Summary:

The study presents the results of the research under contain a nitrogen and a phosphorus in the Dobczyce reservoir's inflows (in a period July-December 2003 year). There was a drought time, which characterized a low precipitations. The research has done on a shot in a five direct inflows of reservoir: Ratanica, Brzezówka, Dębnik, Wolnica i Trzemeśnianka and in the Raba river (Osieczany section). Obteinable results of the research with six measuring sections were compared and on this basis, water was qualified to an appropriate grade. The direct inflows of the Dobczyce reservoir, which was investigated on a contain a nitrogen and a phosphorus, wasn't serious endangered in a half a 2003 year. The inflows was moderate prosperous in a nitrogen compounds and affluent in a phosphorus compounds. The water of streams investigated rest on value of concentration nitrogen in a form: amonium nitrogen, nitrate nitrogen and nitrite nitrogen according to a decree of 1991 can qualify for a first class purity. According to a proposal decree can qualify for a first class with exception of the Ratanica stream and the Trzemeśnianka stream, concering to nitrite nitrogen. There is a worse qualify of water in the Raba river, becouse of amonium nitrogen and nitrate nitrogen can rank for a III and I class, contain of nitrite nitrogen qualify water for a non class. According to a proposal decree, water of the Raba river can qualify for V, I i III class purity. In the water of the Raba river a min concentration phosphates (0,017 mg*dm^-3) was observed in November, a max in August (0,892 mg*dm^-3). The water in the Raba river concering to PO4 according to decree of 1991 qualify for II class, according to a proposal decree of 2003 for III class.