A recent study released by WaterAid and Tree Aid has found alarming evidence that deforestation is directly driving freshwater scarcity across West Africa, threatening the health and livelihoods of over 122 million people in Ghana, Nigeria and Niger. The 12-year research project, From Roots to Rivers: How Deforestation Impacts Freshwater Access, uses satellite and population data from 2013 to 2025 to map how forest loss is eroding both the quality and quantity of available water, and how climate change is deepening the crisis.
The findings are clear and quantifiable. For every 1,000 hectares of forest lost in Niger and Nigeria, an average of 9.25 hectares of surface water disappears. In Ghana, while rainfall has increased, water quality has sharply deteriorated in deforested areas, leaving millions exposed to unsafe sources. Across the three countries, 45 percent of the population, nearly half of all people living there, now live in zones where water is unsafe or insufficient for daily use.
The data paints a troubling picture. Ghana loses an average of 24,800 hectares of forest every year, equivalent to an area the size of Edinburgh. Nigeria’s annual loss exceeds 27,000 hectares, while Niger, through reforestation efforts, has managed to gain about 101,000 hectares of vegetation. The report links Niger’s vegetation gains directly to measurable improvements in water availability: every 1,000 hectares of regrown forest increased surface water by 11.6 hectares. It is a rare and tangible sign that ecosystem restoration can reverse environmental decline.
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The implications go far beyond West Africa. Globally, 75 percent of accessible freshwater originates in forested landscapes, and one-third of the world’s largest cities depend on protected forests for their water supply. The findings reinforce what hydrologists and forest ecologists have long warned: when trees disappear, rivers follow.
In the three focus countries, the human cost of this trend is already visible. In Niger, 99.5 percent of available surface water is now classified as unsafe due to sedimentation and pollution. In Nigeria, over 85 million people live in high-risk water scarcity zones. In Ghana, water sources once used for drinking and irrigation are increasingly contaminated by agricultural runoff and silt from eroded landscapes. The study warns that as deforestation accelerates and rainfall becomes more erratic, these problems will worsen, compounding the risk of disease, food insecurity, and poverty.
The researchers describe what they call the “rainfall paradox.” While rainfall across West Africa has intensified, by 59.5mm per year in Ghana, 15.2mm in Niger, and over 100mm in Nigeria, this has not translated into better water security. Instead, heavy rains, falling on deforested ground, run off too quickly, carrying sediment and pollutants into rivers and reducing groundwater recharge. What appears on paper as an increase in rainfall masks a long-term collapse of the natural systems that sustain clean water.
At the heart of the crisis are interconnected pressures: rapid population growth, dependence on rain-fed agriculture, and unsustainable land use such as charcoal burning and slash-and-burn farming. Poverty, weak governance, and inadequate forest protection laws have made it harder to enforce conservation policies. The report notes that many communities rely on forests not just for water but also for food, medicine, and income, leaving them little choice but to exploit the same ecosystems that sustain them.
Climate change is intensifying this cycle. Ninety percent of weather-related disasters in Africa are caused by too much or too little water, and the UN warns that over five billion people globally could face water scarcity by 2050. For the Sahel and sub-Saharan Africa, where average temperatures are rising 1.5 times faster than the global rate, the combination of deforestation and unpredictable rainfall represents an existential threat.
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The report comes with some optimism; Niger’s reforestation success demonstrates that planned restoration, through community-led tree planting and natural regeneration, can rebuild ecosystems and water reserves. The study’s case examples, such as the Daka River restoration in Ghana, show measurable improvements: reforested zones recorded a 33 percent improvement in downstream water quality within two years of intervention.
WaterAid and Tree Aid urge governments and donors to end the “siloed approach” that treats forests and water as separate issues. They recommend integrating forest protection and water security into national climate plans, financing frameworks, and adaptation strategies. This includes investing in climate-resilient water systems, expanding access to clean water, and funding locally led adaptation projects that involve women, indigenous communities, and other groups most affected by environmental change.
In practical terms, the report calls for climate finance that supports both reforestation and water infrastructure, including green catchment systems and nature-based solutions. It stresses that sustainable water access; through reliable boreholes, storage systems, and water governance, must form the foundation of any meaningful climate adaptation strategy.
The message for Africa is stark but actionable: the continent cannot address water insecurity without tackling deforestation, and cannot tackle deforestation without securing water. The two crises are one and the same. As the authors conclude, “When communities are supported to regenerate degraded land, forest cover and water availability recover together, restoring ecosystems and building climate resilience.”
With 122 million West Africans already living the consequences, the report urges leaders heading to COP30 to make integrated forest-water action a central pillar of climate policy, because in Africa, the fight for clean water starts with protecting the trees that make it possible.
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