Hydrological rehabilitation of the Blausee

The Blausee is one of the few bog ponds in the Allgäu and is home to many rare species. Peat digging and ditches have changed the hydrology in the edge area of the pond so that it became threatened to dry out. In order to maintain the water level of the Blausee, to stop peat decomposition and to restore the habitat of many species, the landscape conservation association carried out extensive and technically complex construction measures between autumn 2017 and spring 2018 to hydrologically restore the bog. The construction of three large dams and the insertion of a sheet pile wall has eliminated the draining and thus destructive effect of deep peat cutting. With the help of these extensive rehabilitation measures, the man-made run-off of the peat bog has been eliminated, the regressive erosion has been stopped and the Blausee has thus been secured for the long term. The damming up of small ditches in the bog forefield ensures rewetting and thus regeneration of the bog edge.Since many bog dwellers depend on flowering meadows as food sources in the vicinity of the bog, targeted scrub clearance was carried out in addition to the hydrological measures. The resulting reduced transpiration capacity of the woody plants contributes to additional irrigation and thus regeneration of the bog.  More moisture and light promote the growth of peat mosses in heathland moor areas and of flowering plants in litter meadows and wet meadows. In addition, the removal of woody plants has reduced the spatial resistance and improved the habitat availability and passability for numerous open land species, which can now migrate more easily from the adjacent meadows. The former litter meadows will be mowed again from 2018 and thus kept open for the long term.