South Carolina's governor warned on Thursday that several coastal areas were about to be hit by a second round of major flooding, while residents inland hauled soaked furniture and appliances from homes left in ruins by unprecedented rainfall.

Gov. Nikki Haley said the inundation expected in Georgetown, home to about 9,000 people, would last up to 12 days and she urged residents to heed evacuation notices.

"Don't underestimate the power of water," she told a news conference in Summerville.