The water tree goes back to a sawmill that was operated in Ockensen between 1904 and 1926. In order to be able to drive an electric turbine with water power, a mill pond was built a few hundred meters up the slope on the Ith, from which the water was led through pipes into the sawmill. This reservoir had to be well filled for the turbine to operate, so that the sawmill had to go to the pond beforehand to check the fill level.
In order to avoid this annoying walk and to be able to see from the sawmill whether the pond was full, the sawmill Hermann Meyer erected a high wooden overflow pipe below the reservoir. When the reservoir was full, water gushed out of the overflow.
The lime precipitates from the heavily calcareous water when it comes into contact with the air and is deposited in large quantities as tufa on the overflow, and mosses also settled. As a result, this overflow has now taken on the curious appearance of a high moss-covered tree stump, from the top of which water gushes.
In the vicinity of the water tree is the Im Heidsieke nature reserve as a spring swamp with a species-rich flora.