About the area
- The West Wimmera groundwater catchment is in the far west of Victoria. The Victorian-South Australian border forms the catchment’s western boundary.
- The West Wimmera groundwater catchment is fully covered by the West Wimmera Groundwater Management Area (GMA).
- Groundwater resources 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 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 10 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.
Climate
Rainfall
More rainfall was received in the West Wimmera groundwater catchment in 2021-22. Rainfall was:
- average in a narrow band along the border with South Australia as well as throughout the south from around Kaniva south
- above average in the north-east around Nhill and up north in the Big Desert.
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 West Wimmera groundwater catchment were the same as the previous year.
Table 1: Groundwater level trends, West Wimmera groundwater catchment
Response to water availability
Groundwater restrictions
In 2021-22, licence holders in the Neuarpur subzone 1 — a trading zone in the West Wimmera GMA — were restricted to 80% of their licence volume.
Entitlements and use
Groundwater licence and use volumes in the West Wimmera 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 West Wimmera groundwater catchment was 23,755 ML, less than 24,596 ML 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 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, 23,755 ML of water was extracted for consumptive purposes, which was less than the 24,596 ML extracted in the previous year. Of this volume, 22,496 ML was for non-urban (irrigation) use, 499 ML was for urban use, and 760 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 |
|---|---|
| GWMWater |
|
| Government of South Australia |
|
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