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 geographical area within the catchment containing licensed entitlement that is 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.
2024-25 overview
Urban supply
Groundwater supplied to 11 towns in the catchment.
Water use
More water was used for consumptive purposes than the previous year.
Climate
Rainfall
More rainfall was received in the Hopkins-Corangamite groundwater catchment in 2024-25 than the previous year, ranging from close to the long-term average to the lowest on record across the catchment. Rainfall was:
- average in the catchment’s far-east towards Geelong
- below average across most of the catchment’s east, and around Port Campbell
- very much below average across parts of the catchment’s north, and most of the west
- the lowest recorded in the reference period (1975 to 2025) in the catchment’s north around Ararat.
Figure 1 displays the rainfall received in 2024-25 compared to the long-term average (1975-2025).
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. These trends are shown in Table 1 below.
Groundwater level trends reporting in the Accounts does not necessarily represent the status of the resource for management purposes. Groundwater resources are actively managed by rural water corporations. For more detail on management responses, go to Groundwater on the Southern Rural Water
In 2024-25, groundwater level trends toward the end of the year were rising in 4 GMUs, stable in 2 GMUs, and declining in 4 GMUs.
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
Response to water availability
Groundwater restrictions
There were no restrictions on licensed groundwater use in 2024-25, the same as previous year.
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 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 Hopkins-Corangamite groundwater catchment was 32,097 ML, more than the 26,216 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 take
The table below shows the total water available and taken under entitlements, and estimated domestic and stock use in 2024-25. Total water available under entitlements is calculated as the sum of: opening carryover from the prior year (where available), allocation issued during the reporting year, and the net trade in or out of water, across all entitlements. The level of allocation issued is reduced if there are any restrictions in place.
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 per bore per year.
More information on groundwater use and availability has been detailed in How we account for
In 2024-25, 32,097 ML of water was extracted for consumptive purposes, which was more than the 26,216 ML extracted in the previous year. Of this volume, 27,777 ML was for non-urban (irrigation) use, 2,297 ML was for urban use, and 2,023 ML was estimated to be for domestic and stock use.
Table 3: Groundwater availability and take, 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 |
|
