6 The Future of Water in African Cities
Arua (Uganda), as case studies for a more in-depth analysis of the applicability of IUWM to their water needs. Upon completion of this study, officials from all three cities expressed interest in implementing practical demonstration projects that would make use of some of the IUWM options presented in the book. Water systems are complex; managers need to account for the interactions between urban water systems and the catchment from which they draw. The various components of the urban water system (water supply, wastewater, and stormwater) have a number of positive and negative interactions that reach beyond the water services sector. Horizontal integration of planning and integration across spatial boundaries is needed to improve services in a sustainable manner and to reduce vulnerabilities. Urban water systems depend increasingly on their water catchment for both quality and quantity of supply. And a city’s water withdrawals and wastewater outputs, in turn, have a huge effect on the catchment from which they draw. Heredia in Costa Rica (66,000 water customers), like Mbale, is located at the foot of a mountain. It is able to supply its citizens with water with no other treatment than chlorination due to a payment for an environmental services agreement with landowners upstream. While these payments might require specific conditions to be effective, source protection and watershed management are becoming urban water issues throughout Africa. Negative system interactions can be addressed with an integrated approach. The impact of poor sanitation on the water quality of potential water sources is an ongoing problem in many African cities. Other cities have successfully addressed this problem. In Indore, India, which has a population of 2 million, the Slum Network Project substantially upgraded the quality of life in slums through the creation of wastewater infrastructure that significantly improved the overall slum environment. But it did more. By looking at the larger picture, these improvements to the slum areas were also able to improve the water quality in the rest of the city, due to sewage no longer being dumped into rivers and streams. The costs of the system were the same as constructing pit latrines, but the overall results were better for people who lived in the slums, and better for the city as a whole (Diacon, 1997). In Latin America, the use of IUWM approaches made it apparent that reducing the blockage of drains from poor waste collection had a bigger impact on flooding than constructing new stormwater drains. Positive system interactions can be exploited. There are opportunities for considering a portfolio of water sources, reuse, recycling, and cascading use in African cities. In Accra, Ghana, irrigated urban vegetable pro-