Castaldini, Doriano 
  
3 STUDY OF FLOODS AND METEOROLOGICAL DATA 
3.1 The flood events of the Panaro River in the Castelfranco Emilia area 
The waters of the Panaro River have 
periodically caused flooding in the area 
between Modena and Castelfranco. The 
flood events of the last two centuries are 
indicated by Moratti (1988) and 
Provincia di Modena (1996); they 
occurred in November 1887, October 
1889, October 1897, November 1928, 
May 1939. The more recent floods 
occurred in November 1966 (flooded 
area: 9,400 ha), September 1972 (fa: 
2,540 ha) and September 1973 (£a.: 
5,700 ha) (Fig. 2). 
In the 19th and 20th centuries, several 
other floods occurred in the lowermost 
tract of the Panaro River. In order to 
reduce flood hazard, several meander 
cuts were carried out along the river: 
these interventions resulted to be 
ineffective, of course, and they only 
transferred the problem to the tract of the 
river downstream of the cut. Because of 
these man's intervention, in the last two 
centuries the length of the Panaro River 
in the Po Plain tract was reduced by 
about 11 km (Castaldini & Piacente, 
1999). The last meander cuts were 
carried out in the early 1970s: four 
meanders were cut west of Castelfranco 
Emilia and the shortening of the 
Watercourse was about 3 km. 
Since these cuts did not reduce flood 
hazard adequately a “flow regulation 
system” was planned and constructed 
along the river. The Panaro river “flow 
regulation system”, operating since 1985 
but finished in November 1999, is 
  
  
   
  
  
T = 
vs 
> M 
> 
> 
5, 
SU 
Castelfranco Nm 
Emilia = 
  
     
L + 
2 et 
3i EJ 
4. E 
3 —— . ÄRA : 00m 
— 
  
  
Figure 2. Areas flooded by Panaro River in more recent flood events. 1) 
River, 2) fluvial scarp, 3) high water bed, 4) built Up area, 5) main road, 
6) boundary of Castelfranco Emilia Municipality, 7), 8), 9) flooded area 
which occurred on 1966, 1972, 1973 respectively, 10) crevasse or 
overflow: a) 1966; b) 1972; c) 1973. 
situated slightly to the west of Castelfranco Emilia, in a quarrying area within a fluvial depression that is 1.5 km wide 
and bordered by artificial embankments. In fact, it is located in a geomorphological situation that is optimal for storing 
large volumes of water without necessitating huge works for such purposes (Castaldini & Pellegrini, 1989). 
The flow regulation system principally consist of the following structures: 
a) a regulating dam: a transversal structure which permits discharge through 9 conduits. During periods of low water, the 
water is discharged through apertures located at the level of the river bed. In the event of floods, no more than a limited 
amount can be discharged through these same apertures. Excess water is stored up-stream from the regulating dam, 
producing an increase in the water levels and regulating the flow downstream. 
b) a main storage basin: the basin is represented by an area of 280 ha 
contained by the regulating structure up to a capacity of about 19 million m3. 
providing temporary storage of the water 
c) an auxiliary storage basin: an area of 70 ha providing temporary storage to a capacity of about 5 million m? for extra 
flow in the event of an emergency. 
  
230 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000.