In her Ireland’s Inland Waterways: Celebrating 300 years [Appletree Press, Belfast 2004], Ruth Delany devotes a paragraph to the Broharris Canal, a two-mile long cut near Ballykelly on the south shore of Lough Foyle. It was said to have acted as a drainage channel and to have carried in goods from Londonderry and sea manures (shells and seaweed for use as fertilisers), which W A McCutcheon, in The Canals of the North of Ireland [David & Charles, Dawlish 1965], says came from
… the banks exposed at low tide along the shallow, shelving coastline stretching westward from Magilligan Point.
The canal was built, the two authors agree, in the 1820s; McCutcheon says that it cost about £4500 and that it was not mentioned in the Railway Commissioners’ report in 1838.
I have found no photos, paintings or drawings of the Broharris Canal on tinterweb, and I have none myself. On the 6″ OSI map, I can find no canal at Broharris itself (it’s slightly to the east of the area shown below) but it does show Ballykelly Canal. I can’t tell in what year that sheet was published.
Note that there is a basin at the inland end of the canal.
The interesting thing is that the canal is not cut through the land: it is dug through the banks that McCutcheon mentions. I guess, therefore, that it would have been underwater at high tide.
An orange line runs to the shore inland of the basin; it seems to be a road. Roughly parallel to it is a green line; at the Ballykelly end, that is marked “Ballykelly River”, but it seems too small to be navigable.
So is the canal through the banks all there is (or was) of the Broharris or Ballykelly Canal?
And could the canal have changed from being underwater to being underground? If you go to the OSI map here, select the Historic 6″ and put the scale at 1:25000, the Overlay slider (at the bottom of the panel headed PREVIEW MAP SERIES) will work, allowing you to show the current coastline on top of the old. [I found that, perhaps because access to the NI mapping is limited for freestaters, the slider did not work at all scales.] If the overlay is working properly, it looks as if most of the canal, including the basin, is now under reclaimed land along the shore.
However, it is possible that some part of it remains. On the Google satellite view, follow Station Road, Ballykelly northwestwards to the sea: it looks as if the road crosses a watercourse before it reaches the shore. I presume that some of that watercourse is the Ballykelly River, but perhaps there is some trace of the canal.
I would welcome more information.