The invention relates to a device (11) for the prevention of liquid overflow from an outside installation comprising a storage tank (10) for said liquid and a liquid retaining means (12) arranged around said tank, said device comprising a plate element (111, 112, 113) to be arranged between the tank and the retaining means, said plate element defining an impact surface (131, 132, 133) hit by the liquid overflowing onto said plate in the event of a rupture of the tank and openings distributed over said surface and through said plate element in order to reduce the kinetic energy of the liquid.