Edit for your edit: Europe definitely could do better in terms of making use of the available water - but there's no shortage of water in nature around us.

For example, the communists have damaged many rivers (made the river basins concrete etc), leading to drying of the surrounding areas. We're slowly correcting the damage. But generally speaking we have enough water. And you choose the place to build a nuclear power plant based on water availability.

Perhaps it's more of a problem in the southern states, I don't know about that. But we have an interconnected grid - we can sell electricity from one state to another (it's being done today).