Africa’s life-sustaining water towers have been overlooked for too long
International researchers’ focus on ice to define natural water towers leaves Africa’s critical systems off the map, and with little protection.
The Angola Highlands water tower is one of the many under-researched natural water towers in Africa. Credit: Cory Richards/National Geographic Okavango Wilderness Project.
Africa is a water stressed continent. It is home to 1.4 billion people – 18% of the world’s population – yet has only 9% of global freshwater. By 2050, when Africa’s population is projected to reach close to 2.5 billion, demand for already limited fresh water will be even higher.
Yet it’s not all doom and gloom. Despite being water-stressed, Africa is endowed with many “natural water towers”, a critical nature-based solution to water and climate challenges.
Take the remarkable Angolan Highlands Water Tower that feeds source lakes and major rivers across seven southern African countries. Every year, 423 cubic km of water – equivalent to 170 million Olympic-sized swimming pools – falls over the area known locally as Lisima Iya Mwono, meaning “Source of Life” in the Luchaze language. This water flows into the Congo Basin and the Zambezi Basin. It is the sole source of the Okavango Basin and provides 95% of the water that makes its way to the Okavango Delta, a UNESCO World Heritage Site.
Rainfall from this south-eastern Angolan plateau sustains food and water security, livelihoods, and the survival of millions of people – in Angola, Botswana, the DRC, the Republic of Congo, Namibia, Zambia, and Zimbabwe – as well as iconic wildlife, including the planet’s biggest concentration of African elephants.
The Angolan Highlands Water Tower system is a prime example of a “natural water tower”. This term refers to the mountain ranges that naturally store and supply water that then sustains environmental and human demands downstream. While human-made water towers supply households via a pressurised piped system, natural water towers are often connected to downstream sinks through ground water reservoirs and major river networks that may traverse country borders over thousands of kilometres. Though, much like their human-made equivalents, natural water towers also provide relatively constant year-round supply thanks to water stored in snow, glaciers, and lakes.
Natural water towers play a significant role in shaping both global and local climates. They are the origin of the majority of rivers. They support biodiversity and are refuges and bridges for many species.
In recent years, recognition of water towers’ importance and the need to better understand them has rightfully increased. In 2019, researchers ranked 78 water towers across the globe, not only by how much water they store and provide, but also by how vulnerable they are to environmental and socioeconomic changes in the next few decades. The resulting Water Tower Index identified some of the most relied-upon systems by continent, including: the Asian Himalayas and Tibetan Plateau, which supply water to the Ganges and Yangtze; the South American Andes Mountains, which are the headwaters of the Amazon; the North American Rocky Mountains, which supply water to the Missouri; and the European Alps, which host the headwaters of the Danube, Rhine, Po and Rhone.
This index has been critical for promoting the protection of mountain glacier-derived water towers, which provide water to up to 1.9 billion people globally – roughly a quarter of the world’s population. However, its focus on the presence of snow and ice to identify water towers left Africa and Australia out of its analysis and out of the spotlight of global concern.
Credit: Kostadin Luchansky/National Geographic Okavango Wilderness Project.
Africa’s shortage of research capacity has made this situation more challenging. While Australia, the only region drier than Africa, established the Australian Rivers Institute as a world leader in research on rivers, coasts, and catchments, Africa lacks any comparative continent-wide rivers and freshwater research institute. And it was only last year that the Angolan Highlands Water Tower was defined within academic literature for the first time, thanks to researchers from the National Geographic Okavango Wilderness Project. Prior to this, the system was largely missing from the “global map” despite its huge hydrological and economic importance.
It is time to bring attention and urgency to Africa’s many natural water towers. To date, the only notable mention of them is in the Africa Water Atlas, complied by the UN Environment Programme (UNEP) in 2010. That database includes numerous water systems that enable otherwise dry areas to support life and that are essential for irrigation, agriculture, domestic and industrial processes. It highlights the Ethiopian, Kenyan and Lesotho Highlands as well as the Jos Plateau, Angolan Plateau, and the Central High Plateau of Madagascar. These areas supply water to Africa’s major rivers such as Blue and White Nile, Congo, Okavango, Orange, Limpopo, Niger, and Zambezi. They are also varied. While the Kenyan Highlands are dominated by closed canopy montane forests that have a wet microclimate, for example, the Lesotho Highlands have a cold, wet and misty climate that lies above the treeline and receives high rainfall in comparison to the surrounding lower elevations.
Nonetheless, the Africa Water Atlas is also limited in its identification of water towers according to elevation, precipitation, and contribution to regions far beyond their delineated boundaries. This rather simplistic definition does not cater for the diverse range of ecosystems and freshwater environments across the African continent. It leaves out, for example, several critical water towers including the Eastern Highlands of Zimbabwe, the Highlands of Cameroon, the Ghana-Togo Highlands and the Central African Highlands of Rwanda, Burundi, and the DRC.
Credit: Kostadin Luchansky / National Geographic Okavango Wilderness Project.
Many regions across Africa grapple with limited access to sufficient data and monitoring infrastructure. This scarcity of long-term studies hampers our understanding of the dynamics and health of freshwater ecosystems. Unlike in many parts of the world where critical water towers are closely observed and analysed given their importance, many of Africa’s are not even recognised as such. African countries have struggled to research these critical water systems and monitor the wide-ranging impacts on them from challenges like pollution, climate change, and increasing water demand, let alone respond to them.
Collaborative initiatives involving local experts, international organisations, and governments have been working to address these gaps. However, there remains a huge need for increased funding, technological advancements, and interdisciplinary research to ensure the sustainable management and conservation of Africa’s diverse freshwater resources. Future research must acknowledge the continent’s diversity and that Africa’s Water Towers go beyond neat categories and broad-based definitions.
In the next decade, climate change is going to affect drinking water for people, for agriculture, for industry, and for nature and ecosystems. In Africa’s water towers, we’re talking about the water security of the world’s fastest growing population. Not only are they scientifically important, but they’re also often sacred, spiritual places for communities. It’s time to challenge the traditional definition of a water tower looks like so that Africa’s water towers, the resources they provide, and the communities who depend on them receive their due protection.
This is a wonderful article. Many thanks for putting this together. It is thorough and well written. The issues raised are of critical importance to achieving water and food security in the continent in the short to medium term. Let’s link up formally
Dear Mr. Mauro Lourenço ,
This is a beautifully written piece. Very well balanced and useful piece which has something for all groups to look at their respective responsibilities that contributes to the destruction of the ecosystem and the beauty of the natural world on which we all depend.
We having been conducting various research on these issues all the time. And even if Africa had been excluded from the water tower index or that Africa does not have water research institutions, having these institutions of research in Africa should not be our focus; African scientists can join a team of researchers wherever that research is being conducted.
The focus should be about what we have been doing to destroying these water resources and how to stop it. If we set up water research institutions, these institution would not produce any research whose findings are any significantly different from the research results that have been conducted elsewhere.
And so, we should instead deploy the resource to setting up water institutions in Africa to mitigating the causes of the destruction of our water resources by relying on research findings that have already been produced elsewhere. The reason for this view of mine is that we often keep repeating the very same mistakes even though we have history and lessons learned and the solutions in other contexts to apply/replicate. But we somehow pretend that the solution to our problems are so unique to our context when that is actually false: “African solutions to African Problems”! And those whose interest these kinds of slogan serves would do anything(often subtly corrupt means) to advance a narrative to ensuring that that interest is pursued/achieved/protected.
I was telling my friend the other day that if there are Nobel prize winners for research into banking and financial crises, then you would think that those Nobel prize winners have found the solution to financial crises and therefore we should only apply their solutions to preventing and solving financial crises in Ghana or in Argentina: why do we need to keep reinventing the wheel(conducting researches and setting up new institutions of water towers in Africa)when we can learn from others?
The needless motivations for competing narratives/researches/positions often detracts us from the solutions even when the solutions are readily available to us.
The key issues and important points you raise too, can form an integral part of the existing curriculum in in the sciences in universities across Africa if they are not already included in the current texts.
Civil Society groups across Africa too, have the platform/capacity to exploring some of the key issues you raise. And people like you too have a voice/influence to promoting a discussion on the issue just as you have done and doing on this platform.
For years, there have been too much talk and not enough action on our continent ,often due to misplaced priorities, regular repetition of past mistakes and cynically myopic interests such as tribalism and then we turn to deflect and blame others for standing in our in our attempts to find answers to our problems.
I have a small plot of land in Ghana Dodowa. It cost me £1700 to build/dig a borehole in 2016.If an NGO want to construct the very same borehole in a village in Dodowa, the NGO would first send in a researcher or consultant for a report or feasibility studies or go through an expensive tendering procurement process. These activities would end up costing about $30,000 to construct a single borehole that costs less(£1700).And yet you would have groups/individuals within the supply chain(for the construction of the borehole)whose interests is served by going through this expensive process who will not raise any objections to the process because the process provides and sustains an income/earning/ a livelihood/employment. And so we would be repeating this same pattern over and over and over again and pretending as though we don’t have the answers to the problems! And if there is no water in Dodowa the it is because if you “dig deeper” you would find that our corrupt politicians have diverted government resources meant for providing water in the country. And then they would find a way to talk about issues that are not a priority or eliminate those who talk about the key priorities.
I hope i fully understood the thrust of your position on the subject.
Many thanks
It is a well written and balanced article and should be disseminated widely especially to universities in Africa