I think at a voltage like that, the water would flash boil, and vaporise almost instantaneously.
Some electrolysis procedures are current/voltage sensitive, such as producing sodium metal from NaOH. Too much juice will often cause the formation of a grayish intermediate "alloy" type compound containing both NaOH and Na metal.
Stuff sparks and cracks on exposure to water, yet even on heating, no sodium metal is liberated from that (evil) intermediate compound.
Of course, with extremely high voltages, I suppose its possible, for the rules to be slightly different, not sure of specifics though.