[en] Flowslides induced by the failure of tailing dams or waste dumps constitute significant industrial hazards. Examples in the past have demonstrated their high potential for casualties and damage. Geotechnical analyses provide nothing more than the failure criteria. In contrast, once the structure fails, the fluidized material propagates rapidly as a non-Newtonian flow, requiring thus a hydraulic analysis. This paper presents an advanced 2D depth-averaged flow model which accommodates the particular rheology of flowslides, including visco-plasticity and frictional behavior accounting for pore pressure. Based on mass and momentum conservation for the mixture of soil and interstitial fluid, the finite volume model handles flow propagation on dry areas and includes an original treatment of the yield stress in 2D. At a crossroads of geotechnical and hydraulic engineering, the paper depicts the elaboration and validation of a new model readily available for hazard mapping, including extent of affected areas, maximum depths and arrival time.