Dam-break sediment flow is an especially rapid unsteady flow, important in terms of risk assessment, mainly observed in flow-type landslides and dam. breaks. The paper presents MUDEP, a computational model under development in IST, Lisbon, Portugal, to model such flows, using the I-D explicit differential TVD MacCormack scheme to solve the adapted St-Venant equations. The function calculating the friction slope varies according to the theological model. In order to verify the results, experiments were performed in a tilting flume, using a highly viscous oil to simulate the expected laminar behaviour of such flows. The fluid was suddenly released down a slope by the removal of a gate. The comparisons of the computational and experimental results demonstrate the validity of the developed model.