The aim is to investigate the feasibility of using a surrogate-based method to emulate the deformation and detachment behaviour of a biofilm in response to hydrodynamic shear stress. The influence of shear force and growth rate parameters on the patterns of growth, structure and resulting shape of microbial biofilms was examined. We develop a novel statistical modelling approach to this problem, using a combination of Bayesian Poisson regression and dynamic linear models for the emulation. We observe that the hydrodynamic shear force affects biofilm deformation in line with some literature. Sensitivity results also showed that the shear flow and yield coefficient for heterotrophic bacteria are the two principal mechanisms governing the bacteria detachment. The sensitivity of the model parameters is temporally dynamic, emphasising the significance of conducting the sensitivity analysis across multiple time points. The surrogate models are shown to perform well, and produced ~480 fold increase in computational efficiency. We conclude that a surrogate-based approach is effective, and resulting biofilm structure is determined primarily by a balance between bacteria growth and applied shear stress.