Die Alte Aare, Naturschutzgebiet nahe Meiningen. Photo/Foto: TES.

The Häftli Nature Reserve

The Häftli near Büren and Meinisberg (canton of Bern) has been a water and bird reserve of national importance since 1991.

After the completion of the Nidau-Büren canal in 1891, during the first water correction of the Jura (the Juragewässerkorrektion of 1868-1891), the water level dropped, and the Häftli developed into a stagnant water body. The rivers Aare and Zihl were the source of this new water landscape.

During the second water correction of the Jura (1963-1973), a permeable dam was built, allowing fresh water from the Nidau-Büren canal to flow into the Häftli.

Juragewässerkorrektion/la correction des eaux du Jura

Following the retreat of the Rhone glacier at the end of the last ice age, around 15,000 years ago, a large lake came into being between the present-day towns of Solothurn and La Sarraz (Canton of Vaud).

The water level dropped over a process of a few thousand years. The debris and rocks filled the plain, and three lakes remained: Lake Neuchâtel ((Neuenburgersee/lac de Neuchâtel, Lake Murten (Murtensee/Lac Morat) and Lake Biel (Bielersee/Lac de Bienne).

The region of Seeland became a marshy area with floods and flood disasters. The correction of the waters in the Three Lakes region in the 19th century is an outstanding example of the Swiss engineering skill, the Delta Works of Switzerland (Juragewässerkorrektion/la correction des eaux du Jura).

The project by engineer Richard La Nicca (1794-1883) was carried out between 1868 and 1891.

It included canals between the lakes of Biel and Neuchâtel (Zihlkanal) and Murten and Neuchâtel (Broyekanal), the diversion of the Aare from Aarberg to Lake Biel (Hagneckkanal), the canalisation of the last part of the (Alte) Aare from Büren to Nidau (Büren-Nidaukanal) and the lowering of the water level in the three lakes by several metres. In 1899, the hydroelectric power station (Laufwasserkraftwerk) Hagneck was also put into operation.

However, the region was still flooded. The second water correction was carried out between 1962 and 1973. It included the construction of the Flumenthal waterworks and extending and widening the channels of Hagneck, Broye, Zihl and Nidau-Büren.

Floodplains and bird species

The Häftli is characterised by water level fluctuations.  This environment created a mosaic of habitats and an extraordinary diversity of flora and fauna.

More than 200 different (migratory) bird species live in this area. Several beaver families found a home.

Rare plant species grow in the alluvial zones. Thanks to the high groundwater level, the trees and their roots reach the water, and the character of the floodplain forest is preserved.

(Source and further information: www.bueren.ch; www.be.ch).