Laboratory experiments with compacted kaolinite-bentonite mixtures indicate that degradation of hydraulically transported clay lumps in a dredge pipeline can be predicted and controlled to some extent. The size reduction of these lumps depends not only on the length of the pipeline but also on the density of the clay being dredged, the plasticity index (PI) of the clay, and the velocity of the dragging slurry in the pipe. A series of graphs shows percent reduction in clay lumps as a function of PI and velocity at three levels of relative compacted density. If the relationships obtained in this study are shown to be valid in the field, this information will be useful in selecting dredging equipment, designing dredged material containment area, and estimating costs. Relatively undisturbed specimens of the in situ clay and simple laboratory tests would provide the necessary information.