Lake Galilee (Queensland) - Wetland Management Profile

Wetland Management Profile

Semi-arid saline lakes occur in internal (closed) drainage basins where the annual average rainfall is less than 500 mm. Water supply is mainly from the creeks of local catchments with infrequent major rain events providing most of the inflows. In-flowing water is invariably fresh, but becomes brackish or saline over time as the lake dries out.

Salinity is due to the pre-existence of salts in the soil and weathered bedrock, and salinity levels range from low (hyposaline) to high (hypersaline). Only a few lakes are distinctly saline for most of the wetting and drying cycle and a single lake may exhibit a mix of both fresh and saline water conditions at one time depending on its topography and the location of the tributaries that carry water into the lake.

The characteristic landform of an almost flat, shallow, terminal lakebed in an arid and semi-arid zone is commonly called a playa. In dry times, playas consist of cracking clay flats that can be crusted and hardened to varying degrees depending on their substrate and position in the landscape, and sometimes might be covered in a thin layer of soluble salt deposits. Some lakebeds are devoid of vegetation, but others support diverse communities of forbs and grasses as they dry out, which make them a valuable potential grazing resource. When they contain water, arid and semi-arid lakes can also support highly productive aquatic plant beds and algal turfs that are an important component of the food chain.

This profile covers the habitat types of a wetland termed semi-arid saline lake, located on cattle grazing properties in the Desert Uplands bioregion of Central West Queensland. It highlights the steps being taken to preserve the biodiversity and natural heritage.