Salinity Province 74, Mildura Colignan

Thumbnail image showing the location of Mildura Colignan Salinity Province in Victoria The medium sized Mildura-Colignan Salinity Province covers some 125,000 ha of the Mallee CMA Region.

Salinity occurrence is mostly seen as primary salinity features such as salt lakes and inter-dune swale scalds. Like all other Mallee provinces, a regional scale Groundwater Flow System (GFS) comprising marine and alluvial origin sediments underlies this area. Local to intermediate scale GFSs adjoining the Murray River trench and overlying the regional aquifers, are involved in saline groundwater conveyance to the Murray River, which is being exacerbated by the large area of irrigation development. The natural groundwater discharge is likely influenced by structural controls (geological faults), and the resulting salinity areas are being enlarged by the irrigation development.

Management approaches have involved progressive changes to much higher irrigation efficiency and the installation of saline groundwater interception works along the river that divert salt to evaporation basins away from it.

Province Attributes

Catchment Management Region:	MALLEE
Priority Status:	High
Province Area:	124,710 ha
Recorded Soil Salinity Area ¹:	3,131 ha
Dominant Surface Geology Type:	Sedimentary
Influence of Geological Structure on Salinity Occurrence/s:	Definite
Relevant Geomorphological Mapping Units (GMUs):	5.1.X, 4.X
Predominant Groundwater Flow Systems (GFSs):	Regional & Local/Intermediate
Relevant Irrigation Areas:	Mildura, Merbein, Redclifs, Colig-Karadoc

Mildura Colignan Salinity Province Map

A detailed map showing the Mildura Colignan Salinity Province

Links to further reading and material related to the Mallee Salinity Province
For further information relating to groundwater levels and salinities in this Province please see: Visualising Victoria's Groundwater (VVG)

¹ Please Note: The ‘Recorded Soil Salinity Area’ indicated in the Salinity Province Attribute Table, comprises the total geographic area that has been mapped as having, or showing symptoms of, dryland soil salinity at some time (past or present). As dryland salinity occurrence in the Victorian landscape exhibits many different levels of severity and can change due to climate, landuse and vegetation, previously mapped areas may no longer be showing symptoms. In addition, as not all parts of the State have been mapped, or mapped in the same way, the mapping may not have captured some occurrences.

The soil salinity mapping used to calculate this ‘area’ does not cover irrigation regions. In irrigation regions, depth to watertable and watertable salinity mapping has been used to convey the threat of high watertables on soil waterlogging and/or soil salinisation and these areas are not included in this ‘area‘ calculation.

Please contact the Department, your Catchment Management Authority or your rural water provider for more information about salinity in your location.

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