By Emma Young
The three-quarter-mile long Neabsco Creek Boardwalk, winding over the environmentally sensitive Julie J. Metz Wetlands, is a design and construction triumph, providing both public access and environmental protection. Located in Neabsco Regional Park, the boardwalk is the crown jewel of the Potomac Heritage National Scenic Trail and 50-mile Woodbridge Pedestrian & Bicycle Loop.
To bring this regional destination to life, Woodbridge District Supervisor Frank Principi worked with a group of dedicated stakeholders over the course of a decade, always with a dual goal of enabling the public to enjoy nature’s beauty while preserving a delicate ecosystem. The working group included local residents and representatives from nonprofits, the National Park Service and Prince William County Parks and Recreation Department.
Wetlands provide crucial fish and wildlife habitats, protect and improve water quality, and help regulate floodwaters. Protecting these benefits during construction begins with research, planning and design.
Research & Design, With Ecology in Mind
First, the design team at Lardner/Klein Landscape Architects conducted extensive inventorying, flood and geotechnical studies. The wetlands, hydrology, aquatic vegetation, cultural resources and other factors were cataloged and documented in detail.
Flood studies ensured the Boardwalk would not negatively impact adjoining properties. Geotechnical studies indicated necessary engineering properties, such as how deep piles should go to maintain boardwalk stability. The studies went beyond engineering technical specifications.
“Archaeologists studied the geologic history of the channel and found very old channels at the south land area where gravel was likely to be found, as opposed to the deep mucky bottoms on the north side,” said Jim Klein, ASLA Principal at Lardner/Klein. This altered the boardwalk’s course.
“The undulating pattern and steel cabling you see are not just decorative. They allow the natural tidal and flood patterns to continue undisturbed,” explained Supervisor Principi.
“The Neabsco Creek is a highly braided channel, meaning that the water flows across different channels over time,” stated Klein.
Keeping Equipment Out of the Wetlands
The County selected Nature Bridges to build the boardwalk in part because it specializes in “top down” construction that protects fragile environments. Building from above, Nature Bridge operated from the top of each previous segment, rather than in the wetland itself. This method prevents heavy construction equipment from entering the fragile aquatic environment.
Varying-sized boardwalk spans were placed over channels to accommodate these flows.
The contractor, Nature Bridges, dropped in two 60-foot long spans over Neabsco Creek’s main tidal section, closest to Blackburn Road, and placed three 20-foot spans over tributary channels.
Engaging the Public in Preservation
“Moving forward, the challenge will be to ensure that our visitors become invested in preserving this natural treasure,” said Principi. “Interpretive panels will highlight the delicate ecology, and encourage conservation. Parks & Rec will help local students engage with aquatic life and learn about the ways humans can both harm and heal the environment. By encouraging an appreciation of nature, we hope to inspire its protection.”
He encourages all boardwalk visitors to pack out any trash or recycling that they generate, and to consider organizing informal cleanups to supplement County efforts, as litter dumped upstream will wash up in the wetlands.
The project presented the significant challenge sustainably building a publicly accessible walkway over an environmentally delicate and important resource. Through careful planning, design and implementation, we can now both enjoy and be proud of the completed project; “the only place you can walk on water in Prince William County,” said Principi.