GRMELA JAN, VITEK TOMAS, KOPP RADOVAN: The water quality of the river Svratka and its tributaries. Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, 2013, LXI, No. 1, pp. 65–70 Water quality in river depends on water quality of its tributaries. During the year 2011 nine selected sites downstream under the Vir dam (from 108 to 79 river km) were monitored. For observation were chosen tributaries Besenek, Loucka, Nedvědicka, Chlebský creek, Hodoninka, Vrtěžiřský creek and Tresný creek. At the same time samples from the places above and under the whole monitored section of the river were taken. Basic physicochemical parameters were monitored monthly during the vegetation period. Flow velocity and discharge were assessed three times. Based on the water quality evaluation of, the river Svratka and its tributaries Hodoninka, Vrtěžiřský creek and Tresný creek belong to the second quality class, tributaries Besenek, Loucka, Nedvědicka and Chlebský belong to the third quality class. In the monitored section the retention of phosphorus in annual amount about 2.2 tons were occurance. Annual volume of phosphorus at the end of observed section (upstream the Tisnov town) was nearly 17.5 tons. Annual total balance of nitrogen at the end of monitored section was 700 tons per year and 6000 tons of carbon per year. The major source of these nutrients is the river Loucka.