About the area
- The Latrobe River flows in an easterly direction in a basin bound by the Strzelecki Ranges in the south and the Great Dividing Range in the north, before flowing into the Gippsland Lakes.
- Annual rainfall in the north of the basin is in excess of 1200 mm per year, reducing to 600-900 for much of the length of the river.
- Water in the Latrobe basin is used for industry including power generation, urban use and agriculture.
More information on water management and accounting is detailed in Water .
2021-22 overview
Available water
Catchment inflow was around the same as the previous year.
Licensed diversion restrictions
There were more restrictions on licensed diversions than the previous year.
Water use
A similar volume to the previous year was diverted for consumptive purposes.
When compared to the previous year, in 2021-22:
- about the same amount of rainfall and catchment inflow was received, and storage levels were similar
- there was one more restriction on licensed diversions from unregulated streams
- a similar volume was diverted from the basin for consumptive uses.
Climate
Rainfall
In 2021-22, rainfall in the Latrobe basin was average to above average, similar to the previous year. Rainfall was:
- average in the western half of the basin
- above average from Traralgon to the east
- very much above average east of Rosedale until the coast.
River basin water balance
In 2021-22, 130,171 ML of water was diverted for consumptive uses: town, domestic and stock, irrigation and commercial supply, similar to the 119,144 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 Latrobe basin in 2021-22.
Table 1: Water balance, Latrobe basin
Storages
Major — greater than 1,000 ML — on-stream storages in the Latrobe basin are included in the water balance.
Storage levels
Major on-stream storage levels in the Latrobe basin were 100% on 30 June 2022.
About the same as the previous year
Storage levels were 99% on 30 June 2022.
Table 2: Storage levels, Latrobe 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.
Above average inflow
Catchment inflow was 114% of the long-term average of 843,300 ML.
About the same amount of water received as last year
Around the same as the previous year (961,926 ML, 114% 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 Gippsland .
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, Latrobe basin
Entitlements and compliance
Entitlements provide the basis for how water is shared in the basin.
Entitlement volumes
Rights to water in the Latrobe 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, Latrobe 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 124,389 ML taken under entitlements in 2021-20, similar to the year before (114,114 ML).
Restrictions on licensed diversions from unregulated rivers
There was a stage 2 roster imposed on Ten Mile Creek in February 2022. All other streams were unrestricted for the year. This is slightly higher than the previous year, when there were no restrictions on licensed diversions from unregulated rivers.
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, a similar volume of water was taken under entitlements to the previous year.
Table 5: Available water and take, Latrobe 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 an allowed increase in the total entitlement volume from the previous year (11,700). See note below.
Total volume diverted
The total volume diverted (124,389 ML) was within the volume available for the year (274,702 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.
Note to increase in total entitlement volume:
- Two new entitlements were created in response to the Yallourn Mine Emergency and will only be in place until 30 June 2023.
Water for the environment
Environmental watering sites
Environmental watering sites and environmental values in the Latrobe basin that depend on water for the environment include:
- the lower Latrobe wetlands (including Sale Common, Dowd Morass and Heart Morass, which are part of the internationally recognised Gippsland Lakes Ramsar site). The lower Latrobe wetlands provide habitat for a variety of waterbirds. Mature river red gums also grow adjacent to the wetlands and provide nesting habitat for sea eagles and other birds of prey that hunt in the wetlands
- the Latrobe River, which contains native estuarine and freshwater fish species including black bream, Australian bass and short- and long-finned eel as well as continuous stands of river red gums in its upper reaches. The banks along the lower reaches support stands of swamp scrub, an endangered vegetation group.
Environmental water reserve
In 2021-22, water for the environment in the Latrobe basin comprised:
- the Lower Latrobe Wetlands Environmental Entitlement 2010, held by the VEWH, which allows water to be diverted to Dowd Morass, Sale Common and Heart Morass when river levels are above heights specified in the environmental entitlement
- the Blue Rock Environmental Entitlement 2013, held by the VEWH, which provides a 9.45% share of inflows into Blue Rock Reservoir
- water set aside for the environment through the operation of passing flow conditions:
- on consumptive bulk entitlements held by Southern Rural Water and Gippsland Water
- 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, no environmental water was delivered in-stream in the Latrobe basin. This was because all target flow components for the freshwater reaches of the Latrobe River were fully met or exceeded with natural flows and operational releases. Environmental flows at the lower Latrobe wetlands were managed in line with a wet climate scenario in 2021-22. All planned watering actions were fully achieved with a combination of natural overbank flows and managed deliveries of water for the environment through inlet-regulating structures.
Management responsibilities
Management of water in the Latrobe basin is undertaken by various parties
| Authority | Management responsibilities |
|---|---|
| Southern Rural Water |
|
| Gippsland Water |
|
| West Gippsland Catchment Management Authority |
|
| Water supply system | 2021-22 (ML) | 2020-21 (ML) |
|---|---|---|
| Erica / Rawson | 65 | 60 |
| Mirboo North | 182 | 178 |
| Moe System | 5,139 | 4,517 |
| Moondarra System | 47,087 | 32,480 |
| Willow Grove | 46 | 50 |
