Hancock County Chief Deputy Don Bass said authorities rescued a Bay St. Louis resident from rising water early Wednesday.
Highway 603, the main route to Bay St. Louis and Waveland, was closed at Interstate 10.
"For the most part, we've been lucky, but we've got a long way to go," he said.
Darryl Antoine, a Waveland city worker, spent the night cutting trees off of roads, then checked the city's wells in the morning. He drove to his cousin's house early Wednesday to check on it.
Most of that street was flooded, but the house was rebuilt on stilts after Katrina and didn't appear to have wind damage. Antwoine said his own house was without power, but otherwise fine.
Jerry Beaugez, an assistant with the Bay St. Louis mayor's office has been working with the fire department, and said things have gone relatively well but it's too early to celebrate.
The water was still rising, a tin peeled off a business on Waveland and street signs fluttered in the wind. The storm could pound the area for hours and officials considered closing Highway 603, the main connector from Interstate 10 to Bay St. Louis and Waveland.
"There's not a lot we can do until everything subsides," he said. "As daylight comes, we'll get out and about and assess damages,"
Along low-lying areas along Mississippi's Gulf Coast on Wednesday hurricane-driven water rose several feet in some spots while thousands waited out the storm in shelters. Utilities were reporting more than 15,000 people without power Wednesday and several hundred more scattered around south Mississippi.
Harrison County emergency management director Rupert Lacy said the storm surge coupled with the high tide could lead to more extensive flooding. Lacy said coastal rivers also were beginning to rise from the rainfall.
Hancock County Emergency Management Director Brian Adam said the water stood up to 4 feet deep in many low-lying areas of Hancock County and was still rising while the vast storm system lumbered off the mouth of the Mississippi River.