It's taken Charleston more than three decades and almost a quarter billion dollars to upgrade less than half of the city's antiquated drainage systems.

The good news is the city has long accepted the problem. In 1984, engineers analyzed each drainage system for flooding issues and handed the city a punch list of areas that needed to be fixed, and which ones it should handle first.

The bad news is that city officials estimate only 37 percent of the improvements have been made — or are being addressed by ongoing projects, such as the $154 million drainage project along the Septima P. Clark Parkway, the most expensive drainage project in the city's history.

Another 7 percent of the projects are already in design but it's anybody’s guess how many more decades it will take to finish all the improvements, how much it will cost or where the money might come from.

"Money really drives everything," said Public Services Director Laura Cabiness, who has helped oversee the city's drainage upgrades since 1990. "It's hugely expensive."

Meanwhile, the city has continued expanding into the far reaches of its suburbs, ushering in a surge of new developments as the population has grown.

Most developers have been required to handle their own storm water runoff but a general lack of coordination has in many cases created chaotic systems that don’t always work with the natural flow of water.

Experts say severe rainfall and other extreme weather are becoming more common, too, adding a new layer of pressure. Even the newest drainage systems are only designed to handle heavy rains, such as those with only a 10 percent likelihood of happening each year, but not the heavy downpours seen here in both 2015 and last year.

Cabiness said she recognizes the compounding problem.

“Looking into the future, the way we design these things is going to change,” she said. “We’ve got to look at wider areas when development is occurring. We’ve also got to look at what is happening with climate change and more storms.”

Overall, though, fewer city homes are suffering flood damage than when the city began this process, an indication that drainage improvements are making a difference.

"I think we're doing a pretty good job with it," Cabiness said.

A longstanding problem

Charleston began experiencing flood problems centuries ago as soon as the city's early settlers filled in and built on top of creeks, which are naturally equipped to drain water. Predictably, these areas, such as Market Street, have been among the city's worst flood spots.

In the mid-19th century, the city installed its first large-scale drainage system — a network of brick, arched tunnels several feet under the streets. The tunnels generally worked well, though they emptied into rivers and could back up during the highest tides.

Also, the city was different then. "The tunnels were not sized to handle the peninsula as it is today," Cabiness said.

Meanwhile, the city and its suburbs began to spread rapidly a century later, but the drainage systems installed in these areas were spotty at best. The developers of Byrnes Downs ran only one trunk line under the street, and built houses over at least one drain.

"It was just bare bones," she said. That's partly why Byrnes Downs was the site of one of the city's earliest drainage fixes, a $6.7 million upgrade finished a decade ago.

Former Mayor Joe Riley, whose Aunt Dorothy's car floated in floodwaters downtown once in the 1950s, said his staff encouraged him to study drainage needs across the whole city, not just focus on projects for the worst areas.

"It really wasn’t about building political support," he said. "The fact of the matter was we realized East Bay and Calhoun was terrible and Ardmore was terrible, but we had drainage challenges all over the city.”

Plus, shortly after he took office in 1975, the Federal Emergency Management Agency was formed and the national flood insurance program was launched, providing the first official flood maps for the Charleston area.

The 1984 drainage study identified $184 million worth of needed work, a vast sum more than twice the city's annual budget at the time — and about $433 million in today's dollars.

"It was the first comprehensive plan when they looked at the entire city and the growing areas and where the drainage problems were and how to fix them," Cabiness said, "and also how to prioritize them."

Getting started

With the 1984 study in hand, it still took the city more than a decade to design and finish its first projects, even after voters approved a $9.5 million bond to be paid off by a property tax increase.

The West Ashley neighborhood of Ardmore, a lower-income suburb once known as "Mudmore," was the first one, along with Calhoun and East Bay streets, where Riley's aunt got stranded. The list includes:

  • Ardmore, done in 2000 at a cost of $5 million.
  • East Bay-Calhoun, done in 2001 at a cost of $15.8 million.
  • Byrnes Downs, done in 2007 for $6.7 million.
  • Church Creek done in 2010 for $3.7 million.
  • Market Street's project, expected to be done completely next year, for $30 million.

Cabiness said even with Market Street only partly finished, its new tunnel and pumps were able to prevent the market sheds from flooding when a hurricane hit downtown last year.

“It worked like a charm through Matthew,” she said. "Kayakers weren’t there.”

Church Creek, a special challenge

The 5,000 acres of land covered by the Church Creek drainage basin in West Ashley is one of the worst flood-prone parts of the city, and experts are still studying how to address it — even though the city already has upgraded it once.

The area on the west bank of the Ashley River was mostly wetlands and phosphate mines about a century ago. Today, 80 percent is filled with commercial and residential developments, such as Shadowmoss Plantation and West Ashley Circle.

Cabiness said one major mistake stemmed from an early FEMA flood map for the area, the key document that dictates elevation standards for new developments.

It underestimated how much the area could flood because it assumed the railroad that runs parallel to Bees Ferry Road would act as a barrier to protect the Shadowmoss area from flooding from a storm surge.

In reality, it also acted as a dam for water flowing in the other direction during a heavy rain.

That’s how the low-lying Bridge Pointe townhouses got built there in the late 1980s. The 32-unit complex in Shadowmoss has flooded about five times in the past decade. During Hurricane Matthew, an elderly couple living there saw 18 inches of water fill their first floor.

The city studied the area and amended the flood maps in 2000, which were adopted by FEMA. But it has not received any of the FEMA grants it applied for to buy out the Bridge Pointe properties.

The city tried other solutions, too. It built a new system to intercept storm water in about a third of the basin, created a retention pond for runoff, and changed development standards to make new buildings retain their storm water better, even in severe events.

And still, the water rises in many areas whenever there’s a major rainfall.

Cabiness said the flooding there is just complicated to address.

“The whole channel way of Church Creek isn’t wide enough to handle the area of drainage,” she said.

City Council passed a nine-month development moratorium in February for the part of the Church Creek drainage basin with the most severe drainage issues while Weston and Sampson Engineering Firm studies its storm water patterns.

The firm’s report is expected by the end of October.

“This will be a very high-level, detailed, scientific way to say 'Here are where the issues are happening,'” said Josh Martin, senior adviser to Mayor John Tecklenburg.

Calhoun-West: As many questions as answers

Back on the peninsula, what promises to be Charleston's largest ever and most expensive drainage project has only begun — and the city currently has no way to pay for it.

It encompasses the three drainage basins that handle flooding along western Calhoun Street south to the low battery, an area that includes the medical district. The city is spending $1.1 million on preliminary engineering now, hoping the early design might improve the city’s chances of getting funds from a federal infrastructure bill, Cabiness said.

"We want this project to be ready to go when that passes," she said.

Progress can’t come soon enough for Harleston Village residents such as Susan Lyons, who has lived on Gadsden Street for 13 years. Her home has flooded twice in two years, forcing her to replace her duct work each time.

“My first floor was not inundated, but my neighbors’ were. It’s really bad. It’s really scary. And you’re just — you’re helpless,” she said.

The most optimistic projections would have the Calhoun-West drainage project done in about 10 years.

It will cover more land than the approximately 500-acre Crosstown project, also known as Spring-Fishburne.

With a larger area, tighter streets and working conditions — not to mention inflation — the project will likely exceed the $154 million price tag for Spring-Fishburne. Like that project, Calhoun West is expected to involve a newly dug deep tunnel and a large pump station.

Spring-Fishburne was able to lure $88 million from the State Infrastructure Bank, which normally funds road construction, not drainage. But the city argued successfully that the state built the Crosstown without proper drainage a half century ago and should help fix that problem. Such an argument is not expected to work for the Calhoun-West project.

Before Riley left office, he had the city raise property taxes once more to double the amount collected for drainage projects, from $16 to $32 per year on a $200,000 home, to keep up momentum. The city's stormwater utility fee — collected on water and sewer bills — also has risen from about $2 to $6 per home per month.

"I felt the responsibility to address everything that was needed and not pass unsolved problems along to the next administration," Riley said. "I also knew it’s hard for a new administration to raise taxes.”

City Councilman Mike Seekings represents the section of the peninsula in the Calhoun-West basin and said the neighborhood faces more challenges than ever without some immediate solutions.

“Inside that basin, you have the Southeast’s preeminent medical districts, neighborhoods, schools, commerce, and it’s to the point now that between rain, flooding, tidal flooding and sea level rise, we’re close to a crisis point,” he said.

Still, the money is tight. The city's drainage dollars don't solely fund big projects. They also go toward maintaining and cleaning existing drainage lines, grates and ditches, as well as replacing damaged pipes and the like. The city's stormwater utility fund has an $8.6 million budget this year.

Headwinds

Whether the city has done enough, fast enough to improve its drainage ultimately might be a political question.

"I’m very pleased, if you look at where we started," Riley said. "Ardmore doesn’t flood. Brynes Downs doesn’t flood. East Bay and Calhoun doesn’t flood. On Market Street, you don’t have ‘no wake’ zones there," he said. "It's steady progress."

Residents still experiencing flooding, however, aren’t as pleased with the pace.

Lyons said she understands how expensive drainage projects are, but she thinks they’re not enough of a priority.

“The projects on the board 15, 20 years ago are still the same projects today,” she said. “It’s just a lot of lip service.”

Deborah Brown of Sherwood Forest in West Ashley feels the same way. Her house has flooded repeatedly over the past 23 years, and she said two other neighbors deal with the same thing.

“I’m sick and tired of the talk,” she said. “We want to know why the taxes we are paying for storm drain improvement are not going in to fix this neighborhood.”

Seekings said the city should budget more money for drainage projects.

“It is imperative we budget more money focused plainly and clearly at flooding and drainage in all parts of the city,” he said.

Meanwhile, Cabiness said she has considered pushing for an update to the city's 1984 master drainage plan, although such a move would divert money that otherwise could go toward projects.

"Some kind of update would be good," she said, "so people can understand where we've come from and where we're going."

Future drainage projects also will have to compete against other big expenses to protect the city against water, such as an estimated $100 million-plus project to turn the city's low battery into a higher levee.

"We'll be doing more,” she said. “Everybody acknowledges the events are becoming more severe and more frequent."

At the end, there's no easy answer to the big question: How much will the rest of the city's drainage work cost?

"I'd have to take a wild extrapolation," Cabiness said, "and I don't know if it would do any good if I did that."

Reach Robert Behre at 843-937-5771. Follow him on Twitter @RobertFBehre.

Abigail Darlington is a local government reporter focusing primarily on the City of Charleston. She previously covered local arts & entertainment, technology, innovation, tourism and retail for the Post and Courier.