July 11, 2025, marked the celebration of the completion of the Log Wall, a historic drylaid stone wall, stabilization near the Carderock Recreation Area. This major $11.4M infrastructure project was made possible through the Great American Outdoors Act (GAOA) Legacy Restoration Fund. The stabilization focused on an approximately 1,015 linear foot long historic drylaid stone wall, which varies in height up to 35 feet tall. The wall was originally constructed between 1828 and 1831 and is often referred to as the “Log Wall,” as found in an 1890 Engineer’s Report.
The project began in 2023, following the formation of sinkholes in 2015 and 2016 above the Log Wall. These sinkholes led to the dewatering and sandbagging of the canal to preserve its structural integrity. The resulting damage left a vital section of the towpath at risk of failure, disrupting the park’s continuity and recreational opportunities. Additionally, the sinkholes increased the vulnerability of the Potomac Interceptor Combined Sewer to potential failures. Installed in the 1960s, this sewer system transports approximately 60 million gallons of combined sewage daily beneath the towpath to a treatment facility in Washington, D.C. A failure of the Log Wall could result in a leak or break in the sewer system, potentially releasing 60 million gallons of raw, untreated sewage into the Potomac River, causing widespread catastrophic damage to the ecosystem and human health.
Photo credit: NPS
To prevent these incidents, the C&O Canal National Historical Park initiated the Log Wall Stabilization project in 2023. The project aimed to maintain towpath continuity, restore water flow in the canal prism, mitigate risks to nearby structures, and reduce sediment emptying into the canal. To accomplish these goals, park staff and partners performed stone masonry repairs, removed sediment from the canal, fixed sinkholes, replaced the canal liner, and buttressed the stone wall. The completion of the Log Wall Stabilization has ensured towpath stability and marked a significant step towards rewatering the canal. It has also prevented damage to the Potomac Interceptor sewage system and surrounding communities.
If you visit today, Log Wall looks much like it did before the project began.
“There’s no way to see a lot of the things that we did because they’re under the surface. That’s really part of our mission, maintaining the historic integrity of these landscapes and preserving these landscapes and those historic structures for current and future generations,” explained Joe Reed, Chief of Professional Services Division and the C&O Canal National Historical Park. “It looks like it did, you know, like it was originally intended back in 1924.”
Photo credit: Francis Grant-Suttie
Photo credit: Tad Achey
Photo credit: NPS
Photo credit: NPS
“We are proud to participate in this celebration for the preservation of the historic Log Wall here along the C&O Canal — an important milestone made possible through the Great American Outdoors Act. This successful project will help ensure the continuity of the towpath — a critical thread from Georgetown to Cumberland that protects the past while offering new experiences for visitors every day,” said Lauren Riviello, C&O Canal Trust President & CEO.
Park staff, the National Park Foundation, project partners, and elected officials joined us to share their love for the park and celebrate the significance of stabilizing this critical section of towpath.
“We are obviously recognizing an important historical marker, but [Log Wall is] also essential for the future of the park to shore up the wall to make sure we have the stability we need to help protect the public and people will be using the canal and the towpath. And it is exactly what we envisioned as the kind of projects that would be funded by the Great American Outdoors Act, which is a historic piece of legislation,” said Chris Van Hollen, a U.S. Senator from Maryland.
April McClain Delaney, U.S. Representative for Maryland’s Sixth Congressional District, retold stories of her family in the park and the importance of towpath continuity.
“This log wall perfectly symbolizes what the Great American Outdoors Act is about. It is really about a place and a space for community. It’s about preservation of our parklands and the beauty and splendor of America.”
“The Trust is proud to serve as a bridge between the National Park Service and a vibrant community of individuals and partners. Whether you’re discovering the canal for the first time or returning year after year, your connection with this place and your support are part of what keeps it thriving,” said Riviello. “At the Trust, we believe in the power of connection — connecting people to nature, to history, and to one another. We actively support towpath continuity and rehabilitation by investing in projects that repair trail conditions, address erosion and storm damage, and improve the visitor experience at some of the most beloved and well-traveled sections of the park. Through donor contributions and volunteer engagement, we help ensure that this treasured resource remains beautiful, safe, and welcoming to all.”
Thank you to all of those who celebrated the Log Wall project with us and who recognize the importance of preserving this historic park. Together, we can ensure the C&O Canal remains a vibrant and sustainable source of inspiration and connection and help keep its resources protected today and preserved for the future.
Missed the livestream? View a recording of the event here: https://www.youtube.com/watch?v=gFgUvCMX7j4
