Namibia is the driest country in southern Africa. The Cuvelai-Etosha Basin in central-northern Namibia is particularly affected: With about 850,000 people, almost half the Namibian population is concentrated here. The region's climate is characterized by a rainy season lasting from October to March, with a mean annual rainfall of 470 mm and a dry season lasting from April to September. The technology of rainwater harvesting was introduced to make harvested rain water available during the dry season too, thus making horticulture possible year round. The challenge of introducing rainwater harvesting in the region was to successfully guide local novice farmers through processes of group building and governance, as well as the development of technical and management skills. Finally, the benefits and feasibility of private gardening and horticulture had to be demonstrated within the local organisational and institutional structures and implemented with locally available construction materials.