Until 1974, the Rhine was a wild river and Rohrschollen was made up of several constantly changing islands: Schollen means a mound (a higher area protected from flooding), Rohr refers to hollow-stemmed reeds.

Find out about the historical development of Rohrschollen here.

 

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When the Rhine alluvial forest was unspoilt

The Rhine once offered varied, fleeting landscapes, a mosaic of islands of various sizes, separated from each other by the river's multitude of arms. It was a world in perpetual movement, before man tamed it.

Each year, in spring and summer, the river's floodwaters, regular but varying in intensity, reached out across the neighbouring forests. They brought water and nutrients at a time when sunshine was at its zenith. All of these factors led to the exuberant proliferation of plant life in the Rhine forest, one of the rare examples of dense temperate forest on the European continent.

Works to bring the river water under control

The Rhine was a wild, unpredictable river that led to devastating flooding; farming was tough, navigation uncertain and the frontiers in flux. It would take man 150 years to control it in three successive phases of development.

In the 19th century, correction of the river was undertaken on the initiative of Tulla, an engineer from Baden Baden. The works were done between 1842 and 1876: containment of the low-water channel to 200 to 300 m in width, flood plain delimited by high water dykes, towards the interior. The new course of the river eliminated the meanders and the majority of the ox-bows were filled in.

So-called regularisation works were undertaken between 1907 and 1956 to prevent erosion of the riverbed and provide a navigable channel, even at low water: transverse groins were installed all along the river, forcing the Rhine to take a sinusoidal course.

Apart from the fact that it improved navigation and enabled electricity production, canalisation also guaranteed the safety of the people living by the river. This phase began in 1925 with the construction of four weirs (Kembs 1932, Ottmarsheim 1952, Fessenheim 1956 and Vogelgrun 1959). Management of these structures was entrusted to EDF (the French electricity authority) in 1946, which had just been set up. However, the main channel had its limits: Germany no longer had access to the river and, owing to a low supply to the water table, farmland dried out. The Franco-German agreement signed in Luxembourg in 1956 recommended a new kind of "scalloped" development between Vogelgrun and Strasbourg. Then, as the gradient was still too great, the French and German states decided to construct complementary improvement schemes at Gambsheim (1974) and Iffezheim (1978) with the Paris agreement of 1969.

Effects of the works on Rohrschollen

After correction of the river, German farmers colonised the land won back from the river, the so-called Bauerngründe (farmers' plots). Owing to the phenomenon of alluviation, some of the islands became attached to terra firma on the western side. Rohrschollen then became part of the Neuhof forest complex. A hundred years after the correction, canalisation of the Rhine separated Rohrschollen from Neuhof forest and Rohrschollen Island was created. It is bordered to the north by the agricultural dam, to the south by the Kehl-Strasbourg diversion dam, to the east by the Old Rhine and to the west by canalised Rhine.

Human activity on Rohrschollen Island in the 20th century

In 1935, this forest covered 1,500 hectares and it could be flooded inside the dykes. But industrialisation of the site encroached on 400 hectares with construction of the southern section of the port of Strasbourg. It was then the turn of development for the reach and Strasbourg hydroelectric plant, which took up a further 400 hectares between 1959 and 1963. The effect of these works was the fragmentation of the Neuhof forest massif, a quarter of which became Rohrschollen Island. In the reach, the water table dropped by 1.20 m and canalisation cut off the former arm of the Rhine, the Bauerngrundwasser, which started to dry out (Carbiener, 2000).

As the land dried out and the level of the water table dropped, German farmers had a tough time irrigating their crops. The German State therefore funded the construction of the Strasbourg-Kehl agricultural dam in 1983-84, downstream from the reserve, to create a dyke and raise the level of the water table.

After 1970, the year in which Strasbourg hydroelectric plant was commissioned, Rohrschollen Island attracted a great many visitors from Strasbourg. They were looking for a place where they could relax and enjoy themselves. The former course of the natural Rhine, now called the Old Rhine, was used for bathing, boating and fishing. Its low flow rate often uncovered immense banks of gravel and made it possible to cross to Germany on foot. At the edge of the forest, an open-air café was open to boatmen and residents of the neighbouring districts at the weekend. A car park was even built at the foot of the dyke. After this café closed down in the 1980s, this place (referred to as the old car park) was occupied by travellers until creation of the reserve in 1997.