[cbhl]

Ancient cities needed to drink the freshwater from the rivers.

Now we have man-made reservoirs and aqueducts to deliver drinking water to the coasts.

Japan certainly seems to have cities along its rivers, but it also has a lot of costal cities (presumably because it's a small island nation, unlike, say, European civilizations).

For Fukushima in particular, I was under the impression they were using the ocean water to cool the plant itself. (Under non-meltdown conditions, you can transfer heat without contaminating the water itself...)