Description

Abstract: A significant portion of the forest within the upper Njoro River drainage basin was converted to agriculture between 1995 and 2003. This portion of the watershed lies within the Mau Forest, a significant water tower in Kenya that supplies both surface runoff and groundwater recharge within the Rift Valley. The Njoro River is a key contributor to Lake Nakuru National Park, which provides a host of ecological and economic services to the region. Previous research in the upper portion of the basin has identified deforestation as significantly altering the hydrologic regime of the river, but was limited to a local analysis where relatively rich data were available. In this research project, a hydrologic model was used to identify how the changes in the upper part of the watershed would be manifest in changes to the amount, timing, and apportionment of water both in terms of the riverine discharge and groundwater recharge. Findings show that the overall amount of water delivered to the river terminus (Lake Nakuru) was relatively unchanged, while the ratio of surface flow to groundwater recharge was significantly changed, that the timing of water flow was altered, and that the number of low flow days increased. These findings have implications for both human and ecological stability in the region, and are intended to provide guidance to planners tasked with watershed management and community development.