Talsperren-Wasserkraft Sachsen-Anhalt planned a hydropower plant with integrated fish ladder in the outlet of the Muldestausee. The existing weir was to be interrupted at one point for this purpose. In the headwater, no or only minor construction measures were required. In the stilling basin of the corresponding weir field, a trough structure with a rake was arranged, which leads into the fish descent shaft. An underwater channel connects to the return to the trough.
ANUVA prepared part of the nature conservation documentation for the water law procedure. The services included a preliminary environmental impact assessment, three FFH impact assessments, a FFH preliminary assessment, a species protection contribution as well as the recording of bats, birds, dragonflies, mollusks, amphibians, reptiles and butterflies including documentation.
The Mulde River is part of the European protected area system Natura 2000. In addition to Annex II fish species, further fish species were to be considered as characteristic species of the flowing water habitat type, and the possible impairment of these species (reference fauna) by the planned hydropower plant was to be assessed. Because the Mulde was an important fish migration axis, it was necessary to examine to what extent a significant impairment of the fish species could be avoided by the integrated fish ascent and descent facility, or which effects would concern other FFH areas. Construction-related impairments of other species protected in the FFH area "Untere Mulde," such as the copper butterfly, were also examined. The section of the Mulde in the tailwater of the planned hydropower plant is still protected as a bird sanctuary "Middle Elbe including Steckby-Lödderitzer Forst." The possible effects of the project on the bird sanctuary and on the function of the Mulde reservoir as an important bird breeding and resting area were therefore examined.