DEPARTMENT OF PRIMARY INDUSTRIES
Victorian Resources Online

Groundwater Benefical Use
State Environment Protection Policy (Groundwaters of Victoria) was recently released by the Environment Protection Authority (EPA) (external link) as a groundwater protection policy for Victoria. This policy:
    • defines the current water quality status of both committed and untapped groundwater resources
    • categorises this current groundwater condition into different Beneficial Use segments, based on water quality criteria (see Table) thus providing a benchmark to which protection measures can be applied.
The policy aims to recognise the highest value of the groundwater resource in all parts of the environment and to protect its highest Beneficial Use. This includes both current and potential future uses.

For example, this may be a current Beneficial Use of groundwater for stock supply, irrigation or industrial use, or a potential Beneficial Use for urban supply. Across all segments, the Beneficial Use 'maintenance of ecosystems' must be protected.

To support this policy, DSE has mapped the quality or Beneficial Use of groundwater across the entire State, according to the published EPA Beneficial Use segments.

These maps should assist members of the community, planners, resource managers and government officers when considering groundwater as a resource to be used and protected.
Groundwater Beneficial Use Maps
Maps are presented as a series of four statewide maps, representing the different aquifer systems present throughout Victoria. The maps depict the Beneficial Use segments of the watertable aquifer and the three deeper aquifer systems corresponding to the groundwater basins of Victoria.

More detailed information and large format maps can be downloaded from DSE's Groundwater Victoria website (external link).
Scroll down for Data Limitations
Spray irrigation of potato crop, Bungaree
Spray irrigation of potato crop, Bungaree, south-western Victoria
Photo: Kevan Richards

Table: Protected Beneficial Uses Of The Water Quality Segments (After EPA, 1998)

Beneficial Use
Water Quality Segments (mg/L TDS)
A1
0-500
A2
501-1000
B
1,001-3,500
C
3,501-13,000
D
above 13,000
Potable Water - desirable1
X




Potable Water - acceptable2
X



Potable Mineral Water
X
X
X


Irrigation
X
X
X


Stock Water
X
X
X
X

Industry
X
X
X
X
X
Ecosystem Protection
X
X
X
X
X
Buildings and Structures
X
X
X
X
X

1Potable Water - desirable, refers to high quality drinking water
2Potable Water - acceptable, refers to lesser quality drinking water


Total Dissolved Solids (TDS)
TDS (total dissolved solids) is a measure of the concentration of dissolved solids in a water sample. This is predominantly salts, but other particles, such as algae or non-conductive ions, may also affect this reading.

Electrical Conductivity (EC) of water is a measure of the conductivity of a solution. It therefore provides an indicator of the level of dissolved salts in a water sample.

EC and TDS usually exhibit a strong correlation for a particular type of water. For most Australian inland waters the relationship is:
EC (µS/cm) * 0.6 = TDS (mg/L)



Groundwater Beneficial Use Maps

Water Table Aquifers
The uppermost aquifers are depicted in the watertable map. This displays the Beneficial Use segments (or water quality) for the aquifers closest to natural ground surface. The actual rock type, or lithology, varies with the location of the water table aquifer.

For instance, in the Mornington Peninsula area, the watertable is largely a fractured bedrock aquifer comprised of sandstones, mudstones or granites; while in the Shepparton area, the watertable aquifer is comprised of clays, sands and gravels.

From the map, a number of features can be seen, including:
the generally high Beneficial Use, good quality groundwater in the Eastern Highlands, contrasted with the lower quality groundwater present in the north west of the State.

Upper Tertiary Aquifer System
This map shows the Beneficial Use segments (or water quality) of the sand and gravel aquifers where they are present beneath the watertable. Upper Tertiary Aquifers are present in the Gippsland, Otway, Murray, Port Phillip and Westernport Groundwater Basins. High quality groundwater can be obtained in areas around Nhill, Cobram, Sale, Morwell and the south eastern suburbs of Melbourne. Good quality groundwater is also found in the "Deep Lead" aquifer systems in northern Victoria, particularly in the Ovens, Campaspe and Loddon Valleys.

Middle Tertiary Aquifer System
This map shows the Beneficial Use segments (or water quality) of the sand and gravel aquifers where they are present beneath the watertable and the Upper Tertiary Aquifer System. Middle Tertiary Aquifers are present in the Gippsland, Otway, Murray, Port Phillip and Westernport Groundwater Basins. High quality groundwater can be obtained in areas around Murrayville, Gippsland and parts of south west Victoria.

Lower Tertiary Aquifer System
This map shows the Beneficial Use segments (or water quality) of the sand and gravel aquifers where they are present beneath the watertable and the overlying Tertiary Aquifer Systems. Lower Tertiary Aquifers are present in the Gippsland, Otway, Murray, Port Phillip and Westernport Groundwater Basins.

High yielding, high quality groundwater can be obtained from this aquifer in Gippsland, south west Victoria, around Nhill and Edenhope, and in some "Deep Lead" systems in the Murray Basin.
Data Limitations
  • The maps show broad ranges, and sometimes generalizations have been necessary, either through a lack of data, or due to the natural complexity of groundwater flow systems, or because subtle changes in salinity cannot be shown at this scale.
  • Though a large amount of groundwater data has been used to produce this map series, there has nevertheless been considerable interpretation, simplification and generalization. There is no certainty that the mapped water quality range applies for a given location, or that groundwater is suitable for a given purpose in terms of chemical composition or yield.
  • The nomination of a beneficial use does not necessarily mean that the given use is occurring, as the use to be protected includes potential as well as existing uses.
  • Salinity is a major, though not the sole determinant of groundwater use. Other chemical parameters, aquifer characteristics and yield considerations may also determine the beneficial use.


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