Among the African termites, the fungus-cultivating genus Macrotermes is among the most tolerant of drought and dry conditions. Xerotolerance in this genus is thought to derive from these termites’ unparalleled capacity to modify the infiltration and catchment properties of local soils, and to actively transport water into the colony from deep soil horizons. This ability derives, in turn, upon a high rate of energy mobilization that is made possible by these termites’ symbiosis with the mutualistic fungus Termitomyces. In this poster, I report results of a six-month study of water potentials in and around two colonies of Macrotermes michaelseni inhabiting a semi-arid savanna in northern Namibia. Mean annual rainfall at this site is about 450 mm. During the rainy season (October through March), water potentials in the mound and soils between mounds are highly variable and strongly driven by intermittent thundershowers. With the onset of the dry season (March through October), the mound progressively dries, the greatest drying occurring in the superficial soils, particularly on mound faces that are strongly insolated. Shaded parts of the mound stay comparatively damp. Deeper soils stay wetter overall, but even deep soils dry as the dry season progresses. Water potential within the nest itself stays remarkably steady, indicating active regulation of nest moisture. The ability to regulate nest water potential in the face of drying everywhere else in the mound may depend upon the proximity of perched water tables that can serve as an extraneous source of water for the nest.