The Hoanib is an ephemeral river flowing from the highlands of Namibia through the hyper-arid Namib Desert to the Atlantic Ocean. Seasonal floods recharge groundwater that supports riparian woodlands, which are vitally important to wildlife and livestock. Previous studies prior to 2001 found that mega-herbivores are having an impact on the main tree species in the river system, Faidherbia albida. In 2002 two permanent boreholes were drilled for wildlife in order to reduce competition with livestock. This paper presents the