Sediment and nutrient transport and groundwater sources in the Nzoia River watershed, western Kenya, East Africa

Lake Victoria has all the signs of advanced eutrophication (LVEMP & COWI CONSULTANTS 2002) with much of the effects due to inputs from inflowing rivers such as the River Nzoia. Wastewater from the Webuye Pan-African Pulp and Paper Mill and two sugar companies discharge high amounts of total solids, total suspended solids (TSS), and total dissolved solids into the Nzoia River (AcHOKA 1998, MoMANYI 2002, ADAMS & SIMIYU 2009). Surface water, which would otherwise supply adequate clean water for domestic use is diminishing due to erosion and sedimentation from land use changes. Ground water is the alternative source of clean water for domestic and industria! use. Kenya receives one of the world's lowest per capita water replenishment rates each year; that, together with the degradation of the existing water resources, rnakes the country very vulnerable to climate variability (MOGAKA et al. 2006). Monitoring and data interpretation of ground water yields, as well as assessment of river sediment and nutrient transport, provides valuable baseline information for understanding impacts of climate and land use changes on water sources in the study area as well as East Africa.