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Downtown Charleston is flooding more, with or without hurricanes. Here’s why

Rising seas plague Charleston

Charleston residents talk about flooding after Hurricane Irma
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Charleston residents talk about flooding after Hurricane Irma

CHARLESTON David and Claudia Cohen were busy raking debris from their yard and reflecting on Charleston’s third big flood in three years when a car whizzed down Gibbes Street near the Holy City’s historic Battery.

Driving the auto was a neighbor, who slowed just enough to yell sarcastically about Charleston’s watery troubles.

“I’m getting a couple of cyanide pills,’’ the neighbor wisecracked through the rolled-down window.

Last week’s brief discourse reflects the frustration many people feel in a city where floods are increasingly affecting every day life – and where climate change is more than an abstract concept.

Rising sea levels and major storms are swamping streets, neighborhoods and popular tourist attractions with a frequency and intensity that is hard for many people to ignore. The flooding is affecting millions of dollars worth of property in South Carolina’s oldest city, one of the state’s top vacation destinations.

Monday’s storm surge from Hurricane Irma was only the latest flood to drench Charleston. Parts of the city also flooded from a huge rain storm in 2015 and Hurricane Matthew last year.

Well aware of increasing flood threats, Charleston leaders have responded with a strategy to protect the city as sea level rises. But that effort is costly and can’t be completed overnight, city officials say.

Since 1990, taxpayers have spent $238 million to patch broken and outdated drainage systems that are overwhelmed by encroaching seawater. The city plans additional drainage work along with efforts to build up a crumbling seawall that rings the Battery to repel storm surges like the one Monday. The price tag for that project could top $100 million.

All told, the cost of fixing drainage and improving seawalls could easily exceed $1 billion.

“This is a citywide problem, it is a massive undertaking,’’ said Mark Wilbert, Charleston’s emergency management director.

Charleston’s flood woes are a prime example of how a coastal community is experiencing the first-hand impacts of climate change and sea level rise, say some city officials, conservationists and federal scientists.

“It is certainly becoming more of a topic and more obvious to people,’’ Nature Conservancy climate specialist Liz Fly said of the increased flooding. “Things are just happening more frequently. This really should be in the conversation about how to live with the water.’’

Like other coastal cities, Charleston has flooded for hundreds of years because it lies in a marshy environment. But statistics indicate flooding is worse now than ever.

From the late 1950s through 2013, Charleston experienced a 409 percent increase in flooding, much of it from water that pools up periodically during high tides, according to the S.C. Department of Health and Environmental Control and the National Oceanic and Atmospheric Administration.

Nuisance floods – which often result from high tides on non-rainy days – hit Charleston an average of 23 days annually from 2007 to 2013, according to NOAA. In 2015, the city had 38 days of flooding, and last year Charleston had a record 50 days of flooding, much of that tied to higher tides, according NOAA.

In the late 1950s, the city experienced fewer than five days of flooding a year.

Higher sea levels threaten Charleston in a variety of ways.

They cause high tides to become even higher, making them more likely to roll onto land and flood streets and people’s yards. In many cases, higher tides send sea water back through drainage pipes that were designed to empty storm water out of Charleston. Tidal flooding regularly occurs on sunny days.

In recent years, tidally driven floods have forced motorists to avoid key roads or risk ruining their cars. Those who admit driving through the salty, flooded intersections have spent thousands of dollars repairing cars that began to rust.

“We have to go through this on a daily basis,’’ restaurant owner Aghapour Shahram said last week as he surveyed a flooded intersection near his house. “All the cars rust after a couple of years of getting a saltwater bath.’’

Sea level in Charleston Harbor has risen by a foot in the past century and is expected to increase by as much as three feet in the next 50 years, according to data from NOAA. At the same time, some evidence suggests that the Charleston peninsula, which includes the city’s treasured historic district, is sinking.

Higher sea levels mean that, during hurricanes, storm surges – like the one from Hurricane Irma – are more likely to rise higher and move farther onto land. That was evident Monday when a large storm surge crashed over the Battery’s seawall and flooded many parts of the peninsula behind it.

But the worst could be yet to come, statistics show.

Doug Marcy, a NOAA coastal hazards specialist, said parts of Charleston would experience almost daily flooding if sea level rises by three feet in the next years, as some forecasts show. That could convert the peninsula to what it looked like in Colonial times, before marshland had been filled to make the peninsula bigger, he said.

“Yeah, it will be reclaimed,’’ Marcy said of the filled in marsh land.

Among the areas most vulnerable to increased flooding include the Battery at the tip of the Charleston peninsula, one of the biggest attractions for sightseers, as well as many of Charleston’s most established neighborhoods nearby, according to NOAA data. Those include areas near South Battery Street on the peninsula’s southwestern side and property near Colonial Lake.

Sea levels are rising globally as the earth’s planet heats up. The warming trend, which is tied to man-made emissions of greenhouse gas pollution, is heating the ocean. That in turn is causing seawater to expand and the water level to rise. At the same time, higher temperatures are causing glaciers to melt faster, which adds to the volume of water in the ocean, research show.

There is evidence that more intense storms are occurring because of climate change, although there is some scientific debate about that. To Wilbert, Charleston’s emergency management chief, there’s little doubt that storms are becoming more intense.

“This is not just about sea level rise, but change in the weather,’’ Wilbert said. “The ground can’t absorb the rain events we are getting.’’

Horror stories

Last week, people living on and around Charleston’s South Battery Street donned old clothes and began cleaning up the mess surrounding their homes after Irma’s storm surged had subsided. Others hired contractors to clean up and make repairs to flooded air conditioning systems beneath houses.

Pluff mud coated neighborhood sidewalks, door steps and streets like a layer of gray paint. The mud, which washed in with Irma’s tides, was so slick it was like walking on ice. Some homeowners stacked ruined furniture, children’s toys and carpets on the street.

Spackled with mud, Mark Mutz said he never remembers storms and flooding like he’s seen in recent years. Mutz grew up in North Charleston and moved into a home near Colonial Lake four years ago – just in time to experience three consecutive years of major storms. He pointed at the high-water marks from floods on his basement wall.

On the wall were marks from a massive 2015 rain storm, Hurricane Matthew in 2016 and Irma this year. The water mark for Irma was the highest.

“Unfortunately, you get used to it,’’ he said. “There is not much you can do except grin and bear it. It seems to be coming a little bit more regularly. They seem to be getting a little dirtier as they come. The mud on this one is worse than we’ve had before.’’

The Cohens said the earth’s changing climate has to be a factor. The crawlspace beneath their home has flooded each time big storms have hit Charleston since 2015. But tidal flooding also is a regular concern, they said.

“I am seeing more street flooding at high tide,’’ said Claudia Cohen, who has lived with her husband on Gibbes Street for nearly 40 years. “I feel like it’s climate change.’’

Rick McGeorge wasn’t sure why the flooding is occurring, but he’s not happy about it.

A former Citadel football player, McGeorge said it cost him more than $20,000 last year to replace much of his heating and air conditioning system after Hurricane Matthew. He moved into the house just before the historic October 2015 floods hit.

“I have been in this home address over the last three years,’’ he said, sitting on his soaked front porch last week. “I got the thousand-year flood, I got Hurricane Matthew and I got the surge of Irma. It’s not fun.’’

For people like restaurant owner Shahram, regular flooding has become a way of life. Shahram lives near a flood-prone intersection at Wentworth Street, one of the main roads that runs across the Charleston peninsula. He has lived in the area since the 1980s.

Last week, the intersection flooded at high tide – two days after Irma had passed – and on a day when it did not rain. Cars plowed slowly through the water, creating small wakes that washed toward people’s yards. High tides often cause problems when sea water pushes into drainage pipes and flows up through pavement. When the tide goes out, the water level drops and the street dries.

“I built this building myself’’ in the 1980s, Shahram said of his home. “At that time, there was a small puddle once a month or so when the high tide was here. But nothing like this. The last two years, it has really gotten worse. They have to bring in this barricade and barricade the road. The tides are getting higher.”

Answers costly

The city of Charleston has a comprehensive plan for dealing with a rise in sea level of 1.5 feet to 2.5 feet over the next 50 years, but not everyone thinks the city is moving aggressively enough.

“We are moving at 10 mph, but we need to move at 60 mph,” conservationist Dana Beach said, noting that Charleston is spending money on questionable road projects that pull funds away from projects to address climate change.

Beach, director of the S.C. Coastal Conservation League, said the city needs a more comprehensive drainage plan, but it also needs to be more aggressive about making improvements. Charleston also needs to move ahead with plans to fortify what’s known as the “low battery’’ seawall, he said. The seawall surrounding the tip of the Charleston peninsula needs to be several feet higher, to match the height of a stronger wall that runs along the east side of the peninsula, Beach said.

“This has always been done piecemeal,” Beach said. “There has not been an ambitious moon shot approach to all this. We need to look at this comprehensively and I think the public is ready to listen.”

Beyond spending public money to improve seawalls and drainage pipes, Beach said the city should work harder to stop new development in flood prone areas.

Wilbert, the city’s emergency management chief, said he understands the frustration from people who want the city to move faster. But he said Charleston is working as quickly as possible. Already, the city is addressing flooding problems in eight major drainage basins, according to its sea-level rise plan. The city also wants to adopt building codes that make new structures more resilient, as well as raise many street elevations so they will not flood as often.

“The City of Charleston recognizes the challenges of rising sea levels and we are addressing them head-on,’’ Charleston’s sea-level rise plan says. “We are all in this together.’’

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