This sign on the pier leading out to the lakefront stage on Lake Constance tells workers what action to take in case of high water at various levels.
From level 494 (which is still one meter below the level of the aluminum pier) they should close the aluminum wall of the orchestra pit. This refers to the old orchestra pit under the stage, where the orchestra used to sit and play for many years up to and including 2004.
From level 524 they should (among other things) seal up the entrances to the concrete core of the stage and install additional pumps.
At level 594 (= “+/- 0”, meaning the water has reached the exact level of the aluminum pier) they should inform the authorities and consult a structural engineer, and turn off the electrical system.
From level 639 they should flood the orchestra pit, flood the core of the stage and dismount the pumps.
I don’t know if they have ever had to do any of this.
My photos in this post are from 2005. I revised the text in 2022.