There is an old legend about the so called "Black Lake":

There is an old legend about the so called "Black Lake":
"The water woman in the black lake" :
In the Satteinser forest is lonely the black lake. Tall fir trees surround the edge of the river bank and the dark mirror shines with an eerie glow. A water woman lives deep in the bottom. Woe, if one dares to go into the flood! It rises and embraces him with strong arms. No one has escaped the lake yet; he does not even return the dead corpse.

Source: In the legend forest, Legends from Vorarlberg, Richard Beitl, 1953, No. 242, P. 140