ABSTRACTDuring a period of five years the medium sized Upper Kafubu catchment (1540 km2) was studied for water discharge and suspended sediment transport. Due to the excessive deforestation, the mean annual runoff (265.3 mm) in the catchment is higher than in the undisturbed adjacent basins. The flood peaks are smoothed by the damping effect of a large swamp area. The observed suspended sediment yields are extremely low and decrease in a downstream direction as a consequence of depositional sinks. The established suspended sediment-discharge relationships are not useful to calculate the total load. The causes of this anomaly are examined.