Still, some residents ignored calls to evacuate.
He said "24 to 36 hours remain for significant threats" from heavy rain, storm surge and flooding.
Some 11,000 power outages have been reported in North Carolina.
As Tropical Storm Florence continues its slow assault on the North Carolina coast, some county sheriffs are grappling with another problem amid the mass flooding: looters.
The National Hurricane Center (NHC) downgraded it to a tropical storm on Friday, but warned it would dump as much as 76 to 102 centimetres (30-40 inches) of rain on the southeastern coast of North Carolina and part of northeastern SC. "There's a lot left to this even though the winds have died down and it's inland".
Gardner said the Cape Fear River, which is now at 2.4 feet is likely to reach 22.9 feet by Monday.
When the graphic expanded to show what nine feet of flood waters look like, the terrifying potential of the storm was clear.
To give a sense of the scope of inundation to come, the river's crest was expected at 19.1 feet, beating the record 17.9 feet set during Hurricane Matthew.
Major river flooding expected to continue into early next week.
"Assistance can include grants for temporary housing and home repairs, low-priced loans to cover uninsured property losses, and other programmes to help individuals and business owners recover from the effects of the disaster", FEMA said in a statement.More news: Hurricane Florence looms over East Coast — WHAT'S HAPPENING
Money also is available to the state, some local governments, and some private nonprofit groups on a cost-sharing basis for emergency work in those counties.
Florence now huge, slow-moving tropical storm.
Florence was moving west-southwest at about 7 kph (5 mph), with its centre located over eastern SC.
The National Hurricane Center said as much as 40in (102cm) was expected on the southeastern coast of North Carolina and part of northeastern SC. Storm totals could reach between 30 and 40 inches in some areas.
The National Hurricane Centre said Florence will eventually make a right turn to the north east over the southern Appalachians, moving into the mid-Atlantic states and New England as a tropical depression by the middle of next week.
It's since slowed down even more than it had been - moving west at just 2 miles per hour. The eye moved from sea to land at Wrightsville Beach in North Carolina.
Rain ranging from one to three and a half feet has already fallen, and it's not over. That, in turn, could trigger epic flooding well inland.
"It's an uninvited brute who doesn't want to leave", said North Carolina Gov. Roy Cooper. The storm is some 400 miles (645 kilometers) wide. As of Friday morning, more than a half a million people had lost power in North and SC. More than 360 people have been carried to safety since Thursday night amid rising waters.
"People that live in flood-prone areas near creeks and rivers need to be prepared".