Buffering performance in a papyrus-dominated wetland system of the Kenyan portion of the Lake Victoria Basin

The study was aimed at assessing buffering processes of the Eldoret Chepkoilel wetland in the Kenyan portion of the Lake Victoria Basin. Changing patterns of use and activities in the region of the wetland have exerted enormous pressure on land and water resources, including increased nutrient loads, increased erosion and thus increased sediment loadings to receiving waters. The Chepkoilel wetland was located a few kilometres north of Eldoret town. The wetland was sited in a shallow trough-like valley that lies at an elevation of between 2,110 and 2,140 m. The dominant wetland vegetation included a central band of dense papyrus (Cyperus papyrus) with narrow fringing stands of shorter emergent macrophytes, Cyperus spp. (C. rotundus, C. triandra, C. laevigatus). The section of the wetland described in the investigations was approximately 10 km long. The wetland received inputs from surrounding agricultural land, a flower farm and also a small domestic sewage treatment plant. The wetland received a permanent stream inflow from the Misikuri river. The Chepkoilel campus of Moi University was located to the west of the wetland, and effluent from the campus sewage treatment plant also discharged into the wetland. The monitoring data indicated significant nutrient-processing performance, reflecting a relatively long water-residence time within the system. Problems and approaches to monitoring the system are discussed.