Update: Hurricane Dorian won’t be as bad as Florence, but forecaster say flooding on tap
10:30 p.m. Update: National Weather Service forecasters say rainfall totals are lower than anticipated leading to lower river level predictions. The Waccamaw River near Conway is expected to crest around 12.4 feet on Friday in moderate flood stage. The river is now not expected to reach major flood status. The NWS still warns the Conway Marina will be flooded.
If major flood level predictions hold following Hurricane Dorian, it could be a top-10 or top-20 historic flood of the Waccamaw River at Conway, according to historical information from the National Weather Service.
On Thursday morning, the Waccamaw River was expected to crest at 15.5 feet at Conway on Friday, according to the current NWS predictions. By Thursday evening it was expected to crest at 14 feet.
If the crest reaches 15.5, 2019 will tie a 1924 flood as the seventh-highest flood levels on record going back to 1896. If it stays at 14 feet, it will only be a moderate flood, but it will be in the top 15 years for historic crests.
If what they predicted is accurate, four of the top 10 historical floods in Conway will have taken place in the last few years. In 2015 the river reached 16.2 feet, and then it rose the following year in 2016 to 17.89 feet.
The flooding that followed Hurricane Florence, however, topped out at 21.16 feet, beating the previous record by more than 3 feet of water.
Horry County Assistant Administrator for Public Safety Randy Webster said Wednesday the flood levels following Hurricane Dorian will not be as devastating as what was experienced after Hurricane Florence.
During Florence the Waccamaw River was above the major flood level for almost 20 days and affected thousands of properties in Horry County. The flood actually began with extremely heavy rains in North Carolina and then filtered its way down into Horry County.
The upcoming flood is expected to crest by Friday afternoon and be out of a major flood level in less than a week. Richard Neuherz with the NWS said most of the flood water will come from rain that fell in Horry County. Additional rainfall in North Carolina could cause a second crest later on in the month.
“The water moving down from Longs up into North Carolina will produce a second crest beyond the time shown on the hydrograph. That rise you see toward the end of the trace shows the water beginning to rise toward that crest,” Neuherz said in an email. “At this point, it looks like that second crest will be lower than the first crest.”
The flood should also reach far fewer homes and won’t threaten critical infrastructure like the U.S. Highway 501 bridge.
The NWS’ river flooding report expects the flooding to affect several residential properties at Riverfront South, the Conway Marina, Lees Landing, Savannah Bluff, Pitch Landing, Jackson Bluff and Bucksville.
In addition, the flood waters will affect other residential areas along S.C. Highway 905 and S.C. Highway 90 closest to the Waccamaw River. The NWS report said hopefully only lawns, roads and swamp land will be impacted.
Neuherz said upcoming flooding reports should give more insight on the long term impacts of the flood once he has a better idea of actual rainfall from Hurricane Dorian.
This story was originally published September 5, 2019 at 10:49 PM.