Stormwater has been a problem in Chapel Hill for over 40 years — maybe longer — because of the hills, lowlands, and the homes and businesses built before floodplain rules.
The lowlands, from Camelot Village Condominiums on South Estes Drive to Eastgate Crossing shopping center and homes to the east, have been especially hard hit. They lie between two major creeks — Bolin and Booker — which meet in a large floodplain to form Little Creek just east of Fordham Boulevard.
The latest flood on Sept. 17 filled buildings, swallowed parked cars, and forced emergency crews to rescue 40 people from the muddy water. Florence was a tropical storm when it hit just after midnight, but it dumped over 6 inches of rain in Chapel Hill by morning.
The waters covered the floodway adjacent to both creeks and most of the 100-year floodplain around that.
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A 100-year flood has a 1 in 100 chance of happening in a given year, according to the U.S. Geological Survey. That means big floods can happen anytime, largely depending on changes in the climate, USGS officials said.
Just over a week later, residents at Camelot Village and other apartment complexes were drying out and starting over. In Eastgate Crossing, Trader Joe’s, Guglhupf and a handful of other businesses recovered quickly. By the weekend, only a few remained closed.
About 9 inches of water covered the wood plank floor at Great Outdoor Provision Co. before it quickly subsided. Store manager Chad Pickens posted about spending the night in the store on the company’s website. Before 4 a.m. Pickens realized the store would have to be evacuated. By 8 a.m., water was rising from the storm drain in the parking lot, he said.
“Within 10 minutes it reached the curb, in another 10 minutes it had crossed the sidewalk and reached the front door, and 10 minutes after that it was about two feet up the front door,” Pickens said.
The store reopened Sept. 21, one of 15 Eastgate stores that opened through the weekend, said Deirdre Johnson, vice president of asset management for property owner Federal Realty Investment Trust.
Around the corner at Mariakakis Plaza, property owner Johnny Mariakakis said his store — Mariakakis Fine Food and Wine — and two others had ceramic tile floors and limited water damage that cleaned up easily. Mariakakis wielded a mop through the storm to keep the flooding to his lobby.
“I’ve been here all my life,” he said. “I grew up as a child in the ‘60s, and I’ve never seen flooding like this before.”
Heartwood Holistic Health and Yarns Etc. had more damage, he said.
Customers rallied to help Yarns Etc. owner Mary Stowe, who moved her business into the strip mall in 2015 after losing a longtime lease at Village Plaza on South Elliott Road. A GoFundMe page raised nearly $6,500 last week to help Stowe recover. On Saturday, an update posted on the store’s Facebook page said the store is clean and drying out.
“I am overwhelmed by this communities love and support,” Stowe wrote. “Thank you! We are going to be OK and open soon. ... I am humbled by your generosity.”
A longtime problem
What’s not clear is whether the flooding was worse this time because the Fordham Boulevard culvert backed up, or because larger buildings are adding to the impervious surfaces around them, Mariakakis said.
The area — now called the Blue Hill District — has had flooding problems since Eastgate’s developers routed Booker Creek through a culvert under its parking lot in 1958.
Village Plaza and other commercial businesses followed, gradually replacing boggy forests and wetlands with pavement and rooftops that create significant runoff during heavy storms.
The concrete culvert under Fordham Boulevard can handle a 100-year flooding event, according to the Lower Booker Creek Subwatershed study. However, the Eastgate culvert, even after a devastating 2000 flood prompted improvements, can still only handle a 10-year storm, the study says.
And then there’s the shopping center’s location in the Booker Creek floodplain — and its position below the creek’s flood levels, a 2013 Kimley-Horne study says.
As heavy rain runs into the creek, the water has to flow faster to keep everything moving downstream. If the creek is full, the water overflows its banks and spreads across low-lying floodplains, such as the one at the meeting of Booker, Bolin and Little creeks.
That buildup of water in the floodplain further slows down the creek, forcing it over the banks upstream and up through Eastgate’s storm drains. The Eastgate culvert fills up, pushing floodwaters over the top of an inlet near East Franklin Street and further compounding the problem.
The Kimley-Horne study noted that even if the Eastgate culvert were three times wider, there would still be a problem.
Recent construction, like the Fordham Apartments going up beside Booker Creek, has residents concerned the flooding will only get worse. Impervious surfaces create more runoff because they don’t absorb any of the rain heading to the creeks.
Redevelopment could increase the district’s impervious surface by 5 percent to 11 percent over the next 20 years, town officials have said. It now covers 57 percent of the 190-acre Blue Hill District.
Most Blue Hill projects so far have replaced existing development, adding little impervious surface. The largest increase has been at the Greenfield Commons and Greenfield Place affordable housing projects on Legion Road, which replaced 10 acres of wooded land.
A Fordham Apartments flooding analysis noted that building up the land underneath the project to meet floodplain rules could raise flood levels 2 inches. The project is roughly doubling the impervious surface on that site to about 3 acres.
The citizens group Chapel Hill Alliance for a Livable Town has advocated for daylighting Booker Creek through Eastgate — removing the pavement and restoring the creek to its natural state — as a way to ease the flooding and create a park-like amenity.
A similar project was completed in 2010 along Little Sugar Creek, a concrete-lined, floodprone waterway near downtown Charlotte.
However, Chapel Hill’s 2017 Lower Booker Creek subwatershed study found that daylighting Booker Creek would require at least a 70-foot span and eliminate about 70,000 square feet of Eastgate’s commercial space.
While daylighting the creek appears unlikely, town officials do expect the shopping center to be redeveloped over the next few decades. Federal Realty officials did not respond to a question about possible changes to the creek.
The town is working with Federal Realty and other developers on a $1.1 million project to expand the wetlands basin behind the shopping center. The hope is that a bigger pond will hold more water, so it doesn’t back up into the parking lot.
It’s the first of roughly $30 million in stormwater projects designed to improve water quality and reduce flooding in the 1,130-acre Lower Booker Creek subwatershed. Eastgate and nearby properties sit at the bottom of that subwatershed.
“This project will help mitigate but won’t prevent flooding from an extraordinary rain event, such as Hurricane Florence,” town spokeswoman Catherine Lazorko said.
Stormwater improvements appear to have eased the flooding risk at University Place, less than a mile south from Eastgate. The mall’s merchants were hit hard in a 2000 flood, but subsequent storms have only filled sections of the parking lot.
In part, that’s because University Place is located across the street from Bolin Creek, and the stormwater has more room to spread out in the condominium complexes along Estes Drive before filling the mall’s parking lot.
But property owner Madison Marquette also worked with the town and stormwater experts after the 2000 flood to build several bioretention basins filled with sandy soil and plants in the parking lot for better runoff drainage and water quality.
N.C. State University reports on the first two basins, which were designed to handle up to 3 inches of rain and channel the rest over a low emergency dam, found they had reduced stormwater flow. Drainage also was improved in parts of the parking lot.
Bioretention basins wouldn’t solve the problem at Eastgate because most of the surrounding land slopes into the shopping center, while University Place is slightly uphill from Bolin Creek.
‘Going to be fine’
Meanwhile, the town is helping affected businesses get the necessary renovation permits and inspections.
An Eastgate property official stopped by Rose Nails on Thursday to let manager Ben Vo know about the requirements. About a foot of water entered the nail shop Sept. 17, Vo said as he helped contractor Amaure Picasso replace floors, walls, counters and equipment.
They have lost thousands of dollars in sales, Vo said, and it’s not clear how much their insurance will cover.
“I want to open soon,” Vo said. “So many customers are calling.”
Lynn’s Hallmark Shop has been there before. It fared better this time, said Curt Mackey, who provides the store with retail support.
The Hallmark Shop and other Eastgate stores laid out sandbags ahead of the hurricane — some also put up temporary floodwalls — but the better weather Sept. 16 lured them into removing the barriers too soon.
Mackey estimated the water rose to over 4 feet in about 45 minutes. By noon, the water was gone. It was the worst he has seen since Federal Realty upgraded the Booker Creek culvert, Mackey said.
But “I do want people to know we’re open,” he said. “Absolutely, we’re going to be fine.”