  In this paper, we analyse the upper limit fluxes of sub-millimeter
ortho-H$_{2}$$^{16}$O 321 GHz, para-H$_{2}$$^{18}$O 322 GHz, and HDO 335 GHz
lines from the protoplanetary disk around the Herbig Ae star HD 163296, using
the Atacama Large Millimeter/Submillimeter Array (ALMA). These water lines are
considered to be the best candidate sub-millimeter lines to locate the position
of the H$_{2}$O snowline, on the basis of our previous model calculations. We
compare the upper limit fluxes with the values calculated by our models with
dust emission included, and we constrain the line emitting region and the dust
opacity from the observations. We conclude that, if the outer edge of the
region with high water vapor abundance and if the position of the water
snowline are beyond 8 au also, the mm dust opacity will have a value larger
than 2.0 cm$^{2}$ g$^{-1}$. In addition, the position of the water snowline
will be inside 20 au, if the mm dust opacity is 2.0 cm$^{2}$ g$^{-1}$. Future
observations of the dust continuum emission at higher angular resolution and
sub-millimeter water lines with longer observation time are required to clarify
the detailed structures and the position of the H$_{2}$O snowline in the disk
midplane.
