The majority of Victoria's groundwater is contained in five major geologic basins. These are the Murray Basin, Otway Basin, Gippsland Basin (including the Tarwin Basin) and Central Basins (Port Phillip & Westernport). Central Victoria is predominately highlands, with the major five basins flanking the highlands to the north and south – see Figure 1 below.
Figure 1.1 Map of Victorian geologic basins
Image courtesy of: Department of Environment and Primary Industries (2013), Victorian Resources Online: http://vro.dpi.vic.gov.au/dpi/vro/map_documents.nsf/pages/groundwater_basins
The aquifers in each of the groundwater basins have recently been defined within the Victorian Aquifer Framework. The Victorian Aquifer Framework provides a common understanding and allows for a consistent approach to the definition of aquifers and aquitards across Victoria.
The resulting framework has recognised 15 Victorian 'aquifers', and three of these aquifers: the Lower Tertiary Aquifer (LTA, 44 per cent), Upper Mid-Tertiary Aquifer (UMTA, 30 per cent) and the Upper Tertiary Aquifer-Marine (UTAM, 13 per cent) hold the majority of Victoria's groundwater resource volume. The average aquifer thickness, and the representative hydrogeological units for the major aquifers are summarised in Table 1.
To identify the major aquifers in your area visit Groundwater resource reports.
Table 1 Victorian groundwater resources – major aquifers (VAF)
(by increasing depth)
Average aquifer thickness (m)
Representative HGUs in each Basin (where present)
Quaternary Aquifer (QA)
Various aeolian deposits, fluvial, lacustrine, alluvial and colluvial sediments (All Basins).
Upper Tertiary/Quaternary Basalts (UTQB)
Newer Volcanics (Otway, Central and NE Murray Basins)
Upper Tertiary/Quaternary Aquifer (UTQA)
Haunted Hill Formation (Gippsland)
Upper Tertiary Aquifer – Marine (UTAM)
Hanson Plain Sand (Otway)
Upper Tertiary Aquifer – Fluvial (UTAF)
Unnamed fluvial deposits (Otway)
Upper Mid-tertiary Aquifer (UMTA)
Port Campbell Limestone (Otway)
Lower Mid-tertiary Aquifer (LMTA)
Clifton Formation (Otway)
Lower Mid-tertiary Basalts (LTB)
LTBA – 35
LTBB - 78
Phase 2 Basalts (Otway)
Lower Tertiary Aquifer (LTA)
Dilwyn Formation (Otway)
Basement (Cretaceous/Permian Sediments and Paleozoic Bedrock)
CPS – 298
BSE – UNK (lower limit unknown)
Paaratte Formation & Eumeralla Formation (Otway)
Groundwater is used by many industries.
Factors influencing development of the resource include depth to groundwater, groundwater quality and salinity concentrations, groundwater accessibility and whether the industry is reliant on groundwater (eg irrigation, urban, stock, etc).
Groundwater is increasingly becoming more valuable as water becomes more scarce. Approximately 60 per cent of groundwater value is from irrigation usage, with a further 39 per cent used for commercial, dairy, urban and stock and domestic.