About the area
- The Tarwin groundwater catchment is in south-eastern Victoria. Bass Strait forms the catchment's southern boundary.
- The Tarwin groundwater catchment contains the Leongatha Groundwater Management Area (GMA) and Tarwin GMA. The area not covered by GMUs is reported as outside management units.
- Groundwater resources supply licensed entitlements, domestic and stock use, and urban use to Leongatha.
More information on water management and accounting is detailed in Water explained.
2021-22 overview
Water use
Less water was used for consumptive purposes than the previous year.
Climate
Rainfall
Rainfall in the Tarwin groundwater catchment was average across the entire catchment, the same as the previous year.
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 Southern Rural Water website.
In 2021-22, groundwater level trends in the Tarwin groundwater catchment were consistent with the previous year.
Table 1: Groundwater level trends, Tarwin groundwater catchment
Entitlements and use
Groundwater licence and use volumes in the Tarwin 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 Tarwin groundwater catchment was 749 ML, less than 813 ML in the previous year.
Entitlement volumes
Rights to water in the Tarwin groundwater catchment are shown below.
Table 2: Groundwater entitlements at 30 June, Tarwin 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 1.5 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, 749 ML of water was extracted for consumptive purposes, which was less than the 813 ML extracted in the previous year. Of this volume, 105 ML was for non-urban (irrigation) use, and 644 ML was estimated to be for domestic and stock use.
There were no restrictions on use in the Tarwin groundwater catchment in 2021-22.
Table 3: Groundwater availability and use, Tarwin groundwater catchment
Management responsibilities
Management of water in the Tarwin groundwater catchment is undertaken by Southern Rural Water.
| Authority | Management responsibilities |
|---|---|
| Southern Rural Water |
|
