Management of flood-prone areas is the result of a complex decision-making process aimed to define and implement, in the analysed zones, all those measures that can determine the compatibility between land-use related activities and the risk to which human, natural and economic resources are subjected (Castelli & Becchi, 1998). Structural mitigation measures modify the characteristics of a flood (i.e., the volume and timing of flood waters, their extent and location, their velocity and depth) or the susceptibility of people and properties to flood damage.