About the area
The Portland groundwater catchment is in the far south-west of Victoria and extends inland from the Southern Ocean coast.
The Portland groundwater catchment contains the Condah water supply protection area (WSPA), Portland groundwater management area (GMA) and South West Limestone GMA. The area not covered by these is reported as outside management units.
The South West Limestone GMA extends into the Hopkins-Corangamite and Glenelg groundwater catchments. The Glenelg WSPA and Portland GMA extend into the Glenelg groundwater catchment.
Groundwater resources within the catchment supply licensed entitlements, domestic and stock use and urban use to 12 towns in the area.
Most groundwater use in the Portland groundwater catchment is for irrigation and urban use, and to a lesser extent, for dairy-wash and industrial purposes.
Groundwater resources from the Glenelg groundwater catchment also supply Hamilton, Tarrington and Dunkeld.
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.
Water use
Less water was used for consumptive purposes than the previous year.
Climate
Rainfall
More rainfall was received in the Portland groundwater catchment in 2022-23 than the previous year, being very much above the long-term average across most of the catchment and above average near Cape Bridgewater.
Figure 1 displays the rainfall received in 2022-23 compared to the long-term average (1975-2023).
Figure 1: Rainfall deciles, Portland 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 Southern Rural Water website.
In 2022-23, groundwater level trends for the Portland and South West Limestone GMAs were stable toward the end of the year. The trend for the Condah WSPA was rising towards the end of the year.
Table 1: Groundwater level trends, Portland groundwater catchment
Entitlements and use
Groundwater licence and use volumes in the Portland 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 Portland groundwater catchment was 15,107 ML, less than the 21,031 ML used in the previous year.
Entitlement volumes
Rights to water in the Portland groundwater catchment are shown below.
Table 2: Groundwater entitlements at 30 June, Portland 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 1.5 ML usage per bore per year.
More information on groundwater use and availability has been detailed in How we account for .
In 2022-23, 15,107 ML of water was extracted for consumptive purposes, which was less than the 21,031 ML extracted in the previous year. Of this volume, 10,259 ML was for non-urban (irrigation) use, 2,995 ML was for urban use, and 1,853 ML was estimated to be for domestic and stock use.
There were no restrictions on use in the Portland groundwater catchment in 2022-23.
Table 3: Groundwater availability and use, Portland groundwater catchment
Management responsibilities
Management of water in the Portland groundwater catchment is undertaken by Southern Rural Water.
| Authority | Management responsibilities |
|---|---|
| Southern Rural Water |
|
