Murray estuary
The Murray Estuary (coordinates: 35 ° 33'29 "S, 138 ° 52'50" E) is the point where the Murray River , the most water-rich Australian river, meets the Indian Ocean . However, this point is shifting. Historical records show that the canal migrates out to sea over time along the sand dunes. If the river carries more water and the sea is rough, the two bodies of water erode the sand dunes and create a new canal, with the old one slowly filling with silt and disappearing.
The estuary is between two sandy peninsulas. The Sir Richard Peninsula to the northwest separates the Goolwa Channel (the main arm of the Murray River) from the ocean. The much longer Younghusband peninsula to the southeast separates the Coorong from the sea.
The Murray Estuary is separated from Lake Alexandrina by a series of flat islands . The largest of them, Hindmarsh Island , is directly across from the estuary. A series of flood barriers connect the islands, separating the salty seawater from the freshwater in Lake Alexandrina and its tributaries. When the water level in the river is high, the flood barriers can be opened.
Early history
The Murray River originally flowed into the Spencer Gulf at what is now Port Pirie (north of Adelaide ). You can still see its large delta there today. But a land uplift blocked the river at the southern end of the Flinders Range and so the Murray River found its new bed at the current mouth at Lake Alexandrina.
Water flow
The water from the Murray River is used by farmers in four Australian states for land irrigation and also for the supply of drinking water to most of the settlements on the river and further away, with the water then being conveyed through pipelines. Today we can see that we are taking too much water from the river, but economic and political reasons make problem solving difficult. A visible consequence of the excessive water withdrawal is the closure of the mouth.
Since October 2002, two river dredgers have been working on the Murray Estuary, removing sand from the canal to ensure at least a minimal flow of water from the sea into the Coorong Lagoon. Without this uninterrupted dredging work, the estuary would close up with silt and prevent the flow of cold seawater into the Coorong. This would cause the water in the lagoon to warm up and cause the water to tip over .
In mid-2006, the dredging work could be reduced because the conditions at the mouth had improved. Now only one excavator is working and a private shipowner is allowed to navigate the channel between Goolwa and the Coorong, past the Murray estuary.
swell
John C. Tolley: South Coast Story . Rowett print. Mt Compass SA (1968). ISBN 0-9587964-3-2