Hurricane Florence's 'catastrophic rainfall' a real test of South Carolina infrastructure

A bulldozer drives along Vernon Avenue as strong winds and rain fall from Hurricane Florence Friday, Sept. 14, 2018 in Kinston, N.C. (Janet S. Carter/Daily Free Press via AP)

COLUMBIA, S.C. -- The torrential rains from Florence will test South Carolina's infrastructure, which failed under historic flooding in 2015.

The devastating 2015 floods contributed to 19 deaths and crippled parts of the capital city, Columbia, for months. The state's infrastructure, weakened by years of neglect, crumbled under the strain of nearly 2 feet (60 centimetres) of rain. Dams burst across the state. Roads washed out and bridges were compromised.

A look at some of South Carolina's existing infrastructural concerns and how Florence could affect them:

DAMS

Given past problems, the thousands of public and private dams across South Carolina are cause for concern. More than 40 dams -- many state-owned -- failed in the aftermath of 2015's historic flooding, sending water cascading into lower areas.

In some places that year, nearly 2 feet (60 centimetres) of rain fell in a single day. Forecasts are similar for Florence, with National Hurricane Center Director Ken Graham warning of "catastrophic rainfall" of up to 40 inches (100 centimetres) in some places before it finally leaves the Carolinas.

In 2015, the bursting and overflowing dams contributed to flooding that covered many parts of Columbia, stranding homeowners and forcing some into recreational boats to rescue neighbours. A year later, Hurricane Matthew caused about 25 more dams to fail and another round of flooding.

After Matthew, South Carolina's environmental agency requested more than $5 million to stabilize or tear down damaged dams and inspect others. State lawmakers also gave the agency $3 million to boost dam safety.

Pete Poore, spokesman for the state Transportation Department, said some roads and bridges in areas involving privately-owned dams still haven't been repaired since 2015, but his agency has to wait for state environmental officials and the owners to reach agreements on the work.

"We can't move until the dam itself is resolved," he said.

Ahead of Florence, environmental officials have urged dam owners to drop water levels in anticipation of the massive amounts of expected rainfall and water flowing into the state from basins in North Carolina.

Tommy Crosby, spokesman for South Carolina's Department of Health and Environmental Control, said inspectors have assessed the safety of more than 250 dams this week so far and urged property owners to clear drainage areas.

ROADS

The condition of South Carolina's roads was of particular concern after the 2015 floods.

Through the years, road improvement and expansion projects were repeatedly put off in part because of concerns about funding. Lawmakers in the Republican-controlled state were hesitant to pass the gasoline tax increase many said was needed to generate money -- $1 billion, by some estimates -- to fix potholes, expand some roads and repave others.

From 2010 to 2016, officials said, the state paid out $40 million in claims for vehicle damage caused by road problems. In 2016, lawmakers approved a one-time, $400 million infusion, but officials said they'd need an adequate, ongoing stream of road maintenance money to make substantive improvements.

That situation changed in 2017, when the legislature overwhelmingly approved the state's first gas-tax increase in 20 years, increasing roads funding by roughly $600 million annually once fully phased in., Reaching a peak of frustration over roads literally crumbling underneath motorists, lawmakers overrode a veto from Gov. Henry McMaster, who had vowed to oppose any tax increase and called the bill an "act of capitulation." Agency Director Christy Hall told legislators that the tax had already provided her department with $149 million in new money this year.

South Carolina has 42,000 miles of state-maintained roads, according to the state Department of Transportation. Ahead of Florence, Poore told AP the agency began positioning crews of its 3,200 maintenance workers across the state to be ready to fix broken traffic signals, barricade problem areas and do whatever else is needed to make the state's roads safe again.

"If the drainage ditches need to be cleared, they will do that, to mitigate any flooding," Poore said, noting crews will also check road shoulders and safety guardrails for any signs of deterioration.

According to Poore, a handful of roads in Clarendon County, south of Columbia, remain washed out after the 2015 flood.

BRIDGES

Officials are also closely monitoring the state's 8,400 bridges. Near Charleston, officials closed the westbound lanes of Interstate 526 over the Wando River in May after discovering that a support cable that helps hold concrete blocks together had snapped. About 35,000 cars typically use the bridge each day. Commutes that typically take minutes turned into hours as officials partially shut down the bridge to inspect the problem and create a plan to fix it.

The cause of the broken cable wasn't clear, but officials said water had seeped into the structure and led to some corrosion at some point. Repairs were made, and the bridge reopened a month later.

After that debacle, McMaster ordered a review of state records concerning the bridge. He also voiced support for expanding I-526, asking staffers: "How in the world could we evacuate James, Johns and Wadmalaw islands in time if there's a bridge down and a hurricane coming straight at Charleston?" his office told The Post and Courier of Charleston.

McMaster has ordered the evacuation of coastal areas including Charleston as Florence approaches, and no problems related to the bridge have been reported.

Poore said department hydrologists also monitor river levels throughout the state, looking for flooding issues that could affect bridges.

"Just because it stops raining after the event, and the sun comes out, don't assume the roads are good to go," Poore told AP. "We want to know if there any land areas that are going to be flooded, any community where people are living, to make sure they're not cut off or surrounded by water."