Today, flood risk is defined by the National Authority of the Adige River (Autorita Bacino Adige, 2006). Very high flood peaks (500m3/s) are diverted into the oligotrophic Garda Lake by the Mori-Torbole tunnel. According to the law 183/89 the Basin Authority is in charge of pursuing integrated planning interventions at the basin scale, thus finding a common intent, goals for public benefits and preparation of a basin plan with an effective implementation schedule.