Delaware’s Urban Coastal Communities: City of Wilmington
Serving Delaware’s urban coastal communities through a blend of partnerships, science-based outreach, and educational programming
As the urban center of Delaware, Wilmington is home to more than 70,000 people. The city sits on the banks of the Delaware Bay, Brandywine, and Christina Rivers.
Delaware Sea Grant Projects in Wilmington
Delaware Sea Grant serves the greater Wilmington area, working with partners and supporting research that benefits the community and the environment.
- The American Shad is a species of fish with a recorded history in Delaware going back more than several hundred years. Members of this species spend their adult years in the salty waters of the Atlantic Ocean. When they are ready to spawn, they return to the freshwater rivers and streams they were born in to reproduce. Young shad live and grow in these freshwater environments until they are ready to enter saltwater habitats. The Brandywine River was a spawning ground and nursery for large populations of Shad. However, human-made dams in Delaware extending from Wilmington up to Rockland have restricted the geographic range and population size of this fish in the Brandywine River.
- In 2019, the first of the 11 dams (located in Wilmington) was removed from the Brandywine River. Delaware Sea Grant Extension Faculty, Dr. Edward Hale, has been studying the impacts of the dam removal on American Shad populations in the Brandywine River.
- To learn more about Dr. Hale’s work and his evaluation of the American shad restoration efforts, visit our Sustainable Fisheries and Aquaculture page.
When rain falls from the sky, it flows over the surfaces of the landscape, including roofs, driveways, sidewalks, lawns, and roads. Many traditional landscape designs include large areas of impervious surface, like concrete, which do not absorb water. This can lead to flooding. Green infrastructure often incorporates nature into landscape design, allowing the flow of stormwater to be slowed down, absorbed, or used in some way. Examples of green infrastructure include bioswales, rain gardens, rainwater catchment systems, constructed wetlands, and green roofs. By using green infrastructure in landscape design, communities have reduced flood risk.
- Cool Spring Park: Delaware Sea Grant supported the addition of educational signage for the Cool Springs Eco-trail at this park in Wilmington. The park was collaboratively developed by the Partnership for the Delaware Estuary, West Side Grows Together, the City of Wilmington, and the community. The colorful signage describes the function and value behind the park's green infrastructure features, including the stormwater planters, rain garden, vegetative pond buffer, and meadow.
- City of Love Church: Delaware Sea Grant is partnering with City of Love Church at Emmanuel Dining Hall East to create a community garden on the church grounds. Together, we are installing a grant-funded rainwater catchment system, building raised garden beds, and a garden shed. A form of green infrastructure, the rainwater catchment system collects rainwater, minimizing the long-term financial and environmental costs of watering the garden. The food grown in this community garden supplements food distributed at the Dining Hall.
- City of Wilmington/Adams Street: In partnership with the City of Wilmington’s project team, Delaware Sea Grant is promoting awareness of green infrastructure projects in the city and native plant species that can be utilized in them. In late 2023, Delaware Sea Grant worked with the City’s team to develop surveys, capturing feedback from community members on the types of native plants they would like to see incorporated into a green infrastructure project at the Adams Street Courts recreational park. The project utilizes rain gardens to capture stormwater, making the existing basketball courts and park more user-friendly.
Delaware Sea Grant partners with programs focused on serving youth in Wilmington, such as the Boys & Girls Club, Network Connect, Green Jobs, and Delaware Nature Society’s Trail Ambassadors. By delivering educational science activities and training emphasizing local phenomena—such as stormwater, green infrastructure, native habitats and species, climate change, and flood risk-related issues—youth gain a deeper understanding of the urban, coastal environment they live in. Additionally, Delaware Sea Grant supports the professional development of Wilmington's next generation of change-makers, delivering training to youth in presentation and meeting-facilitation skills.
- Southbridge Wilmington Wetlands Park: The south Wilmington neighborhood of Southbridge sits at a low elevation on the floodplain of the Christina River. Like many older cities across the United States, the city of Wilmington utilizes combined sewer stormwater systems. This leaves Southbridge especially vulnerable to flooding and contamination issues. Wetlands naturally absorb and filter water. The City of Wilmington and its partners unveiled a 17-acre wetland in 2022 to help address some of the environmental challenges faced in Southbridge. This wetland is known as the Southbridge Wilmington Wetlands Park and is a former Brownfield site. The land underwent remediation to remove contaminated soils. The design also includes unique material that traps certain chemical contaminants, allowing them to break down through natural processes. In addition to reducing flood risk for the adjacent neighborhood, it is also a spot for walking and nature viewing. The restored wetland is filled with plant species native to Delaware and is home to many native species of animals as well.
- Understanding the impact of the Southbridge Wilmington Wetlands Park on the community: The Delaware Sea Grant-funded project, Community Perceptions of Social, Economic, and Health Impacts of Green Infrastructure Revitalization and Redevelopment in South Wilmington, DE, brings together the expertise of Drs. Victor Perez, Jennifer Horney, and Martin Heintzelman of the University of Delaware. The team’s experience spans sociology, epidemiology, and economics. Together, they are researching the impacts of the Southbridge Wilmington Wetlands Park as perceived by residents of the Southbridge neighborhood in south Wilmington. Their work includes surveying community members on metrics such as their awareness of the Wetlands Park and how they utilize the site. Additionally, the team uses PhotoVoice, providing community members with cameras and asking them to capture images of their local environment. To further support this research, Delaware Sea Grant partnered with project PI Dr. Victor Perez and the Delaware Nature Society’s Trail Ambassadors program to organize and hold two workshops at the Neighborhood House, a community center in Southbridge. Attendees toured the Southbridge Wilmington Wetlands Park and learned place-based information on flood risk, climate change impacts, stormwater infrastructure, environmental contamination, and the function and value of wetlands and native species. Attendees also received laminated, mini-field guides to the native plant and animal species inhabiting the Wetlands Park.
DESG Resource:
To learn more about the plant and animal species native to the Southbridge Wilmington Wetlands Park, please view the Southbridge Wilmington Wetlands Park mini-field guide.
Urban Coastal Climate Challenges
Urban heat, rising sea levels, and flooding all come into play in Wilmington.
By definition, urban communities have high population densities. The high density of people living in the area requires many human-built structures and surfaces within that space, such as sidewalks, parking lots, buildings, and roads. Frequently, there are few trees in urban landscapes. Without trees to provide shade, these human-made structures and surfaces absorb heat from the sun. Heat absorbed during daylight hours is released even during the evening after the sun has gone down. The combined lack of trees and large quantity of human-made surfaces leaves communities in urban spaces significantly hotter than their neighbors in surrounding areas. According to the National Integrated Heat Health Information System, this can have many negative consequences, including health-related problems such as heat exhaustion, heat stroke, and even death.
The University of Delaware has multiple centers working on this issue, including the UD Climate Change Hub and the Center for Environmental Monitoring & Analysis. In Summer 2023, these groups teamed up with the Delaware Department of Natural Resources and Environmental Control (DNREC) and volunteers from the community to map out temperatures and identify hot spots as part of the Wilmington and Surrounding Townships (WiST) Heat Watch.
Resources: To learn more about the UD Climate Hub’s work as part of WiST, visit the UD Climate Hub WiST page.
Situated near the headwaters of Delaware Bay, Wilmington sits along the Brandywine and Christina Rivers. Wilmington’s location on the floodplains of these rivers makes the area especially vulnerable to flooding. Additional phenomena such as sea level rise and storm activity also contribute to flooding.
Sea Level Rise: Sea levels are rising worldwide largely due to increasing temperatures. This rise in sea level contributes to flooding in coastal areas, even in the absence of stormy weather. Scientists estimate that from the year 2000 to 2100, sea levels in Delaware will have increased by 1.7-5 feet.
Resources: To learn more about sea level rise impacts in Delaware, visit the NOAA Sea Level Rise Viewer
Floodplain: The flat banks of land along rivers are often referred to as floodplains. For centuries, humankind has built cities on floodplains as they provide easy access to water for various needs. Rivers naturally go through periods of flooding during periods of intense rainfall. This flooding can create problems for Wilmington residents, as a large portion of the city falls within what is known as a 100-year floodplain. Areas within the 100-year floodplain have a 1% chance of flooding annually. While a 1% annual risk may seem small, this amounts to a 26% chance of flooding over 30 years.
- Storms: Storms Hurricane Ida
Delaware Bay is an expansive estuary, spanning New Jersey, Pennsylvania, and Delaware. The Delaware River and smaller rivers like the Brandywine and Christina Rivers, feed the Bay. These smaller rivers, also known as tributaries, run through Wilmington. Due to their connection to Delaware Bay, the Brandywine, Christina, and Delaware Rivers are all tidally influenced, meaning they have daily periods of high and low water levels. Kayakers and other nature explorers must be aware of the tidal cycles when exploring nature in this area.
The Brandywine and Christina Rivers are both major drinking water sources for the northern Delaware region. According to the University of Delaware Water Resources Center, the Christina River Basin (which includes the Brandywine River) supplies drinking water for 60% of Delaware’s New Castle County. In fact, the Brandywine River itself supplies all of the drinking water for the city of Wilmington. However, the river water is filtered, treated, and tested by the City of Wilmington for common contaminants before it travels to residents’ taps.
Like many urban environments, Wilmington has many human-built structures and surfaces, such as asphalt roads and highways, concrete sidewalks and driveways, office buildings, and housing. These areas tend to add to the urban heat effect and provide little ability for the earth to absorb or slow the flow of stormwater.
Though Wilmington is an urban center, green spaces exist there as well. These include city, county, and state-run public parks and trails, wetlands, as well as a wildlife refuge. Trees and other plants in the wetlands and riparian buffers (areas along rivers) absorb and slow stormwater runoff. Plants in these zones have many benefits, including:
- Filtering water before it enters nearby rivers, improving water quality;
- Trapping sediment, improving water clarity and quality;
- Absorbing and slowing the flow of stormwater, reducing flood risk to nearby communities.
The U.S. Environmental Protection Agency (EPA) defines a brownfield as a property where expansion, redevelopment, or reuse may be complicated by the presence or potential presence of a hazardous substance, pollutant, or contaminant. Brownfield sites are not uncommon in urban areas and can include but are not limited to former industrial sites and abandoned properties. Contaminants found at such sites can vary and may include chemicals such as heavy metals, PCBs, petroleum, and volatile organic compounds (VOCs). Funding to remediate (clean up) these contaminated sites is available through the federal government (via the U.S. EPA) and the state of Delaware (via the Delaware Department of Natural Resources and Environmental Control). Remediated brownfield sites may potentially be redeveloped for a variety of uses including housing and commercial developments.
- Learn more about the federal brownfields program administered by the U.S. Environmental Protection Agency
- Learn more about the state of Delaware's Brownfield Remediation program
- Map of Brownfields in CBR4 area
Just as there are indicators of human health—such as blood pressure, heart rate, and bone density—there are metrics of water health as well, known as water quality. Several water quality indicators include temperature, water clarity, levels of oxygen dissolved in the water (known as dissolved oxygen or “D.O.”), and chemical contaminants. Chemical contamination levels along the bottoms and banks of water bodies are also often monitored.
Have you ever thought about what happens to rainwater after it flows into a storm drain? Or wondered where the water goes after it disappears down the sink drain or when you flush the toilet? Some municipalities rely on one set of underground pipes to direct stormwater out to a major water body, like a river. This helps to reduce flood risk to local communities, making it very important to keep storm drains clear of any litter or debris. A separate set of underground pipes are used to carry sewage to wastewater treatment plants. Wilmington, like many other historic cities, instead utilizes a combined sewer overflow (CSO) system. This means the same underground infrastructure handles both sewage and stormwater. During times of heavy storm activity, the system may become overwhelmed, meaning that both stormwater and sewage exit the underground pipes into the receiving water body. The City of Wilmington is currently undertaking a multi-year project of separating the CSOs into separate systems for sewer and stormwater, with the goal of reducing environmental contamination.
Resource: Read on to learn more about the Wilmington Combined Sewer Overflow System (CSO) or about the importance of storm drains with this DESG outreach fact sheet.
