The potential role of constructed wetlands in protection and sustainable management of lake catchments in Kenya

Constructed wetlands are man-made ecosystems, which are specially designed for treatment of wastewater and non-point source pollution. Constructed wetland technology is gaining popularity due to its economically and environmentally sound attributes as a wastewater management option. Freshwater lakes in Kenya are under threat from degradation as human populations in the catchment areas increase, demands for natural resource extraction grow and urbanization and industrialization intensify. Consequently, there is increased surface runoff, causing sedimentation and eutrophication and ultimately deterioration of water quality, habitats and biodiversity. This trend requires integrated and sustainable water resource management strategies. Strategies for integrated and sustainable lake catchment management should target alternatives that are attractive to communities and other stakeholders in a lake basin. However, in developing countries like Kenya, innovative technologies like constructed wetlands have not been widely adopted for wastewater improvement. Although substantial progress has been made in the provision of services including collection, treatment and disposal of wastewater, much still remains to be done to ensure sustainable wastewater management within lake catchments. This paper presents a synthesis of the potential and challenges with respect to two case studies in Lake catchments: The Splash and Chemelil constructed wetlands. An attempt is made to explore their design, performance and limitations to their use in sustainable management of lake catchments. A number of challenges are threatening sustainable lake catchments management goals achievable through wastewater management and pollution control using constructed wetlands. Such challenges, which include lack of awareness, legislation, financial, technical and institutional resources as well as the poor understanding of constructed wetland potential, may limit the potential use of constructed wetlands for sustainable lake catchment management. There is also lack of crucial data and information about the state of constructed wetlands in Kenya. The paper presents recommendations for wider adoption of constructed wetlands use in Kenya.