The spring Stierenberg, is located in the lower part of the Euscheltal between Schwarzsee and Jaun. In connection with current water supply projects in the neighboring Breccaschlund, in the Euschel valley as well as for the village of Schwarzsee, the community of Plaffeien decided to supplement the investigations carried out in 1977 to check whether the Stierenberg spring could be used for drinking water.