CURRENT DETOURS AND CLOSURES
The towpath near Lock 5 (Mile 5) has detours in effect.
The towpath in Georgetown (Mile 1 – 0.4) has detours in effect.
Visitors are asked to obey all signage and flaggers, using caution around all work areas.
FREQUENTLY ASKED QUESTIONS (FAQs)
What is the need for the project?
This project will preserve multiple historic canal infrastructure features across a five mile stretch of the canal. Work at each of the areas will stabilize critical structures to increase safety, resiliency, reliability, and sustainability. This work is essential to maintaining the watered canal experience in the lower five miles of canal through the Washington, DC portion into Georgetown. If this project were not completed, operations of the water flow into this section of the canal would be difficult.
What does the project include?
This project includes removing debris from the feeder channel - the gateway for water being diverted from the Potomac River into the historic canal. It includes repairs to critical water regulation structures such as the Guard Lock, Lock 1, 2, 5, and the Inlet Lock. It includes replacement of the bridge over the Inlet Lock and Lock 5. It includes repair of multiple historic stone walls along Level 4 of the canal in Georgetown.
Where will the project take place?
There will be multiple work sites along the canal in Washington, DC and the southernmost end of the park in Montgomery County, MD. The two primary work areas will be at the Feeder Channel, Guard Lock, Inlet Lock, and Lock 5 area (Mile 5) & the others main focus in Georgetown at the Level 4 walls, Lock 1, and Lock 2 (Mile 0.4-1).
How will this project benefit park visitors?
This project will result in a reliable water regulation system and resilient canal infrastructure that are preserved for current & future generations. It is vital to ensuring the long-term functionality of the historic structures throughout the lower five miles of the canal.
When will the project begin and end?
The project began in February 2024. The project was scheduled to conclude in Spring 2026, however, in late February 2026 part of the Level 1 north wall of the C&O Canal partially collapsed. The wall was already of concern and scheduled to be repaired as part of this construction project. NPS was working to address the existing repair needs by mitigating soil pressure and water runoff and stabilizing the bulge in the wall. Contractor had been on site doing repointing repairs on the masonry, though work was temporarily paused due to unforeseen existing conditions behind the wall and a change in the repair design. Due to now necessary construction modifications as NPS works to fix the wall collapase, it is anticipated that the project will last through Fall 2026, weather dependent.
How will this project impact park visitors?
The parking area at Lift Lock 5 along the Clara Barton Parkway will be closed for the duration of work in that area. Alternative parking is available at the Lock 6 parking area as well as other nearby Lock parking areas along the Clara Barton Parkway. Sections of the towpath in Georgetown will be closed with detours in place as shown in the above detour mapping.
Water levels in the canal are normally lowered in the winter months to protect historic masonry from freeze/thaw cycle. Following the 2023 season, the canal was dewatered in preparation for winter and will remain dewatered for the duration of this major infrastructure improvement project.
How does the wall collapse impact visitors?
Visitors to the area near the Level 1 north wall collapse are safe. The area around the collapse, including the C&O Canal towpath, was closed to visitor access as part of the repair work and remains closed as we work to address the wall collapse. NPS urges the public to follow posted signs and ask visitors to be mindful that crews are actively working to stabilize and address the wall collapse.
At this time, NPS does not anticipate that the wall collapse will impact adjacent properties. We are actively working with any owners of adjacent properties to assess and mitigate potential future complications.
What caused the Level 1 north wall collapse?
The wall was already of concern and scheduled to be repaired as part of this project. The existing stones in the lower portion of the wall had moved towards the canal resulting in bulging at the face of the wall. NPS was working to address the existing repair needs by mitigating soil pressure and water runoff and stabilizing the bulge in the wall. Contractor had been on site doing repointing repairs on the masonry, though work was temporarily paused due to unforeseen existing conditions behind the wall and a change in the repair design.
Contributors to the wall's instability are still being investigated, but likely include saturation from moisture which increases the weight of the retained soil behind the wall and also decreases friction between the stone to stone contact of the individual stone masonry units comprising the wall, vegetation growth in the wall, and freeze/thaw cycling (expansion of water during freezing induces internal stress in the wall which displaces or otherwise damages stone – this repeats itself in cycles during warmer/colder weather).
While recent weather and the ice/snow melt or additional water runoff may have had an impact on this section of wall, NPS is still assessing what specifically caused the wall to collapse.
What work needs to be done to fix the collapse?
The first step to fix the wall collapse is to get a more detailed picture of what is happening with the surface of structures in and around the wall. NPS will do a 3D terrestrial LIDAR survey/scan to document the sections of remaining wall to establish baseline condition of existing masonry, local features, and the ground around the area.
NPS and the contractor will also monitor the area for potential additional movement and divert surface water away from upslope runoff areas as a precautionary measure/to mitigate the impacts of surface water.
How will this project impact natural and cultural resources?
Every project the NPS executes undergoes review by a multidisciplinary team to ensure compliance with Section 106 of the National Historic Preservation Act (NHPA), National Environmental Policy Act (NEPA), and other federal, state, and local laws.
What is the park doing to protect those resources during the project?
NPS resource protection experts, engineers, and the contractor’s team will be monitoring the stone and towpath work along this stretch of the towpath, along with contractor’s operations and visitor safety team during the project with the goal of safely protecting the environment surrounding the project. Every project undertaken by the NPS is conducted in compliance with the National Environmental Protection Act (NEPA), the National Historic Preservation Act (NHPA), and other regulations.
How much does the project cost?
The construction contract was awarded in 2023 for $12.7 million and was funded from the National Park Service’s Line Item Construction Program.
Who can I contact if I have further questions regarding the project?
Additional questions are to be directed to the park headquarters at 301-739-4200.
