About the area
The East Port Phillip Bay groundwater catchment stretches to the east of Melbourne, covering much of its suburban area, and the Mornington Peninsula.
The East Port Phillip Bay groundwater catchment contains the Frankston groundwater management area (GMA), Moorabbin GMA, Nepean GMA, Koo Wee Rup water supply protection area (WSPA), and Wandin Yallock GMA. The area not covered by these is reported as outside management units.
The Koo Wee Rup WSPA extends into the Westernport groundwater catchment.
Groundwater resources within the catchment supply licensed entitlements and domestic and stock use. Groundwater resources are not used for urban supply in the East Port Phillip Bay groundwater catchment.
More information on water management and accounting is detailed in Water explained.
2023-24 overview
Water use
Water used for consumptive purposes was similar to the previous year.
Climate
Rainfall
Less rainfall was received in the East Port Phillip Bay groundwater catchment in 2023-24 than the previous year, ranging from close to very much below the long-term average across the catchment. Rainfall was:
- average in central parts of the catchment from Craigieburn to the upper reaches of the Yarra River and south to Dandenong
- below average along the northern border of the catchment around Healesville, and in the west from the northern suburbs of Melbourne to Mornington
- very much below average across the Mornington Peninsula.
Figure 1 displays the rainfall received in 2023-24 compared to the long-term average (1975-2024).
Figure 1: Rainfall deciles, East Port Phillip Bay 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 resources are being actively managed. For more detail on management responses, go to on the Southern Rural Water website.
In 2023-24, groundwater level trends for the Frankston and Moorabbin GMAs, and the Koo Wee Rup WSPA were rising towards the end of the year. The trend for Nepean and Wandin Yallock GMAs was stable towards the end of the year.
Table 1: Groundwater level trends, East Port Phillip Bay groundwater catchment
Response to water availability
Groundwater restrictions
There were no restrictions on licensed groundwater use in 2023-24, the same as previous year.
Entitlements and use
Groundwater licence and use volumes in the East Port Phillip Bay 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 East Port Phillip Bay groundwater catchment was 11,104 ML, similar to the 10,152 ML used in the previous year.
Entitlement volumes
Rights to water in the East Port Phillip Bay groundwater catchment are shown below.
Table 2: Groundwater entitlements at 30 June, East Port Phillip Bay 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 2023-24. 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 2023-24, 11,104 ML of water was extracted for consumptive purposes, which was similar to the 10,152 ML extracted in the previous year. Of this volume, 7,524 ML was for non-urban (irrigation) use, and 3,580 ML was estimated to be for domestic and stock use.
Table 3: Groundwater availability and take, East Port Phillip Bay groundwater catchment
Management responsibilities
Management of water in the East Port Phillip Bay groundwater catchment is undertaken by Southern Rural Water.
| Authority | Management responsibilities |
|---|---|
| Southern Rural Water |
|
