This unusual measure is being taken in order to avoid flooding and is set to be carried out by this autumn. Depending on weather conditions, lowering procedures might even start earlier.
In 2001, Vänern’s average water levels rose by 1.3 meters after a long and intensive rain period. Several major cities around the lake, like Mariestad and Lidköping, had to fight severe flooding.
Source: By Sveriges Radio 2008
