Munich

Water supply is one of the toughest issues facing the world's poorest countries. But an innovative project in West Africa could offer a way forward, according to hydrologists involved in the scheme.

German and Ghanaian researchers are working together to create a model of how meteorological, environmental, social and economic variables affect the Volta basin. By 2006, they hope to be able to use the model to make practical decisions about water management in the region.

The Volta basin comprises parts of Ghana, Burkina Faso and several adjacent countries. Agriculture is the main source of income in this area, and population growth is now putting pressure on land and water resources.

The scheme is part of the GLOWA (Global Change in the Hydrological Cycle) initiative, set up by the German government in 2001 to improve water management in several different river catchments. Other pilot studies are taking place on the Elbe and Danube rivers in Germany, the Jordan River Basin, the Wadi Drâa in Morocco and the River Ouémé in Benin.

In the first phase of the Volta project, researchers assessed the water flows and patterns across the Volta basin. In the second phase, they plan to use this information to build a model that will enable local planners to assess the impact of their actions on water management, agriculture, ecology and power supply. The German government this month approved €10 million (US$11.3 million) to support this second stage.

“This is the most comprehensive science-led approach ever tried in West Africa to guarantee the effective allocation of water resources,” says Daniel Adom, a water engineer and executive secretary of the Ghanaian Water Resources Commission (WRC).

“We envisage a smart scientific toolbox for modelling, at different scales, the likely impact of different water-management options on power production, industry, agriculture and human health,” says GLOWA Volta's scientific coordinator, Nick van de Giesen, a hydrologist at the Center for Development Research at the University of Bonn in Germany.

Looming water crises were the subject of the 3rd World Water Forum in Japan (see Nature 422, 251–256; 2003). But experts think that the real action will take the form of relatively small initiatives, targeted at specific river basins.

Ghana, with its relatively strong scientific infrastructure and stable political system, is an ideal location for the project, van de Giesen says. The country has decades of experience with major water projects, and the dam on the river at Lake Volta supplies most of its electricity. But the growing population and a shortening rainfall season mean that Ghanaians are drawing off more of the river's flow for household use and for farm irrigation, which is relatively new in the region.

This pressure has led to growing political conflict over the use of water, leading the WRC to revise its water-management and regulation practices in the Volga basin. But, says van de Giesen, “the knowledge base is narrow — and that's where GLOWA Volta comes in”.

→ http://www.glowa-volta.de