Nature is incredibly complex. My feeling in general is that we should imitate the natural systems as much as possible. In one study on the shifts of regional water availability due to global tree restoration the authors come to the conclusion:
Large-scale tree-cover expansion can increase water availability by up to 6% in some regions, while decreasing it by up to 38% in others. There is a divergent impact on large river basins: some rivers could lose 6% of their streamflow due to enhanced evaporation, while for other rivers, the greater evaporation is counterbalanced by more moisture recycling.
Difficult thing: Should we consider planting forests where forests have been before, even if water availability is decreasing (after the models)? What are other impacts of planted forests? More humidity in the air, more water circulation, more precipitation somewhere else?