River development interventions, such as dams, impact multiple facets of river systems including food production, energy generation, water availability, and public health outcomes, often in unanticipated ways. In particular, the incidence of certain diseases can increase following the construction of hydroelectric dams.
The Senegal River basin in West Africa faces these issues. At over 1,000 miles long, the Senegal River crosses Guinea, Mali, Senegal, and Mauritania, and has long been a main source of water for drinking, irrigation, and industry. After two major dams—including the hydroelectric Manantali Dam—were constructed in the 1980s, the incidence of the snail-borne disease schistosomiasis has increased throughout the region. The dam blocked the migration of river prawns in the Sengal River, which had been the natural predators of freshwater snails infected with the worms that cause the disease. According to the World Health Organization, schistosomiasis is the third most devastative tropical disease which, untreated, can lead to organ damage and impaired growth and cognitive development.
While dam managers are aware of this problem, most efforts to combat the spread of schistosomiasis have been limited to treatment campaigns. Options for how Manantali Dam could be managed differently in order to prioritize public health, while maintaining other important development goals such as agriculture and energy production, could potentially mitigate the disease’s impact.
For two years, Rebecca Wall, a Stanford PhD candidate in history, and Andrea Lund, a PhD candidate from the Emmett Interdisciplinary Program in Environment and Resources, have been part of a research team that includes graduate students from ecology and public health, urban and environmental planning, geography, civil engineering, resource economics, and history. Together, they have been researching a historical perspective on environmental planning, dam development, and health in the Senegal River basin, and determining the feasibility of dam management scenarios that could reduce disease transmission, given other priorities like agriculture and energy production.
Recently, Wall received a Capacity Building and Policy Engagement Grant from the Stanford King Center on Global Development which enabled her and Lund to travel to Bamako and Manantali, Mali. Their goal was to better understand current dam management practices and to share findings from a preliminary hydrological model that changed reservoir levels in order to disrupt snail habitats with river basin managers and solicit their feedback in order to determine how dams could be managed to reduce negative health impacts.
This research is critical given the high rates of schistosomiasis in the Senegal River basin and the fact that this same problem occurs in other river basins throughout the world. Integrating public health into other considerations could provide a path for better managing the spread of dam-related diseases.
While in Mali, Wall and Lund interviewed local experts in environmental impact management, public health, and hydrology. They also visited the Manantali hydroelectric dam and reservoir. Local dam officials expressed skepticism about the idea of shifting reservoir levels in order to combat schistosomiasis, arguing that reservoir levels were contingent on other priorities. A series of detailed discussions provided context on how Malian dam management officials see public health fitting into their work, as well as the limitations of certain approaches to combatting disease.
The meetings with local stakeholders deepened ongoing dialogue between officials and the research team, establishing new contacts who will continue to provide critical insight into future research. The interviews also provided greater awareness as to why it is so difficult to manage dams for public health outcomes given other development priorities.
Going forward, Wall will incorporate the feedback from the stakeholders in Mali into a revised version of the dam management model that will be shared with officials in Manantali.
Wall points out that a key insight from the time spent this summer in Mali was how important it is to have extensive stakeholder involvement in the early stages of the research process. Speaking directly to people who manage the dams on the Senegal River was pivotal to understanding the tradeoffs between food, energy, water, and public health.
“I’m grateful to the King Center for their support in facilitating meaningful discussions that shed light on critical tradeoffs at the local level, and that will ultimately make the work of the research team much more relevant by focusing on feasible levers of change,” Wall said.