The Tarash watershed, upstream of Kakuma Camp, is harvesting an average of 2.2 billion m³/year with an estimated annual recharge capacity around 360 million m³.
The boreholes, for safety reasons, must be concentrated only in the drilling corridor, along the Tarash River, along a 5 km wide stripe, reducing the recoverable groundwater flow of some 50 million m³/year, accessible by drilling boreholes.

Considering the daily water consumption of 20 l/day per person, which corresponds to 1.5 million m³/year for 200,000 refugees, the capacity of the Tarash watershed extends broadly over human consumption, leaving interesting possibilities for Kakuma camp extension and irrigated agriculture to supply food for the camp itself. 

In the Kakuma area, the WATEX™ study revealed that most aquifers lie at a shallow to moderate depth, often less than 50 m. These aquifers are situated amongst inter-volcanic layers and within fractured geological formations initiated by the shallow granitic basement.
Drilling in the Kakuma area carries high risk due to the pervasive intrusive volcanic plugs, which are often not visible on the surface.

The WATEX™ system is also a tool to minimize risk in drilling operations. Hence, it was recommended to drill within the fracture corridor of the Tarash River, where conductive fractures converge with high potential areas. Drilling outside of the corridor carries a risk of difficult geology or low yields.