Previous studies have shown that the adhesion strength of Pseudomonas biofilms can increase with applied shear stress, including for the PAO1 strain. Although this feature can improve adherence under temporary flow increases in engineered water systems, overgrowth of small conduits will eventually result in biofilm disruption due to the corresponding increases in shear stress. This process was observed after growth of both PPF-1 and PAO1 strains, with the initial effects presenting as a shifting-type displacement at approximately 41 hours in both cases. We define displacement as an abrupt movement of the biofilm, which nevertheless remains surface adhered. The changes in biofilm morphology due to displacement were initially more extensive for the PPF-1 strain, which demonstrated a significant corrugated structure afterwards. It appears that the PPF-1 may have only maintained contact with the walls via tethering to the channel while the biofilm largely lost contact with the horizontal channel surfaces. Two factors were likely responsible for the propensity for these displacement events after a certain time. The first is related to rapid changes to biofilm viscosity following the growth phase, which is especially pronounced in media solutions with high ionic strength, and this has been linked with changes to biofilm morphology via sudden partial detachment events. The second factor is a gradual increase in fluid velocity in the continuously decreasing head space above the growing biofilm, which increases the applied shear stress. After displacement, OD continued to increase, indicating the progression of biofilm overgrowth in the channel.