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2026 - Repair Leak in Canal Prism within Georgetown
Chesapeake and Ohio Canal National Historical Park » 2026 - Repair Leak in Canal Prism within Georgetown
The park proposes to repair a leak in the canal prism located at milepost 1.17, which is behind the east bay of the Washington Canoe Club boathouse located at 3700 Water Street, NW. The leak first appeared in 2022. A substantial stream of water was noted flowing out of the earthen berm of the towpath, across the Capital Crescent Trail, and through the Washington Canoe Club grounds, to include the building itself. Upon further investigation by the NPS, it was determined that the leak was associated with an abandoned headrace that once provided water to power the Tenney and Sons feed mill. This historic headrace had not been noticed nor documented by the NPS in recent decades but had been recorded on past documents predating the 1971 establishment of the canal as a national historical park.
The NPS attempted to stop the leak in 2023. Park maintenance staff and archeologists manually excavated the soils to expose the headrace headwall. The headwall is comprised of concrete with a wooden sluice gate in front of a cast iron pipe measuring two feet in diameter. This pipe passes under the towpath where it daylights as a riveted iron flume that had been concealed by dense vegetation. Park staff, upon exposing the feature, documented it using a combination of LiDAR scanning, measured drawings, and photography. After it was documented, the headwall was then reburied using compacted Bentonite chips to make the earthen prism wall watertight.
This repair functioned for about a year. However, upon filling the canal with water, the leak reappeared in 2025, apparently following the headrace pipe as a path of least resistance. To resolve this problem, park engineers are proposing to mechanically excavate into the towpath to expose the pipe and the back side of the inlet headwall. A small segment of the pipe will then be removed and a concrete plug poured behind the headwall. The towpath will then be reestablished by backfilling the trench with impervious fill. Both the inlet headwall and the exposed pipe outfall on the riverside of the towpath will be preserved as is.
Although a portion of the historic iron pipe will be removed, it constitutes only a small portion of historic fabric and the remaining headwall and iron outfall pipe on the riverside of the berm will be retained.
The NPS attempted to stop the leak in 2023. Park maintenance staff and archeologists manually excavated the soils to expose the headrace headwall. The headwall is comprised of concrete with a wooden sluice gate in front of a cast iron pipe measuring two feet in diameter. This pipe passes under the towpath where it daylights as a riveted iron flume that had been concealed by dense vegetation. Park staff, upon exposing the feature, documented it using a combination of LiDAR scanning, measured drawings, and photography. After it was documented, the headwall was then reburied using compacted Bentonite chips to make the earthen prism wall watertight.
This repair functioned for about a year. However, upon filling the canal with water, the leak reappeared in 2025, apparently following the headrace pipe as a path of least resistance. To resolve this problem, park engineers are proposing to mechanically excavate into the towpath to expose the pipe and the back side of the inlet headwall. A small segment of the pipe will then be removed and a concrete plug poured behind the headwall. The towpath will then be reestablished by backfilling the trench with impervious fill. Both the inlet headwall and the exposed pipe outfall on the riverside of the towpath will be preserved as is.
Although a portion of the historic iron pipe will be removed, it constitutes only a small portion of historic fabric and the remaining headwall and iron outfall pipe on the riverside of the berm will be retained.