About the area
The Hopkins-Corangamite groundwater catchment covers a large area of south-west Victoria.
The catchment contains the Bungaree groundwater management area (GMA), Cardigan GMA, Colongulac GMA, Gellibrand GMA, Gerangamete GMA, Glenormiston GMA, Newlingrook GMA, Paaratte GMA, South West Limestone GMA, Loddon Highlands water supply protection area (WSPA), and Warrion WSPA. The area not covered by these is reported as outside management units.
The South West Limestone GMA extends to the west beyond the Hopkins-Corangamite groundwater catchment. The Loddon Highlands WSPA has a very small section within this catchment and is mostly contained within the Loddon groundwater catchment.
Groundwater resources within the catchment supply licensed entitlements, domestic and stock use, and urban use to Dean, Ballarat, Carlisle, Port Campbell, Timboon, Peterborough, Curdie Vale, Beaufort, Darlington, Mortlake, and Streatham.
Groundwater resources from the Wimmera-Mallee groundwater catchment supply Willaura, although it is located inside the Hopkins-Corangamite groundwater catchment.
More information on water management and accounting is detailed in Water explained.
2022-23 overview
Urban supply
Groundwater supplied to 11 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 Hopkins-Corangamite groundwater catchment in 2022-23 than the previous year, being very much above the long-term average in most of the catchment. Rainfall was above average in areas east of Lake Corangamite and south of the Brisbane Ranges.
Figure 1 displays the rainfall received in 2022-23 compared to the long-term average (1975-2023).
Figure 1: Rainfall deciles, Hopkins-Corangamite 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 Bungaree, Colongulac, Gellibrand Newlingrook, Paaratte and South West Limestone GMAs were stable towards the end of the year. Trends for the Cardigan and Gerangamete GMAs, and Loddon Highlands and Warrion WSPAs were rising towards the end of the year.
There are insufficient state observation bores in the Glenormiston GMA to adequately define the groundwater resource or changes to the resource over time.
Table 1: Groundwater level trends, Hopkins-Corangamite
Entitlements and use
Groundwater licence and use volumes in the Hopkins-Corangamite 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 Hopkins-Corangamite groundwater catchment was 21,267 ML, less than the 28,284 ML used in the previous year.
Entitlement volumes
Rights to water in the Hopkins-Corangamite groundwater catchment are shown below.
Table 2: Groundwater entitlements at 30 June, Hopkins-Corangamite 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, 21,267 ML of water was extracted for consumptive purposes, which was less than the 28,284 ML extracted in the previous year. Of this volume, 18,295 ML was for non-urban (irrigation) use, 916 ML was for urban use, and 2,056 ML was estimated to be for domestic and stock use.
There were no restrictions on use in the Hopkins-Corangamite groundwater catchment in 2022-23.
Table 3: Groundwater availability and use, Hopkins-Corangamite groundwater catchment
Management responsibilities
Management of water in the Hopkins-Corangamite groundwater catchment is undertaken by Southern Rural Water.
| Authority | Management responsibilities |
|---|---|
| Southern Rural Water |
|
