I know that up here (more on the west coast when I lived there) there was a lot of worry about NAFTA, and the impact it could have on the fresh water we have up here.
I saw pictures of these massive water bladders, they looked like zeplins, being floated down the rivers to head south for sale. Having cities exist where they normally couldn't comes at a price.
http://en.wikipedia.org/wiki/Flexible_barge