Lake Argyle is Western Australia's largest and Australia's second largest freshwater man-made reservoir by volume. The reservoir is part of the Ord River Irrigation Scheme and is located near the East Kimberley town of Kununurra. The lake flooded large parts of the Shire of Wyndham-East Kimberley on the Kimberley Plateau about inland from the Joseph Bonaparte Gulf, close to the border with the Northern Territory.
The primary inflow is the Ord River, while the Bow River and many other smaller creeks also flow into the dam. The lake is a DIWA-listed wetland. Lake Argyle and Lake Kununurra were listed in 1990 as Ramsar Convention protected wetlands. Argyle mine was previously situated here from 1985 until November 2020 following several years of discoveries and yielded 865 million carats of diamonds.
History and construction
The construction of the Ord River Dam was completed in 1971 by Dravo Corporation.
In 1996, the spillway wall was raised by , which doubled the dam's capacity. Sediment flowing into the dam caused concerns in the mid-1990s that the dam's capacity could be dramatically reduced. By 2006 continual regeneration of the upper Ord catchment appeared to have reduced the amount of sediment inflow.
The dam received a Historic Engineering Marker from Engineers Australia as part of its Engineering Heritage Recognition Program.
Geography
thumb|left|Dam wall
Lake Argyle normally has a surface area of about . The storage capacity, to the top of the spillway is . The lake filled to capacity in 1973, and the spillway flowed until 1984. Lake Argyle's usual storage volume is , making it the largest reservoir in Australia. The combined Lake Gordon/Lake Pedder system in Tasmania is larger but is two dams connected by a canal. At maximum flood level, Lake Argyle would hold of water and cover a surface area of .
Higher areas have become permanent islands within the lake's area.
Irrigation
Lake Argyle, together with Lake Kununurra, is part of the Ord River Irrigation Scheme. There are currently some of farmland under irrigation in the East Kimberly region. The original plan was for dam water to irrigate rice crop for export to China.
The lake is now home to 26 species of native fish and a population of freshwater crocodiles currently estimated at some 25,000. Fish species that are present in Lake Argyle include barramundi, southern saratoga, archer fish, forktail cat fish, mouth almighty, long tom, bony bream and sleepy cod. other experts disagree.
Cane toads reached the dam in late 2008, mostly via traveling along the Victoria Highway, with numbers rising significantly during the 2009 summer.
Common larger-bodied bird species found at the lake include the Australian pelican, black swan, eastern great egret, royal spoonbill, osprey and wedge-tailed eagle. Common smaller-bodied bird species include the spinifex pigeon, peaceful dove, common sandpiper, white-winged tern and budgerigar, while mid-sized bird species include the red-winged parrot, blue-winged kookaburra and barking owl.