About the area
The West Wimmera groundwater catchment is in the far west of Victoria. The Victoria-South Australia border forms the catchments western boundary.
The West Wimmera groundwater catchment is fully covered by the West Wimmera groundwater management area (GMA).
Groundwater resources within the catchment supply licensed entitlement, domestic and stock use, and urban use to Apsley, Harrow, Miram, Serviceton, Edenhope, Kiata, Goroke, Lillimur, Kaniva, and Nhill.
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 Grampians Wimmera Mallee Water and the Government of South Australia.
More information on water management and accounting is detailed in Water explained.
2022-23 overview
Urban supply
Groundwater supplied to 9 towns in the catchment.
Groundwater restrictions
The same as the previous year, 80% allocation for Neuarpur subzone 1.
Water use
Less water was used for consumptive purposes than the previous year.
Climate
Rainfall
More rainfall was received in the West Wimmera groundwater catchment in 2022-23 than the previous year, being very much above the long-term average across most of the catchment and the highest recorded in the reference period (1975 to 2023) around Goroke.
Figure 1 displays the rainfall received in 2022-23 compared to the long-term average (1975-2023).
Figure 1: Rainfall deciles, West Wimmera groundwater catchment
Sourced from the Australian Bureau of Meteorology
Groundwater level trends
In the Accounts, groundwater level trends for groundwater management units (GMUs) have been determined by 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; for example, a summer record is compared to the summer record from 5 years earlier to account for seasonality.
Groundwater resources are being actively managed. For more detail on management responses, go to on the Grampians Wimmera Mallee Water website.
In 2022-23, groundwater level trends for the West Wimmera GMA and Neuarpur subzone 1 were stable and declining, respectively towards the end of the year.
Table 1: Groundwater level trends, West Wimmera groundwater catchment
Response to water availability
Groundwater restrictions
In 2022-23, licence holders in the Neuarpur sub-zone 1 - a trading zone in the West Wimmera GMA - were restricted to 80% of their licence volume, the same as the previous year.
Entitlements and use
Groundwater licence and use volumes in the West Wimmera groundwater catchment are shown below. Domestic and stock use does not require a licence, so in the Groundwater availability and use table, these rows only report water taken.
The licensed volume used under entitlements must not exceed the volume made available to individual licensed entitlement holders. We report on compliance in the GMU local reports and in Statewide groundwater.
Water used
Use in the West Wimmera groundwater catchment was 13,052 ML, less than the 23,755 ML used in the previous year.
Entitlement volumes
Rights to water in the West Wimmera groundwater catchment are shown below.
Table 2: Groundwater entitlements at 30 June, West Wimmera 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 2022-23. 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, the assumed usage is 2 ML usage per bore per year.
More information on groundwater use and availability has been detailed in How we account for .
In 2022-23, 13,052 ML of water was extracted for consumptive purposes, which was less than the 23,755 ML extracted in the previous year. Of this volume, 11,825 ML was for non-urban (irrigation) use, 419 ML was for urban use, and 808 ML was estimated to be for domestic and stock use.
Table 3: Groundwater availability and use, West Wimmera groundwater catchment
Management responsibilities
Management of water in the West Wimmera groundwater catchment is undertaken by various parties.
| Authority | Management responsibilities |
|---|---|
| Grampians Wimmera Mallee Water |
|
| Government of South Australia |
|
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