Ice-affected stream discharge measurement.

Hydrologic Technician, James Albrecht, from the North Platte Field Office making a measurement of discharge under ice using a Flowtracker acoustic velocity meter on a top-setting wading rod.  The string going across the picture is a tagline, used for measuring distance across the channel so that he can note the location of the ice hole he is working in.  Typically, the technician will drill about 25 holes across the channel to get a cross section of depths and velocities, which are used to compute the measurement of discharge.