By Kala Fleming
On the tiny island of Antigua where I grew up we always had enough water. We never had to call a water truck and to our knowledge, no one ever got sick from drinking the water in its natural state. The ‘natural’ state of water on Antigua is straight to the downpipe from the roof and into a concrete tank in the ground under each house. Community ponds also captured extra rainfall that others used for watering animals and washing cars.
Rainwater harvesting in the Caribbean provides a more reliable source of supply than piped systems and the geology of the region limits the availability of ground water. In the Virgin Islands, building regulations even require all new houses to harvest rainwater. So, in places such as urban Africa where ensuring water security has become increasingly tricky, why has this approach not caught on?
My conversations with individuals across Africa have uncovered a mixture of reasons for shunning water harvesting. Some people simply don’t see it as an obvious option. Others think that the payoff for the investment is unclear, especially as rainfall patterns become more erratic. Some think it is a quaint but anachronistic approach to water management.
In our studies of the 15 largest cities on the continent, rainwater harvesting barely shows up on the map as a water management option despite its tremendous viability. What is popular? Groundwater accessed via boreholes. They serve as an extremely common source of backup supply for households in cities across sub-Saharan Africa. Lagos has more than 20,000 boreholes. Accra has more than 9,000 boreholes. Nairobi and Dar es Salaam each have more than 3,500 boreholes.
The reliance on groundwater in Africa is not the primary concern. The unmanaged approach to the resource, especially in urban areas, is. In many African cities, annual withdrawal via boreholes is greater than the portion of rainfall that goes into recharging groundwater. If withdrawals exceed recharge, groundwater levels decline. A recent survey in Kenya showed groundwater levels in some areas are falling as fast as 14 meters per year.
As a changing climate brings more frequent and intense droughts and floods across the continent, mismanagement of groundwater resources is not only a risk to economic activity but also to health. In the 2008/2009 rainy season, a breakdown in Zimbabwe’s piped water system sparked the country’s most deadly cholera outbreak after thousands in Harare turned to contaminated shallow wells for water. More than US $35 million was mobilized for the humanitarian response. Following incidents like this, politicians and NGOs across Africa renew calls for more harvesting and deeper boreholes but progress is limited – in part because of a lack of accurate data and understanding on what motivates water preferences across the continent.
At a scientific colloquium at IBM’s new research lab in Nairobi last week, we opened our doors to over 400 scientists, business leaders, NGOs, government officials and students to demonstrate the strategy for executing on Project Lucy – a 10-year, $100M initiative to bring Watson technologies to Africa. Through a series of demonstrations we showcased the potential of cognitive computing systems in providing the insight needed to tackle some of Africa’s most pressing issues in areas such as healthcare, education, water and sanitation. One of these demonstrations was a solution called the ‘Digital Aquifer’ that links the physical and social systems that influence water security. We illustrated the connections between changing rainfall, the presence of boreholes and fluctuations in water prices. Changes in water prices can reflect the shifting arrangements for water in the face of shortages and provide a glimpse into the underlying social structure of a community.
The opportunity to more closely probe and understand how the complexities of society, tradition, bureaucracy and everyday practices, influence approaches to water usage and management is one of the promises of cognitive computing in Africa. With Project Lucy and the Digital Aquifer, we seek data-driven insights on why harvesting is not that popular across African cities and what it might take to change perceptions on its utility. Rapid urbanization, a changing climate and increasingly strained centralized water systems, are driving the need for greater individual action around water security. Increased rainwater harvesting complemented by strategic access to groundwater is a workable strategy that can be implemented by leveraging data and the coordinated will governments, communities and individuals.
Peninah Waweru, IBM Research Intern and 4th year student at Jomo Kenyatta University of Agriculture and Technology, and Nathan Wangusi, IBM Research Scientist contributed to compiling the data referenced in this article. For more on data management around boreholes go to Bringing Clarity to Water Management in Africa, One Borehole at a Time.