It's not unprecedented, and there's no current threat to water supplies, but officials are prepared to start building an underwater barrier to block the denser saltwater from moving further upstream, Corps spokesman Ricky Boyett said Friday.
Even at a coffee break, be aware that you may create a barrier by holding your cup and saucer in a way that seems deliberately to block your body or distance you from others.
He defended Illinois' efforts to block the advance of silver and bighead carp toward the lakes by hiring commercial fishermen and operating an electric barrier, but acknowledged more needs to be done.