As it widens I-95, NCDOT will raise the road to try to keep it from flooding
Torrential rain from Hurricane Matthew in 2016 sent the Lumber River over its banks onto Interstate 95 in Lumberton, closing the East Coast’s main north-south highway for several days.
Two years later, it happened again after Hurricane Florence.
Now the N.C. Department of Transportation is moving to both widen I-95 through Lumberton and raise it up high enough that engineers hope it won’t get covered with flood waters ever again.
NCDOT signed a $432 million contract this month to rebuild eight miles of I-95 through Robeson County’s largest city. Starting next year, contractors will widen the highway from four lanes to eight and replace bridges at three interchanges with wider and longer ones.
They’ll also build a new, higher bridge to carry I-95 over the Lumber River, where flood waters left the interstate impassable for several days after both hurricanes.
“This modernization is long overdue,” Grady Hunt, a state Transportation Board member who lives in Robeson County, said in a statement. “This vital corridor needs to be widened, but also upgraded to be more resilient against future hurricanes.”
Contractors will use fill dirt to raise the highway anywhere from 1.5 to 10 feet above its current elevation through Lumberton, according to Matt Lauffer, NCDOT’s hydraulics design engineer. The goal, according to Lauffer, is to raise all bridges and culverts high enough to handle a 100-year flood, plus provide a foot-and-a-half cushion so floating logs and debris can pass underneath.
A 100-year flood is one that has a 1% chance of happening in any given year.
NCDOT works to flood-proof I-95
The changes in Lumberton are part of a broader effort to try to flood-proof I-95 as the road is widened in stages between Johnston County and the South Carolina line.
Contractors who are already widening a 26-mile stretch of I-95 from I-40 south to near Fayetteville are also raising the road or replacing culverts with bridges to try to prevent future flooding, particularly where the highway crosses the Black River in Harnett County.
The fixes come out of a study commissioned by then Secretary of Transportation Jim Trogdon after Florence to determine how to keep both I-95 and I-40 from flooding after catastrophic storms that seem to come more frequently. Both Matthew and Florence rivaled Hurricane Floyd in 1999, which caused historic flooding that people never expected to see again.
NCDOT estimates that the extra efforts to flood-proof I-95 will add about 11% to the cost of widening the highway, though the exact cost will vary by segment. So far, the state has signed contracts worth about $1.1 billion to widen 34 miles.
The extra expense should pay off in the long run, Lauffer said. National research on disaster damage and federal government spending suggests that every $1 spent preparing for floods and other calamities will save $4 to $6 in future repairs and reconstruction, he said.
Construction on the Lumberton section of I-95 is scheduled to begin next summer, after final design work, and be completed by late summer 2026. It includes five interchanges, many surrounded by hotels, restaurants and other businesses.
NCDOT expects to award two more contracts to widen another 15 miles of I-95 between Lumberton and Fayetteville, starting next fall. Those contracts are expected to be worth about $300 million.
When that project is completed, also in 2026, 49 miles, or about a quarter, of I-95 in North Carolina will be widened to eight lanes.
This story was originally published October 11, 2021 at 11:08 AM.
