Swift Ditch

Swift Ditch as it leaves the Thames

Site of the old lock for the Swift Ditch just downstream from the main branch

The Swift Ditch or Back Water is a backwater of the River Thames cutting through Oxfordshire on the opposite side of the main river to Abingdon. It was once a prime navigation channel, though it is not now navigable.

The Swift Ditch comes off the Thames above Abingdon, rejoining below Caldecott. Between the main River Thames and the Back Water is a large island named Andersey Island containing Rye Farm. The main A415 road from Abingdon, Berkshire crosses the Thames into Oxfordshire here and crosses Andersey Island on a causeway.

As early as 955 to 963 AD, the monks of Abingdon Priory built a canal to the Abbey from the direction of Swift Ditch. There is also evidence that the current course of the river to the confluence had been built by 1060. However the Swift Ditch remained the faster route (hence the name), and a pound lock was built at its head by the Oxford-Burcot Commission in 1624. In 1788 several citizens of Abingdon wanted to divert navigation back to the current course and as a result Abingdon Lock was built near the town. Within ten years, the Wilts & Berks Canal connected to the current navigation channel at Abingdon.

Culham Bridges

The Swift Ditch is crossed by three bridges. The original Culham Bridge was built about the same time as the Abingdon Bridges across the site of a ford. It has been replaced by a more modern bridge carrying the A415 road beside it. A wooden footbridge further downstream carries the Thames Path.