The flash flooding closed dozens of roads in Brunswick County, including U.S. Highway 17, which is the main coastal route. Floodwaters swamped the highway at several points for most of the day, trapping some drivers on high ground that became an island.
Emergency workers brought food and water to people as they waited for the waters to recede, Brunswick County emergency officials said. No deaths were reported but dozens of roads in the county were damaged and many washed out.
Monday's deluge centered on Carolina Beach south of Wilmington, where more than 18 inches (46 centimeters) of rain fell in 12 hours. That amount of rain in that period of time qualifies as a so-called 1,000-year flood expected only once in a that era, meteorologists at the National Weather Service office in Wilmington said.
Several blocks of the coastal town were flooded to the bottom of car doors for hours Monday as the system, known as Potential Tropical Cyclone No. 8, never organized enough to become the eighth named tropical storm of the season, Helene.
It's not the first historic flood in the region by any measure.
Hurricane Diana in 1984 brought more than 18 inches of rain to the area and forecasters noted that it was the first time a tropical event had dropped a foot of rain to the area.
Since then, the area just southwest of Wilmington saw 20 inches of rain in Hurricane Floyd in 1999, which was once the benchmark for heavy rain.
