<p>The mitigation of hydrogeological risk entails a multifaceted approach requiring careful planning, analysis and implementation. The expertise gained by ISPRA (Italian Institute for Environmental Protection and Research) in studying hydrogeological events affecting Italian territory and in monitoring the prevention and mitigation measures, has detected that in many cases the assumed design solutions do not always properly considers some relevant components referred to the failure areas and the relations that exist between the latter and the elements exposed to risk. Starting from this consideration, ISPRA developed a method and web-GIS application, named RaStEM (Standardized Representation of Mitigation Effects) and built by PostgreSQL database, to provide a freely accessible tool for technicians to represent, in a standardized way at national scale, the significant elements of hydrogeological risk mitigation designs and to analyse their implications. RaStEM plays a crucial role in promoting a sound approach to design hydrogeological risk countermeasures, not only looking at the effectiveness in terms of safety and serviceability of the design works but also considering the interplay between the vulnerability, the exposure and the level of hazard involved. The present work describes and analyses the features of RaStEM; it delves the risk scenarios by representing the areas of instability, the exposed elements and the design works. The discussion emphasizes the effectiveness of RaStEM for the environmental management practices across several geographical and administrative boundaries by providing decision-makers with clear and concise information regarding measures effects to support their decisions and the fundings for hydrogeological risk mitigation planning.</p>