Summary:

This paper presents the research results of pollution level in Stobrawa river. The research was carried out on 19,5 km of the river in six test points: from the cross-section of the planned Kluczbork storage reservoir (point St.1) to the river source (point St.6). The test was carried out between November 2006 and October 2007. In the tested samples following compounds were determined: NO3-, NO2-, NH4+, PO43-, Ptot., BOD5, DO, TSS, water temperature, water reaction and elektro-lytic conductivity. Beside water quality tests, the hydrometric measurements were carried out. The paper also presents Stobrawa river quality valuation. The valua-tion of eutrophication of the Stobrawa river has been presented as well and it has been determined if the water is prone to nitrogen compounds pollution from agri-culture. The Stobrawa river catchment area has been valuated taking into consid-eration the flowing matter into the body water.
The test has shown vast pollution of water flowing into the Kluczbork water body. Subsequently it may negatively influence the water quality in the body of water in terms of its future possible water retention.
It has been shown that the familiarity of the profile of water quality indica-tors changeability is crucial while taking decision whether to build or not a body of water. On that knowledge the water quality in the planned storage re-servoir should be forecast, allowing taking the right economical decisions in cat-chment of planned storage reservoir in the aspect of retention, water management and protection in the storage reservoir.