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 Portland GMA extends into the Glenelg groundwater catchment.
Groundwater resources within the catchment supply licensed entitlements, domestic and stock use and urban use to 9 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 within the Portland groundwater catchment boundary.
More information on water management and accounting is detailed in Water explained.
2023-24 overview
Urban supply
Groundwater supplied to 9 towns in the catchment.
Water use
More water was used for consumptive purposes than the previous year.
Climate
Rainfall
Less rainfall was received in the Portland groundwater catchment in 2023-24 than the previous year, being the lowest recorded in the reference period (1975 to 2024) across the entire catchment.
Figure 1 displays the rainfall received in 2023-24 compared to the long-term average (1975-2024).
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. These trends are shown in Table 1 below.
Groundwater resources are being actively managed. For more detail on management responses, go to on the Southern Rural Water website.
In 2023-24, groundwater level trends for South West Limestone GMA and Condah WSPA towards the end of the year were stable and declining, respectively. The trend for the Portland GMA could not be determined towards the end of the year due to data availability, but it was declining in the prior September 2023 quarter.
Table 1: Groundwater level trends, Portland groundwater catchment
Response to water availability
Groundwater restrictions
There were no restrictions on licensed groundwater use in 2023-24, the same as previous year.
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 take table (Table 3), 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 the Statewide groundwater summary.
Water used
Use in the Portland groundwater catchment was 20,993 ML, more than the 15,107 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 take
The table below shows the total water available and taken under entitlements, and estimated domestic and stock use in 2023-24. 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 2023-24, 20,993 ML of water was extracted for consumptive purposes, which was more than the 15,107 ML extracted in the previous year. Of this volume, 17,059 ML was for non-urban (irrigation) use, 2,234 ML was for urban use, and 1,700 ML was estimated to be for domestic and stock use.
Table 3: Groundwater availability and take, 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 |
|
