Demonstration site: Gambia River Basin
This case study focusing on the Gambia River basin has been implemented by Wetlands International in close collaboration with the Organisation for the Development of the Gambia River (OMVG) in order to develop a program to monitor the impacts of the future Sambagalou hydroelectric dam on the Senegal-Guinea border, with the longterm additional aim for creating an observatory for the Gambia River basin.
The Gambia River runs for approximately 1,130 km in western Africa from Guinea, through Senegal to The Gambia. The basin contains a range of habitats (including estuaries, marshes, swamps and mudflats), and harbours a high level of floral and faunal biodiversity.
The Issue
These habitats will inevitably be affected by the development of the Sambagalou hydroelectric dam – a 368MW dam which will be connected to power networks for The Gambia, Guinea, Guinea Bissau and Senegal. The major adverse impacts on the biophysical environment will be the loss of biological resources and habitats, including “the decline in the salt front during the dry season (positive and negative impact), the degradation of the reservoir water quality and downstream thereof, the modification of the estuary’s morpho-sedimentary balance, the gradual depletion of mangroves in the central estuary, the loss of habitat downstream from the dam during the dry season, and a significant change in some populations of species”.
What has been done?
A multi-stakeholder consultation workshop took place in July 2008 Banjul, The Gambia. It involved representation from all the countries within the Gambia catchment. The species assessment data were refined to a finer resolution and information gaps were identified and filled. Species were then selected to be monitored based on endemism, IUCN Red List threatened status, socio-economic importance, and suitability as ecological indicators. In December 2009, in Simenti (Senegal), a second multi-stakeholder workshop was held to standardise the species and habitat survey methodology and data collation and to develop a comprehensive monitoring plan. Sites to be monitored were identified based on the species identified, ecological /habitat representation, data availability, accessibility and likelihood to be impacted by the dam. Within Senegal 11 sites were identified, three within The Gambia and four in Guinea. A multi sectoral (including OMVG) and national Monitoring Committee was set up to continue to co-ordinate the work.
