La Loire vue de Chaumont

The Loire River, seen from the castle at Chaumont, looking downriver toward the west. There's not much water in the river in this shot and it looks rather benign. But let it rain for a while upstream or in the mountains where the river begins, and it can fill up and become rather treacherous.

The Loire is France's longest river at over 1,000 kilometers.

I had always heard that the Loire is a wild river because it is not dammed and is only contained by earthen levees on either side. However, I did see a tv program not long ago that showed at least two dams, Grangent (built in the mid 1950s) and Villerest (built in 1978), with reservoirs up near the river's source, so I'm confused about that.