The Goolwa Barrages comprise five barrage

Barrage (tidal)

A barrage is an artificial obstruction at the mouth of a tidal watercourse.-Purpose:The common primary functions of a barrage are:* Increase the depth of a river * Maintain a separation between fresh and salt water...

 structures in the channels linking Lake Alexandrina

Lake Alexandrina (South Australia)

Lake Alexandrina is a lake in South Australia adjacent to the coast of the Southern Ocean, about 100 kilometres south-east of Adelaide.-Name:The lake was named after Princess Alexandrina, niece and successor of King William IV of Great Britain and Ireland...

 to the mouth of the River Murray and the Coorong in Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

. They were constructed in order to (1) reduce salinity levels in the lower reaches of the River Murray, Lake Alexandrina and Lake Albert and (2) to stabilise the river level, for both upstream irrigation and pumping.

History

Prior to the barrages, during periods of low flow tidal effects and the intrusion of seawater were felt up to 250 km upstream from the mouth of the River Murray, approximately as far inland as present-day Swan Reach.

From the 1900s, with the advent of large irrigation schemes, landowners along the lower reaches of the river strongly urged for the construction of barrages, primarily to keep the water fresh in the lower reaches of the River Murray, as well as Lake Albert and Lake Alexandrina.

In 1931, the Murray-Darling Basin Commission authorized the construction of five barrages. Work on the barrages commenced in 1935 and was completed in 1940. South Australia's Engineering and Water Supply Department undertook the works, with costs shared equally by the Governments of South Australia, Victoria, New South Wales and the Commonwealth of Australia.

Location

The Goolwa Barrage connects Sir Richard Peninsula on the mainland 35.528552°S 138.808077°E
with Hindmarsh Island

Hindmarsh Island

Hindmarsh Island is an island in the lower Murray River near the town of Goolwa, South Australia. Located on the Fleurieu Peninsula, it is a popular tourist destination, which has increased in popularity since the Hindmarsh Island bridge was opened in 2001...

35.523210°S 138.809190°E.
The Mundoo Barrage connects Hindmarsh Island with Mundoo Island.
The Boundary Creek Barrage connects Mundoo Island with Ewe Island.
The Ewe Island Barrage connects Ewe Island with Tauwitchere Island.
The Tauwitchere Barrage connects Tauwitchere Island with Pelican Point on the mainland.