Canal pound

A canal pound, reach, or level (American usage), is the stretch of level water impounded between two canal locks. Canal pounds can vary in length from the non-existent, where two or more immediately adjacent locks form a lock staircase, to many miles.

The longest canal pound in the United Kingdom is between the stop lock on the Trent and Mersey Canal at Preston Brook (Dutton Stop Lock No 76) and the start of the Leeds and Liverpool Canal near Leigh (Poolstock Bottom Lock No 2), a distance of 39.5 miles (63.6 km). Another long pound is on the Kennet and Avon Canal between Wootton Rivers Bottom Lock and Caen Hill top lock. The longest level on the Erie Canal in New York was the 60 mile level (actually 64.2 miles) between Henrietta and Lockport.

History

Pounds came into being with the development of pound locks to replace the earlier flash locks. A key feature of pound locks was that the intervening level between locks remained largely constant, as opposed to the variable levels created by the opening of flash locks.