River bridge notification

Factual Questions
1

The bridge across the Arkansas river, between Little Rock and North Little Rock is being replaced. One span is across, and the second is on barges, waiting to be moved after underwater obstructions are cleared.

The scene is well lit, but how are barge boats coming from, say, Oklahoma notified of this hazard to navigation?

2

The Coast Guard has weekly updates on navigable river cnditions and hazards.

Here’s the one that includes theArkansas River. (PDF) I think the information on that project is on Page 12.

3

Thanks!