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2026 - Repairs to Culverts 150, 151, and 160
Chesapeake and Ohio Canal National Historical Park » 2026 - Repairs to Culverts 150, 151, and 160
This project includes repair of existing impairments of the clay liner of the Chesapeake & Ohio Canal National Historical Park at Culverts 150, 151, and 160 in Washington County, MD. Assessments were based on a site visit by NPS on 3/11/26. The culverts run underneath the Chesapeake & Ohio Canal towpath and canal and were historically used to convey stream water under the towpath and canal. The total length of the typical barrel of the culvert is approximately 113 linear feet. Existing impairment in the canal liner has created a preferential seepage path for surface water to infiltrate into the culvert barrel. This appears to be largely attributable to root intrusion from adjacent trees. The leakage of surface water from the canal into the historic stone culverts presents issues with freeze-thaw cycling concerns for damage to the mortar joints and displacement of the stone masonry units.
Proposed work will reduce freeze-thaw cycling and subsequent pressure on the stone masonry culverts by reducing seepage of water out of the canal liner and into the culvert barrel via repair of the sinkholes. Work will follow below steps:
1) Dewater work area
2) Excavate loose organic debris down to competent material. Stockpile any salvageable material for reuse. Plow, scarify, bench, or break up sloped surfaces steeper than 1 vertical to 1 horizontal so fill material will bond with existing material
3) Compact 4" lifts of impervious fill with weight of excavator bucket or comparable method to result in a total canal liner thickness of a minimum of 3-feet
4) Install 6" of topsoil and seed to provide stable surface with positive surface drainage away from the culvert alignment
5) Remove trees with root systems directly affecting the stability and structural integrity of the canal liner and the masonry culverts. Tree removal will be completed outside of time-of-year restrictions and in coordination with US Fish and Wildlife Service to avoid impacting listed species.
Proposed work will reduce freeze-thaw cycling and subsequent pressure on the stone masonry culverts by reducing seepage of water out of the canal liner and into the culvert barrel via repair of the sinkholes. Work will follow below steps:
1) Dewater work area
2) Excavate loose organic debris down to competent material. Stockpile any salvageable material for reuse. Plow, scarify, bench, or break up sloped surfaces steeper than 1 vertical to 1 horizontal so fill material will bond with existing material
3) Compact 4" lifts of impervious fill with weight of excavator bucket or comparable method to result in a total canal liner thickness of a minimum of 3-feet
4) Install 6" of topsoil and seed to provide stable surface with positive surface drainage away from the culvert alignment
5) Remove trees with root systems directly affecting the stability and structural integrity of the canal liner and the masonry culverts. Tree removal will be completed outside of time-of-year restrictions and in coordination with US Fish and Wildlife Service to avoid impacting listed species.