Water and sanitation: the invisible foundation of West African development

A country's modernity is measured by what it renders invisible. Water that runs safely from the tap, excreta disposed of without contaminating the water table, soap within reach: in wealthy countries, this foundation has vanished from public debate because it works. In West Africa, it remains tragically visible. In Benin, only 17.7% of the population uses a safely managed drinking-water service, one of the lowest documented levels on the continent (World Bank / JMP, 2024). This is not one figure among many. It is the foundation on which a country's health, schooling and productivity rest, and it silently commands, upstream, just about everything else. The question is therefore not whether the region can develop, but whether it decides to finally build the invisible ground on which all development stands.

The most lagging region in the world

The 2024 data from the WHO and UNICEF leave no doubt: sub-Saharan Africa remains the most lagging region on the planet for safely managed drinking water, with 32% of its population covered, against a global average of 74%. In other words, more than two thirds of the region's inhabitants have no access to water that is at once available, close to home and free of contamination. This indicator, SDG 6.1.1, does not merely count water points: it requires that water be safe, accessible and available when needed. It is the highest bar, and that is where the gap widens most.

The gap with the rest of the world is not narrowing over time, it is holding steady. While other regions converted their growth into connections, sub-Saharan Africa saw its population grow faster than its networks, so much so that the absolute number of people deprived of safe water rose over certain periods. The lag is therefore not a simple shortfall to be closed mechanically: it requires a pace of investment higher than that of demographics, failing which coverage stagnates even as facilities are being built. This is the region's central paradox: building a great deal is not enough if the population grows even faster than the infrastructure.

Within West Africa, the regional average masks a striking dispersion. Ghana reaches 42.9% for safely managed water, Cote d'Ivoire 36.4%, while Togo falls to 20.5% and Benin to 17.7%. A ratio of more than two to one thus separates the first from the last, between neighbouring countries, often endowed with the same rivers and the same aquifers. This ranking maps onto neither the map of rainfall nor that of GDP: it tells a story of investment choices, institutions and budget priorities, not of geographic fate. Benin shares the Niger River with Niger, and hydrographic systems comparable to those of Nigeria and Togo, yet safe access varies twofold there: nature offers everyone a similar base, it is policy that widens the gap.

A chain, not a sum of pipes

The costliest mistake is to treat water and sanitation as two separate files. They form an inseparable chain: a protected source is useless if excreta contaminate the water table and the hands that carry the water to the mouth. The final link, handwashing with soap, remains marginal in the region. In Benin, only 12.9% of the population has a handwashing facility with water and soap at home (JMP, 2024). Water captured cleanly can thus be recontaminated downstream, for want of a hygiene gesture that itself costs almost nothing.

This chain logic has a formidable consequence for public action: the return on an investment is dictated by its weakest link, not its strongest. A country may multiply boreholes; if it lets open defecation persist and soap remain absent, faecal contamination cancels out part of the expected health benefit. Conversely, a franc devoted to the broken link, rural sanitation or hand hygiene, often produces more years of life gained than an additional franc on an already solid link. Reasoning in terms of a chain, rather than budget silos, already means redirecting spending towards where it saves the most.

The human price of this broken link is considerable. The WHO estimates that nearly one million diarrhoeal deaths a year worldwide are attributable to unsafe water, sanitation and hand hygiene. More serious still, 395,000 deaths of children under five could be prevented each year if these risks were addressed. Behind the statistic lies a brutal reality: diarrhoea remains one of the leading causes of preventable child mortality, and it is fought as much by latrines and soap as by medicines. Repeated diarrhoeal episodes also feed chronic malnutrition and stunting, which compromise cognitive development and school success: the broken WASH link does not only kill, it lastingly handicaps the survivors.

A protected source is not enough if excreta contaminate the water table and hands. Water and sanitation do not add up: they form a chain, and a chain is only as strong as its weakest link.

Open defecation: a burden that varies manyfold

No indicator better reveals the scale of regional gaps than open defecation, at once a symptom and a cause of faecal contamination. In 2024, it still concerns 66% of the population of Niger, two thirds of the country, against 47% in Benin and barely 3.9% in Mali and 6.1% in Senegal. The burden thus varies manyfold within a single region. These figures are not anecdotal: every area where open defecation persists is an area where the water table, the soils and the watercourses remain laden with pathogens, whatever effort is made elsewhere on drinking water.

What matters is not only the level, but the trajectory. Senegal brought its open defecation down from 24.8% in 2000 to 6.1% in 2024, one of the best West African trajectories. Burkina Faso did even better in pace, moving from 74.1% to 29.9% in a quarter of a century. Niger, for its part, also fell markedly (from 81.1% to 66%), but starts from so high that the road remaining is immense. These curves prove that rapid progress is possible, provided there is a constant and targeted effort, carried out village by village.

Behind these slopes lies a precise action mechanism, not merely abstract political will. The countries that brought down open defecation have almost all adopted a community-led approach to sanitation, which triggers demand for latrines at village level rather than subsidising supply from the top down. The shift is only secured beyond a threshold: as long as a minority continues to defecate outside, the whole village remains exposed, for faecal contamination does not respect plot boundaries. That is why the operational objective is not an average coverage percentage, but complete elimination, village by village, certified in the field. This threshold logic explains why progress is slow at first and then accelerates, and why sanitation must be measured at the local scale, not the national one.

What national averages hide: the urban-rural divide

A reassuring national figure can hide an entire village deprived of safe water. The divide between towns and countryside is the black hole of aggregate statistics. In Burkina Faso, basic drinking water covers 81.5% of city dwellers but 34.4% of rural residents, a gap of 47 percentage points within the same country. For sanitation, the gulf is more violent still: in Niger, basic sanitation reaches 53.1% in town against 8.7% in the countryside. A policy judged by its national average may therefore show progress while leaving the rural world far behind, where the most exposed populations nonetheless live.

The divergence plays out not only in space, but also in time. Between 2000 and 2024, Ghana raised its access to basic drinking water from 65.5% to 89.9%, a gain of more than 24 points. Over the same period, Burkina Faso fell back, from 55.6% to 50%, its population growth and the expansion of rural areas having outpaced the rate of new connections. Two opposite trajectories, on the same continent, over the same generation: proof that progress is anything but automatic and can even reverse when investment does not follow the population.

The weakest link: rural sanitation

If one had to name the single breaking point of the West African WASH chain, it would be rural sanitation. In Benin, basic sanitation covers 32.4% of the urban population but only 11.8% in rural areas. In other words, nearly nine rural Beninese out of ten have no basic, unshared latrine. That is where the health risk concentrates, where open defecation persists, and where data is most lacking, for scattered countrysides are precisely the most costly to survey.

Catch-up exists, but it is slow. Benin raised its national basic sanitation from 8.5% in 2000 to 22.2% in 2024, while Ghana progressed from 5.7% to 31.6% and Senegal, starting higher, from 36.6% to 62.5%. These slopes show that progress is real and cumulative, but that at the current pace, universal access remains out of reach for the present generation. The foundation is built brick by brick, and the missing brick is almost always rural.

The school and the health centre: the WASH foundation beyond the home

The debate almost always focuses on water at home, but the WASH foundation is also at stake in the places where health and human capital are built: the school and the care centre. And that is where the deficit becomes a contradiction. According to the WHO-UNICEF joint programme (JMP, 2024 update), only 60% of sub-Saharan Africa's health-care facilities have a basic water service, against 76% in North Africa and Western Asia. One health centre in forty operates with no water point at all: to give birth, dress wounds or operate without clean water is to turn the place of care into a source of infection. The WASH deficit does not merely make people ill at home, it compromises care at the very place meant to heal.

The school tells the same story, with a cost deferred over a whole generation. Worldwide, the JMP estimates that 42% of schools, nearly 802 million schoolchildren, lack a complete service of basic water, sanitation and hygiene, a deficit concentrated in the least developed countries and fragile contexts, where most of West Africa lies. The absence of clean, separate latrines weighs first on girls, whose attendance drops at puberty for want of a dignified place to manage menstruation. A tap and a latrine in a school are therefore not a comfort: they are, strictly speaking, part of the educational infrastructure, on the same footing as the blackboard and the textbooks.

The forgotten dimension: water, sanitation and the burden on women

The WASH deficit is not neutral from a gender standpoint: it weighs very unequally on women and girls. It is they who, in the vast majority of rural West African households, carry the water, sometimes over several kilometres and several hours a day. Every hour spent on the water chore is an hour taken from school, from paid work or from childcare, an invisible tax levied on half the population. The absence of safe, lit latrines further exposes women to risks of assault and forces them into avoidance strategies, holding on all day, waiting for night, which damage their health. When water moves closer to the home and the latrine becomes safe, it is above all time and safety returned to women.

Yet this dimension remains the blind spot of policies, for want of being measured. National indicators count households and water points, rarely the chore time by sex or the perceived safety of facilities. And what is not measured is not arbitrated. Documenting the differentiated burden of water, girls' school attendance according to the presence of separate latrines, the use of maternal-health services according to their water equipment, means revealing a reservoir of development that aggregate averages erase. The CRAD has built precisely this expertise in sex-disaggregated data in the energy sector, with the regional WOCEWA project and its gender-equality index across the twelve ECOWAS countries; the same method sheds light on the field of water and sanitation.

The cost of inaction: several points of GDP

The invisible foundation carries a very real macroeconomic price. The World Bank, through its Water and Sanitation Program, put at 5.5 billion dollars a year the losses of 18 African countries, including Benin, Niger, Burkina Faso, Nigeria and Ghana, between 1 and 2.5% of their GDP. These losses are made up of premature mortality, of morbidity that swells health spending and empties classrooms, and of time lost fetching water or a place of ease. Poor sanitation is therefore not only a health problem: it is an annual levy on growth.

The order of magnitude warrants caution, and that is precisely where data counts. More recent estimates, relayed in the press and by certain actors, put the figure as high as 200 billion dollars a year and around 5% of GDP at the scale of the continent. The perimeters differ (number of countries, valuation method), and it would be imprudent to add them up or to conflate them. What remains solid is the order of magnitude: several points of GDP go up in smoke each year for want of a decent WASH foundation. A rigorous costing, country by country, is precisely what turns this intuition into a budgetary arbitration.

The true cost is not that of acting, but that of not acting: it is paid every year in children's lives, in lost school days and in vanished points of GDP.

The return on investment: every dollar brings back more than four

If the cost of inaction can be quantified, the return on action can be quantified just as much, and it is spectacular. The WHO estimates that a dollar invested in water and sanitation generates on average 4.3 dollars of return, in the form of health spending avoided, work and school days preserved and productivity recovered. Few public investments show such a multiplier, and the return climbs higher still for basic rural sanitation interventions, precisely the most deficient link in the region. In other words, the budgetary argument does not play against water and sanitation: it plays powerfully in their favour, provided the spending is targeted where the deficit runs deepest.

This high return nonetheless comes up against a very real financing constraint. Reaching universal safely managed access would require tripling, or more, current investment levels in the region, and a large share of resources still depends on external aid, volatile and sometimes poorly aligned with rural priorities. The real challenge is therefore not to prove that water and sanitation are profitable, that much is settled, but to mobilise capital in time, to direct it towards the rural and towards hygiene, and to demonstrate its results in order to reassure funders. Here too, a credible measurement system is not a supplement to the soul: it is the condition for unlocking and retaining financing.

The 2030 countdown: accelerate by a factor of six to eight

Sustainable Development Goal number 6 aims for universal access to safely managed water and sanitation by 2030. Yet the JMP calculates that at the current pace of progress, the region will not get there, and by a wide margin. To meet the target, the rate of improvement would have to be multiplied by six for safely managed water and by eight for safely managed sanitation. These multipliers are not slogans: they quantify the scale of the acceleration required and rule out from the start any policy based on mere continuity. Without a change of gear, the 2030 deadline will be missed.

An accelerator rarely reaches six or eight without a compass. Multiplying the effort by such a factor requires knowing exactly where to concentrate resources: which villages, which schools, which health centres are the worst served, and which would tip with the least investment. It is a targeting problem before it is a budget problem, and targeting rests on fine, geolocated data renewed over time. Accelerating blindly means wasting the scarce resource at the very moment when every franc must count.

The CRAD angle: turning an invisible foundation into a quantified priority

Steering a water and sanitation programme requires exactly the CRAD's craft: disaggregated, geolocated data, comparable over time, from mobile field collection to the decision dashboard for funders. The safely managed indicators, the SDG 6.1.1 and 6.2.1 targets, cannot be read on a meter: they rest on robust household surveys that few actors know how to conduct in Francophone West Africa. Measuring the urban-rural gap, tracing the fall of open defecation village by village, evaluating the health impact of a borehole or a latrine campaign, means turning an invisible foundation into a quantified investment priority.

This conviction follows from a simple observation: national averages, useful for comparing countries, never say where to act within a country. The same budget of boreholes or latrines does not produce the same health gain depending on whether it targets high-gap areas or areas already close to universality. Mapping gaps by commune, tracking contamination and access campaign after campaign, means moving water policy from intention to precision. The CRAD carried this approach from the field to the dashboard in the energy sector, with the regional WOCEWA project across the twelve ECOWAS countries; the logic holds, identically, for water and sanitation.

• Disaggregated collection. Without geolocated household surveys, the urban-rural gap (47 points in Burkina Faso, 44 points on sanitation in Niger) remains invisible in the averages, and investment is deployed blindly.
• Tracking over time. The 2000-2024 trajectories (Senegal a success, Burkina Faso in retreat on basic water) can only be read on a long series, renewed with the same method, the only one able to distinguish real progress from a fluke.
• Impact evaluation. Relating a borehole or a latrine campaign to a measured health outcome is what allows arbitration between projects and conditioning budgets on results rather than on resources committed.
• Gender-sensitive data. Measuring water-chore time by sex and girls' school attendance according to the presence of separate latrines reveals a reservoir of development that household averages erase.

A challenge already met elsewhere

The lag may seem dizzying; yet it has already been closed, including in West Africa. Senegal divided its open defecation by four in a quarter of a century, Ghana gained nearly 25 points of access to basic water over the same period. The regional challenge is therefore not to invent a novel technical solution, but to apply a proven recipe with consistency: invest in the rural, sustain the effort over a decade, measure results where they are decided. The decisive difference between Senegal and Niger lies not in the technology available, but in the duration and coherence of public commitment. The invisible foundation is built when we finally decide to make it visible in the figures before making it real on the ground.

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