PREEMPT Case Studies

Po River Basin ( Italy )

The Po is the longest river in Italy , with a length of 652 km from its source in Cottian Alps (at Pian del Re) to its mouth in the Adriatic Sea, in the north of Ravenna . It is also the largest river with an average discharge of 1540 m³/s. The river basin area extends on about 71.000 km² and includes a large part of the Padan Plain, and is fed by a main reticulum of more than major 140 water courses (more than 20km of length) and an almost ten time larger secondary reticulum of natural and artificial water bodies, irrigation and reclamation channels. In the Alpine area, 174 water reservoirs manage 2.803 billion m³ a year, of which 143 artificial reservoirs for hydropower production, controlling 1.513 billion m³ and another 1.290 billion m³ controlled by natural lakes; furthermore the basin comprises circa 600k m 2 of glacier areas.

Weser River Basin ( Germany )

With 452 km length is the Weser river the longest German river to reach the sea of which the basin lies entirely within the national territory. The river basin includes an area of 49,000 km² and about 9.3 million inhabitants. The northern part of the river basin is characterized by the Atlantic climate, the southern part is influenced by continental climate. The average annual rainfall ranges from 600- 1,100 mm and the average temperature from 5°C to 9°C . Long term average discharges (1941-2002) at the gauging station Intschede (approx. 80% of river basin catchment) are: 327 m³/s (average flow); 118 m³/s (minimum average flow); and 1,230 m³/s (maximum average flow). The Weser is a pluvio-nival type with high water flow in winter and low water flow from June to October (Galbiati et al. 2008).

Scheldt River Basin

The River Scheldt originates in the north of France . It runs for 350 km , flowing through France , Belgium and the Netherlands , before it discharges in the North Sea . The river Scheldt is an important navigable waterway, connecting the port of Antwerp to the sea, which is the 2nd largest European harbour. The Scheldt can be divided into two categories; the river Scheldt , and the Sea Scheldt. In the latter category two more types can be distinguished as well: the Upper Scheldt and the Lower Scheldt. In Belgium it runs in a small part of the Walloon region, but mostly in the Flemish part of Belgium. The Scheldt can flood both due to high sea water levels and storm surges (coastal), but also due to high levels of rainfall (fluvial). Concerning the safety and the chances of flooding the Belgian government approved the so-called Sigmaplan in 2005, which should be ready by the year of 2030. The plan includes measures like building a storm surge barrier at Oosterweel (near Antwerp ); raising levees/dikes and creating more space for the river to flow (for instance by creating wetlands).

Ebro River Basin

The Ebro River system flows on the North-East of the Iberian Peninsula through 9,309 km and the basin includes a surface of around 85,000 Km2 and 347 main rivers. It passes through seven different Autonomous Communities in Spain, starting with Cantabria in the very north east and finishing in Valencia in the west, going though Castilla y León, Basque Country, Navarra, Aragón and Catalunya. It gathers most of it waters from the North Spain (mainly from the Pyrenees and pre-Pyrenees) and is probably the most important river basin in Spain in terms of water resources that provides.
In terms of capacity the Ebro River is well supplied of water but in a quite irregular manner. During the summer it can carry up to 10 times less water than average mean water flow. The range of the annual water flow can vary from 3.811 hm3 to 26.134 hm3 and the level of the water can go up to 7- 9 meters above average in some areas during the heavy rain season. It also severely affected by the winter snows in the Pyrenees and the Cantabrian mountains. Looking back at the average flow, this has been decreasing with around 18,286.7 hm3 /year in the 1960s to 8,253.8 hm3 /year at the 1990´s, and an average of 8,832 hm3/year for the period 2000- 2008.