The U.S. Coast Guard is warning travelers in the Gulf Coast and Southeast to be cautious about entering flood-prone areas.
According to the U.N. agency, flood waters from Hurricane Irma have washed away more than a dozen bridges and structures along the Mississippi River in Louisiana, Tennessee, Georgia and Alabama.
In the Atlanta metro area, the storm is expected to crest this week, according to the National Weather Service.
In some parts of Louisiana, there is a high risk of flash flooding, the agency said.
Floodwaters can be deadly in high tide and are dangerous when they come ashore.