Australia and Oceania > Australia

Lake Eyre: The Largest Lake in Australia

lakeLake Eyre
countryAustralia
surface area8,027 km2
maximum depth6 m
average depth3 m
lake typeSaline, endorheic, intermittent, natural
catchment area736,714 km2
altitude-15 m
volume25 km3
inflowsWarburton River
outflowsevaporation
shore length2,800 km
ageMore than 20 million years
residence time226 days
originTectonic
average discharge1,243 m3 / sec.

Lake Eyre Information and Facts

Lake Eyre is the largest lake in Australia, with an estimated surface area of 9,500 km2. However, the lake is rarely filled with water, since it’s located in the desert. It is also home to the lowest natural point in Australia, 15 meters below sea level.

Geography

Lake Eyre is located in the Lake Eyre Basin 700 km north of Adelaide, which includes large parts of Southern Australia, Northern Territory and Queensland, as well as a small part of Western New South Wales. The lake basin makes up almost 1/6th of the total surface area of Australia. It is the lowest and driest geographical point of the country. The landscape in the basin is mostly made up of low relief, dotted with a few higher areas. The basin is a large endorheic system surrounding the lakebed. Its lowest point is filled with salt pan, caused the seasonal expansion and the evaporation of the trapped waters. These salt crusts are most concentrated in southern Belt Bay, Jackboot Bay and Madigan Gulf.

The lake area is normally dry, but it is subject to irregular flooding. When it’s empty, it becomes a giant salt pan, on which white crystals reflect the sunlight. Evidence taken from the western part of the lake basin show that the saline depression was the result of a downfaulting in the surface of the Earth 30,000 years ago, which blocked off an outlet to the sea.

Since 1883 proposals have circulated about flooding Lake Eyre with seawater, which would be brought to the lake either through a canal or a pipeline. The main purpose of this action would be the increase of evaporation and rainfall in the area, and the goal is to enlarge the lake itself. But because of the lake’s low elevation and the region’s high annual evaporation rate, such plans have been ignored, since it’s likely that due to these factors the accumulation of salt deposits would rapidly block the engineeres channel. The land around the lake is used for grazing, mining, oil and gas exploration and production, as well as for tourism and conservation.

Hydrology and Climate

Each year the amount of water coming from the monsoon determines whether any water will reach the lake, and if it does, how deep it will get. Since the average rainfall in the area is between 100 and 150 mm every year, the lake has only been totally filled a couple of times since 1885: in 1886, 1889, 1816, 1950, 1955, 1974 and 1999. When it manages to completely fill up, it takes approximately two years for Lake Eyre to dry up.  Since the water evaporates quickly, the surface of the lakebed has a thin crust of salt on it. Although the lake is fed by a vast drainage basin, with its main tributary being the Warburton River, because of the high evaporation, the rivers dry up before reaching the lake itself.

Besides the monsoon, local rain can also fill the lake with water levels up to 3-4 meters. The most frequently-seen fish during the flooded time of the lake are bony bream and subspecies of golden perch and various small hardyhead species. During the rise of the water, the salt crusts dissolve, thus resulting in increased salinity and a massive fish kill. When water levels are more than 4 meters deep, the lake is no saltier than the sea, but as the evaporation process starts, salinity in the lake increases. The lake gets a pink hue when it’s saturated, mostly because of the presence of beta-carotene pigment, which is caused by a type of Algae called Dunaliella Salina.

The lake has two main sections: Lake Eyre North (with a length of 144 km and a width of 65 km), and Lake Eyre South (with a lenth of 65 km and a width of 24 km), which are joined by the Goyder Channel.

In 2009 the flood in in the lake peaked at 1.5 meters deep in the month of May, and thus 9 km3 of water crossed the Queensland-South Australian border with most of it coming from massive floods in the Georgina River. The flood started filling the lake merely in March, although the monsoonal rain occurred in January.

In the summer of 2010 the abundance of rain sent flood water into the Fiamantina, Georgina and Cooper Creek catchments, enabling Cooper Creek to reach Lake Eyre for the first time since 1990. Because of the increase in the lake’s water levels, many different birds migrated back to the region to breed at Lake Eyre.

Ecology and Protection

A number of phytoplankton can be found in the lake waters, including Nodularia spumigera and a few types of Dunaliella. When the lake’s water levels are high, pelicans from as far as Papua New Guinea come to breed and nest at Lake Eyre. During the flood of 1989-1990 an estimate 200,000 pelicans (80% of Australia’s total population) came to feed here. Several regions are home to rare plants, and the snake fauna is unusually diverse here.

The Lake Eyre Basin is an area of high conservation significance, which includes wetland (such as the Ramsar-listed Coongie Lakes), grasslands and deserts (Simpson Desert National Park), rare and endangered plans (like the kowari and the Waddi Waddi trees), and animals (the greater bilby).

The magnitude of the lake is protected by two distinct areas, the Kati Thanda – Lake Eyre National Park and the Elliot Price Conservation Park, both declared by the Government of Southern Australia. The lake is also on the list of wetlands of national importance, as A Directory of Important Wetlands in Australia. Since the lake supports major breeding events of the Banded stilt and the Australian pelican when it’s flooded, Lake Eyre has been recognized as an Important Bird Area by Bird Life International. Also, more than 1% of the World’s population of Red-necked avocets, Sharp-tailed sandpipers, Red-necked stints, silver gulls and Caspian terns can be found here.

History and Culture

The area around Lake Eyre was inhabited by the Arabana people, who have been living in the region for thousands of years. It represents an important cultural site for local Aboriginal people. The lake is named in honor of Edward John Eyre, who was the first European to see and document the lake in 1840. In the mid-1880s, the settlers began farming around Lake Eyre. One of the farms called Anna Creek is currently the largest cattle property in Australia.

Tourism and Recreation

The best way to observe the lake’s vastness and majesty is from the air. Several local tour companies offer aerial tours of the region. The best view from land can be observed from Halligan Bay. If the lake is abundant in water, one can explore it through either boats or kayaks. Access to the lake is simplest through the Oodnadatta Track and the Halligan Bay Public Access Route.

Lake Eyre National Park offers great campgrounds for camping enthusiasts. Halligan Point Campground offers bush camping with no facilities. For those not so eager to spend the night in the great outdoors, caravan parks, and William Creek Hotel offer comfortable stays at great rates.

Lake Erie Yacht Club has a number of dedicated sailors, which organized their first regatta in 2010, since 1976. When the lake is full, on a clear midday the surface can often become very flat and reflects the sky in a way that leaves the horizon and the surface of the water impossible to tell apart. Lake Eyre is also the site for various land speed record attempts on its salt flats, including the attempts of the famous Donald Campbell.