Culverts & Aqueducts
Sometimes, the canal has to cross a deep gap that cannot be filled in. In these cases, a bridge, called an “aqueduct” is built to carry the canal water. There is an aqueduct between bridges 9 and 9B on the Leeds and Liverpool Canal where it crosses the River Alt. Boats are not allowed to moor on aqueducts.
There are many aqueducts on the canal system. Some of them are world famous, and the most famous of them all is the Pontcysyllte aqueduct on the Llangollen canal in North Wales.
The Alt aqueduct is a modern construction, having been renewed in the 1970s. Next to the aqueduct is a run off, which channels excess water from the canal into the R. Alt, maintaining a constant water level.
Sometimes, the stream crossed by the canal is quite small and a culvert is put in instead of an aqueduct.