The River Kennet was made navigable to Newbury in 1723, and the River Avon to Bath in 1727. The canal between Newbury and Bath opened in 1810 and is 92 km (57 miles) long. The two river navigations and the canal total 140 km (87 miles) in length.

In the later 19th century and early 20th century the canal fell into disuse following competition from the Great Western Railway, which owned the canal. In the latter half of the 20th century the canal was restored, largely by volunteers, and today is a popular heritage tourism destination.

The section from Bristol to Bath is the course of the River Avon, which flows through a wide valley and has been made navigable by a series of locks and weirs. In Bath the canal separates from the river but follows its valley as far as Bradford on Avon. The ornate Bath Locks lead to a stretch through Limpley Stoke valley with few locks. The flight of locks at Devizes raises the canal to its longest pound, which then ascends the four Wooton Rivers locks to the short summit pound which includes the Bruce Tunnel. Pumping stations are used to supply the canal with water. The canal continues through the rural landscape of Wiltshire and Berkshire before joining the River Kennet at Newbury and becoming a navigable river to Reading, where it flows into the River Thames.

At Semington there are two locks and now two aqueducts - the original structure, built in 1810, is a single span stone arch over a small stream; it is Listed Grade II. The Semington New Viaduct, opened in 2004, is the first navigable aqueduct to be built in the south west of Britain for almost two hundred years, Built from concrete, it contains 529 tonnes of steel reinforcement and is part of the Semington bypass which carries the A350 around Semington.