About the area
- The Wimmera-Mallee groundwater catchment is in north-western Victoria.
- The Wimmera-Mallee groundwater catchment contains the Murrayville Groundwater Management Area (GMA). The area not covered by Murrayville GMA is reported as outside management units.
- Groundwater resources supply licensed entitlements, domestic and stock use, and urban use to Cowangie, Landsborough, Murrayville and Willaura, and they provide a backup urban supply for Horsham.
- The Wimmera-Mallee groundwater catchment forms part of the Murray-Darling Basin, and groundwater management arrangements are subject to the requirements of the Murray-Darling Basin Plan.
- The area that extends 20 km east from the border forms part of the Designated Area for the purposes of the 1985 Border Groundwaters Agreement between Victoria and South Australia.
- Management responsibilities within the Designated Area are shared between GWMWater and the Government of South Australia.
More information on water management and accounting is detailed in Water explained.
2021-22 overview
Urban supply
Groundwater supplied 5 towns in the catchment.
Water use
More water was used for consumptive purposes than the previous year.
Climate
Rainfall
Rainfall in the Wimmera-Mallee groundwater catchment was above average in most areas, higher than the previous year. Rainfall was:
- average in a narrow band along the border with South Australia and average in the south from around Natimuk to Navarre
- above average everywhere else from the Murray River down to around Horsham.
Groundwater level trends
In the accounts, groundwater level trends for groundwater management units (GMUs) have been determined based on monitoring data from key bores in the State Observation Bore Network. Trend determinations are made quarterly by comparing each reading to a previous reading in the same season 5 years prior. That is, a summer record is compared to the summer record from 5 years before to account for seasonality.
Groundwater resources are being actively managed. For more detail on the management responses go to the groundwater on the Grampians Wimmera Mallee Water website.
In 2021-22, groundwater level trends in the Wimmera-Mallee groundwater catchment were the same as the previous year.
Table 1: Groundwater level trends, Wimmera-Mallee groundwater catchment
Entitlements and use
Groundwater licence and use volumes in the Wimmera-Mallee groundwater catchment are shown below. Some groundwater licences incorporate domestic and stock use, and in these cases the use is reported in the licensed volume.
The licenced volume used under entitlements must not exceed the volume made available to individual licensed entitlement holders. We report on compliance in the GMU local report and the Statewide groundwater .
Water used
Use in the Wimmera-Mallee groundwater catchment was 7,717 ML, more than 6,812 ML in the previous year.
Entitlement volumes
Rights to water in the Wimmera-Mallee groundwater catchment are shown below.
Table 2: Groundwater entitlements at 30 June, Wimmera-Mallee groundwater catchment
Available water and use
The table below shows the total water available and used under entitlements, and estimated domestic and stock use in 2021-22. Total water available under entitlements is the sum of: opening carryover, allocation issued and the net trade in or out of water.
Estimated domestic and stock use is calculated based on an assumed usage per registered bore per year. In this catchment 2 ML usage per bore per year is assumed.
More information on groundwater use and availability has been detailed in the How do we account for section.
In 2021-22, 7,717 ML of water was extracted for consumptive purposes, which was more than the 6,812 ML extracted in the previous year. Of this volume, 7,053 ML was for non-urban (irrigation) use, 344 ML was for urban use, and 320 ML was estimated to be for domestic and stock use.
There were no restrictions on use in the Wimmera-Mallee groundwater catchment in 2021-22.
Table 3: Groundwater availability and use, Wimmera-Mallee groundwater catchment
Management responsibilities
Management of water in the Wimmera-Mallee groundwater catchment is undertaken by various parties.
| Authority | Management responsibilities |
|---|---|
| GWMWater |
|
| Lower Murray Water |
|
| Government of South Australia |
|
