About the area
- The Mallee basin in Victoria’s north-west has few well-defined waterways.
- The Murray River forms the northern boundary of the basin, and for water accounting purposes, it is included in the water balance of the Murray basin.
- The area’s average annual rainfall is around 300-400 mm in the south, decreasing north to below 300 mm at Mildura.
More information on water management and accounting is detailed in Water .
2021-22 overview
In 2021-22 the same amount of water was available under entitlements (10 ML) as the previous year.
The Mallee basin relies heavily on groundwater use and almost all surface water used in the Mallee basin is sourced from other basins.
Groundwater use in this area is reported in the West and groundwater catchment reports.
Climate
Rainfall
In 2021-22, rainfall was above average throughout most of the basin except for a narrow band along the border with South Australia and in the far south where it was average.
River basin water balance
Almost all surface water used in the Mallee basin is sourced from other basins. The Mallee basin does not include:
- a water balance – limited information is available on surface water availability and use
- storages – there are no major storages
- catchment inflow – there are no well-defined streams other than the Murray River which is reported in the Murray basin
- an estimation of the volume of water leaving the basin – there is no reliable estimate of surface flows in the Mallee basin
- wastewater treatment plants information – there are no plants in this basin
- small catchment dam information – while there are some small catchment dams in the Mallee basin, no information about them is available, and they are not a significant source of water in the basin.
Entitlements and compliance
Entitlements provide the basis for how water is shared in the basin.
Entitlement volumes
Rights to water in the Mallee basin are shown in table 1 below.
Table 1: Annual entitlement volumes at 30 June, Mallee basin
Available water and take under entitlements
Total water available under entitlements represents the volume of water that was available to be taken by entitlement holders in 2021-22.
More information on available water and take has been detailed in the How do we account for surface section on the How do we account for water page.
Table 2: Available water and take, Mallee basin
Compliance
Compliance against water entitlements is reported for this basin in one area:
- entitlement issued: the volume of entitlements issued in a basin does not exceed formal caps, and has not increased without appropriate approvals
Due to a lack of reliable information, the total volume diverted in the Mallee basin is not estimated.
Total entitlement volume
There was no net increase in the total entitlement volume from the previous year.
Water for the environment
Environmental watering sites
Environmental watering sites in the Mallee basin that depend on water for the environment include the internationally significant Hattah Lakes system, the Lindsay-Mulcra Wallpolla Living Murray Icon site and the lower Murray wetlands including Catfish Billabong in the Merbein Common Flagship Waterway Site.
These environmental watering sites receive environmental water from the Murray River and the Wimmera Mallee pipeline.
Environmental water reserve
In 2021-22, water for the environment from within the Mallee basin comprised all water in the basin not allocated for consumptive use: this water also provided social, recreational and cultural benefits.
Information on the total volume of environmental water delivered in the Murray system, which includes sites in the Mallee and Wimmera basins, is reported in the Murray page and the Wimmera page.
Management responsibilities
Management of water in the Mallee basin is undertaken by various parties
| Authority | Management responsibilities |
|---|---|
| GWMWater |
|
| Lower Murray Water |
|
| Mallee Catchment Management Authority |
|
