I'm not sure. Multiple people see it as opaque towards the back in the Bellegarde Mines, but it makes collecting the ores there a hassle. This probably hasn't come up before because nobody wants to use the place, but for a few level 20's, it's relatively convenient to start into smithing in Dementlieu.
If/when they put Iron inside of the mines, I'd maybe fiddle with the water tileset, or just remove it from the Bellegarde mines. The effect it was intended to achieve just makes picking things up really hard, when it's opaque.