Water covered streets in communities along Barataria Bay, where Republican presidential nominee Mitt Romney was to visit later on Friday.
The flooding, driven by Hurricane Isaac, was receding somewhat after isolating the area as the storm made landfall on Wednesday.
Romney was to visit the Jean Lafitte-Crown Point area along with Republican Louisiana Gov. Bobby Jindal.
In Crown Point, police were telling people not to drive because wakes caused by their vehicles were pushing water toward homes.
In advance of Romney's visit, Secret Service agents were checking out the area along the Lafitte-Larose Highway, the only roadway into the area.