Photo: Twitter - The Weather Network

In a terse warning, South Carolina's governor urged thousands of people in low-lying areas near the coast to evacuate Thursday before a mass of water rumbling back toward the ocean floods some places for up to two more weeks.

Gov. Nikki Haley said at a news conference that people in flood-prone parts of four counties should "strongly consider evacuating," including the 10,000 residents of Georgetown. Officials expect to close two of the main state roads out of the historic town in the coming days.

She asked people watching on television to call relatives who may have a false sense of confidence from surviving hurricanes, calling the second round of expected flooding "a different kind of bad." She said the standing water could last up to 12 days.

"We are having an issue getting those people to leave because they have been in hurricane situations," she said.

The warning applies to parts of Dorchester, Charleston, Georgetown and Williamsburg counties near the rising Waccamaw and Edisto rivers, but technically it isn't a mandatory evacuation order, said South Carolina Emergency Management Division Director Kim Stenson. Officials couldn't put a number on how many people are affected, but the counties have a combined 600,000 residents.

Haley planned to travel to the four counties Thursday afternoon.

"Our number one goal is to convince those people to get out of their homes," she said.

Earlier, city officials sought to dispel rumours the Columbia was on the verge of running out of water. Despite a setback involving efforts to plug a breached dam near the main water treatment plant, workers had already been working on an alternative plan to pump water directly from another location on the river, Assistant City manager Missy Gentry said.

Officials said efforts to secure the city's water supply will succeed.

"There are no plans to shut off the water system," Mayor Steve Benjamin said. "Zero plans."

And just a day after the governor praised residents for resisting the temptation to loot, two people have been arrested on felony charges of taking items from people's front yards and stealing street signs.

South Carolina's top agriculture official said he estimates the state may have lost more than $300 million crop losses in recent flooding. Commissioner Hugh Weathers said he flew over flooded areas several times this week and his initial estimate is conservative.

The Federal Emergency Management Agency said at least 16 counties had been declared disaster areas.

Overall, U.S. Sen. Lindsey Graham has said there could be a potential billion-dollar cleanup bill.

At least 19 people in South Carolina and North Carolina have died in the storm.