Correlation between L_IR and L_H2O in local ULIRGs and high-redshift Hy/ULIRGs. The black points represent local ULIRGs from Y13. The blue points with solid error bars are the H-ATLAS source in this work together with some previously published sources. Red points with dashed error bars are excluded from the fit as described in the text. Upper limits are shown in arrows. The light blue lines show the results of the fitting. The insets are the probability density distributions of the fitted slopes α. We find tight correlations between the luminosity of the three H₂O lines and L_IR , namely L_H2O∝L_IR^1.1−1.2.