About the area
- The Portland groundwater catchment is in the far south-west of the state 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), South West Limestone GMA, and Glenelg WSPA. The area not covered by GMUs 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 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.
2021-22 overview
Urban supply
Groundwater supplied 9 towns in the catchment.
Water use
More water was used for consumptive purposes than the previous year.
Climate
Rainfall
Rainfall in the Portland groundwater catchment was average across the entire catchment, lower than 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 Portland groundwater catchment were generally consistent with the previous 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. 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 Portland groundwater catchment was 21,031 ML, more than 17,809 ML 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 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, 21,031 ML of water was extracted for consumptive purposes, which was more than the 17,809 ML extracted in the previous year. Of this volume, 16,080 ML was for non-urban (irrigation) use, 2,947 ML was for urban use, and 2,004 ML was estimated to be for domestic and stock use.
There were no restrictions on use in the Portland groundwater catchment in 2021-22.
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 |
|
