Africa’s Emerging Urban Water Challenges 31
throughout Africa are vulnerable to droughts and floods. For example, a large proportion of Kenya routinely suffers from both floods and droughts, often in the same year, and stream flow in the Niger River and its tributary, the Benue River, have varied greatly since 1900. There is not enough water storage infrastructure (including both small check-dams and larger multipurpose storage systems) to compensate for hydrological variation in almost all areas. In Africa, storage capacity averages about 200 cubic meters per person per year, compared to about 6,000 cubic meters per person per year in North America and 2,400 cubic meters per person per year in China. Most countries in Africa for which data are available have less than 500 cubic meters storage per capita and many are significantly below this amount. At the same time a country such as Kenya has about the same (low) availability of fresh water per capita as Tunisia, which in turn has several times as much storage (Figure 1.12). In Africa existing storage infrastructure is generally inadequate to reduce flood peaks and augment low-season flows in highly variable river systems (World Bank, 2011a). Floods affect the highest number of people in Africa after famine and epidemics; droughts and floods account for 80 percent of loss of life and 70 percent of economic losses linked to natural hazards (World Bank, 2012b). Recent floods in Accra, Dakar, and Maputo are a grim example of the serious impact of floods on African cities. In the last few years, many countries have suffered from repeated floods, with up to 1.7 million people affected and economic losses of up to US$330 million from a single flooding event. In West Africa alone, floods affect an average of 500,000 people per year, and this number is growing. Between 2008 and 2010, major floods in Benin, Burkina Faso, the Central African Republic, Madagascar, Namibia, Senegal, and Togo caused more than US$1 billion in damages and losses, and affected more than 2 billion people (World Bank, 2012b). In addition, the incidence and intensity of natural disasters in the region is rising (see Figure 1.13): the number of natural disasters in Africa has grown from about 20 per year in the 1980s and 1990s to about 60 per year in the 2000s (World Bank, 2010c, based on EMDAT2), with a marked increase in the number of flood events. Although disaster data is not disaggregated for urban and rural areas, urban areas are likely to suffer more deaths and economic losses. There is a strong link between high rates of urbanization and increased vulnerability to natural hazards (World Bank, 2010c). Low-income urban residents often suffer the most as they move into marginal land that is prone to flooding. In 2009, floods in Senegal caused US$56 million in damages and