U radu je prikazana analiza protoka rijeke Vrljike mjerenih na stanici Opačac. Na temelju mjerenih dnevnih podataka u razdoblju od 1995.-2000. godine dani su grafički prikazi histograma otjecanja, krivulje trajanja protoka, transformirane krivulje trajanje protoka te sumarni prikaz krivulje trajanja i sumarni prikaz transformirane krivulje trajanja protoka za navedeno razdoblje.This study presents the hydrological analysis of river Vrljika (the karst spring Opačac). Graphical representations of hydrograph are given based on the measured daily data in period 1995-2000 year, and it was performed statistical data processing and analysis of the histogram, flow duration curves, transformed flow duration curves, summary display of flow duration c...