In this work are presented 3-mathematical-dimensional quantum mechanical energy-dependent cross sections for the two isotopic reactions H+X2O-->Products; X=H,D. The results are compared with experiment and with other calculations. The comparison between theory and experiment leads to two contradictory conclusions regarding the application of the Walch-Dunning-Schatz-Elgersma (WDSE) potential energy surface: (a) The WDSE surface seems to adequately describe the abstraction process; (b) however, the WDSE barrier for the exchange process seems to be too high and therefore yields small cross sections in contrast to those found in the experiment.