This study investigates the potential of satellite remote sensing (Landsat Thematic Mapper) data for mapping variations in deep drainage beneath agricultural land, in an area of relatively uniform geology. Variations in reflectance measured with the Thematic Mapper are correlated with rates of deep drainage measured with soil tracer techniques. Variations in drainage are detected as variations in soil and vegetation cover. Statistically significant, positive correlations between reflectance and drainage flux were observed in the visible and mid-infra-red portions of the spectrum in all images obtained. -from Authors