In this paper, Incompressible SPH (ISPH) is used to simulate free-surface mudflow for two case studies, including dambreak and flow under a gate. The mixture of water and sediment in mudflow is treated as a non-Newtonian fluid. Mass and momentum conservation equations in a 2-D Lagrangian frame, along with the Herschel-Bulkley rheology model, were solved to simulate mudflow using ISPH. Further, a Large Eddy Simulation (LES) model was used to evaluate the effect of turbulence on the free surface flow for these cases. The divergence-free velocity projection method was applied to enforce incompressibility of SPH. The results of the ISPH modeling compared well with experimental data and FVM-VOF results. The capability of the ISPH Lagrangian numerical model to capture large deformations makes it a powerful and efficient method for simulating mudflow case studies.