GEORGETOWN, SC (WBTW) – Georgetown County is bracing for the last wave of flooding after Hurricane Florence. 

Traffic has already been reduced from four lanes to two on the U.S. Highway 17 bridges over the Waccamaw, Pee Dee and Black rivers. An aqua dam is in place, but the department of transportation says it may not be enough to keep U.S. 17 open.

Businesses are removing their inventories and sandbagging their front doors on Georgetown’s historic waterfront, as flood waters from Hurricane Florence make their way to the ocean.

“This is an unprecedented event for South Carolina, especially in this region,” said Christy Hall, secretary of the state department of transportation.

On the U.S. 17 bridges over the Waccamaw, Pee Dee and Black rivers, DOT and National Guard crews are installing 1,000 feet of aqua dams, which fill up with water to try to block flooding from roads. The goal is to keep U.S. 17 open as long as possible, but DOT forecasts say the road will likely close.

Engineers will also monitor threats to bridge safety like erosion or how fast debris is floating.

“We’ll be looking at that velocity to make sure there’s not any lateral force pushing on the bridge,” said LeLand Colvin, deputy secretary for engineering with the state DOT. “So we’ll be measuring that velocity and we understand what it would take to actually damage the bridge.”

Crews are also putting 4,000 feet of aqua dams along U.S. 17 in the Waccamaw Neck area of Georgetown County towards Pawleys Island. Another bridge on U.S. 17 south of the city near Maryville could also be closed.

Officials are also worried about another road.

“We won’t be surprised if we lose the U.S. 701 access from Horry County coming into Georgetown County, which leaves U.S. 521 to the west as the lifeline,” said Georgetown County administrator Sel Hemingway.

River flooding in the Georgetown area is expected to crest Wednesday night.

Until then, county officials say they’re preparing for the worst.

“We’ve watched what happened in Dillon (County), Marlboro County and Marion County. As it comes down through Horry County, it’s coming to Georgetown,” said Georgetown County emergency manager Sam Hodge.

The county has two shelters open at Georgetown High School and Waccamaw Middle School in Pawleys Island.

While the county says it likely won’t order mandatory evacuations, up to 8,000 people are urged to stay safe and leave flood-prone areas.