Along the margins of the Cávado river can be found a riverside birch wood (habitat 91E0pt2) which falls within the alluvial forests of alder (Alnus glutinosa) and ash (Fraxinus excelsior), a priority conservation habitat. This birch wood is dominated by birches (Betula celtiberica) although the alder (Alnus glutinosa) grey willow (Salix atrocinerea) and hazel (Corylus avellana) are also present.
Animals characteristic of this habitat are, amongst others, the otter (Lutra lutra), long-tailed tit (Aegithalos caudatus), and the dipper (Cinclus cinclus), Iberian emerald lizard (Lacerta schreiberi), Lusitanian salamander (Chioglossa lusitanica) and, in the river itself, trout (Salmo truta) and the Iberian nase (Chondrostoma polylepis). The fact of being near to the dam is prejudicial for fish fauna, many predatory fish species have been introduced into the reservoir waters such as the pumpkinseed (Lepomis gibbosus) and largemouth bass (Micropterus salmoides) that threaten the autochthonous fish species.