Paw Paw Tunnel Scaling Project

A 2020 current conditions image shows a rock slide from April 2016 near the northern (downstream) entrance of the tunnel. The current scaling and repair project is one to prevent rock slides like this in the future and to remove debris from the canal prism.

NPS | Joe Reed, Park Engineer

The Paw Paw Tunnel is currently open.

Phase 2 of construction for the interim slope stabilization at the north (downstream) portal of the Paw Paw Tunnel was completed in July 2019. The next phase of work is currently in design. A design–build contract is anticipated to be awarded in 2020 for this next phase of work. Once the design is completed and permitted, construction is anticipated to begin in early 2021.

Frequently Asked Questions

When will the project begin and end?

Construction for the interim slope stabilization at the north portal of the Paw Paw Tunnel began in June of 2017. Construction was expected to last through fall of 2017, but the timeline has been changed. Phase 1 of the project, which addressed the most urgent sections of the deteriorating rock slope, has been completed. In July 2019, the park completed Phase 2 to address additional hazards downstream of the newly completed section. The 2020 work, which is in the design phase, will continue with addressing rockfall hazards and aim to remove rock and debris caused by the rockslide of 2016. This work will also address the timber boardwalk portion of the towpath by removing and replacing it. A design–build contract is anticipated to be awarded in 2020 for this next phase of work. Once the design is completed and permitted, construction is anticipated to begin in early 2021.

This work will provide long-term safe passage through this stretch of towpath. The National Park Service is doing everything possible to minimize closure time and impacts to visitors.

What is the need for the project?

Loose rock above the towpath at the “cut” and north portal (downstream entrance to the tunnel) presents potential safety hazards to visitors. The rock also threatens to damage the boardwalk section of the towpath. This project provides for visitor safety from rock fall as well as protection for the boardwalk/towpath.

What does the project include?

While the next phase is still in design, it is anticipated that the project will include measures similar to the previous two phases. Typical measures include “scaling,” or removing, loose and unstable rock and debris from above the towpath/boardwalk in the “cut” approaching the north tunnel portal. Additionally, rock was “pinned” in place to provide further stability and long-term protection. Rock scaling and pinning has occurred in this area before. Measures to better manage surface and ground water are also included. In some areas a pinned mesh will be used to stabilize localized rock slopes.

What is the history of the Paw Paw Tunnel?

The Paw Paw Tunnel is one of the most significant engineering features on the Canal. To save building six miles of canal along the river, the C&O Canal Company decided to construct a tunnel through a steep topographic ridge now called Tunnel Hill. When work began on the tunnel in 1836, the builders estimated the project would be complete within two years. The tunnel ultimately required 14 years to complete due to labor issues and violence, funding shortfalls, work stoppages, and the challenges of digging a 3,118-foot tunnel through the hard, loose shale. The tunnel opened in October 1850 with rockslides continuing to be a challenge throughout the tunnel’s history.

 

During the 2017-2019 project work, the rock wall along the towpath was bolted and pinned with rockfall mesh to prevent future rockslides.

NPS | Joe Reed, Park Engineer

How will this project benefit park visitors?

Visitor safety is improved by removing loose rock and debris from above the towpath and by stabilizing the remaining rock to reduce potential for future rock fall. This work also protects the boardwalk section of the towpath from potential rock fall.

Currently a slide that occurred in 2016 has deposited a large amount of rock debris into the canal, which stretches over to the boardwalk. This material will be removed, and slope stabilized to restore the canal.

How will this project impact natural and cultural resources?

Every project the National Park Service 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.

An environmental assessment (EA) was prepared by the park for phase 1 & 2 and for the project currently being designed. Documents can be found on the Planning, Environment and Public Comment website.

What is the park doing to protect resources during the project?

National Park Service resource protection experts will be monitoring the stone and brickwork in the tunnel, along with contractor’s operations and visitor safety during the project with the goal of safely protecting this unique cultural resource and the environment surrounding the project. Every project undertaken by the National Park Service is conducted in compliance with the National Environmental Protection Act (NEPA), the National Historic Preservation Act (NHPA), and other regulations. Please see the Environmental Assessment (EA) prepared by the park for further details.

How will this impact park visitors?

To facilitate the work, construction equipment staging is anticipated to require closing a section of the Paw Paw Tunnel Campground Parking Lot. Additionally, temporary delays are expected as work crews and equipment move to/from the work site. As the design develops and construction work approaches, additional updates regarding detours, shuttle services, and other impacts to visitors will be provided by the NPS. All areas currently remain OPEN.

How much does the project cost?

The first project (consisting of phase 1 and 2) was completed in 2017 – 2019 for a cost of less than $1 million and was funded by the National Park Service’s National Recreation Fee Program.

The project currently in design has not yet been awarded for construction, but it is being funded from the National Park Service’s Line Item Construction Program.

Who can I contact if I have further questions or concerns regarding the project?

Reach out to the park Headquarters at 301-739-4200.

 

A graph and map showing the Tunnel Bypass Trail and elevation change.

NPS | Andrew Landsman

Tunnel Bypass Trail

How long is the Tunnel Bypass Trail? How steep is it?

The Tunnel Bypass Trail is approximately a mile and a half in length with an elevation change of 375 feet. From the upstream (parking lot) end, the Tunnel Bypass Trail begins by crossing the canal prism and climbs 0.63 miles to the top (or about one foot of rise per nine feet of distance). On the downstream (construction) end, the bypass begins where the Tunnel Hill Trail meets the towpath near mile marker 155 and climbs 0.82 miles to the top (one foot of rise per 11.5 feet of distance).

What should I know about the Tunnel Bypass Trail?

Wear sturdy shoes that have good traction. Carry and drink lots of water during ascent and descent. Plan for the Tunnel Bypass Trail taking between one and a half to two and a half hours depending on your load, fitness level, and pace. Cyclists are reminded that they are required to dismount along the Tunnel Bypass Trail.