Highlights from the NaBWIG-funded MSc thesis aiming to assess the recharge and storage potential of the Toroka sand river in Kenya were presented at the “Groundwater, Key to the Sustainable Development Goals” international conference organized at the Sorbonne University in Paris. The oral presentation was given by Michel Frem on the 18th of May 2022 during the session that addressed the links between SDGs, nature based solutions, ecosystem services and groundwater.
The adopted multidisciplinary research methodology included remote sensing applications, rainfall-runoff analysis, water balance estimations, hydrogeological and water quality field investigations, hydrochemical and stable water isotope analyses, comparative analysis between storage, water availability and demand, as well as field surveys.
The study concluded that the Toroka sand river is characterized by two distinct behaviors, a function of the prevailing geological context: an upstream gneiss-dominated area where baseflow is the controlling factor and a downstream quaternary-dominated area where a more typical sand river behavior is noticed as the storage is mainly replenished by infiltrated surface runoff.
The study also showed that the sand river’s storage is hardly used in many areas along the river course. Hence, a more consistent use of the sand river’s water would help covering parts of the total demand. This research thereby concluded that storage enhancements (such as sand dams and subsurface dams in the downstream parts of the Toroka sand river) are necessary to cover the current demands and to support additional socio-economic development projects.