Mitigating economic damage in Kenyas Upper Tana River Basin

The Upper Tana River Basin is one of Kenya's most important natural resource bases. Its Masinga Reservoir supplies water and hydroelectric power for 65 percent of the nation. Unregulated deforestation and expansion of cultivation practices onto marginal soils has resulted in significant reservoir siltation, reduced ecosystem function, and more erratic downstream flows. An appraisal conducted for this study identified potential areas where reforestation could occur, enabling a doubling of the reforested areas currently in the Upper Tana River catchments. The Soil and Water Assessment Tool (SWAT) model was used to evaluate alternative reforestation scenarios. An economic model was developed to determine the opportunity costs associated with reforestation and the economic incentives, i.e. green payments, which would be required to induce upper catchment users to reforest.