Given how much human conflict has erupted over access to rivers and other water sources, I can't imagine it will go well if a lot of countries start to do this at scale...
It's also fascinating how we muck-up water management in seemingly contradictory ways. I live in a temperate climate with a good amount of rainfall, but my town is already jockeying with its neighbors for the last remaining access points on the local water reservoir. Meanwhile, every time we get a heavy downpour, local creeks overflow due to excessive runoff from parking lots and what not and end up flooding all kinds of places (the local mall floods pretty much once every year or two, it seems). Fascinating how we can have not enough fresh water and too much fresh water all at the same time.
Water, water everywhere and not a drop to drink.