Conococheague Aqueduct Restoration Project

Artist rendering of the completed Conococheague Aqueduct post-restoration.
An artist's rendering of the completed Conococheague Aqueduct, post-restoration.


Towpath Closure at Williamsport, MM 99.76

An historic restoration of the Conococheague Aqueduct in Williamsport began August of 2017; construction necessitates closing the towpath upstream of the Cushwa Basin for the duration of the project. Here is some preliminary information about the construction that will be taking place on the aqueduct.

What is the PLAN?

Purpose? [Why are we closing the Conococheague Aqueduct and towpath?]

  • The project restores the aqueduct piers, “trunk,” and towpath to protect this historic resource. The project will also re-water the canal through the aqueduct, providing a unique visitor experience.

Length? [When are we closing, and how long?]

  • The project began August of 2017 and is expected to last 18 months to complete. The aqueduct and towpath are closed (starting Aug 8) until the project is finished.

Alternate Activities? [What can I do instead?]

  • All activities continue to be available in the Williamsport area during the project. Visitors can bike, walk, run, and fish along the towpath from the aqueduct downstream (east).

  • Observe the aqueduct restoration from the Cushwa Basin area and continue to use the towpath and canal resources downstream (east) of the work site.

  • The Cushwa Basin Visitor Center and seasonal interpretive programs will remain available.

Next Step? [What are the future benefits?]

  • Once the work on the aqueduct and canal prism upstream of the aqueduct is complete, this section of the canal will be re-watered allowing for public use and interpretive boat programs.

The beginning of the Conococheague Aqueduct Restoration
The beginning of the Conococheague Aqueduct Restoration

NPS | Joe Reed

Interested in learning more about the project? Here are our Frequently Asked Questions (FAQ's):

What is the history of the Conococheague Aqueduct?

C&O Canal aqueducts are “water bridges” that carry canal boats over creeks and rivers that flow into the Potomac River. Built from 1833 to 1835, the Conococheague Aqueduct is the fifth of eleven such “works of art” on the canal. It consists of three equal 60’ arch spans extending 196’ between abutments. In August 1863 Confederate soldiers damaged the Conococheague Aqueduct in an effort to stop the canal’s transportation of coal to Georgetown where it was used by the Union. Repairs took four days and the canal returned to operation. In April 1920 a canal boat broke through the upstream wall of the aqueduct falling into the creek below. This shut down the canal for over four months. Repaired with a timber wall this aqueduct functioned until two 1924 floods closed the canal for good.

What is the need for the project?

The Conococheague Aqueduct is perhaps the most publically accessible aqueduct on the entire C&O Canal. It is in poor condition and will continue to deteriorate without stabilization and additional repairs. Additionally, completing this project will provide visitors with a nationally unique experience of being able to enjoy an interpretive boat tour across a watered aqueduct or to paddle their own boat through the aqueduct.

What does the project include?

The project includes constructing cofferdams within Conococheague Creek and rebuilding the aqueduct piers; rebuilding and lining the aqueduct prism so that it is safe, sustainable and watertight; repairs to the stone work; installation of a period-appropriate guardrail; clearing the canal prism upstream including constructing a berm; and removal of the existing berm on the downstream side so that entire stretch can be re-watered.

Thru-cyclists and hikers are required to detour around the aqueduct and construction site by following a signed route using Fenton Ave, Route 68, and West Potomac Street (US 11).

To facilitate the work, construction equipment staging requires closing a section of the parking lot and towpath adjacent to the Cushwa Basin and also associated areas within and upstream of the project site. Additionally, temporary delays on the towpath approaching from the west (upstream) can be expected as work crews and equipment move to/from the work site. Work crews access the work site from both upstream and downstream (from the Cushwa Warehouse side) of the Conococheague Creek Aqueduct.

When will the project begin and end?

Construction staging began August of 2017 and will last for approximately 18 months. Anticipated completion is fall/winter of 2018/2019. During the work, the aqueduct and towpath immediately west (upstream) is (starting Aug 8) closed to the public. Visitors can access the towpath at Cushwa Basin and Lock 44 in Williamsport for local and downstream use. For west (upstream) access, the Gift Road Parking (mile 103.25) and Dam 5 (mile 106.8) both provide parking and towpath access. The National Park Service is doing everything possible to minimize closure time and impacts to visitors.

How will this project benefit park visitors?

Completion of this project will provide park visitors an opportunity to experience a watered transportation canal aqueduct. The project also restores a significant historic resource and provides unique opportunities for visitors.

How will this project impact natural and cultural resources?

The project helps protects a significant cultural resource by restoring and stabilizing the historic aqueduct piers preventing further damage and enhances the historic landscape. The project will return the aqueduct to working condition with the appearance of the early 1920s. Work in the Conococheague Creek will be timed to minimize impacts to fish and other aquatic species and the stream/river environments.

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

National Park Service resource protection experts will be monitoring the contractor’s work in the stream to ensure environmental protection and the contractor’s work when working with the historic stone and masonry of the aqueduct. NPS managers will also monitor the 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.

How much does the project cost?

Estimated costs for planning, design and construction is approximately $9 million. These funds are being provided by several sources including: a Federal “TAP” grant (Transportation Alternatives Program), NPS funds, Maryland Bikeways and Bond Bills programs, and park donations.

Why is it necessary to close the aqueduct and towpath immediately west of the project during the project?

Heavy equipment and materials will be in use throughout the project and will be actively moving in the aqueduct area and on the towpath immediately upstream of the project. Closing the area to public use provides for visitor safety and allows the work to progress in an efficient and timely manner resulting in a shorter project duration. For through cyclists and hikers, a temporary detour route has been established (see map below).

How do I visit the Cushwa Warehouse Visitor Center and have thru-passage when the aqueduct is closed?

Visitors have access to the Cushwa Warehouse Visitor Center and the towpath at Williamsport throughout the project. Additionally, visitors will be able to view the aqueduct restoration project from the Cushwa Warehouse and turning basin area. Hikers and bikers will continue to be able to access the towpath and go east/downstream during the project. A signed detour is marked so that long-distance hikers and bikers can go around the aqueduct and construction site by following a signed route using Fenton Ave, Route 68, and West Potomac Street (US 11); see map below.

The upstream end of the detour departs from the towpath near milepost 99.75, travels along Fenton Avenue, an alleyway, Route 68, and Potomac Street until rejoining the towpath near mile post 99.60 (directly adjacent to the Cushwa Basin).
Conococheague Aqueduct Restoration Project Re-Route Map


For more information, contact Matt Graves, Supervisory Park Ranger, at the Williamsport Visitor Center, 301-582-0813.

Elevational profile of the 1.1 mile detour through the town of Williamsport
Elevational changes of the 1.1 mile detour route through the town of Williamsport.


During the time of project construction, towpath users can take the 1.1 mile detour. The upstream end of the detour departs from the towpath near milepost 99.75, travels along Fenton Avenue, an alleyway, Route 68, and Potomac Street until rejoining the towpath near mile post 99.60 (directly adjacent to the Cushwa Basin).

Last updated: March 31, 2018

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