Riverine floods are natural phenomena that affect many people living in floodplain areas and cause serious damages to the built environment, urban services and natural ecosystem. In this regard, the EU Flood Directive 2007/60/EC requires member States to establish flood risk management plans, in order to reduce the potential adverse consequences caused by flooding.This work has been developed within the research project Flood-IMPAT+ (an Integrated Meso and micro-scale Procedure to Assess Territorial flood risk), undertaken by the Politecnico di Milano in collaboration with the Po River District and the partnership of several other stakeholders.The province of Lodi has been selected as a case study for the research work, because hit by a large flood in 2002 and several data are available for this event. The thesis assesses the effectiveness of structural mitigation measures built on the hydraulic right of the Adda river through a Cost-Benefit Analysis (CBA). Benefits, in terms of avoided damages have been computed with tools developed within the project Flood-IMPAT+. A two-dimensional river modelling has been used to create hazard maps for different return periods.