Recent studies show that there is not a significant decrease in precipitation amounts, although a reduction of total precipitation in the last twenty years has been observed over Italian country [1]. However, a new and more frequent distribution of extreme events has been shown [2], as occurred in the most recent drought episodes of the years 2003, 2005 and 2006 in the Lombardy region. Probably the year 2003 was the most unusual year with few precipitations and high temperatures for long periods over the Po basin; it has been perhaps the most recent event, in which the social perception has felt the lack of (water) resource [3].