This paper examines the discharge and velocity distributions in natural open channel flows using the entropy theory. Flow measurements were carried out at four different cross-sections in central Turkey. The mean and maximum velocities at these stations exhibited a linear distribution and the entropy parameter was calculated to be M=1.31. Using this value, discharges for all flow conditions were calculated as a function of the measured maximum velocities (umax). It was observed that the umax/H and zmax/H ratios remained relatively constant when 0.2=y/T=0.8, especially for the wider channels. Using these constant values for each station, umax and zmax could be determined solely as a function of the water depth H. Although the calculated velocities were higher than those measured at some verticals, the entropy-based approach presents an attractive alternative to the traditional flow-measurement techniques for the determination of flow properties because of its simplicity and quick application.