Fluvial geomorphology and river restoration: Tiroler Lech Nature Park

Most major Alpine rivers have undergone extensive regulation in order to gain arable land and to control flooding in Alpine communities. The Tiroler Lech River is often considered the only near-natural river landscape in the northern Alps. Although it has undergone manifold alterations since the end of the nineteenth century—later than most other Alpine rivers—it is granted sufficient space to form a braided river landscape, with huge gravel banks and ecologically valuable riverine forests along a major part of its course. Also in these sections, longitudinal and transversal manmade structures containing the river are obvious features in the landscape. Those measures have resulted in gravel deficits and subsequent incision of the river bed, increased flood risk due to increased human activities on the floodplains, and have caused a threat to ecological diversity. These ramifications were recognized towards the end of the twentieth century and were later countered by restoration efforts, such as widening of the river bed, removal of retention dams in the tributaries, reconnecting detached lateral branches with the main river course, the management of target species, and by increasing public awareness.