The richness with water on Papuk, is a natural feature of the Nature Park Papuk, made by specific geological built and relief, as well as the climate features of the area. The ridge crest of Papuk represents hydrological watershed of two basins, the basin of the river Sava and the river Drava.
Papuk is rich with mountain wells and creeks, representing the habitat of specific fish sorts, amphibians, reptiles and numerous sorts of aquatic invertebrates. The endangered Hippurus vulgaris, the narrow leaf buttercup (Ranunculus trichophyllus) and the yellow iris (Iris pseudoacorus) which are widespread only in Europe, stand especially out from the aquatic plants.
The cool, clear creek water is the habitat of the autochthonous river trout, and there can be barbells lappets, bleaks, lampreys and other. We find here also the endangered population of river crabs (Astacus astacus) and turtles, and several sorts of frogs. Otters (Lutra lutra) sometimes visit the Papuk creeks. The dipper (Cinclus cinclus) is an unusual bird, diving and walking on the bottom of the creek, searching for water insects, besides him, the mountain wagtail (Motacilla cinerea) found his habitat there too.
On the Jankovac well, a endemic sort of snail, Graziana papukensis, was found, living in gypsum rocks on wells and creeks on Jankovac.