The lakes are located approximately south-east of Broken Hill in the semi-arid zone on grey clay and duplex soils, and siliceous and calcareous sands of the far west region. The lakes range in size from. The largest are Lakes Menindee, Wetherell, Pamamaroo and Cawndilla. These four, with Tandure, Bijijie and Balaka, are part of the Menindee Lakes Water Storage Scheme, with Cawndilla and Menindee also within the Kinchega National Park. Lakes Nettlegoe, Kangaroo, Stir Tank, New and Malta are unregulated. Lake Tandou is managed as irrigated cropland and is no longer subject to flooding. The shallow margins of the overflow lakes are studded with dead black box trees while the shores are dominated by bluerod and sandhill canegrass.
Menindee Lakes Storages
The Menindee Lakes Storages is a major gated dam, including multiple weir and lake impoundments and a concrete spillway, with six vertical lift gates, across the seven lakes that form part of the Menindee Lakes Water Storage Scheme. The lakes were originally a series of natural depressions that filled during floods. As the flow receded the floodwaters in the natural depressions drained back into the Darling River. In 1949, work began on building dams, weirs, levees, canals and regulators to catch and retain floodwaters. Major works were completed in 1960 and final completion was in 1968. There were electrical upgrades in 2007. The scheme was built by the New South Wales Water Conservation and Irrigation Commission, to manage river flows, town water supplies and other domestic requirements, irrigated agriculture, industry, and flood mitigation. It has become increasingly important for regulating environmental flows. Construction of the retaining walls required of rock fill, high and long. The average water depth is and, at 100% capacity, the dam walls hold back of water at an average of above sea level. The surface area of the lakes within the scheme is and the combined catchment area is. The uncontrolled concrete spillway with six vertical lift gates is capable of discharging water at.
Birds
Some of the lakes and their surrounds, with the exception of Lake Tandou, have been identified by BirdLife International as an Important Bird Area because it has supported up to 222,000 waterbirds, including over 1% of the world populations of freckled ducks, grey teals, pink-eared ducks, red-necked avocets, sharp-tailed sandpipers and red-capped plovers. Other waterbirds sometimes using the lakes in large numbers are Australasian shovellers, Australian shelducks, pied cormorants, yellow-billed spoonbills, Eurasian coots and white-headed stilts. Other species recorded in the IBA include Australian bustard, black and pied honeyeaters, chirruping wedgebill and grey falcon.
