A canal pound (from impound),[1] 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 kilometres/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 (103.3 km)) between Henrietta and Lockport.