Catchment Profile
The Lachlan Catchment is located in central western New South Wales and covers an area of approximately 84,700 km2. The Catchments main infrastructure is Wyangala Dam, which has a capacity of 1,220,000 megalitres. It is the major water storage on the Lachlan River and is located at the junction of the Lachlan and Abercrombie rivers approximately 50 km upstream of Cowra. It is used to regulate supply of water to the downstream irrigation industry. Other important water storages include Carcoar Dam, Lake Cargelligo and Lake Brewster.
The landform of the Lachlan valley varies markedly from east to west, and can be divided into three general divisions. These are the headwaters and tablelands, the slopes, and the plains.
Generally soils in the Lachlan Catchment are old and very weathered and, as a result, they have been classified as fragile, chemically infertile and with relatively low levels of organic matter. They can be broadly classified into 3 general landscape divisions – the Tablelands, Slopes and Plains.
The geology of the Lachlan Catchment is quite complex and has a significant impact on salinity and the management options available to land managers.
The broad vegetation types of the Lachlan Catchment consists of forests, woodlands, mallee, riverine communities, shrublands, heaths and grasslands. Within these broad types over 114 different plant communities have been identified within the Lachlan catchment.
The Lachlan catchment exhibits a rich diversity of wildlife with over 32 amphibians, 109 reptiles, 337 birds, 78 mammals recorded in the Lachlan.
The climate of the Lachlan Catchment varies throughout with summers being relatively hot, and winters are cool to mild. Rainfall varies on an east-west gradient across the catchment.
The waterways of the Lachlan catchment are unique in the Murray Darling Basin as the Lachlan River terminates in wetlands and effluent (diverging creeks) in the lower part of the catchment. These effluent streams include Willandra, Merrowie and Middle Creeks. The Lachlan River itself is only intermittently connected to the Murrumbidgee River when both rivers are in flood.