Watersheds aren't a local resource - they're a regional resource. This decision made no sense to begin with since, for instance, Vermont acting like a bad neighbor will cause environmental devastation in Massachusetts, Connecticut and New York - water sheds very rarely stay neatly within state boundaries. This becomes an even bigger issue when you look at the Mississippi - mining in North Dakota can cause issues in Louisiana.

I do hope that states can work together to protect the environment but it does seem likely to become a partisan issue.