Floods are a very common natural process in Italy. In the 20-year period from 1980 to 2000 the State set aside 7,400 million euro for flood damage, or roughly one million euro per day. With this study we developed a flood damage estimation model which land administration bodies and insurance companies could find useful in the management of flood-related damage data. The model simulates event scenarios and evaluates expected economic losses. Potential economic loss assessment implies knowledge of the event, exposed asset values and the degree of damage. Following a widely shared simplifying assumption, flood water level was taken as the only factor indicating event magnitude. The model incorporates the following steps: a) event description: definition of flood parameters (flooded area and water level), utilizing real-time measurements or data from event simulation with a hydraulic model; b) asset damage and identification of the affected population; c) evaluation of the degree of damage as a function of event magnitude; d) attribution of an economic value to different exposed assets; e) quantification of economic loss by multiplying economic losses and damage severity. The method could be used either as a forecasting tool to define event scenarios or for “real-time” damage assessment after a catastrophe. The approach is suitable primarily to large-area damage assessment but could also be appropriate for land use planning, civil protection, and risk mitigation.