4. Northern Riverine Plain (RP)
4.2 Older alluvial plains
|Plains with lakes, basins and lunettes occur predominantly within the older alluvial plains (4.2) and comprise lakes and basins with lunettes of various sizes and complexity as well as the plains within which they occur. The largest of these lake-lunette systems are in the northwest of the State as part of the Lowan Salt Valley in the form of Lake Albacutya and Lake Hindmarsh, which are the terminal lakes associated with the Wimmera River. Smaller examples occur east of Horsham as part of the broader alluvial Wimmera River system (Green, Pine and Taylors Lakes). Other lakes and their associated streams include Lake Buloke (Richardson River), Lake Bael Bael, Lake Cullen, Kangaroo Lake and Lake Tuchewop (Avoca River), and Reedy, Middle and Third Lake and Lake Charm (Loddon River) and Lake Cooper (Corinella Creek). Lake Mokoan, near Benalla, is the most easterly and is probably associated with an earlier course of the Broken River.These units adjoin older alluvial plains (4.2) as well as modern flood plains (4.1), or as isolated units in the plain ridge complex (5.5). Lake Mokoan adjoins the older alluvial plains and aprons (4.3).|
The dry lake beds are dominated by organic rich fine sediments on which cracking clay soils, often self mulching, (Vertosols) and Sodosols have evolved. The lunettes vary in composition according to the nature of the lake sediments. For example the lunette at Lake Hindmarsh is mainly fine sand, whereas others, for example those at Bael Bael and Lake Kangaroo, are clayey and calcareous.
Depending on their water supply and salinity, the lakes and basins may be used as water storages, conservation areas, including wildlife habitats, and salt mining. The surrounding plains are mostly used for dryland grazing.