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.
2022-23 overview
Water use
Water used for consumptive purposes was similar to the previous year.
Climate
Rainfall
More rainfall was received in the East Port Phillip Bay groundwater catchment in 2022-23 than the previous year, being very much above the long-term average in most of the catchment. Rainfall was:
- very much above average over the Mornington Peninsula, in the far east, and across most the central regions of the catchment
- above average along the western border of the catchment from Beveridge to Mornington and Sorrento, and in a region in the Yarra Ranges around Warburton.
Figure 1 displays the rainfall received in 2022-23 compared to the long-term average (1975-2023).
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.
Groundwater resources are being actively managed. For more detail on management responses, go to on the Southern Rural Water website.
In 2022-23, groundwater level trends for the Frankston, Moorabbin and Wandin Yallock GMAs, and the Koo Wee Rup WSPA were rising towards the end of the year. The trend for the Nepean GMA was stable towards the end of the year.
Table 1: Groundwater level trends, East Port Phillip Bay groundwater catchment
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 use table, 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 Statewide groundwater.
Water used
Use in the East Port Phillip Bay groundwater catchment was 10,154 ML, similar to the 10,175 ML used in the previous year.
Entitlement volumes
Rights to water in the East Port Phillip Baygroundwater catchment are shown below.
Table 2: Groundwater entitlements at 30 June, East Port Phillip Bay groundwater catchment
Available water and use
The table below shows the total water available and used under entitlements, and estimated domestic and stock use in 2022-23. 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 2022-23, 10,154 ML of water was extracted for consumptive purposes, which was similar to the 10,175 ML extracted in the previous year. Of this volume, 6,562 ML was for non-urban (irrigation) use, and 3,592 ML was estimated to be for domestic and stock use.
There were no restrictions on use in the East Port Phillip Bay groundwater catchment in 2022-23.
Table 3: Groundwater availability, East Port Phillip Bay groundwater catchment
Management responsibilities
Management of water in the East Port Phillip Baygroundwater catchment is undertaken by Southern Rural Water.
| Authority | Management responsibilities |
|---|---|
| Southern Rural Water |
|
