Blanchetown is a town in South Australia, on the right (West) bank of the Murray River 130 km northeast of Adelaide. The Blanchetown Bridge is the westernmost (and furthest downstream) of the four times that the Sturt Highway crosses the Murray River. It is widely regarded as the entrance to the Riverland. It was originally surveyed in October 1855 as Blanche Town. It was named after Lady Blanche MacDonnell, the wife of the Governor of South Australia, Sir Richard MacDonnell. The Governor selected the site personally, to replace an earlier settlement of Murrundi (or Moorundee) – 5 km downstream – which was subject to flooding. Murrundi had been chosen as the base of the Protector of Aborigines by Edward John Eyre since 1841.
There had been a ferry crossing at Blanchetown since 1869 (private before 1879, then Government-run). A bridge was constructed in 1963. It was the first major prestressed concrete highway bridge in South Australia. In the 1990s it was found to not be structurally sound enough to safely carry B-double trucks. Until a new bridge could be built, these were diverted from near Monash via Morgan and Eudunda to rejoin the highway at Gawler, thus travelling further but avoiding the Kingston and Blanchetown bridges. The replacement bridge was completed in November 1998.
Blanchetown is north of Goyder’s Line, and so the land around it is unsuitable for farming unless it is irrigated using water drawn from the Murray. Upstream of Blanchetown, land above the cliffs on the west bank is mostly used for sheep grazing, while land on the east bank is irrigated for citrus orchards.
Lock 1 on the Murray River is at Blanchetown. It was the first of the 13 locks and weirs built on the Murray, and was completed in 1922. The lock chamber is approximately 56 feet by 275 feet (17 by 83 metres). The original purpose was to facilitate navigation for trade along the Murray, but by the time the weirs had been built, trade was declining. The primary purposes now are for recreational boating and to maintain water levels for irrigation. The pool upstream of the weir is 3.6 metres above sea level. It is 274 km from the Murray Mouth.
Blanchetown is in the Mid Murray Council local government area, the South Australian House of Assembly electoral district of Stuart and the Australian House of Representatives Division of Barker.