CIFOR in partnership with the Justus Liebig University Giessen started in 2014 a project in Kericho county to estimate water-related ecosystem services from the largest mountain forest of Kenya, the Mau forest complex. The project monitors water flows and quality with state-of-the art-equipment to estimate water provisioning from catchments dominated by natural forest, smallholder agriculture, and tea plantations. Three permanent monitoring systems record water level, discharge, and concentrations of nitrate, dissolved organic carbon and turbidity by in situ UV hyperspectrometry . The information collected, although highly valuable to inform land use planning, is insufficient to manage water resources at the large scale. That project assessed the effect of land use on water supply and water quality. To be able to estimate the effect of land use, we have selected sub-catchment of similar size, where land use is relatively homogeneous, and where geology is similar. The research design to answer this specific question determined that we monitor a relatively small area of the basin, and that we do not capture mixed sub-catchments (various combinations of land uses) where other factors may play an important role. Therefore, to be able to scale the estimates of the high resolution monitoring, we need to map the variability of water quality together with a number of explanatory variables at basin level. This is a missing element in the earlier work.
In this project, we build on that earlier work, but focus specifically on the gaps that were not yet covered. The Water Resource Management Authority (WRMA) is the lead agency in the management of water resources in Kenya. This project provides an innovation to assist WRMA to make sound decisions on water management and to influence counties on their land use planning.