An embodiment provides a method for measuring velocity and depth of fluid flow in a channel, including: transmitting, using a transmitter, directed energy comprising a single energy beam slant-wise toward a surface of a fluid in a fluid channel producing a plurality of reflections, wherein the transmitting comprises modulating a frequency associated with the single energy beam; detecting, at a receiver, received signals from the plurality of reflections; and determining, based upon differences between parameters of the transmitted single energy beam and parameters of the received signals, the velocity of the fluid and the depth of the fluid. Other embodiments are described and claimed.