Australian Natural Resources Atlas

Natural Resource Topics

Salinity - Impacts & Costs - Tasmania

Tasmania

Location map

Dryland Salinity Impacts : Tasmania overview

Table: Potential impacts of dryland salinity in Tasmania:
Assets 2000 2020 2050
Agricultural land (ha) 53 000 69 500 93 600
Wetlands of international significance (number) 6 6 6
Wetlands of national significance (number) 44 44 44

The assessments framework used in Tasmania was unable to determine the degree of impact on biodiversity, nor quantify the impacts on infrastructure or water resources.

Impacts on agriculture have been determined by inference, that is, it is assumed that if a land system has any known outbreaks of dryland salinity then all occurrence of that land system across Tasmania also have a potential for developing dryland salinity.

The above table identifies wetlands that occur within land systems that are known to have incidence of dryland salinity. No investigation was undertaken to assess direct impact on wetlands.

What, and how much, agricultural land occurs in areas at high risk from dryland salinity?

There is about:

of which about 53 500 ha were possibly salt affected in 2000. Thus, about three percent (3%) of agricultural land may be salt affected.

Assuming an enterprise mix of 80% extensive and 20% cropping , and that in 1992 the average regional gross margin for this mix was $250, then the total Gross Margin for the same area as that assumed to be salt affected would have been $11 250 000. Assuming salinity continues to rise and decreases production by 40%.

Estimated production losses due to salinity ($)
Annual
increase		 Year
2000 2020 2050
1.5% 5 350 000 6 955 000 9 362 500
3.0% 5 350 000 8 560 000 13 375 000

What biological resources occur in areas of high dryland salinity risk?

Biodiversity

The Flinders and Northern Midlands BioRegions are potentially the most affected.

The following occur in land systems containing areas of salinity and are considered to be of medium to high risk of rising salinity:

Wetlands: 132
National significance 44
International significance 6
Reserves 25
Vegetation - non forest 12
Vegetation - forest 12
Flora species 44
Fauna species 17

For more detail please refer to the Tasmania Dryland Salinity Assessment 2000 report.

What water resources occur in areas of high dryland salinity risk?

Water Quality

The only quantifiable impact is that on water in the Coal River in the South East Irrigation Scheme which is at times at Electrical Conductivity (EC) threshold levels which make water risky to use for irrigation.

For more detail please refer to the Tasmania Dryland Salinity Assessment 2000 report.

What infrastructure occurs in areas of high dryland salinity risk?

Ten Local Government Areas contain 95 per cent of the land thought to be salt affected, and four contain 80 per cent.

These four include 6 000km of roads which cost $19 000 000 annually to maintain including associated bridges.

A very small proportion of these may be damaged by dryland salinity as there is no evidence at present and little expertise to estimate risk.

There is some evidence of damage to four golf courses which is being remediated at minimal cost, and to some sports ovals which has not been addressed. No assessments have been made on adjacent holdings.

Further information

Tasmanian landsystems containing areas of salinity in 2000

Link to Map maker to make a map using this information.

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