Tributaries of large rivers are characterize by the substantive changeability along their length. While the upper parts of the mountain character with strong slope and bed build from gravel and pebble the lower parts already in the big tributary valley close to the river mouth meandering with small slope and bed with mostly sands and organic bottom coming from main river floods. Changed on short distance water movement conditions creates challenge for existence of plants and animals. But the ecological evaluations of the river as any of ecosystems can be to the certain point achieved through environmental indication using species witch can only exists in positively developed and differentiated ecosystem. The practical way to rich this aim is to obtain the information’s about hydraulic parameters of water movement on the analyzed river part and confront it with results from environmental indication. What kind of parameters can be used to describe the river and what is the human influence on them? Answering this questions takes the hydraulically and hydrological analyzing of water movement into consideration. The paper presents the analysis of water quantity and quality (temperatures) parameters in the Skawinka River on the lower part close to the mouth with the Vistula River where the thermal-electric power station of once-through cooling system returns water withdraw from Vistula. Long term retuning large amounts of water has changed and formed morphologically Skawinka bed and on the same time in upper parts of this stream and on its tributaries a positive ecological indication is been made proving its possible good water condition. How is it possible to evaluate this two opposite information’s? Is there an immediate thread for the endangered species and which of the water movement parameters shall by taken by this evaluation into consideration? –this are the issues aimed in this paper.

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