We invest billions of dollars to find evidence of water and life on Mars, but here on Earth, we struggle to mobilise the funds needed to develop the full potential of the water resources we depend on for life and growth. 

Was the glass half-full, or half-empty, on World Water Day on Friday?

We celebrate the fact that almost two-thirds of the people on the African continent have gained access to water.  But that leaves millions of people who are still denied this most basic of rights. 

We estimate that it will cost us another $50 billion a year for the next 20 years to meet Africa’s water needs, and – if that figure seems beyond our means – some perspective may help: It is less than the world spends on bottled water every year.

Water means far more than what we drink and how we wash.  It powers economies; it is the lifeblood of communities; it can bind countries together, it can force them apart. 

One look at the challenges facing countries along the Nile over their shared natural resource — or at the repercussions of the worst drought in the Horn of Africa for 60 years, in 2011 — and we see that water is not just the source of life, but a turnkey of political, social and economic stability.

That is why holistic water management is a pillar of development that is every bit as important as meeting our energy and infrastructure needs. 

While the significance of water management for economic growth is generally understood, and while ways of  preventing water-based crises and conflicts are known, there are still major bridges to cross if we are to turn our knowledge into action.

In this International Year of Water Co-operation and beyond, it is only by working together — locally, nationally, and regionally — that we will get to the other side.

The turn of the millennium saw the launch of the Africa Water Vision 2025.  The vision was above all one of co-operation for the common good. 

Since then, we have drawn deep from the well of shared experience, and seen progress — as much in supplying the basic needs of water and sanitation, as in using water as an agent of economic transformation.

Countries sharing basins and rivers are also sharing plans and gains: The Manantali hydropower dam on the Senegal River, for instance, has brought food and electricity to millions of people in Mali, Mauritania and Senegal itself.

However much we have achieved, our water resources still face an existential threat, and an existential challenge. The existential threat is climate change. 

It is clear there is no conceivable future for any water-intensive activity or industry that has not adapted to a changing climate, in regions where normal rainfall is replaced by extreme floods or droughts, and where the population continues to expand. Nor will there be any easy future for cities prone to water disasters, particularly those whose urban planning fails to include measures to prepare for such onslaughts of nature. 

Planning and co-ordination are paramount, as governments begin to move away from managing sectors separately, and adopt national water strategies and policies that acknowledge the links between water security, agriculture, energy and urban development.

The existential challenge, meanwhile, is the costly and complex task of unlocking the vast potential of Africa’s untapped water reserves, only a fraction of which are yet on stream. 

Again, the only way to do this is in partnerships. There are countries that are sitting on quantities of water large enough to overcome all of their developmental needs.  There can be no reason why that water fails to flow… or why — with Africa’s 80 international river and lake basins — only five per cent of the continent’s arable land is irrigated… or why the development of Africa’s hydroelectric power generation capacity remains at less than 10 per cent of its potential.

The African Development Bank itself is bringing its knowledge, networks and funds to both the challenges and the opportunities of water. 

Mobilising the power of co-operation, it has provided water and sanitation access to some 50 million people in rural Africa.  It supports water, crop and livestock management in a new $125 million project just begun in the Horn of Africa, for instance; and is launching a new hydropower project to benefit 24 million people along the Mano River.

There is more than enough water in Africa. The immediate task is to source it, and the next task is to work better together to use it — not just to meet the basic needs of millions, but to power and empower societies and economies at large.  Only by working together have we come this far, and only by working together can we go even further.

Donald Kaberuka is president of the African Development Bank.