable’ groundwater resources. Renewablegroundwater is replenished under current climatic conditions, often seasonally orevery few years. Non-renewable groundwater, sometimes called ‘fossil groundwater’,is groundwater that receives little or no modern recharge. Although non-renewablegroundwater cannot be used indefinitely, it can sometimes be used for decades orlonger. For example, Libya’s ‘great man-made river’ project uses fossil groundwaterfrom the Nubian Sandstone aquifer to provide water to coastal cities, in theknowledge that this resource is finite (Voss & Soliman, 2014), analogous to the miningof a mineral resource.11 Rebouças (1999:235) reported similar misconceptions of groundwater resourcesin Latin America, describing it as ‘‘frequently approached as something mystic ormetaphysical by the public in general, and even by professionals”.12 These figures for groundwater include overlap with surface water resources (i.e.pumping groundwater would reduce surface water flows), but do not include non-renewable groundwater resources, which are substantial in SSA.

While average regional figures mask significant variationbetween countries (Table 1), it is also evident that only seven of43 (16%) SSA countries are currently using more than 10% of theirrenewable groundwater resources, and 26 of 43 (60%) countriesuse less than 5% of their renewable groundwater resources. Onlytwo countries (Djibouti and Mauritania) exceed their renewablegroundwater limits. Only Mauritania uses more groundwater percapita than India (220 m3/yr) – the next three heaviest per capitausers (Botswana, Namibia and South Africa) all use less than onethird of that.

Based on a synthesis of available information by the BritishGeological Survey (MacDonald et al., 2012), Fig. 3a links spatialvariation with estimates of depth to groundwater across SSA.Fig. 3a illustrates that many areas contain groundwater resourcesat depths of less than 50 or 100 m, where development could con-tribute to resilience and economic opportunities. While some ofthese groundwater depths may be outside the range of accessibil-ity for many individual smallholder farmers and household watersupplies, they are within range of more collaborative developmentfor similar purposes. Furthermore, linking spatial and geologicalvariation with estimates of recharge to groundwater, work by theBundesanstalt für Geowissenschaften und Rohstoffe (BGR) andUNESCO (BGR & UNESCO, 2008) – as presented in Fig. 3b – synthe-sizes available information on groundwater recharge and aquifertype at regional scale across SSA. Both Fig. 3a and b suggest thatin many parts of SSA, including dryland areas, groundwater is oftenavailable (and recharged) where it is most needed.

2.2. Potential for sustainable use

Hence, for 41 of 43 countries in SSA where there are estimatesof renewable groundwater resources, there is significant unutilizedpotential. This is despite well-documented benefits of groundwateracross key sectors, such as: (i) irrigated agriculture, (ii) urban andrural water security, and (iii) drought resilience, each of which isbriefly discussed below.

Agricultural productivity is generally a strong driver of struc-tural change (McArthur & McCord, 2017). More specifically forSSA, authors such as Van Loon and Van Lanen (2003) andWijnen, Barghouti, Cobbing, Hiller, and Torquebiau (2018) high-light the salience of agricultural water development for economicgrowth and poverty eradication in SSA. Growth in GDP in SSAdue to agriculture is estimated to be multiple (�11) times moreeffective in reducing poverty than growth from other sectors(Shah, Verma, & Pavelic, 2013). It is estimated that irrigated agri-culture could boost SSA agricultural yields by more than 50%, sup-port diversification to higher-value crops13 and achieve beneficialsupply-chain effects which help to catalyze local virtuous circles ofeconomic growth and development14. Some experts contend thatincreasing agricultural productivity, including specialist horticulture,is part of a new pattern of structural change in SSA, different to themanufacturing-led boom in South Asia (Page, 2018). The total area ofcultivated land in SSA is about 237 million hectares (MHa), of whichonly about six to seven MHa, or approximately �3%, is thought to beirrigated (the comparable figure for irrigated land for South Asia is42% (Ward et al., 2016)). Despite comprising such a small proportionof total agricultural land in SSA, Shah et al. (2013) found that irri-gated land currently contributes 25% of the region’s agricultural out-put. Only eleven SSA countries have irrigated areas larger than0.1 MHa, and only two (Madagascar and South Africa) have irrigatedareas larger than one MHa (Table 2). In comparison, the US state of

13 Supported by a series of studies by FAO, IFPRI, IWMI, Villholth 2013 and severalregional and national research and development agencies.14 Results from a groundwater-based irrigation study by Lejars, Daoudi, and Amichi(2017) in North Africa.

Fig. 2. Comparison between renewable groundwater and groundwater abstracted: for SSA, SSA drylands (countries with >40% land area classified as dry sub-humid or drier)and India (Source: FAO, 2016).


Nebraska alone has about 3.4 MHa under irrigation (much of thisfrom groundwater), about the same as the top three SSA countriescombined (Johnson, Thompson, Giri, & Van NewKirk, 2011). Criti-cally, the percentage of cultivated land irrigated by groundwater inSSA is lower still – only about 1% of cultivated land, or about twoMHa. This is despite multiple recent studies (Xie, You, Wielgosz, &Ringler, 2014; Villholth, 2013; Pavelic, Villholth, & Verma, 2013;Wijnen et al., 2018) confirming significant groundwater irrigationpotential in SSA. For example, Pavelic et al. (2013) estimated that a120-fold increase in groundwater-supported irrigable area was pos-sible across a sample of 13 SSA countries (taking into account waterdemands from other sectors, including the environment). Sub-regions of SSA, such as the Sahel, exhibit great potential for irrigationfrom groundwater to support higher value agricultural and horticul-tural products (Wijnen et al., 2018).

We argue that comments made above regarding the availabilityof groundwater for irrigation also often hold true for potable watersupplies in SSA, since the volumes and quality required can be sim-ilar. The potential of groundwater for improving urban and ruralwater security in SSA – both for municipal water-supply systemsand for direct in situ water supply – has long been recognized(Foster et al., 2011, 2012), along with its potential for local over-abstraction and contamination (Braune & Xu, 2010; Nlend et al.,2018; Tuinhof, Foster, van Steenbergen, Talbi, & Wishart, 2011).While some large SSA cities are partially or mostly dependent ongroundwater (e.g. Abidjan, Addis Ababa, Dar Es Salaam, Dodoma,Lusaka, Pretoria, Windhoek), the resource is still not widely seenas a strategic asset by most SSA water utilities (Foster, vanSteenbergen, Zuleta, & Garduno, 2010). However, as witnessed in2018 in the South African city of Cape Town, many growing urbansettlements in SSA are outgrowing their increasingly vulnerablesurface water sources and face the possibility of ‘Day Zero’, whentaps run dry (Wijnen et al., 2018). With half of the SSA cities in2035 not yet built and the secondary15 cities of today expected tobecome the mega cities of tomorrow (Jacobsen, Webster, &Vairavamoorthy, 2013), a quadrupling in water supply service rateswill be required just to maintain current levels16 (let alone to

15 Currently with populations under 1 million people.16 A recent World Bank report confirms that although water delivery services inseveral SSA urban centers have improved, the portion of households connected toclean water supplies have declined by more than 15 percent (IEG, 2017).

increase proportional coverage), much of which will need to comefrom groundwater (Banerjee & Morella, 2011). UPGro (2017:64) sug-gests that wherever high-yielding aquifers exist within 30 km of anurban demand center in SSA, their managed and staged developmentby water utilities ‘‘can significantly increase water-supply security”.Pavelic et al. (2012) found that drinking water supplies sourced fromgroundwater in rural/small towns in SSA can be high in some coun-tries (e.g. 92 percent in Niger, 70 percent in Nigeria). Indeed, Tuinhofet al. (2011:21) found that many SSA towns ‘‘depend on groundwa-ter for their municipal water-supply over a wide range of hydrogeo-logical settings”. SSA does contain some world-leading examples ofgroundwater innovation, such as in Windhoek, the capital of Namib-ia, which operates a managed aquifer recharge (MAR) scheme wheresurplus water is stored underground in aquifers during times ofplenty, to be extracted as high-value water during droughts(Murray, van der Merwe, Peters, & Louw, 2016). The phased capitalcost of groundwater development may permit greater water sourceand supply coverage to poorer consumers (UPGro, 2017) and MARschemes could be coordinated with improved sanitation/wastewatermanagement (Lapworth et al., 2017; Adelana, Tamiru, Nkhuwa,Tindimugaya, & Oga, 2008).

UNISDR (2009) report that droughts in SSA account for less than20% of natural disasters but account for over 80% of the affectedpopulation. Shiferaw et al. (2014:67) describe the economic, socialand environmental impacts of drought in SSA as ‘‘huge”, withnational costs and losses incurred threatening to ‘‘undermine thewider economic and development gains made in the last few dec-ades in the region”. In recent history, SSA has suffered numerousdroughts, most notably across the Sahel, southern Africa and theHorn of Africa (Sheffield et al., 2014). For example, between 1970and 2017, more than 30 countries in SSA experienced at least eightdroughts, with sub-regions, such as the Horn of Africa, experienc-ing frequently recurring and widespread events (Burney et al.,2013; Pavelic et al., 2012) and countries, such as Kenya, experienc-ing associated economic costs of up to 1% of annual GDP(Demombynes & Kiringai, 2011; Stockholm EnvironmentInstitute, 2009). However, there has typically been little sustainedinterest in drought mitigation measures in SSA (Benson & Clay,1998) and the current paradigm (globally and in SSA), is focusedpredominantly on disaster response, rather than prevention andpreparedness. For example, only four percent of global humanitar-ian aid goes towards prevention and preparedness, despite it being

Table 1Groundwater resources and groundwater use in SSA (supplementary material1).

SSA country Renewablegroundwater (km3/yr)

Groundwaterabstraction (km3/yr)

Proportion of renewablegroundwater that is used (%)

Groundwater abstractionper capita (m3/yr)

Angola 58 0.41 0.7 21.5Benin 1.8 0.17 9.4 19.2Botswana 1.7 0.14 8.2 69.8Burkina Faso 9.5 0.39 4.1 23.7Burundi 7.47 0.16 2.1 19.1Cameroon 100 0.37 0.4 18.9Central African Rep. 56 0.08 0.1 18.2Chad 11.5 0.45 3.9 40.1Congo Dem. Rep. 421 1.22 0.3 18.5Congo Brazzaville 122 0.03 0.0 7.4Cote d’Ivoire 37.84 0.37 1.0 18.7Djibouti 0.015 0.02 133.3 22.5Eq. Guinea 10 0.01 0.1 14.3Eritrea 0.5 0.09 18.0 17.1Ethiopia 20 1.49 7.5 18.0Gabon 62 0.03 0.0 19.9Gambia 0.5 0.03 6.0 17.4Ghana 26.3 0.51 1.9 20.9Guinea 38 0.09 0.2 9.0Guinea-Bissau 14 0.03 0.2 19.8Kenya 3.5 0.62 17.7 15.3Lesotho 0.5 0.02 4.0 9.2Liberia 45 0.07 0.2 17.5Madagascar 55 0.38 0.7 18.3Malawi 2.5 0.28 11.2 18.8Mali 20 0.34 1.7 22.1Mauritania 0.3 0.76 253.3 219.7Mozambique 17 0.44 2.6 18.8Namibia 2.1 0.15 7.1 65.7Niger 2.5 0.14 5.6 9.0Nigeria 87 3.44 4.0 21.7Rwanda 7 0.2 2.9 18.8Senegal 3.5 0.74 21.1 59.5Sierra Leone 25 0.11 0.4 18.7Somalia 3.3 0.28 8.5 30.0South Africa 4.8 3.14 65.4 62.6Sudan and S. Sudan 7 0.59 8.4 13.3Swaziland 0.66 0.04 6.1 33.7Tanzania 30 0.98 3.3 21.9Togo 5.7 0.11 1.9 18.2Uganda 29 0.62 2.1 18.5Zambia 47 0.3 0.6 22.9Zimbabwe 6 0.43 7.2 34.2

1 Figures after Margat and van der Gun (2013), Döll and Fiedler (2008), Siebert et al. (2010), and FAO (2016 – AQUASTAT database). Continental models calculategroundwater recharge using available rainfall data, and take topography, soil type and geology into account. They use a monthly time-step function, often with a spatialresolution of around 0.5� by 0.5�. Inherent uncertainty in the data is acknowledged, but the point remains that large increases in sustainable use of groundwater, on average,are possible for most SSA countries.


more cost-effective, helpful in mitigating the worst effects ofhumanitarian emergencies, and protecting development gains invulnerable communities (Kellet & Sweeney, 2011; Cabot Venton,Fitzgibbon, Shitarek, Coulter, & Dooley, 2012). While water man-agement cannot prevent drought17, ex-ante management strategies(Shiferaw et al., 2014), such as strategic development of groundwa-ter resources could help mitigate both the acute and chronic socialand economic impacts for many SSA countries. We propose develop-ing a strategic network of deep groundwater bores in drought ‘hot-spots’ to improve resilience for future emergency events,particularly in the context of climate variability and change.

Finally, environmental sustainability of groundwater resourcesis a concern (Villholth, 2013; Braune & Xu, 2010). Locally, aquifersmay be over-exploited, with a range of disbenefits, reinforcing theneed for better local data, and for local-level investigations prior togroundwater development. Fig. 4 summarizes work by Altchenkoand Villholth (2015), who calculated potential irrigable areas per

17 Drought is a natural hazard caused by large scale climate variability (Van Loon &Van Lanen, 2013; Sadoff, 2016).

SSA country, whilst also reserving a proportion of groundwater(30%, 50% or 70%) for environmental purposes. It is evident that,for nearly all SSA countries, groundwater abstraction could begreatly increased on average, even with stringent environmentalprovisions.

3. An empirical model of groundwater development

Confirmation that most countries in SSA use less than 5% oftheir renewable groundwater, coupled with the knowledge thatgroundwater contributes to structural development in many otherglobal regions, poses the question of why SSA’s groundwater devel-opment trajectory should be any different. An empirical model(Fig. 5) helps to understand the process of groundwater develop-ment, with the goal to help facilitate progress in SSA.

The model is built around three key phases: (i) Trigger phase:where multiple factors combine to reach a tipping point to ‘trigger’intensive groundwater utilization; (ii) Boom phase: a rapid scalingup of increasingly sophisticated groundwater utilization (andassociated economic development); and (iii) Maturation phase:where (volumetric) utilization peaks before either plateauing or

Fig. 3. (a) Depth to groundwater across SSA (after MacDonald et al., 2012) and (b) Groundwater recharge across SSA (after BGR & UNESCO, 2008).

Table 2Cultivated land and irrigation in India and Sub-Saharan Africa (FAO, 2016 and World Bank data).

Pop.(billions)

Total area of cultivableland (Mha)

Area of land that iscultivated (Mha)

Area of land that isirrigated (Mha)

Cultivated land that isirrigated (%)

Surface waterirrigation (Mha)

Ground- waterirrigation (Mha)

SSA 0.9 400 237 7 3% 5 2India 1.3 173 160 66.3 39% 24.5 41.8

Fig. 4. Potential areas in SSA irrigable with groundwater, whilst reserving a percentage of groundwater (30%, 50% or 70%) for environmental requirements (Altchenko &Villholth, 2015).

18 Arguably, select other global regions, such as parts of South America, also havenot undergone significant groundwater development, although they have advancedfurther than SSA (Rebouças, 1999; International Groundwater Resources AssessmentCentre (IGRAC), 2014).


moderating, conservation and/or remediation measures becomeinfluential factors, and economic advancement continues via inno-vation and efficiency gains.

The model is based on empirical evidence from various regionsglobally that have experienced the trigger-boom-maturationphases (see Fig 6a and B in the United States and the PRC respec-tively, and Fig. 7 in India, as examples). Authors such as Shah(2009) have reported similar empirical trends in local groundwaterdevelopment.

However, the most critical component of Fig. 5 is the trajectoryof groundwater development in SSA, which, in general, has notexperienced the groundwater trigger-boom-maturation phasingevident in many other global regions18. Below we analyze each of

Fig. 5. Empirical model of groundwater development – trigger, boom and maturation phases.

Fig. 6. a – United States national groundwater withdrawals (billions of gallons per day) (United States Geological Survey (USGS). December 2017, 2017), and b – PRC nationalgroundwater withdrawals (billions of cubic meters per year).


the three phases of groundwater development, with a focus on theprevailing conditions in SSA relative to other global regions and onidentifying potential factors to trigger SSA’s groundwater boom.

The observed correlation between more intensive groundwateruse and economic or structural development is not evidence for acausal relationship. Nevertheless, we demonstrate the potentialof untapped groundwater resources in SSA to impact positivelyon at least three sectors (irrigated agriculture, urban and ruralwater security, and drought resilience), all of which are likely tobe important components of the required structural economicchange in SSA. The secondary or political-economy factors whichwe outline in the section below influence the relationship betweengroundwater use and economic development in complex ways.Different political-economy considerations apply to the three sec-tors, and the presence of a groundwater resource is only one of sev-eral necessary attributes. The successful utilization of groundwaterin one area does not necessarily imply that the conditions will be

right for success in others. Instead, we use the empirical modelto extract principles of practice associated with different phasesof groundwater development and draw upon examples from differ-ent global regions to help understand factors contributing to phasechanges. We acknowledge that each region’s experience comprisesa unique combination of physical, social, political and economicconditions (taken at specific junctures) and is illustrative and infor-mative rather than directly comparable with other regions.

3.1. The trigger phase

While groundwater resource availability is determined by phys-ical factors, the dynamics and sustainability of groundwater useare determined by socioeconomic and institutional factors(Pahuja et al., 2010). As we described in Section 2, the theoreticalavailability of renewable groundwater in SSA does not appear tobe the main reason for the region’s low groundwater utilization

Fig. 7. Tube wells are increasingly the main source for irrigation in India (irrigated area, ‘000 ha) (after Indian Ministry of Agriculture and PRS Legislative Research. 2014,2014).


(Chokkakula & Giordano, 2013). Similarly, Pahuja, Tovey, Foster,and Garduno (2010:79) found in India that there is ‘‘almost no cor-relation between groundwater availability and groundwater use”.Whilst poor local groundwater availability clearly precludesgroundwater-based development, once this threshold is passed itappears that factors other than the physical availability of ground-water control the ‘triggering’ of development.

Several authors have identified and discussed ‘secondary’ orpolitical economy factors that combine in various ways to con-strain groundwater exploration, drilling, borehole installation andmechanized pumping (e.g. Villholth, 2013; Chokkakula &Giordano, 2013, Shah et al., 2013; van Koppen, 2003; Wijnenet al., 2018; Foster et al., 2012). Secondary factors include a diverserange of issues (discussed below) and may be more important tooverall water supply viability and sustainability than physicalgroundwater availability. DeFries and Nagendra (2017) concludedthat groundwater physical conditions and secondary factors inter-act in any groundwater economy to give rise to complex or‘wicked’ problems with non-linear components and feedback atvarious levels.

In SSA, it is likely that secondary factors are collectively the lar-gest obstacle to a step change in groundwater use (Shah et al.,2013; Chokkakula & Giordano, 2013; Tuinhof et al., 2011). Never-theless, and as their name implies, such factors are often seen assubordinate or ‘secondary’ to primary groundwater availability,which is presumed to be the controlling variable. In other globalregions, some critical secondary factors contributing to triggeringof groundwater development included irrigation technology inno-vations in the USA (Ashworth, 2006), energy subsidies in SouthAsia (Shah, 2009), and macro policy in the PRC (de Marsily &Abarca-del-Rio, 2016). However, comparatively little is knownabout secondary factors generally, despite their apparent impor-tance in influencing groundwater development. The interactionof possible secondary factors that may play a critical role in trigger-ing groundwater development in SSA is explored below, drawingon a relatively scant base of available information.

3.2. Secondary factors

Empirical observation suggests that hydrogeological data doesnot automatically lead to better or more widespread groundwaterdevelopment; in fact, it is often widespread groundwater develop-

ment that leads to better data. Increased groundwater use in turnhelps shape the wider political-economy, such as subsidies andother policy structures for agricultural products in Midwest USA(Ashworth, 2006) or the nature of electricity pricing in India(Shah, 2009; Shah, Verma, & Durga, 2014). These outcomes wouldhave been difficult to foresee prior to widespread groundwaterdevelopment since they are the products of iterative political inter-actions in a particular social context. These political-economydevelopments have still wider backward and forward linkageswith further implications for the pace and characteristics of devel-opment. The nature and trajectory of economic development basedon groundwater development is therefore likely to be a complexsystem rather than an arrangement of predictable cause-and-effect linkages.

Secondary factors that initially appear relatively minor canderail a groundwater project as effectively as the physical absenceof groundwater. For example, lack of access to credit facilities orcollateral may make drilling even shallow boreholes impossible(Colenbrander & van Koppen, 2013). Alternatively, more affordableenergy can make pumping from greater depths viable, with thesame overall outcome on a groundwater project as a shallowerwater table. Hence, a favorable political economy can bring anexisting physical groundwater resource within easier reach, whilsta political economy indifferent to groundwater development canplace a viable resource out of bounds.

Here, we draw on the limited literature on secondary or politi-cal economy factors which may affect the triggering (and ongoingnature) of groundwater development, broadly categorizing themas: (i) material, financial and technical factors, and (ii) social, legaland institutional factors. The factors we identify are not exhaustivebut serve to illustrate the types of secondary factors that could beinfluential in SSA.

3.2.1. Material, financial and technical factorsEnergy availability and price: determine pumping (and treat-

ment) potential of groundwater, via electricity and alternativeenergy sources, such as diesel or kerosene. According to WorldBank data, less than 25% of SSA’s rural population has access toelectricity in all but eight countries. Penetration of energy servicesand price were critical factors in triggering groundwater irrigationin India (Shah et al., 2014) and indeed, groundwater irrigationconsumes up to 31 percent of India’s electricity, with government


subsidies helping shield farmers from the full cost of pumping(Pahuja et al., 2010). Authors such as Shah et al. (2013) state thatmotorized irrigation is needed to truly transform agricultural out-put, as evidenced from a study of smallholders in nine SSA coun-tries where irrigation by motorized pumps more than doubledoutput. The advent of increasingly affordable solar pumping sys-tems presents intriguing possibilities in accessing groundwaterresources, as well as new challenges for management (Shahet al., 2014; World Bank, 2015).

Cost and availability of drilling equipment, pumps, spare parts, andrelated equipment: tend to be high in SSA, relative to other globalregions (Shah et al., 2013). Real drilling costs may be higher thanequipment costs imply, due to large distances, rugged conditions,need for prompt return on investment, lack of competition,and/or poor regulation. The full benefits of cheaper foreign pumpsand related equipment have yet to be realized in many parts ofSSA, partly due to import restrictions (Colenbrander & vanKoppen, 2013). Pahuja et al. (2010) identified the increase in avail-ability of modular well and pump technologies (coupled withaccess to credit) as an important contributing factor to triggeringIndia’s groundwater revolution. Similarly, Shah et al. (2014:10)point out that ‘‘in effect, electric and diesel water extraction mech-anisms have become the engine of India’s agricultural and ruraleconomy”. These costs link to other factors: for example, a studyin Zambia (Colenbrander & van Koppen, 2013) found a lack ofinformation and spare parts, coupled with transport costs, can con-stitute a third of delivered pump costs.

Technical data and information: extends beyond hydrogeologicaldata to include information on climate and hydrometeorologicalsystems, technical options for equipment such as pumps, clearrules on import and export procedures, specialist extension ser-vices, local technical advice, regulatory regimes and incentives,social/cultural norms, prices for commodities and existing ground-water usage/s. Small improvements in (for example) local radioprogramming, cellphone coverage, or internet access may have dis-proportionately large downstream benefits in facilitating access totechnical data and information for groundwater development.Information and communication technology extension is stillemerging across much of SSA and is tied to other factors such aselectricity availability, transport networks and private sector activ-ity and investment.

Access to capital and credit: is important for all groundwaterinstallations, particularly when larger and deeper groundwaterinstallations are envisaged (e.g. city supplies). Access to credit,banking systems, currency stability and interest rates all impacton groundwater development feasibility and in many parts ofSSA, access to simple banking facilities is complex and onerous.Without access to credit (perhaps secured using land title deedsas collateral), it is impossible for poor farmers to ‘bootstrap’themselves into the irrigation economy or for pastoralists or poorurban/peri-urban dwellers to drill their own boreholes. Moreresearch is needed to understand the collective impacts offinancing and banking services on facilitating or retarding an SSAgroundwater revolution.

Transport infrastructure: facilitates movement of machinery,product delivery to market, movement of extension officials,migration of labor, provision of supplies, and numerous otherinputs essential to modern business practices. For agriculture,transporting goods to market requires road, rail or air infrastruc-ture and potable groundwater supply schemes require similarinfrastructure to access areas to drill boreholes and deliver assetssuch as pumps and conveyance piping.

Sector-specific conditions and access to technologies: contribute tothe viability of groundwater-led development. For example, whileSouth Asia’s ‘green revolution’ and groundwater-led irrigationdepended partly on the availability of cheap fertilizers and high

yielding crop varietals (Pingali, 2012), such inputs in SSA are cur-rently expensive and their availability is poor, hence their use isnot popular (Druilhe & Barreiro-Hurlé, 2012; de Marsily &Abarca-del-Rio, 2016; Dethier & Effenberger, 2012). Furthermore,assets such as product storage facilities are relatively rare in SSA,which leads to crop losses, as well as the need to sell crops soonafter harvesting, when prices are low and transport costs may behigh. Lack of refrigerated facilities precludes storage of high valueagricultural commodities (e.g. meat, cut flowers, vegetables) andprevents local processing of these commodities. Low control overinputs, sales timing, pricing and value-adding contribute to a reluc-tance to invest in upstream infrastructure, such as groundwaterdevelopment. For potable groundwater supply systems, decentral-ized infrastructure approaches incorporating new and increasinglyaffordable technologies (such as solar pumping) may overcomesome traditional sectoral challenges (Cherunya, Janezic, &Leuchner, 2015), but may require greater public-private collabora-tion to scale. For drought resilience, improved hydrometeorologicalforecasting technologies may contribute to increased resilienceand better conjunctive management of water resources.

Groundwater knowledge and state of existing essential services:can influence community demand for groundwater development.For example, Pahuja et al. (2010) reported in India that increasedpublic awareness of the availability of groundwater (particularlyin areas where resources are more accessible), as well as moresite-specific benefits – such as realization that groundwater pump-ing could help alleviate challenges of waterlogging and salinity –contributed to groundwater development. Additionally, the poorstate of some water utility services in India (which is oftenreflected in parts of SSA), prompted farm and non-farm users toseek out their own local source and supply systems, using ground-water. Hence, the appetite for improved groundwater developmentmay be high in some areas in SSA to help improve local drinkingwater, health and sanitation conditions.

3.2.2. Social, legal and institutional factorsRule of law and regional stability: in the forms of physical secu-

rity, and predictable legal and political regimes, are fundamentalrequirements for investment, including in groundwater infrastruc-ture (Wijnen et al., 2012). As at 2018, there was poor or deteriorat-ing civil stability in parts of several SSA countries, includingSomalia, Mali, Chad, South Sudan, Central African Republic, andthe DRC. This factor can be roughly quantified at national level,but local resolution is dynamic and less well understood.

Policy and regulation: analyses relating to groundwater are rarein SSA and Tuinhof et al. (2011) suggest that institutional capacityto implement existing policy is poor. Chokkakula and Giordano(2013:796) provide one of the few available studies, arguing‘‘clearly there is limited policy or institutional support for thedevelopment of groundwater irrigation in SSA”. They suggest thatexisting regimes may even hinder groundwater development byover-emphasizing regulation and by favoring surface water.

Household income and resilience: contributes to decision-makingon investment in groundwater extraction technologies and broaderrisk management. Household resilience is precarious in many partsof SSA, especially in ‘dryland’ areas threatened by worseningdrought and regional instability. Many local SSA incomes maynot permit savings accumulation sufficient for the purchase ofeven basic technologies. Low resilience may discourage invest-ment, which in turn can expose households to shocks, potentiallyfurther lowering resilience.

Local community and institutional structures: may embedgroundwater use in practice and tradition, and in turn facilitatespecific solutions to local groundwater problems. They can helpestablish critical mass for repair, maintenance and drilling servicesand thereby reduce the risk and cost of extracting groundwater.


Conversely, in areas where no local groundwater development hasoccurred, effort may be required to remove institutional obstaclesto overcome the ‘first mover’ disadvantage of using groundwater.

Land rights, land tenure and collateral: are essential for privategroundwater developers to access loans, particularly for individu-als whose land is their largest asset (Chokkakula & Giordano,2013). Conversely, uncertain land tenure makes long-term invest-ments unattractive (USAID, 2016). Land tenure is often closelyrelated to access to capital and credit, and security of tenure is typ-ically associated with sets of rights (user-, transfer-, exclusion- andenforcement-rights) (Feder & Feeny, 1991). However, land tenuresystems in large parts of SSA remain tied to structures vested intraditional leaders or the state (which often deters lenders) andspecific studies of the impacts of existing land tenure arrange-ments on capital-raising at local levels in SSA are rare. One excep-tion is in Niger, where a process of securing land tenure for existingand future irrigation schemes jointly recognizes both state andfarmer rights (Niger National Office for Irrigation Schemes, 2017).

Additional secondary factors, not explored here, may include:disease burden (humans and livestock), cultural beliefs regardingwater use, changing gender roles, and the impact of urbanization.While the relative importance of each secondary factor will varywith context, we posit that the most influential limiting factorswill need to be identified and overcome before more intensivegroundwater development can be triggered at scale in SSA.Evidence suggests that addressing these political economy factorshas contributed to the relatively advanced groundwater-irrigation economies in South Africa and in parts of North Africa(Massuel et al., 2017; Vegter, 2001), despite these regions havinglower overall groundwater availability than many parts of SSA.

3.3. The boom phase

Acknowledging the importance of political economy factors intriggering groundwater development has implications for theway in which ‘management’ of groundwater development is envis-aged. It is often assumed that groundwater development can beregulated or controlled, however empirical data suggests that thisoften doesn’t reflect the reality (Shah, 2017). Economic develop-ment, enabled or catalyzed by a step change in groundwater-based development, is a process of dynamic structural change insociety, rather than a series of isolated adjustments to existing(static) water use arrangements. Political economy factors will pro-gress in unpredictable ways as local economies develop anddiverse new economic relationships are established (Lejars et al.,2017). Contemporary political economy factors, even if data wasavailable, would evolve as development progresses and requireongoing data gathering and interpretation (Manghee & Poole,2012).

Some authors (e.g. Pahuja et al., 2010; Shah, Molden,Sakthivadivel, & Seckler, 2000) have described the initial growthin groundwater use as ‘explosive’ – reflecting its pace and scaleof utilization. The challenge of management during the boomphase can be illustrated by global experiences in groundwater irri-gation and water security. The difficulty of trying to control orunderstand, ex-ante, the characteristics of a step change in SSAgroundwater irrigation is illustrated by the fact that even in Cali-fornia, where extensive groundwater irrigation takes place in asophisticated institutional and data-rich context, most of the 445groundwater basins in the state have inadequate management,despite serious overdraft in some of them (Ayres, Edwards, &Libecap, 2017). The ‘anarchy’ of groundwater irrigation growth inIndia provides a comparable lesson (Shah, 2009) and similarly inthe PRC, the ability of the state to control groundwater abstractionsduring this phase can be limited (Shah, 2017). Nevertheless,enormous and transformative socioeconomic benefits linked to

groundwater development have accrued to California, India andthe PRC, and continue to do so.

Hence, the real value of a groundwater boom is the conversionof resource utilization into socioeconomic development, which is ashift in the relative importance of different sectors and activities,for example, moving from low-productivity agriculture and lowvalue-added extractive activities towards higher productivityactivities (McMillan & Rodrik, 2011; McArthur & McCord, 2017),with benefits accruing to society. Often, this process of changehas been supported by a modernizing agricultural sector whichboosted labor productivity, increased agricultural surplus to accu-mulate capital, and increased foreign exchange via exports(McArthur & McCord, 2017). In many cases, use of groundwaterhas supported improved agricultural productivity, and subsequenteconomic structural change.

Closer analysis of the challenges India has faced in taming itssemi-anarchic groundwater boom can be contrasted with the greatsocial and economic benefits derived. India is now the largest userof groundwater in the world, with more than 60% of irrigated agri-culture and 85% of drinking water supplies nationally beinggroundwater dependent (Pahuja et al., 2010). The economic valueof groundwater irrigation in India (in 2002) was conservativelyestimated at US$8 billion annually – a figure greater than allgovernment expenditures on poverty reduction and rural develop-ment programs (Shah, 2008). Despite the presence of major surfacewaters such as the Ganges, Indus and Brahmaputra Rivers, Pahujaet al. (2010:91) describe groundwater in India as ‘‘arguably themost critical water resource”, supporting irrigated agriculturalproduction and rural livelihoods, as well as urban and rural watersupplies. India experienced a boom period between �1960 and2010, which saw the area of irrigated agriculture supported bytube wells grow from effectively zero to reach greater than30 million hectares – an area at least double that supported byany other water source (Fig. 7). This boom period coincided withthe Green Revolution, which was supported by intensive inputsof (ground)water and fertilizer (Quinlan, Sen, & Nanda, 2014;Suhag, 2016). The increased socioeconomic resilience providedby groundwater is evidenced by a rainfall deficit in 1963–66 (priorto wide tube well use) causing a 20% reduction in national foodproduction, but a similar drought in 1987–88 (when tube wellirrigation was far more widespread) had much lower impact onfood production (Pahuja et al., 2010).

Harms done by overdraft and other problems associated withover-abstraction are undeniable, but they must be balanced byan assessment of the benefits derived during that process. It maybe more constructive to understand enabling and/or facilitatinggroundwater development by addressing political economy bottle-necks or hurdles, than of controlling or planning such develop-ment. In this context it is useful to consider the economist AlbertHirschman’s perspective on economic development – one that isincremental, local, and builds on ‘what works’ (Ellerman, 2001).This is opposed to more generic continental overviews and associ-ated sweeping recommendations. Hirschman’s ‘Theory of Unbal-anced Growth’ requires an element of disequilibrium in thepursuit of a step-change in economic development. In the sameway, a step-change in SSA groundwater development is unlikelyto happen ‘naturally’, since large parts of the region remain in acycle of low investment, low returns and low expectations (triggerfactors have not coalesced as needed). Such groundwater develop-ment may also not respond well to a predetermined top-downplanning or management approach, since so many unknowns exist(mainly secondary factors, but also hydrogeological factors). Themost productive intervention therefore may be to work to incre-mentally remove bottlenecks to groundwater development, likelyto be mainly secondary factors but also including hydrogeologicalfactors (such as the lack of data on depth to groundwater) where


necessary. Such pragmatic interventions will of course dependheavily on the country, and on the sector (e.g. irrigated agricultureversus urban/rural supply versus drought resilience).

Different governance and management instruments tend tobecome more prominent as the boom phase progresses, including:regulatory measures (requiring sound legislation and capacity tomonitor and enforce), economic measures (pricing mechanismssuch as volumetric charges, taxes, and user fees), tradable ground-water rights (to help users reach optimal outcomes), and commu-nity management of groundwater (with local users as custodians ofwater resources via regulation, property rights, pricing, etc.)(Pahuja et al., 2010). These can help transition to the maturationphase.

3.4. The maturation phase

The maturation phase of groundwater development occurswhere (volumetric) utilization peaks and then either plateaus ormoderates; efforts towards conservation and/or remediation pre-vail; and economic and structural development continues and par-tially de-couples from groundwater use through innovation andefficiency gains. It is ideally characterized by a shift from develop-ment of groundwater to management (Shah, 2009).

This phase may be transitioned to consciously and proactivelyviameasures described in the boomphase – regulatory or economicmeasures, tradeable rights, community management – but in otherglobal regions it has usually been prompted as a response to casesof overexploitation or mismanagement. Many global regions havealready reached this maturation phase. For example, Pahuja et al.(2010:3) describes India’s ‘‘era of seemingly endless reliance ongroundwater for both drinking water and irrigation purposes isnow approaching its limit. . ..”, as almost one-third of groundwaterblocks are in the ‘semi-critical’, ‘critical’, or ‘overexploited’ cate-gories. Better knowledge of secondary factors could help proac-tively manage the boom and maturation phase, rather thanreactively limit the costs of overexploitation and mismanagement.

This maturation phase can also be characterized by innovationand efficiency gains to permit continued economic development,via: (i) demand-side measures (e.g. water efficient supply and con-sumption schemes, behavioral changes and water reuse to reduceconsumptive groundwater use), (ii) conjunctive use (achieving sav-ings by aligning surface and groundwater use/management), and(iii) groundwater recharge enhancement (physical interventionsto concentrate and encourage infiltration). For example, drought-prone areas in the Indian state of Andhra Pradesh have achievedlarge scale success in self-regulation of groundwater use, wherefarmers have doubled their income and continue to safeguard theircrops, all the while reducing their groundwater use close to sus-tainable levels (Pahuja et al., 2010). Similarly, evidence from NorthAfrica suggests that better irrigation techniques can realize multi-ple times more benefit for the same volume of groundwater used(Kuper et al., 2017). Shah et al. (2014) and others have proposedthe innovative roll-out of ‘electricity farming’ in areas of ground-water overdraft – i.e. small farmers would be paid by electricityutilities to ‘grow’ solar power as a remunerative ’cash crop’, ratherthan consume electricity to pump dwindling groundwater. Suchstrategies could be available to policymakers in SSA for possibleearlier intervention.

19 This is analogous to the health sector, where more easily measurable variableslike stunting or weight are used as proxies for nutrition or overall health.

4. Discussion

Having confirmed significant groundwater potential in SSA andderived an empirical model to chart a notional three-phase path-way for groundwater development, we now pose three key ques-tions for discussion:

(i) A range of complex interacting political economy factorsappear to be the predominant barrier to triggering SSA’sgroundwater development revolution, hence is there a wayto better identify, understand and quantify these?

(ii) Given experiences in other global regions, what are theadvantages and drawbacks in adopting a pro-developmentapproach to groundwater in SSA?

(iii) Is the prevailing international discourse on groundwaterconservation and remediation limiting SSA’s developmenttrajectory?

4.1. Proxies for secondary factors

The empirical model suggests that SSA needs to tackle an (asyet) unconfirmed mix of secondary factors to trigger a groundwa-ter boom. There may be opportunity to use ‘proxy factors’ – indi-rectly or loosely related to groundwater use, but which cannevertheless shed light on groundwater use trends – to helpimprove resolution and understanding of both hydrogeologicaland secondary factors. For example, proxy factors for groundwaterirrigated agriculture could include data on fertilizer sales, time ofelectricity use, electricity grid coverage, crop export figures, satel-lite estimates of groundwater irrigation clusters, import enquiriesby pump manufacturers, profitability of drilling contractors, andmany others. Data on proxy factors may be much more widelyavailable (and possibly more useful) than data on actual ground-water use (Mayer-Schönberger & Cukier, 2014). Analysis of proxyfactors is one way in which the large data gaps on SSA groundwateruse and secondary conditions may be bridged efficiently andeffectively19.

4.2. The sustainability challenge

If a step-change in groundwater use in SSA – once catalyzed bythe removal of political-economy impediments – cannot be easilymanaged or controlled, this raises the possibility of falling watertables and contamination, and their disproportionate impacts onthe poor or vulnerable. There is a growing and influential literaturethat points out the negative effects of the boom in groundwateruse elsewhere in the world (e.g. Sekhri, 2014), and a concern thatadvocates for increased groundwater use may inadvertently beresponsible for future hardship. As such, a cautious or managedapproach to SSA groundwater development is often recommendedby specialists, stressing better up-front management as a way ofhedging against the possibility of overdraft (e.g. Edmunds, 2012;Foster et al., 2012). There are several points relevant to this debatein SSA.

Firstly, whilst it is sometimes assumed that a boom in ground-water use will be ephemeral or unsustainable, the synthesized fig-ures quoted in Section 2 show that, on average, large increases insustainable groundwater use are possible in SSA even when allow-ing for conservative environmental requirements (see Fig. 4).Whilst the average figures do mask possible hotspots, and thereare already small areas in SSA where unsustainable use of ground-water occurs, in general large increases in renewable groundwaterutilization are feasible across most countries in the region. In short,SSA is nowhere near unsustainability of resource use, at a regionalscale.

Secondly, surveys of the disbenefits of groundwater abstractionfor development in other global regions cannot easily compare theoverall economic impacts, including growing overdrafts, with acounterfactual in which no groundwater development in the same

22 Defined as projects which may potentially involve the utilization of groundwaterresources and/or impact them directly or indirectly.23 A total of 254 projects in SSA with relevance to groundwater were reviewedbetween 1997 and 2017. The number of projects approved annually did not exceed 10between 1997 and 2002 and peaked in 2013 and 2014, at 19 and 22 respectively. 85project completion reports were reviewed.24 Current includes all pipeline, lending, ongoing and approved projects.25 For example, the Millennium Development Goals (which transitioned into theSustainable Development Goals), the Kyoto and Paris climate agreements, and the


region has occurred. It is likely that overall economic and struc-tural benefits are considerably higher, despite the clear drawbackslinked to areas of overdraft, than if no groundwater developmenthad taken place at all. Indeed, India’s ‘green revolution’ was largelypredicated on groundwater (Shah, 2009) and the PRC’s grain pro-duction has shown correlation with groundwater abstraction ratesat a national level for approximately 60 years (Fig. 8). Where theexploitation of unsustainable or ‘fossil’ groundwater is considered,arguments like those made by mining companies for the catalyticimpact of economic development based on a finite resource aremade by some authors (e.g. Maliva & Missimer, 2012). In suchcases, authors such as Collier (2014, 2017) justify the use of non-renewable resources only where the income from their use con-tributes to improvements to future public social goods.

Thirdly, there are powerful humanitarian and social justice ele-ments to consider. The real choice in SSA may be between the cur-rent situation in which little groundwater is being used andtherefore it is not significantly contributing to economic develop-ment, and future groundwater development where only partialcontrol may be possible (semi-anarchic) until the maturationphase is reached. We argue that the potential benefits of muchwider groundwater development in the region are too importantto delay, and that potential disbenefits due to possible incidentsof over-abstraction are preferable to the current challenges of pov-erty and vulnerability in many SSA countries while availablegroundwater resources lay dormant. There may be moral hazardin advocating for caution in the use of groundwater, just as thereis in promoting the growth in its use.

Finally, economic dynamism (potentially supported by ground-water use, for example) is likely to be essential to the political andsocial stability needed to overcome long-term environmentalproblems. Economic development today should be built on pro-gressive and sustainable environmental policies, but a narrowemphasis on the latter may preclude the former and thereby riskboth. A commentary on the current broader discourse in the inter-national development sector is provided below.

4.3. Elevating groundwater up the development agenda in SSA

Our model in Fig. 5 shows SSA at an earlier phase of groundwa-ter development compared to India, California, the PRC, and otherglobal regions of higher intensity groundwater use. The emphasisin these latter regions has rightly shifted from the boom tomaturation phase, giving rise to a large contemporary literatureon over-abstraction (e.g. Shah et al., 2000) and conservation andremediation (Wada et al., 2010; Famiglietti, 2014). This discourseis often applied to SSA today (e.g. Xu, 2008; Braune et al., 2008),although the region has not yet experienced the groundwaterboom seen elsewhere. Where this facilitates better groundwaterdevelopment it is appropriate, but if it adds to the alreadyconsiderable inertia in initiating even small improvements ingroundwater-based development in SSA, it may be stronglycounter-productive. If groundwater is perceived as a resource toconserve from the outset, rather than one to develop sustainably,it may lie effectively dormant.

We observe evidence of this discourse permeating groundwaterinvestment in SSA, which remains low relative to surface waterand has even declined as a priority for some development agencies.For example, while the World Bank has significantly increasedinvestment in SSA’s water sector20, this is concentrated in surfacewater infrastructure21. Over a twenty-year period (1997–2017),

20 For example, World Bank lending to the SSA water sector increased from US$820m in 2006/07 to US$1780m in 2016/17, concentrated in water supply andsanitation and irrigation and drainage (Wijnen et al., 2018).21 Dams and irrigation canals, watershed and river basin management.

the number of World Bank funded projects with ‘relevance togroundwater’22 increased23, however almost none had groundwateras their central focus. Less than 1% contained groundwater in theirproject title; only 3% contained reference to groundwater in the pro-ject appraisal document abstract; and no project completion reportabstracts referenced groundwater (Wijnen et al., 2018) – indicatingthat groundwater is either rarely being integrated in projects, or isbeing grossly under-reported, or both. Similarly, a 2018 review ofthe African Development Bank’s (AfDB) portfolio24 of projects acrossall sectors (including water supply and sanitation, agriculture andagro-industries, environment) revealed only one project with‘groundwater’ in the title.

For the World Bank, trends in overlooking groundwater havebeen recognized formally by its own Independent EvaluationGroup (IEG) at both global and regional scales. For example, asillustrated in Fig. 9, the World Bank’s investment (globally) ingroundwater extraction declined significantly between the mid-1990s and late-2000s – a trend described by IEG (2010:79) as‘‘problematic”. IEG’s 2010 analysis of the World Bank’s globalwater portfolio (1997–2007) found that groundwater was the leastcommon theme and a lower or diminishing priority both at the glo-bal scale and for SSA, and for which IEG (2010:27) recommendedthe World Bank be ‘‘more ambitious in addressing issues criticalto the long-term use of groundwater”.

To contextualize these decreasing and low levels of investmentin groundwater, such trends have occurred against a backdrop ofincreasing international and regional focus on climate change,extreme events, resiliency and poverty alleviation25. Beyond mini-mal strategic prioritization, other reasons for historical and currentlow levels of groundwater investment in SSA may include: poorunderstanding of groundwater resources and their sustainable man-agement (IEG, 2010); the potentially complex and hidden nature ofgroundwater, both politically and physically (Wijnen et al., 2012);a general hesitancy in SSA to invest in groundwater irrigation, basedon mixed results of past interventions (Ward et al., 2016)26; anemphasis on River Basin Organizations (RBOs) as regional bodiesfor freshwater governance inclining policy and funding towards sur-face waters; relatively few dedicated groundwater experts innational and international organizations (Llamas and Custodio,2001); and groundwater cutting across multiple sectors, meaningthat it is potentially everywhere but also nowhere specifically27.While it can be argued for SSA country governments to be moreproactive in their own groundwater development, we believe that,as thought-leaders, organizations such as the multilateral develop-ment banks and United Nations agencies do have a role to play inhelping countries become more aware of the potential benefits ofsustainable groundwater development, and supporting them toachieve that.

Beyond a general dearth of groundwater investment in SSA,there is also no strong evidence of groundwater being developedstrategically and at scale to counter chronic water stress or therecurrent and increasing threat of drought in hard-hit regions of

Sendai Disaster Risk Reduction Framework.26 Irrigation development during the 1970s and 1980s in SSA delivered low rates ofreturn and many nationally financed schemes failed. Such poor results deterredgovernments and donors in financing further irrigation expansion (Ward et al., 2016).27 For example, at the World Bank, projects in SSA with relevance to groundwater(between 1997 and 2017) cut across 62 different units in the institution.

Fig. 8. Groundwater Exploitation and Total Grain Production from 1950 to 2011 in the PRC (after Liu & Zheng, 2016).

Fig. 9. The focus of groundwater projects across World Bank global portfolio (1997–2007) (after Independent Evaluation Group (IEG), 2010).


SSA. For example, in the Horn of Africa – a region of high waterstress and repeated drought events (2018 was its third consecutiveyear of drought) – only one of the three countries in the WorldBank’s SSA Horn of Africa region has had more than one nationalproject relevant to groundwater in the past 20 years28. Other coun-tries which have suffered from recent severe drought, and whichhave had very few (or no) national projects with relevance togroundwater supported by the World Bank between 1997 and2017, include Namibia (0), South Africa (2), South Sudan (1), Swazi-land (1), and Zimbabwe (1). There is little evidence of national orinternational actors explicitly linking strategic groundwater invest-ments to areas experiencing frequent and recurrent drought events.To put this lack of investment in focus (and building upon Table 1),Table 3 highlights the strong dichotomy between the serious state ofwater stress (current and future) and vulnerability to climate changeand drought, contrasted with the dormant renewable groundwaterresources available in most countries in SSA. As stated previously,

28 These don’t include regional projects, which primarily relate to transboundarysurface water basin interventions.

we recommend multilateral agencies collaborate with regional andnational agencies to explore how a strategic network of deepgroundwater bores in drought ‘hotspots’ could proactively build resi-lience against future events.

Hence, there is an opportunity for many actors to support amore balanced narrative by acknowledging the current predomi-nance of surface water investments and proactively addressingthe low levels of groundwater investment in SSA. Institutions suchas the multilateral development banks span the technical and sec-toral spectrum, have strong convening power and can play criticalroles as advocates and knowledge brokers to help raise the profileof groundwater as a reliable and climate resilient resource aroundwhich countries can orient elements of economic and social trans-formation and disaster prevention. Such institutions also have thecapacity to work collaboratively with interested SSA countries tohelp understand and address some of the limiting secondary fac-tors in SSA and facilitate knowledge exchanges from other globalregions to learn how to trigger and then navigate a boom phasein SSA, all the while helping to better manage the potential perilsof over-development from the outset.

Table 3National1 states of water stress and vulnerability contrasted with low levels of renewable groundwater utilization.

Water stressa Vulnerability of national freshwater supplies to climatechangeb

Drought vulnerabilityindicatorc

Percentage renewablegroundwater usedd

Present Future

SSA Countries (Only high andmoderate-high risk countriesare listed for water stress andvulnerability. Only lowutilization countries are listedfor renewable groundwater).

High:Eritrea,Lesotho,SouthAfrica,Swaziland.

High:Botswana,Eritrea,Namibia,SouthAfrica.Moderate-High:Swaziland.

High: Benin, Chad, Congo(Democratic Republic), Congo(Republic of), Eritrea, Ethiopia,Kenya, Madagascar, Mali,Mauritania, Niger, Nigeria,Senegal, Somalia, Sudan,Swaziland.Moderate-High: Angola, BurkinaFaso, Liberia, Mozambique,Sierra Leone, Tanzania, Togo.

High: Burundi, Chad, Ethiopia,Guinea-Bissau, Mali, Niger,Nigeria, Sierra Leone, Somalia.Moderate-High: CentralAfrican Republic, Congo(Democratic Republic),Liberia, Malawi, Mauritania,Mozambique, Rwanda, SouthSudan, Sudan, Togo.

Low: Angola, Benin, Botswana,Burkina Faso, Burundi, Cameroon,Central African Republic, Chad,Congo (Democratic Republic),Congo (Republic of), Cote D’Ivoire,Equatorial Guinea, Eritrea,Ethiopia, Gabon, Gambia (The),Ghana, Guinea, Guinea-Bissau,Kenya, Lesotho, Liberia,Madagascar, Malawi, Mali,Mozambique, Namibia, Niger,Nigeria, Rwanda, Senegal, SierraLeone, Somalia, South Sudan,Sudan, Swaziland, Tanzania, Togo,Uganda, Zambia, Zimbabwe.

High risk and moderate-high risk rating by the authors is based on the following sources: aGassert, Reig, Luo, and Maddocks (2013), Luo, Young, and Reig (2015); bNotre DameGlobal Adaptation Initiative (www.gain.nd.edu); and cNaumann, Barbosa, Garrote, Iglesias, and Vogt (2014). Low classification defined as country currently using less than25% of national renewable groundwater resources, sourced from: dFAO (2016) AQUASTAT data.

1 Caveats to the analysis in the matrix above include: (i) the indicators come from different sources, and hence methodologies and consideration of groundwater resourcesare not consistent; (ii) national-level assessments do not capture the variability across regions within countries (for example, a country assessment may reveal low overallwater stress or vulnerability, but have select areas where water stress is high); and (iii) sustainable groundwater resource development potential is high across all countries(except Mauritania), meaning groundwater development should be considered as part of an integrated water resources strategy for all SSA countries.


5. Conclusions and recommendations

We confirm, at regional scale, that SSA hosts significant ground-water resources, often in areas where it could be most impactful,and which have the capacity to contribute significantly as a base-line resource for regional development. Despite the wealth ofregional resources, groundwater use is thought to remain under5% of sustainable yield for most countries in SSA, meaning that sig-nificant renewable resources are currently dormant.

We substantiate that ‘secondary’ or political-economy factorsare the primary impediments to further groundwater developmentin SSA. There is further work to be conducted to understand polit-ical economy factors, their complex interactions, and how to trig-ger them. This work will allow appropriate policy to bedeveloped, to remove bottlenecks.

We identify a predominance of limiting, rather than enablingconditions in groundwater development, which have discouragedinvestment at scale. Based on the development cycle of groundwa-ter in other parts of the world which have already experiencedtrigger-boom-maturation phases, the international discourse ongroundwater has shifted towards conservation and remediation,which may inadvertently be denying SSA its opportunity to expe-rience social and economic benefits derived from groundwaterdevelopment.

We also argue that attention and funding for groundwater pro-jects should be of similar scale to that afforded to surface waterprojects in SSA. Groundwater has the potential to act as the foun-dational resource to underpin regional development in sectorssuch as irrigated agriculture, urban and rural water security, anddrought resilience, just as it has in other global regions. We arguethat it is now unconscionable and unjustifiable not to developSSA’s groundwater resources.

Finally, while the primary intentions of this paper are to informreaders about SSA’s renewable groundwater potential and encour-age discussion on future groundwater development actions foreconomic and humanitarian purposes, we draw on our empiricalmodel to offer some non-prescriptive elements of a roadmap tohelp support this process:

� Dissemination of study findings to decision-makers and policy-makers in SSA countries, highlighting the significant latentrenewable groundwater potential and the importance of sec-ondary (political economy) factors in triggering wider ground-water development.

� Encourage improved resolution and coverage of hydrogeologi-cal data, including exploration of proxy indicators, asappropriate.

� Provide financial and technical resourcing for adequategroundwater-specific investigations to be included in nationalwater resource assessments in all SSA countries.

� Educate and encourage international institutions to prioritizegroundwater development support in SSA, including bolsteringinternal technical capacities.

� Establish a taskforce (comprising relevant stakeholders such asthe UN agencies, multilateral development banks, disaster relieforganizations, local community representatives, etc.) to explorethe potential benefits of a strategic network of deep groundwa-ter boreholes in recurrent (and predicted future) droughthotspots.

� Explore linkages between groundwater development andemerging climate (financing and convening) mechanisms topromote adaptation and resilience building.

Simultaneously, we encourage countries to help themselveswhilst also calling upon international and regional institutions toprovide financial and technical support to help realize SSA’s pend-ing groundwater revolution.

Acknowledgements

We extend thanks to our colleagues, Marcus Wijnen andShawki Barghouti, for their guidance and advice on our joint inves-tigation into groundwater in SSA in 2017, and to Cleo Rose-Innesand Maarten de Wit for kindly providing feedback on a draftversion of this paper. We also acknowledge the two anonymousreviewers whose comments improved the final manuscript.

http://www.gain.nd.edu


Declaration of Competing Interest

The authors have worked as consultants to the World Bank.

Funding sources

This research did not receive any specific grant from fundingagencies in the public, commercial, or not-for-profit sectors.

Author approval

Both authors have approved this version of the article.

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