I don't think that is necessarily true. Whatever rain falls evaporates again. If you increase the amount of rain in one place then evaporation also increases. Y

I don't think that is necessarily true. Whatever rain falls evaporates again. If you increase the amount of rain in one place then evaporation also increases. You have increased the capacity of the water cycle at least in a local area. Also most of earth is ocean so increasing rain on land does not necessarily take from other land.