Stream discharge measurements with chemical dilution techniques have
been proposed in several forms since the beginning of this century (Groat).
Early techniques consisted of introducing a chemical, usually brine, at a
known rate into flowing water and determining the resulting concentration
of the chemical in the stream at a section far enough downstream to assure
adequate mixing of the chemical with the water. A variation of this method,
and the technique used in the present study, was described by Barbagelata
in 1928. In that method, a known quantity of tracer was added, as a slug, to
the stream to be measured. At a sampling station sufficiently far downstream
for adequate lateral mixing, the tracer concentration-time curve was determined.
The stream discharge was then calculated from the amount of
tracer added and the area measured under the curve
