Upper panels: comparison between profiles obtained when the computation of the water line emission is internal to the shock code (steady-state approximation: blue curves) or external to the shock code (statistical equilibrium approximation: red curves); the temperature of the neutral fluid (continuous line) and the fractional abundance of water (dashed lines) are shown for our two reference, C-type (left-hand panel), and CJ-type (right-hand panel) shock models. In both cases, the shock parameters are displayed in the corresponding panels. Lower panels: integrated line intensities for all para-water transitions; steady-state approximation to the computation of the water emission (dark blue open circles); same shock model, but with the statistical-equilibrium approximation to the computation of the water emission (large light-blue open circles); present shock model, with the statistical-equilibrium assumption (small red filled circles).