One low-lying Wilmington neighborhood is expected to be highly susceptible to rising sea levels down the road. But before tackling that challenge, a solution to the chronic flooding it already faces is being built.
Delaware Public Media’s Sophia Schmidt explores that project, and what else might need to be done to keep the neighborhood livable long term.
Marie Reed, president of the Southbridge Civic Association, stands on B Street, remembering a flood that devastated her neighborhood in 2012.
“This whole street was underwater, and it even came into the Neighborhood House,” she said. “All of Bradford Street— that was probably our worst— was underwater. The cars got destroyed.”
Reed is a lifelong resident of the neighborhood. She says flooding was already an issue when her family moved there in 1947. She remembers her family staying up at night when it would rain. “I still have that little girl fear. I don’t sleep. I look out the window constantly,” she said. “It’s always going to be with me.”
“It’s the sound of the rain,” she added. “That noise, that horrible, horrible sound.”
Southbridge, the southernmost neighborhood in the City of Wilmington, is surrounded on multiple sides by the Christina River, a tidal tributary of the Delaware. The historically African-American community is connected to the rest of the city to its north by several bridges.
The neighborhood’s position and topography make it among the most vulnerable areas in the state to sea level rise. Models show the Christina River could inundate parts of the neighborhood by the end of the century. But Southbridge already deals with chronic flooding, mainly from rainfall. A green infrastructure project being built by the city aims to address the
current flooding problem — but likely will not be the only solution the neighborhood needs to handle water long term.
The neighborhood’s low elevation as well as an old sewer system which combines sanitary and stormwater has meant that, for decades, a good rain leads to water backing up in the sewer pipes and pooling on roads, or in basements. The flooding brings with it other issues, like mosquitoes and mold in homes.
Residents say the flooding has eased a bit in the last few years thanks to the City cleaning pipes and inlets and the Delaware Department of Transportation (DelDOT) resurfacing one of the main roads where it crosses flood-prone train tracks.
But Southbridge’s flooding is expected to worsen in the future as a result of climate change, says University of Delaware professor Philip Barnes.
“If you’re flat and you’re right on top of it, the sea level rise is going to push your flooding back inland,” said Barnes. “Southbridge is the worst-case scenario. It’s right there. It’s right on the water. And it’s flat.”
Barnes says from inundation alone — not including flooding from rainfall— the neighborhood could face serious issues by the end of the century. The Delaware Department of Natural Resources and Environmental Control (DNREC) uses planning scenarios of between 1.7 and about 5 feet of sea level rise by the year 2100.
“At this point without doing any additional projects or engineering, one foot is going to be a pain— but probably manageable,” said Barnes. “Two feet gets close to a tipping point. And then I think at three feet you’re looking at a situation where Southbridge may become uninhabitable.”
The state considers 3.25 feet of sea level rise by the end of the century an “intermediate” scenario. John Callahan of the Delaware Geological Survey says sea levels have a 50 percent chance of exceeding those in this scenario by 2100.
Maps developed by DNREC and the Delaware Geological Survey show that scenario would put Bradford Street, and parts of Christina Ave., Lobdell, Peach, Apple, S. Claymont and even New Castle Ave. under water. It would submerge Barbara Hicks Playground on the east side of the neighborhood, and impact several homes, churches and businesses.
The state’s “high” scenario is a little over 5 feet of sea level rise by 2100. That would inundate much of the eastern half of the neighborhood. Callahan says sea levels have a 5 percent chance of exceeding this scenario by 2100.
“But it’s important to remember that that’s at high tide, and that doesn’t account for any flooding from a precipitation event,” said Barnes. “So when it rains, the sea level rise amplifies the flood risk.”
The City of Wilmington is currently working to mitigate the neighborhood’s chronic nuisance flooding.
A project known as the South Wilmington Wetlands Park broke ground this summer on the site of a former natural wetland— and later brownfield— to the west of the neighborhood.
“So the idea here is to build a wetland that serves almost as a bathtub,” said Jeff Flynn, the City of Wilmington's director of economic development. “Put a separate set of pipes under the streets that only carry rain water. And instead of carrying it to the wastewater treatment plant or to the river, we’re going to bring it to this wetland where it’s going to circulate, sit and interact with the wetland ecosystem until the tide in the river exhausts. The low tide cycle comes, and then the wetland drains.”
Flynn calls the roughly $28 million South Wilmington Wetlands Park and sewer separation project a “water quantity and water quality” system.
Models by RK&K, the engineering firm that designed the project, show it is expected to reduce the extent of flooding in the neighborhood by 12 acres during a 10-year storm.
Engineers also evaluated the project’s resiliency to sea level rise. Justin Reel of RK&K said in an email that tidal flushing of the wetland park could be eliminated around 2060 under a high sea level rise scenario. He noted this would cause the park’s plant community to eventually turn into open water. But he says the flood protections the project is expected to afford the neighborhood will not be eliminated until “well after 2100.”
Clarence White owns White’s Body Shop on Buttonwood Street, one of the closest streets to the future wetlands park.
“Every time it would be a full moon or the end of the month, the Christina River couldn’t take the water, so it would always come over here, all the way up to our step,” he said.
He thinks the wetland park’s impact on flooding will ripple into other areas of life in Southbridge. “I think the project’s nice. I came here in, what, ‘71 and I’ve been here ever since. And we have endured the flooding ever since then. Now that they’re going to correct it, I think it’s going to increase the area, and the population, people, stores, whatever in this area.”
White’s business is expected to benefit directly from the project — but businesses on the neighborhood’s eastern side will not be so lucky.
The park and sewer project will only drain water from part of Southbridge — west of around South Heald Street. Flynn says three flooding hotspots identified in a flooding analysis are outside of the current project’s “drainage shed.” He says the city hopes to study the volume of flooding at these points after the wetlands park and sewer separation project are up and running, then evaluate the possibility of creating a second wetland on the east side of the neighborhood if necessary.
The eastern half of the neighborhood— including Bradford street, where Reed says flooding was worst in 2012— is outside of the current project’s drainage shed. But Flynn says 75 percent of the neighborhood’s residents and structures are located within it.
The wetlands park is scheduled to be functional this spring — and the sewer separation project is expected to be finished by the following spring.
The project has been more than a decade coming. In 2003, the neighborhood got a grant from the National Oceanic and Atmospheric Administration (NOAA) to develop a plan — which recommended the park as a solution to flooding as well as a recreation facility.
Marvin Thomas was the Civic Association president at the time and a major force behind the 2006 plan.
"We are small, compact — 1.64 miles, Southbridge. It’s populated primarily by African Americans. And we have not been able to get the attention financially, the support that we think we deserve, over the years,” he said. “We find ourselves today a little bit better off because of this document.”
Rysheema Dixon is an at-large City Council member with a history of community work in Southbridge. She says the wetlands park project is finally becoming a reality thanks to a group of residents like Marvin Thomas who “stood fast” and demanded City action. But she recognizes the project’s limits.
“It’s going to really help one side of Southbridge and not the other,” she said. “There’s still a need for more to be done, especially when you get future down the line, to make sure that Southbridge is not underwater at a certain point.”
Dixon thinks a community-led emergency evacuation plan is among several solutions needed to help keep residents safe long term.
Marie Reed is working on such a plan and hoping to formalize it with emergency management officials. She says it should consist of gathering residents at a safe common space like a nearby school until they can be transported out.
“We are a tight-knit, close community — so using residents to help residents with their children, help with our seniors, help those make sure they have their medication, to be at a holding place until help comes,” she said. “Because I really do believe that again there will be another major storm or another major situation where we have to evacuate.”
Dave Gula is a planner at the Wilmington Area Planning Council (WILMAPCO), who recently worked on a study of the flood-prone 7th Street Peninsula just across the river from Southbridge.
“There are places where the city needs to say we are going to armor the shoreline here, we are going to put in flood mitigation measures, we’re going to protect an area,” he said. “But there are other parts of the city where they might say we are looking at a lot of money thrown in, and we’re going to continue throwing money in ... At some point, you’re wise to just buy those areas out— and say, there’s a reason water’s going there, in a previous life this was a buffer area for flooding, and we’ve built on it. Maybe we need to let it go back to some degree.”
Wilmington public works engineer Bryan Lennon said in an emailed response to questions that the City “has not received feedback from the community seeking to incorporate managed retreat into [city] planning efforts”— and the wetlands park project team has not pursued it. Researchers define managed retreat as the strategic movement of people and structures away from risk— in this case, posed by sea level rise and flooding.
Lennon said the City “favors living shorelines where applicable but will consider hardened shorelines where the conditions limit available options.” He said some degree of “barrier type protection” may be needed to prevent inundation of inland areas by the Christina.
Lennon says the City has applied for a FEMA planning grant which will evaluate the need for such solutions as well as the possibility of an ‘east wetland’ in Southbridge.
The City also expects to finish a plan assessing the broader Wilmington’s current and future risk from climate change next month. The Resilient Wilmington Study, funded by a DNREC Sustainable Communities Planning Grant, will offer recommendations to mitigate and prepare for the effect of climate change on transportation, waterfront development, sewer and stormwater infrastructure, and public health and safety in the city.
WILMAPCO planner Gula says the state should take the lead on sea level rise adaptation policy.
“We’re one of the first states that are dealing with sea level rise because we already have problems,” he said. “We’re the lowest lying state in the country. So we’re sort of a model. We can borrow
anecdotes from other states, but as a state, we really need to see a strong state policy on this.”
DNREC spokesman Michael Globetti said in an email the agency does not determine adaptation outcomes, but rather provides the science and technical assistance to help local governments choose their own paths.
But he called the South Wilmington area “not a particularly good candidate” for managed retreat— because of the “critical regional infrastructure” that exists there, including the Port of Wilmington and interstate highways and rail lines. He said strategies of “protect” and “elevate” are generally most appropriate for urban areas.
Marie Reed of the Southbridge Civic Association says retreating is not an option.
“We’re going to fight to keep living here. We’re up there with ‘hell no, we won’t go’,” she said. “This has been my home always, always.”
This story was reported in conjunction with From the Source: Stories of the Delaware River, a year-long collaborative reporting project produced with support from the National Geographic Society, the Lenfest Institute for Journalism, and the William Penn Foundation. Editorial content is created independently of the project’s donors.