Wilhelm Urban

Small Scale Rain- and Floodwater Harvesting for Horticulture in Central-Northern Namibia for Livelihood Improvement and as an Adaptation Strategy to Climate Change

This paper presents research results of the German-Namibian joint research project CuveWaters in which different technologies for small-scale rain- and floodwater harvesting were introduced as pilot plants in central-northern Namibia as part of a broader Integrated Water Resources Management (IWRM) approach. Central-northern Namibia has semi-arid climate conditions with clearly distinctive dry and wet seasons. Rain- and floodwater harvesting for irrigation purposes are intended to increase resilience in agricultural production by building buffers for interseasonal dry spells and to make irrigation farming possible during the dry season. This is intended to improve availability of vegetables in rural parts of Namibia and to derive income on local markets. Besides raising temperatures, climate change in sub-Saharan Africa is predicted to increase rainfall variability. Therefore, these adaptations also present a precondition for adapting to future climate change. Within the project, different organisational approaches such as harvesting of rainwater at the household as well as at the communal level were tested, as well as different locally available tank construction materials. All technologies were developed in cooperation with the local communities and framed by capacity development measures which yielded very good results and enabled a diffusion of the technology in the region. Based on 5 years of research the construction of ferrocement tanks on the household level and ponds covered with shade nets on the communal level can be recommended. Due to high evaporation rates all gardens irrigated with harvested rainwater were equipped with water saving drip irrigation systems. In combination with capacity development focusing on water management this enabled the users to irrigate their gardens throughout the dry season.

From the Concept to the Tap—Integrated Water Resources Management in Northern Namibia

Namibia is the most arid country in Sub-Saharan Africa. The Cuvelai-Etosha Basin (CEB) in central northern Namibia in particular is experiencing various ecological and social-ecological challenges such as high climate variability, saline groundwater, dependence on Angola for freshwater supply, high population growth and density, and increasing urbanisation. These challenges make water supply and management difficult and threaten the livelihood of the local population and the health of the ecosystem. Facing up to these challenges, the German-Namibian research project CuveWaters has developed, adapted and set up different technologies as pilot plant s. The Integrated Water Resources Management (IWRM) concept of CuveWaters is based on a multi-resource-mix in which water is obtained from different sources (rainwater, floodwater, groundwater and wastewater) and used for various purposes. High quality water is used as drinking water; water of a relatively low quality is used for irrigation. In cooperation with the residents of four villages and one small town, the project partners are implementing different technologies to collect and store, produce, treat and reuse water. The implemented technologies are rain- and floodwater harvesting, groundwater desalination, and the combination of sanitation, wastewater treatment and water reuse. The aim is to improve peoples’ livelihood through research on innovative and adapted solutions which contribute to a successful and adapted application of IWRM. To this end, the project integrates science, technology and societal aspects in a transdisciplinary research approach by linking scientific knowledge from natural, engineering and social sciences with the everyday practices and know-how of the stakeholders involved. Thus, the technical aspects are complemented by a wide range of societal and scientific components, such as capacity development, monitoring, participation or knowledge management. These ensure societal embedding of the technologies and knowledge transfer. This paper will illustrate the transdisciplinary approach, implemented technologies and accompanying measures as well as key results.

The Management of Water Resources Under Conditions of Scarcity in Central Northern Namibia

The amount of water in the hydrological cycle is constant. At the same time, water demand is increasing due to population as well as economic growth (GWP 2000). These circumstances lead to competition and potential conflicts over water resources and a water gap (contribution of Kluge in Part V). A deficient water management or its complete absence is likely to have negative social, economic, and environmental implications. Especially, political and technical dependencies as well as power structures which disadvantage certain population groups have to be mentioned in this context. These issues are of particular importance in developing countries where securing water supply is paramount. This is why management approaches have been developed of which one will be presented in the following. Beside of institutional and political aspects, demand management and technical contributions play a key role when solving these kinds of problems. Before the proposed water supply techniques will be explained in detail, the specific case study and the objectives of the corresponding research project are introduced.