Lake Jipe receives its main inflow from Mt Kilimanjaro in Tanzania via River Lumi passing through Kenya. The other main inflow is via River Muvulani from the Pare Mountains. Several temporary streams, mainly from the Pare Mountains, also drain into Lake Jipe. The lake has one outflow, the River Ruvu, located in Tanzania to the south of River Lumi, the main inflow. The Pangani River Basin provides water for hydropower plants at Nyumba ya Mungu that generates 8 MW, Hale 17 MW and Pangani Falls 66 MW, which accounts for at least 20 per cent of the country’s power output.
The collapse of the fishery is due to changes in water quality (increase in salinity and turbidity reported by riparian communities), breeding and nursery environments, increase in siltation due to increased human activities in the catchments. Expansion of the emergent fringe of macrophytes dominated by T. domingensis facilitated by declining lake level and/or heavy siltation in the lake, reduced inflow into the lake possibly due to increased water abstraction in the catchments and/or interference with initial water flow patterns into the lake by heavy siltation in the wetlands at the mouth of River Lumi, disappearance of the original euhydrophytes such as Nymphaea and Water lettuce, possibly due to changing water quality and apparent decline in the diversity and number of avifauna are among the major challenges facing Lake Jipe.
The priority areas for management of Lake Jipe include the need to forge partnerships of riparian scientists and socio-economists to ascertain the causes and assess the impacts of resource degradation especially on the deterioration in water quality, the collapse of the lake fisheries and changes in the composition and distribution of fringing aquatic. Secondly, it is necessary to to involve riparian communities of the lake and the influent streams in the development of management strategies for the Lake Jipe ecosystems and finally to integrate the management of Lake Jipe into the downstream context of Lake Nyumba ya Mungu and River Pangani ecosystems.