About the area
- The Moorabool River begins as two 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.
- The Moorabool River is regulated by a number of storages, the largest of which is Lal Lal Reservoir.
- Annual rainfall 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 .
2021-22 overview
Available water
Catchment inflow was higher than the previous year.
Licensed diversion restrictions
There were no restrictions on licensed diversions – the same as last year.
Water use
Less water was diverted for consumptive purposes than the previous year.
When compared to the previous year, in 2021-22:
- around the same amount of rainfall was received, catchment inflow was higher and storage levels peaked and declined at higher levels
- there were no restrictions on licensed diversions from unregulated streams (same as last year)
- less water was diverted from the basin for consumptive uses.
Climate
Rainfall
In 2021-22, rainfall in the Moorabool basin was above average in most areas, similar to the year before. Rainfall was:
- average in the north-west
- above average in the rest of the basin from the Brisbane Ranges National Park to the coast.
River basin water balance
In 2021-22, 20,568 ML of water was diverted for consumptive uses: town, domestic and stock, irrigation and commercial supply. This was less than the 23,922 ML diverted in the previous year.
Water balance table
The table below shows the total volumes of water available and supplied from water resources in the Moorabool basin in 2021-22.
Table 1: Water balance, Moorabool basin
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 85% on 30 June 2022.
Higher than the previous year
Storage levels were 82% on 30 June 2021.
Table 2: Storage levels, Moorabool basin
Catchment inflow
Catchment inflow represents the volume of water flowing into the waterways of a basin. It is calculated to be the difference between the total outflows, the known inflows and the net change in storage volume.
Below average inflow received
Catchment inflow was 80% of the long-term average of 103,400 ML.
More than the previous year
This is higher than the previous year (60% 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 now 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 Highland and Barwon .
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 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 below.
Entitlement volumes represent a maximum volume that can be taken in a one-year period. The volume available in a particular year is dependent on the rules for allocating water set out in the entitlement and the seasonal conditions in that year, which varies. The rules for allocating water under an entitlement can 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 2021-22. The volume includes carryover from the previous year, seasonal allocations and net trade into the basin.
Water taken
There was 20,663 ML taken under entitlements in 2021-22, less than the year before (22,939 ML).
Restrictions on licensed diversions from unregulated rivers
There were no restrictions on licensed diversions from unregulated streams in 2021-22; the same as in the previous year.
Available water and take table
This table shows the volume of available water and the volume taken under entitlements in 2021-22.
More information on available water and take has been detailed in the How do we account for surface section on the How do we account for water page.
In 2021-22, less water was taken under entitlements than the previous year.
Table 5: Available water and take, Moorabool basin
Compliance
Compliance against water entitlements is reported for this basin in three areas:
- entitlement issued: the volume of entitlements issued in a basin does not exceed formal caps, and has not increased without appropriate approvals
- water taken: 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: holders of entitlements do not breach any provisions that are documented in their bulk entitlement orders.
Total entitlement volume
There was no net increase in the total entitlement volume from the previous year.
Total volume diverted
The total volume diverted (20,663 ML) was within the volume available for the year (57,240 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
- the lower Barwon Wetlands, which is part of the Port Phillip Bay and Bellarine Peninsula Ramsar Site
- extensive areas of endangered remnant vegetation including streambank shrubland and riparian woodland ecological vegetation communities
- platypus, water rats and a range of waterbugs.
Environmental water reserve
In 2021-22, water for the environment in the Moorabool basin comprised:
- the Moorabool River Environmental Entitlement 2010, comprising 11.9% of inflows held by the VEWH
- 3,274 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 2021-22, a total of 2,563 ML of environmental water was delivered in-stream in the Moorabool basin. Adding to the environmental benefit in the system; 3,274 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 |
|---|---|
| Southern Rural Water |
|
| Barwon Water |
|
| Central Highlands Water |
|
| Corangamite Catchment Management Authority |
|
| Melbourne Water |
|
| Water supply system | 2021-22 (ML) | 2020-21 (ML) |
|---|---|---|
| Geelong/Bellarine | 5,994 | 7,340 |
| Greater Ballarat system | 4,665 | 4,597 |
