Ornithological investigation of water reservoirs and fish-ponds were carried out in 2003–2004 in 7 sites. We have identified 109 bird species, 50 of them were bound on water biotopes. Eudominant, dominant or euconstant nesting species bound on water (Tachybaptus ruficollis, Podiceps cristatus, Anas platyrhynchos, Aythya ferina, Fulica atra and Acrocephalus arundinaceus) are characteristical species of water reservoirs of the study area. On the basis of Sřrensen-index the species diversity in this biotope type is dependent mainly on the development of water and shore vegetation and relief configuration. The studied sites belong to significant landscape segments substituting the destroyed marsh biotopes.