The selected events encompassed a wide range of climatic conditions (Table 2). The rainfall duration for the 18 events ranged between 20 min (20/11/1997) and 1650 min (03/05/1999). Rainfall depths (Ptot) varied from less than 4 mm (20/11/1997) to more than 96 mm (03/05/1999). Maximum rainfall intensities over a 30-min period (I30max) ranged from 7 mm h−1 (20/11/1997) to 106 mm h−1 (06/08/1999). According to rainfall amount–duration in the area ( Masson, 1980), the return period of the 18 events ranged from a few days for event 10 to about 25 years for event 18, averaging 62.7 mm in one hour.