The revitalization of the Inn floodplains

Since September 2020, one of the most beautiful revitalisation projects in Switzerland can be visited near Bever. Surrounded by rich flora and fauna, the Inn, which used to be restricted by dams as flood protection, is now making its way again.

History to the present day

The 1950s are considered to be a decade of floods: in 1951, 1954, 1955, 1956 and 1957, the masses of water from the River Inn ravaged the region, leaving the people of Engadin hardly any time to repair the damage caused by the last flood. The flood of August 1954 caused particularly devastating damage when large dam breaches allowed the floodwaters to pass through. Mud, sand and gravel covered large areas.

Once-built dams are demolished

At the end of the 1950s, two more flood dams were built in Bever to provide better protection. But almost 50 years later, considerable damage came to light: cracks and subsidence made the dams a case for renovation. To be more precise: a 700,000 franc renovation project. Apart from the enormous investment required, a ‘just plaster it over!’ method was out of the question, as the cracks had become a habitat for numerous protected reptiles, such as the adder.

A case study by ETH students on the expansion of the canalised Inn provided the decisive impetus: it pointed out the wet meadows along the river, which were valuable breeding areas and therefore already classified as ‘floodplains of national importance’. However, as they lacked a connection to the river, this important biosphere was in danger of drying out. The ‘reintroduction’ of the Inn could therefore provide a remedy, as it would lead to a considerable widening of the riverbed.

Of course, it was not enough to simply tear down the dams. The revitalisation was carried out in two stages with extensive measures: The first phase on the left bank of the river from 2012 to 2013 included the evacuation of the adders and the demolition of the dam, while the second phase since 2017 has provided 1.5 kilometres of new wildlife on the right bank.

Floods: once feared, now welcome

Small and large floods are necessary ‘life stages’ in order to significantly change the river's appearance so that this new biodiversity can develop. Without these floods, foreign flora such as pines or spruces would overgrow the breeding grounds of protected bird species and displace the native floodplain vegetation. In the knowledge of this valuable natural cycle, we are happy to accept the fact that instead of flowers and blossoms, there are only bare branches and roots lying around in the floodplain.

Legally enshrined water protection

Since 2011, revitalisation has also been a central component of the Water Protection Act, which obliges cantons and municipalities to strategically plan and implement revitalisation measures. However, the federal government not only demands but also financially supports the projects, which has clearly benefited the Inn floodplains, as they now make an invaluable contribution to biodiversity as well as local recreation for locals and visitors.