Repair Level 33 Dry-Laid Stone Wall

Restored Harpers Ferry Road
Restored Harpers Ferry Road

NPS | Joe Reed, Park Engineer

Harpers Ferry Road between Hoffmaster Road and the School Bus Turnaround on Sandy Hook Road is open.

The towpath between miles 61 and 62 is open.

Maryland Heights Trailhead is open.

The park plans to reconstruct a historic dry-laid stone wall on Level 33 of the Chesapeake & Ohio Canal just across the Potomac River from Harpers Ferry, WV. This wall is located approximately at Mile Marker 61.5 on the C&O Canal and directly supports public traffic on Harpers Ferry Road. The wall is showing significant signs of instability and stone loss, causing distress on the supported public roadway.

The project aims to prevent future negative impacts to the local community that utilizes Harpers Ferry Road and preserve historic features of the C&O Canal by reconstructing the unstable section of stone wall and repairing the supported roadway. During monitoring of this wall, multiple changes of the wall, including stone loss have been noted. Several asphalt patches have been placed on this section of Harpers Ferry Road to mitigate the distress on the roadway.

Completion of the project will minimize the probability of future instability and reduce the risk of loss for the cultural & natural resources that are influenced by this substantial engineered feature.

 
 

CURRENT DETOURS AND CLOSURES

Harpers Ferry Road between Hoffmaster Road and the School Bus Turnaround on Sandy Hook Road is OPEN.

The towpath between miles 61 and 62 is OPEN. Maryland Heights trailhead is OPEN.

FREQUENTLY ASKED QUESTIONS (FAQs)

What is the need for the project?

The historic stone wall has experienced significant stone loss and sagging, leading to distress on the supported roadway. The wall and road have undergone several repairs over the past decades, including extending the wall from its original height. Recent changes in the horizontal and vertical alignment of the wall, as well as localized stone loss have already been observed. These conditions require stabilization to ensure the safety of the overlying road and increase the reliability of the underlying wall.

What does the project include?

The project consists of dismantling and rebuilding the critical failing section of the historic stone wall to restore its structural integrity. A few isolated areas of the wall outside the major repair segment will be stabilized without full wall reconstruction. During the early phases on the project, the roadway and guardrails supported by this wall were removed and Harpers Ferry Road was closed between Hoffmaster Road and the School bus turnaround on Sandy Hook Road (road closure began March 20, 2023 and ended December 19, 2023). Concrete backfill and a temporary vehicle barrier were installed to allow one lane of the roadway to be reopened later during construction for emergency/authorized vehicles.

It is anticipated that some intermittent daily impacts to traffic will be required with flaggers pausing vehicular traffic once masonry work is complete to install the permanent guardrails and remove the temporary concrete barriers that were installed to facilitate the current roadway reopening. At the end of the project, the guardrails along Harpers Ferry Road will be replaced and both lanes of the road will be reopened to the public. 

 
Restored Level 33 Masonry Wall
Restored Level 33 Masonry Wall

NPS | Joe Reed, Park Engineer

Where will the project take place?

This project will take place at approximately Mile Marker 61.5 of the C&O Canal towpath between Lock 33 (mile 60.7) and Lock 34 (mile 61.6) approximately 3.5 river miles downstream of the Dargan Bend Recreation Area, and 6.5 miles upstream from Brunswick, MD.

The project area (between Lock 33 & Lock 34) is upstream of the pedestrian bridge crossing Potomac River that connects the C&O Canal with Harpers Ferry, WV. This bridge will remain unaffected by the project.

When will the project begin and end?

The contractor mobilized for the construction phase February 6, 2023 and is anticipated to continue through January 2024, weather dependent.

How will this project impact park visitors?

The towpath adjacent to the project area (between miles 61 and 62) is open. Access to the Maryland Heights Trailhead will remain OPEN and can still be reached via the towpath footbridge at Mile Marker 61.27. The section of the towpath between Lock 34 and the project area will be shared with construction vehicles during the construction phase of the project. However, flaggers will be in place to ensure visitor safety.

Harpers Ferry Road (between Hoffmaster Road and the School Bus Turnaround on Sandy Hook Road) is currently OPEN. At the end of the project, the guardrails along Harpers Ferry Road will be replaced and both lanes of the road will be reopened to the public. 

How will this project benefit park visitors?

Once the project is complete, the safety and reliability of the wall will be significantly increased. Additionally, the cultural & natural resources that are influenced by this substantial engineered feature will be preserved for current and future generations of visitors. The structure’s stability will be improved to meet current engineering standards and ensure safety to the local community that utilizes the roadway.

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 construction contractor’s team will be monitoring the walls along this stretch of the canal, along with construction operations and visitor safety 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 is the project funded?

The contract for the repairs to the historic dry-laid stone wall on Level 33 of the C&O Canal just across the Potomac River from Harpers Ferry, WV, was awarded in September 2022 for $1.9 million and was funded from the National Park Service’s Repair/Rehabilitation 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.

Additional Information

3D Model of the Level 33 Wall can be seen here: C&O Canal Level 33 Road Wall - 3D model by Heritage Documentation Programs.
 

Project Photos

August - September 2023

 
Lock 33 Wall Vertical Form
Level 33 Wall Vertical Concrete Form

NPS Photo

 
Lock 33 Wall Vertical Pour Two
Concrete pouring at Level 33 Wall

NPS Photo

 
Lock 33 Wall Formwork Concrete Mat
Level 33 Wall Formwork Concrete Mat

NPS Photo

 
Lock 33 Wall Form Removal MFC_01
Level 33 Wall Concrete Mat

NPS Photo

 

June - July 2023

 
A sagging stone wall holding up a road A sagging stone wall holding up a road

Left image
Pre-construction conditions showing sagging and stone loss of the historic dry-laid stone wall supporting Harpers Ferry Road.
Credit: NPS Photo | Joe Reed, Civil Engineer

Right image
Ongoing construction conditions showing stone removal from the historic dry-laid stone wall.
Credit: NPS Photo

 
The contractor works on repairs to a dry-laid stone wall
Ongoing construction conditions showing stone removal from the historic dry-laid stone wall.

NPS Photo

 

Last updated: March 22, 2024

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Contact Info

Mailing Address:

142 W. Potomac St.
Williamsport, MD 21795

Phone:

301-739-4200

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