A new study warns that deforestation across Ghana, Niger and Nigeria is intensifying West Africa’s water crisis, threatening the health and livelihoods of more than 122 million people.

Drawing on 12 years of satellite data from 2013-2025, the joint report by WaterAid and Tree Aid finds a direct correlation between forest loss and the decline of both the quality and quantity of freshwater. For every 1,000 hectares of forest cleared in Niger and Nigeria, 9.25 hectares of surface water disappear, leaving communities more exposed to disease, food insecurity and dehydration.

In Niger 99.5% of freshwater is already of poor quality and at risk of being unsafe to drink directly, according to the report. Deforestation is making that dire situation worse, as forests would effectively filter sediments and pollution.

“Trees and water are the essence of life in West Africa’s forest communities and around the world. Trees draw water into the earth, enrich soil for farmers, and shield land from floods. But as forests fall, water is vanishing at a ruthless rate,” Abdul-Nashiru Mohammed, WaterAid’s regional director for West Africa, said in a statement.

In the same statement, Ghanaian scientists Justine Kojo and Thomas Burns Botchwey, who contributed to the study, said their data reveal a “dangerous new reality” in which deforestation and climate change reinforce one another.

“What looks like more water on the surface is often a sign of flooding, runoff, and pollution beneath,” they noted, citing surveys showing that 93% of Ghanaians fear for their future because of climate change.

The report estimates that 45% of people in Ghana, Niger and Nigeria now live in areas of high water risk. In Nigeria alone, roughly 85.6 million people are affected by surface water loss linked to deforestation. Nigeria loses roughly 27,000 hectares (66,7000 acres) of vegetation cover annually.

Still, there are signs of progress. Niger has reforested more than 100,000 hectares (247,000 acres) since 2013, potentially making more than 1,000 hectares (2,470 acres) of surface water available once again, the study notes.

Georges Bazongo, Tree Aid’s director of programs, said the findings underscore the need for “reforestation and land restoration efforts grounded in inclusive forest governance that balance environmental protection with local needs.”

The report was released ahead of the COP30 climate summit in Belém, Brazil, and adds urgency to calls for governments to integrate forest and water protection into their climate finance pledges. WaterAid and Tree Aid say treating the two crises separately is “doomed to failure.”

The report concludes that climate change is compounding the crisis. Rising temperatures, erratic rainfall and extreme weather are accelerating deforestation and degrading water sources, while floods and droughts become more frequent and severe. Researchers say that without urgent climate adaptation and forest protection, millions of West Africans will face worsening water scarcity and food insecurity as the twin pressures of deforestation and climate change converge.

Banner image: Loggers inside Omo Forest Reserve in Nigeria. Image by AP Photo/Sunday Alamba.