. The oldest record of flooding on the
Alpine Rhine dates to 1206. One of the worst instances took place on 28 September 1868, when almost the whole of the Rhine valley from
Sevelen to
Lake Constance stood under water. The embankment broke at three points. The Alpine Rhine meandered through the
Alpine Rhine Valley in a riverbed wide, accompanied on both sides by inland waters and embankments apart. From 1861 to 1881, the
canton of
St. Gallen, supported by the Swiss Federal Treasury, the
Principality of Liechtenstein and the
Austrian Empire, created a regular riverbed between
Landquart and
Au. However, the capacity of the river bed was still insufficient, which is why the
embankments were raised again by 1890. More than 30 streams still flowed into the Alpine Rhine below Landquart. At high water these were filled up and flooded. As a result, the long Werdenberg Canal was built in less than two years, from 1882 to 1884, collecting all the
tributaries between
Wartau and
Rüthi and feeding their waters into the Rhine. Twenty years later the
Rhine Valley Canal was opened, collecting all the streams from Rüthi to Au. In 1910, the
Vorarlberg Rhine Valley Canal was completed, which drained the area between the catchments of the
Frutz and
Dornbirner Ach. The
Liechtenstein inland canal, just under long, was not finished until 1943. For the construction and maintenance of the
levees on the Swiss and Austrian side of the Alpine Rhine, the
International Rhine Regulation Railway was constructed. It opened in 1892 and since 2008 it is a
heritage railway.
1892 Treaty The 1892 treaty between
Austria-Hungary and Switzerland on the regulation of the Rhine put to an end the many flood disasters on the
Alpine Rhine between
Sargans and
Lake Constance, reducing the course of the river by means of two cuts in order to increase the gradient, raise the flow rate of the river and prevent deposition of sediments. The company,
Internationale Rheinregulierung (IRR) is the umbrella under which the two countries, Austria and Switzerland, coordinated the construction and they still maintain the banks today. They have their head office in
Rorschach, Switzerland, and a construction department in Austrian
Lustenau and Swiss
St. Gallen. == See also ==