Flooding of the Lin plain
The flooding of the Lin plain was part of the military line of defense of the Swiss Army in World War II against an enemy incursion from the north. The planned flooding ( inundation , French inondination) and swamp would have created the medieval Tuggenersee between Uznach , Giessen, Schübelbach and Tuggen as well as three smaller lakes between Benken-Giessen and Schänis .
Strategic importance
The Linthebene was a preferred axis of incidence of the German operation plans for mechanized associations and airborne troops, because they access into the basin of Schwyz and direction Gotthard enabled and the entrance to the Glarnerland and the three Alpine passes Pragel , Klausen and Kistenpass formed. It played an important role in the army's defense system as part of the Limmat position and from July 1940 as the northern border / presentation of the Reduit front . You should to the utmost kept are.
This important strategic importance was recognized even before the outbreak of war and studies were carried out on a possible flooding in order to prevent tank advances and tactical air landings in the Lin plain. On October 30, 1939, General Guisan ordered the construction of the dams immediately and approved a loan of 200,000 francs for flood preparations.
The position of the 7th Division on the Linth also included the two bridgeheads and infantry fortresses Grynau and Möslifluh near Benkner Büchel as well as numerous tank barriers and bunkers along the Linth. The 7th Division was also responsible for guarding and defending the dams.
Dam
During the entire active service ten men of the sapper company II / 34 were busy with the defense structures. The dam consisted of dams, weirs, culverts and earth plugs. The two Hintergraben canals of the Linth could be dammed by means of earth plugs, needle and dam bar weirs . This led to flooding, a general rise in the water table and swamping. Tank advances and tactical airborne landings in the Lin Plain were to be prevented or made more difficult. The needle weirs consisted of individual wooden planks lined up closely together, the so-called needles. They supported themselves at the bottom against a massive defensive substructure and at the top against needle rests made of metal on the bridges, which made it possible to let in and block the wooden planks.
The passages of the Linth into the two side canals (back ditch), the main weirs in the swamp outlet, Giessen and Grynau were structurally permanent structures. Around 40 small stowage devices for local traffic jams were made makeshift. All weirs were installed without plugs for the dam.
In 1945 there were 82 weirs and plugs. The fortress watch corps had to ensure the operational readiness of the main dams and a few ancillary systems.
In 1974, Chief of Staff Jakob Vischer decided not to flood.
Stowage organization
In order to make the dams operational in the event of an emergency, around 1800 men were needed for the six devices available in February 1940 for filling 3000 m 3 of material each in three shifts and a three-day filling time.
Since the 7th Division could not provide these troops, the cantons of Schwyz and St. Gallen called up auxiliary service personnel and formed the auxiliary service detachments 1 SZ and 1 SG as military troops with a population of 230 men. For the damming, only the military troops to install the needles and dam beams in the needle and dam beam weirs were required, for the entire dam the defensive troops and another 16 auxiliary service detachments from the cantons of Zurich and St. Gallen were needed as plug troops.
When the army alarmed "Fall Nord" on May 15, 1940, the entire Linth plain was temporarily dammed.
Cultivation battle and improvement
With the Linth correction (1807-1822) the previous floods of the Linth Plain could be prevented. The draining of the marshy level by drainage was carried out as part of the Linthmelioration . A first project, caused by the food shortage in the First World War, was set up in 1921 on the left-hand Lint plain. In 1938 the Federal Council submitted a project to obtain fertile arable land, which was also intended to serve as a job creation measure to overcome the consequences of the global economic crisis .
During the Second World War, the development of additional land for agriculture as part of the cultivation battle enjoyed high priority in order to ensure the supply of food to Switzerland, which was surrounded by warring neighbors.
The makeshift traffic jam of May 1940 and the deepening and widening of the two rear canals (Linthhbackgraben) in 1941, which served as the main receiving waters of the plain, caused major agricultural damage on both sides of the Linth. The association of landowners and the governments of St. Gallen and Schwyz applied to the command of the 4th Army Corps that the Linth barriers and plugs at the Grynau and the lowest dam in the Läuferbach should be removed in the interest of additional cultivation.
As a solution to this conflict of interests, the suggestion of Linth engineer Jaques Meier was implemented from November 1942: The old Linth was extended as a continuation of the left-hand rear canal to the Spettlinth. The developed canals and ditches were able to drain the water from the plain, which ensured the cultivation of these areas and the possibility of flooding could be retained.
literature
- Walter Lüem et al .: The position of the Limmat in World War II . Baden-Verlag, Baden 1997, ISBN 3-85545-105-2
- Werner Rutschmann: The Linth position 1939–1945 with the planned flooding of the Linth plain . In: Terra Plana - magazine for culture, history, tourism and economy, No. 2/96, Mels 1996.
- Gertrud and Paul Wyrsch-Ineichen: In the Réduit - The canton of Schwyz during the Second World War. Situations and events about which not everything was in the newspaper at the time . In: Communications from the Historical Association of the Canton of Schwyz MHVS, issue 87, 1995.
- Valentin Kessler: The fortifications in the canton of Schwyz . Schwyzer Festungswerke Foundation , Lachen 2004. Reprint from the communications of the Historical Association of the Canton of Schwyz, Issue 95, 2003.
Web links
Individual evidence
- ^ Valentin Kessler: The fortifications in the canton of Schwyz . Schwyz Fortress Foundation, Lachen 2004
- ^ Report on the active service of the sapper company II / 34
Coordinates: 47 ° 12 '58 .8 " N , 8 ° 58' 13" E ; CH1903: 716015 / 230620