FAYETTEVILLE, N.C. — Hurricane Matthew is gone, but the disaster its rains unleashed will slowly unfold all this week as rivers across eastern North Carolina rise to levels unseen since many of the same areas were destroyed by a similar deluge from Hurricane Floyd in 1999.

Emergency planners are now using models that can pinpoint exactly how high the rivers can get and which buildings will be flooded days in advance. But they can’t predict dams and levees breaking from the stress of more than a foot of rain in some places.

In Lumberton, a levee broke overnight and crews were scrambling to rescue 1,500 people. Most of them were in knee deep water, but there were people on rooftops waiting for boats or helicopters, North Carolina Gov. Pat McCrory said.

Evacuations were being ordered in cities along three different rivers. Some rivers were expected to be at record levels Friday — six days after Matthew’s rains ended.

State resources are being stretched to their limit, and McCrory told the thousands of people being told to leave as rivers rise to heed the warnings.

“If you’ve been told to evacuate, then evacuate. If you don’t we have to divert resources to the area to save you,” the governor said Monday.

Immediately after Saturday’s rains, thousands of people found themselves suddenly trapped in homes and cars during the torrential rains. Rescuers in Coast Guard helicopters plucked some of them from rooftops and used military vehicles to reach others, including a woman who held on to a tree for three hours after her car was overrun by flood waters.

The storm killed more than 500 people in Haiti and at least 21 in the U.S. — nearly half of them in North Carolina. Most were swept away by flood waters.

McCrory and others fear the death toll may rise as impatient people drive around road barricades into swiftly moving floodwaters.

The National Hurricane Center issued its last advisory on Matthew at 5 p.m. Sunday when the storm was about 200 miles off the North Carolina coast.

Princeville, a town of 2,000 that disappeared in the waters of the Tar River during Floyd, was evacuated Sunday. The river was expected to rise to 17 feet above flood stage by late Monday — a level not seen since Floyd, which was another storm whose eye brushed by North Carolina’s coast but poured 15 to 20 inches of rain inland.

McCrory expected more evacuations as some rivers were predicted to crest next Friday.