Ábrahám Levente: Biomonitoring a Dráva folyó magyarországi szakasza mentén 2000-2004 - Natura Somogyiensis 7. (Kaposvár, 2005)
Závodszky, Szabolcs: Hydroelectricity or national park? - Vízerőmű vagy nemzeti park?
8 NATURA SOMOGYIENSIS such as the summer snowflake (Leucojum aestivum), Peucedanum verticillare, and the giant scouring rush {Equisetum hyemale). Alder gallery forests {Alnetum) are more limited here than willow woods, containing the dominant common alder {Alnus glutinosa) and some specimens of grey alder {Alnus incana). A particular problem is that the planned tailwater canal would not flow back into the river right at the dam, but would arrive back to the Drava bed at Hungarian border from a 2 km long, concrete bed. Thus, water regime in the present Drava main bed woud change drastically - decrease critically -, with the returned water volume planned to be only 40 m 3 /s. This would actually mean that the present main bed (being only Hungarian for more than 1000 m) and the connecting dead branch system near Bélavár and Vízvár (belonging to the national park) would completely dry out, because these areas are situated on the gravel table of the Drava river and are thus continuously connected to the main bed which determines their water volumes and levels. Wetland areas found here are part of habitats for several protected and strictly protected species, and are included in the NATURA 2000 network. Fig. 3.: The location of the tailwater canal (tail-race) near the Hungarian border Operating regime Another problem arises from the operation regime of the power plant. The fluctuation of released water volumes during damming would make it impossible for breeding bird communities to nest on the gravel shoals in the tailwater section near Vízvár. Abrupt water level changes (even as much as 2 m a day) would significantly influence breeding success, and would lead to the elimination of wildlife forms on such gravel shoals.
