About the area
The Moorabool River begins as 2 major tributaries on the southern slopes of the Great Dividing Range near Ballan and flows south-east to join the Barwon River near Geelong. The Moorabool basin also includes Little River, which flows into Port Phillip Bay.
Flow in the Moorabool River is regulated by releases from Lal Lal Reservoir.
Annual rainfall in the basin decreases from 900 mm in the headwaters to 400-600 mm in the middle and lower reaches.
More information on water management and accounting is detailed in Water
2024-25 overview
Available water
Catchment inflow was lower than the previous year.
Licensed diversion restrictions
There were more restrictions on licensed diversions than the previous year.
Water use
More water was diverted for consumptive purposes than the previous year.
When compared to the previous year, in 2024-25:
- more rainfall was received; however, catchment inflow was lower, and storage levels peaked and declined at lower levels
- there were more restrictions on licensed diversions from streams
- more water was diverted for consumptive purposes than the previous year.
Climate
Rainfall
In 2024-25, rainfall received in the Moorabool basin was higher than the previous year. Rainfall was:
- average around the basin’s southern boundary, encompassing Lara
- below average in the rest of the basin.
Figure 1 displays the rainfall received in 2024-25 compared to the long-term average (1975-2025).
Figure 1: Rainfall deciles, Moorabool basin
Sourced from the Australian Bureau of Meteorology
River basin water balance
This section describes the known and estimated inflows, outflows and change of storage volumes in the basin.
More detail on major on-stream storages, catchment inflows, diversions and small catchment dams can be found in the sections below the water balance.
Of the total inflows, 34% flowed out into the Barwon River (Moorabool River), Port Phillip Bay (Little River), and other small coastal streams in 2024-25.
Water balance table
The table below shows the total volumes of water available and supplied from water resources in the Moorabool basin in 2024-25.
Table 1: Water balance, Moorabool basin
Major on-stream storages
Major - greater than 1,000 ML - on-stream storages in the Moorabool basin are included in the water balance. Volumes in off-stream storages are presented for additional information about the resource condition.
Storage levels
Major on-stream storage levels in the Moorabool basin were 46% on 30 June 2025.
Lower than the previous year
Storage levels were 76% on 30 June 2024.
Table 2: Storage levels, Moorabool basin
Inflows
Catchment inflow
Catchment inflow represents the volume of water flowing into the waterways of a basin. It is calculated as the total outflows and change in storage minus the known inflows.
Below average inflows of 12,218 ML were received (12% of the long-term average of 100,400 ML), less than the previous year (28% of the long-term average).
Below average inflow received
Catchment inflow was 12% of the long-term average of 100,400 ML.
Less water received than the previous year
Catchment inflow was less than the previous year (28% of the long-term average).
Wastewater treatment plants
Water treated at wastewater treatment plants can be used to supplement water available in the basin. Water discharged to waterways from treatment plants is included as an inflow to the water balance.
Information on treatment plants is reported in the water supply local reports for the water corporation responsible for managing the plant.
In this basin, wastewater treatment plants are managed by Central Highlands Water and Barwon Water.
Outflows
Diversions
In 2024-25, 20,667 ML of water was diverted for consumptive uses: town, domestic and stock, irrigation and commercial supply. This was more than the 18,906 ML diverted in the previous year. While the diversion volume was more than the previous year, there was less water transferred to the Barwon basin, and a decrease in the estimation of small catchment dam use volume.
Small catchment dams
Water harvested, used and lost by small catchment dams (farm dams) is included in the water balance.
Table 3: Small catchment dams, Moorabool basin
Entitlements and compliance
Entitlements provide the basis for how water is shared in the basin.
The Victorian Environmental Water Holder (VEWH) holds an environmental entitlement in the Moorabool basin, but the water available under the entitlement is used to support streamflows and is not diverted out of the waterway. As this water use is not a diversion from the waterway, it has not been included as part of the water balance diversions in Table 1.
Entitlement volumes
Rights to water in the Moorabool basin are shown in Table 4.
Entitlement volumes represent an indication of a maximum volume of water that can be taken or allocated in any one year depending on the rules of the entitlement. The volume available in a particular year is dependent on the rules for allocating water set out in the entitlement, the seasonal conditions in that year and how much water was carried over from the previous year, which can vary. The rules for allocating water under an entitlement differ between entitlements and systems. This affects the ability and likelihood of water being taken in a particular year.
Table 4: Annual entitlement volumes at 30 June, Moorabool basin
Available water and take under entitlements
Total water available under entitlements represents the volume of water that was available to be taken by entitlement holders in 2024-25. The volume includes carryover from the previous year, seasonal allocations and net trade into the basin.
Water taken
There was 22,127 ML taken under entitlements in 2024-25, more than the previous year (19,947 ML).
Restrictions on licensed diversions from streams
- There were bans in place for licensed diversions from the Moorabool River between November 2024 and June 2025, and from the Little River between January and June 2025.
- During the previous year, the Moorabool River had restrictions for fewer months, and there were no restrictions in place for Little River.
Available water and take table
This table shows the volume of available water and the volume taken under entitlements in 2024-25.
More information on available water and take has been detailed in How we account for surface
In 2024-25, more water was taken under entitlements than the previous year.
Table 5: Available water and take under entitlements, Moorabool basin
Compliance
Compliance against water entitlements is reported for this basin in 3 areas:
- entitlement issued: that the volume of entitlements issued in a basin does not exceed formal caps, and has not increased without appropriate approvals
- water taken: that the volume of water taken during the year does not exceed the volume considered to be available for consumptive and/or in-stream use during that year
- bulk entitlement provisions: that holders of entitlements do not breach any provisions that are documented in their bulk entitlement orders.
Key points on compliance against entitlements in 2024-25
Total entitlement volume
There was no net increase in the total entitlement volume from the previous year.
Total volume diverted
The total volume diverted under entitlements (22,127 ML) was within the volume available for the year (53,998 ML).
Individual bulk entitlements
No individual bulk entitlement holder took more than the annual volume made available to them.
Exceptions to compliance
Individual bulk entitlement holders complied with all provisions in their entitlements.
Water for the environment
Environmental watering sites
Environmental watering sites and environmental values in the Moorabool basin that depend on water for the environment include:
- river blackfish between Lal Lal Reservoir and She Oaks Weir
- extensive areas of endangered remnant vegetation including streambank shrubland and riparian woodland ecological vegetation communities
- platypus, water rats and a range of waterbugs.
Water for the environment in the Moorabool River can also benefit environmental values in the lower Barwon River, including the lower Barwon wetlands which are part of the Port Phillip Bay and Bellarine Peninsula Ramsar Site.
Environmental water reserve
In 2024-25, water for the environment in the Moorabool basin comprised:
- the Moorabool River Environmental Entitlement 2010, which includes 11.9% of inflows held by the VEWH
- 3,005 ML of treated groundwater discharged from the Fyansford quarry to the lower Moorabool River
- water set aside for the environment through the operation of passing flow conditions:
- on consumptive bulk entitlements held by Central Highlands Water and Barwon Water
- on the VEWH’s Moorabool River Environmental Entitlement 2010
- on licensed diversions
- all other water in the basin not allocated for consumptive uses: this water also provides social, recreational and cultural benefits.
Environmental water use
In 2024-25, a total of 2,498 ML of environmental water was delivered in-stream in the Moorabool basin. Adding to the environmental benefit in the system; 3,005 ML of treated groundwater was discharged from the Fyansford quarry to the lower Moorabool River.
Management responsibilities
Management of water in the Moorabool basin is undertaken by various parties.
| Authority | Management responsibilities |
|---|---|
| Barwon Water |
|
| Central Highlands Water |
|
| Corangamite Catchment Management Authority |
|
| Melbourne Water |
|
| Southern Rural Water |
|
| Water supply system | 2023-24 (ML) | 2024-25 (ML) |
|---|---|---|
| Geelong/Bellarine | 7,721 | 6,970 |
| Greater Ballarat system | 4,162 | 9,688 |
