state of the environment report - land resources · 4 land resources the rate of dryland salinity...

STATE OF THE ENVIRONMENT REPORT 2003 81

1 Electrical Conductivity units are a common measure ofsalinity in the River Murray. EC units are not equivalent toother measures of salinity such as milligrams per litre orparts per million. To convert a measure of salinityexpressed in EC units to milligrams per litre or parts permillion (ppm) the EC measure must be multiplied by afactor of 1.82. For example, 800 EC units is equal to 1456ppm or 1456 milligrams per litre.

Dryland SalinityTrends

• Extent of dryland salinity in South Australia:

STABLE NOW but INCREASING in the

long term.

Goal

• To protect land resources from salinisation,minimising the area of land affected by drylandsalinity beyond the current 326,000 hectares;

• To protect the quality of River Murray water,keeping salinity at or below the guideline level of800 Electrical Conductivity1 (EC) units for drinkingwater at Morgan 95% of the time;

• To protect our natural environment and biodiversityresources, keeping salinity impacts to currentlevels or, where possible, reducing them;

• To protect our economic resource base, developingproductive uses for irreversibly saline land and water.

South Australian Dryland Salinity Strategy(Government of South Australia, 2001)

What are the issues?

Salt is a natural feature of the Australian landscape.Until European settlement this salt remained deep inthe soil, below the root zone of native vegetation. Thisdeep-rooted native vegetation tended to use most ofthe rainfall that it received; little rainfall percolateddown to the underlying groundwater.

However, since settlement, large areas of nativevegetation have been cleared for agriculture andreplaced with shallow-rooted annual crops andpastures which have significantly disrupted the naturalbalance. Shallow-rooted crops and pastures do not useas much rainfall, so excess rainfall tends to seep downthrough the soil profile.

This excess water is recharging the underlyinggroundwater systems at a much faster rate than wasoccurring under natural conditions and consequentlygroundwater levels are rising. When they rise towithin a metre or two of the ground surface, thewater is lost by evaporation, leaving the salt behind todegrade the landscape.

While in the short term the extent of drylandsalinity in South Australia is relatively stable, theprocesses set in train many years ago as aconsequence of vegetation clearance mean that we arelikely to see further increases in the area affected,particularly in the regions adjacent to the River Murray.It is predicted that without on-ground action, such asrevegetation and drainage to intercept risinggroundwater, groundwater will slowly drain towards theRiver, significantly increasing its salinity in the future.

Besides environmental impacts such as land andhabitat degradation, dryland salinity has significanteconomic and social implications as well. Thisincludes the high costs associated with lostagricultural production, salt damage to roads andbuildings, and the accompanying impact this canhave on rural communities.

The off-site impact associated with drylandsalinity, the high costs of its management and longtime frame to see results make dryland salinity achallenging resource management issue forGovernment and landholders alike. Dryland salinity is aproblem that can not be fully solved; this must berecognised and proactive action taken to at least slow

Samphire and sea barley grassindicating inland dryland salinity

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the rate of dryland salinity and reduce theenvironmental, economic and social consequences.

See also chapters on Soil Erosion and Acidity;Water Quality; and Land Use.

Environmental indicators

CONDITION INDICATOR

• Area of land affected by dryland salinity(reported on in the State of the EnvironmentReport 1998)

Reports on the area currently affected bydryland salinity.

PRESSURE INDICATOR

• Area threatened by dryland salinity(reported on in the State of the EnvironmentReport 1998)

Identifies the area at risk from dryland salinity.

Area affected by dryland salinity

What is the current situation?

CONDITION INDICATOR: Area of landaffected by dryland salinity

Dryland salinity occurs to some extent in all the majoragricultural districts of the State, and is one of themost significant forms of land degradation.

Current estimates (NLWRA, 2001) put the area ofSouth Australia affected by dryland salinity atapproximately 326,000 hectares. While this estimateappears large it is, in fact, only 2.2% of the totalagricultural area of the State. Dryland salinity istherefore probably not as significant a problem in SouthAustralia as it is in some of the other States, notablyVictoria and Western Australia. The estimate of 326,000hectares is considerably less than reported in the Stateof the Environment Report 1998 (391,900 hectares) dueto the increased accuracy of mapping techniques.

FindingsMaking progressThe inception of the Natural Heritage Trust (NHT) has resulted in a more regionalised and strategic approach todryland salinity. Salinity planning and management is now relatively well advanced in the Murray-DarlingBasin. The Upper South East drainage scheme represents an integrated approach to salinity management.

South Australia was the first jurisdiction to strike a bilateral agreement with the Commonwealth toimplement the National Action Plan (NAP) for Salinity and Water Quality. This will build on and extend workalready undertaken through the NHT. The South Australian Dryland Salinity Strategy will provide an importantaction-oriented document that will underpin and guide our efforts to deal with the issue.

Considerable progress has been made in identifying and mapping the areas affected by dryland salinity,providing quality information upon which to base management actions.

Attention requiredWhile the extent of dryland salinity has temporarily stabilised (most likely due to a series of dry years) in thelong term the extent of dryland salinity is predicted to increase by 60% in 50 years’ time, unless significanton-ground action such as drainage is undertaken.

Dryland salinity is affecting water quality, natural ecosystems and biodiversity, and is causing land andwetland degradation in key areas around the State, including several conservation parks. Regional economicand social consequences are also significant.

Over the next few decades groundwater levels in the areas adjacent to the River Murray (Murray Mallee)are predicted to rise due to the consequences of historical land management practices. Without on-groundintervention, this will increase salinity in the River Murray, making Adelaide’s water supplies too salty to drink40% of the time on an annual basis by 2050.

Water ‘leakage’ from annual crops and pastures is the major cause of dryland salinity problems. Whilemarket forces continue to favour these agricultural systems, salinity will persist and increase.

What more should we be doing?The Environment Protection Authority recommends that:4.1 Ongoing and adequate funding and technical support for coordinated on-ground works, beyond the

lifespan of the National Action Plan and Natural Heritage Trust, is provided. This should include provisionfor long term monitoring and evaluation.

4.2 The needs of regional dryland salinity planning and investment projects and current agronomic,hydrological and biological programs are extended and maintained.

4.3 There is more investment in research, by both the public and private sectors, that will lead to thedevelopment of technologies that will provide profitable and sustainable options for living with salt andmanaging salt affected land.

4.4 Research and development by the public and private sectors is extended to investigate new farming,forestry and land use systems that are commercially viable and will reduce recharge, particularly in lowerrainfall areas (250–450 millimetres) such as the Murray Mallee.

KEY FACTS

• The area of land affected by

dryland salinity in South

Australia will increase 30% by

2020 and as much as 60% by

2050 unless significant action

is taken.

• Important natural ecosystems

are increasingly under threat

from rising saline groundwater.


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Figure 4.1: Regional estimates of currentareas affected by dryland salinity – 2000

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The Upper South East is the most significantlyaffected region in South Australia (Map 4.1). It isestimated that around 250,000 hectares are currentlyaffected by dryland salinity in the Upper South East,more than twice the area affected across the rest ofthe State (Figure 4.1). The nature of the region’sunderlying groundwater and geological systems andnaturally low-lying land combined with historicbroadscale native vegetation clearance havecontributed to this situation.

What is likely to happen in the future?

PRESSURE INDICATOR: Areathreatened by dryland salinity

Current estimates indicate that if no further action istaken, a total of 521,000 hectares of land will beaffected by dryland salinity in South Australia (Table4.1) before a natural balance is reached – a legacy ofpast vegetation clearance and agriculturaldevelopment. This is expected to occur by 2050 andwill represent a 60% increase over current levels.

Without intervention, such as drainage, thegreatest increases in dryland salinity are predicted to

occur along the Coorong District Coastal Plain, with a72% increase in area affected by 2050, and the UpperSouth East, with a 63% increase in area affected by2050 (Figure 4.2).

What impact will increasing drylandsalinity have?

Some of the environmental, social and economic effectsassociated with dryland salinity are listed below toillustrate the broader implications for sustainability.Impact on biodiversity. Salinity is directly contributingtowards species extinctions and a decline inecosystem health, and is a critical issue for biodiversityin Australia.

In South Australia, low-lying remnant nativevegetation, seasonal watercourses and wetlands are allpotentially at risk from rising groundwater (Table 4.2).

Several significant National Parks and WildlifeReserves have been identified as having a highpotential for biodiversity degradation (Table 4.3). Thesesupport areas native vegetation that is of highconservation value and include Messent and GumLagoon Conservation Parks in the Upper South Eastand Murray’s Lagoon on Kangaroo Island.

Table 4.3: Significant habitat affected by dryland salinity

Region Habitat Conservation Parks

Upper South East Seasonal wetlands, watercourses Messent and Gum Lagoon

Coorong District Tea-tree shrublands, native grasslands

Lower Eyre Peninsula Native vegetation, seasonal swamps Hincks and Bascombe Well

Kangaroo Island Sedgeland, tea-tree ecosystems Murray’s Lagoon

Source: Barnett, 2000

Table 4.1: Estimates of areas at risk from rising groundwater by 2020 and 2050

Region 2000 2020 % increase from 2000 2050 % increase from 2000

Upper South East 250,500 324,000 29 409,500 63

Coorong Coastal Plain 19,800 29,600 50 34,000 72

Eyre Peninsula 20,400 24,000 18 27,000 32

Kangaroo Island 5600 6500 16 8000 43

Mid North 14,800 18,000 22 21,000 42

Yorke Peninsula 13,900 17,500 26 20,000 44

Mount Lofty Ranges 1200 1400 16 1500 25

Total 326,000 421,000 30 521,000 60

Source: NLWRA, 2001

Table 4.2: Summary of threats to biodiversity in the agricultural regions of South Australia

Impact Current 2020 2050

Remnant vegetation (hectares) 18,000 22,000 25,000

Rivers ephemeral (kilometres) 160 190 210

Wetlands (hectares) 45,000 52,000 57,000

Wetlands of National Significance 4 4 4

Source: Barnett, 2000

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Figure 4.2: Regional estimates ofcurrent and predicted areas affectedby dryland salinity – 2000, 2020 & 2050

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DRYLAND SALINITY

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Whyalla

Renmark

Adelaide

Port Pirie

Port Lincoln

Port Augusta

Mount Gambier

Primary Salinity

Secondary Salinity

Lake/Lagoon

Major Road

Impact on rural communities. Rural communities aremost at risk from dryland salinity. Landowners whohave dryland salinity problems can face economiclosses and, in the most severe cases, some propertiesmay ultimately become non-viable.

By 2050 it is expected that, without furtheraction, rising groundwater will have a particularlysignificant impact on the townships and environs ofTintinara and Coomandook, including infrastructureand land degradation.Impact on drinking water. Predicted increases in thesalinity of River Murray water, which will affectAdelaide’s drinking water supplies, are likely to costthe community an extra $7 million per year by 2050(Table 4.4).Losses in agricultural production. The loss inagricultural production as a direct result of drylandsalinity has been estimated to be $26.1 million (Table4.4). It should be noted, however, that this representsonly between one and two per cent of the State-widegross margin from production on all agricultural land.This loss is predicted to increase to $42 million by2050 (Barnett, 2000).

These production losses may occur as a result ofreduced productivity, the need to switch to lessprofitable enterprises, or, in severe cases, the inabilityto continue farming a particular area.Damage to infrastructure. Dryland salinity can alsocause damage to built infrastructure such as roads,railway lines and buildings (Table 4.4). Maintenancecosts are increased and the capital value of assets isreduced. Railways, vehicles, plant and machineryoperating in damp, saline conditions can be damagedprematurely by rusting and corrosion. The lifeexpectancy of sealed roads is reduced and unsealedroads require maintenance more often.

What are we doing about it?

Dryland salinity is a priority issue for both Governmentand the community and will be one of several keyissues addressed on a regional basis via the National

Action Plan for Salinity and Water Quality andregional Natural Resource Management (NRM)

groups. To address the issue effectively and for thelong term will require a significant funding

Fairview drain near Woolumpool in theUpper South East of South AustraliaPhoto: Rural Solutions SA

Map 4.1: The estimated area affected by dryland salinity in South Australia – 2000Note: Primary salinity refers to areas thought to have been saline before European settlement; secondary salinity refers to areas that havebeen salinised due to shallow groundwater.

SOURCE: DWLBC


The Tungkillo Landcare site before(1989) and after (2002) revegetationto intercept groundwater rechargePhotos: Bruce Munday

DRYLAND SALINITY

KEY FACTS

• It is predicted that, without

intervention, Adelaide’s water

will be too salty to drink two

days out of five by 2050.

• Current estimated costs

associated with dryland

salinity are $44 million –

predicted to increase to

$81 million by 2050 if action

is not taken.

Table 4.4: Interim total costs of dryland salinity ($ million/year) in South Australia

Impacts 2000 2020 2050

Losses in agricultural production 26.1 34.0 42.0

Road and rail maintenance 17.1 23.5 30.5

Building maintenance 1.2 1.4 1.9

Costs of increase in River Murray salinity 0 3.1 7.0

Total cost 44.4 62.0 81.4

Source: Barnett, 2000; Barnett et. al., 2002

commitment by the State Government beyond thecurrent lifespan of the NAP and NHT.

One of the Government’s major strategicinitiatives is the South Australian Dryland Salinity

Strategy, developed in 2001. While it is too early tojudge the effectiveness of the Strategy, its focus ison-ground action, monitoring and, importantly,reporting on progress. The Strategy places a strongemphasis on a partnership approach betweenGovernment, industry and the community, via regionalNRM groups.

The Upper South East Dryland Salinity and

Flood Management Program was initiated in theearly 1990s in an effort to address some of the worstdryland salinity problems in the State and nation. Todate, the South Australian Government, in partnershipwith the Commonwealth and local communities, hasinvested in on-ground works including:• construction of over 255 kilometres of drainage

channels;• fencing of 6560 hectares of remnant native

vegetation;• revegetation of 1250 hectares;• protection of 2650 hectares of wetlands via the

Wetlands Waterlink project;• establishment of salt tolerant pasture on more than

60% of salt-affected land.In order to finalise the Program, activities over

the last couple of years have included seekingenvironmental approval of a Notice of Intent for stage

Digging Fairview DrainPhoto: Rural Solutions SA

3 (the central catchment), passage of the Upper

South East Dryland Salinity and Flood

Management Act 2002, and recent endorsement

of an additional funding package. The Act providesthe legal framework necessary to allow theconstruction of around 410 kilometres of additionaldrains. Further action involves improved protectionand conservation of native vegetation and integratedwetland management.

There continues to be considerable effort andcommitment on behalf of community groups toaddress local dryland salinity concerns. The Coorong

and Districts Local Action Planning Group has ledthe implementation of significant on-ground works toincrease rainfall utilisation and reduce salinity threats.Their approach has become a national model for localcommunity groups. Similar projects are emerging inother parts of the State (see Case Study).

South Australia is also at the forefront of research

and development initiatives in dryland salinity. Aspart of the NAP, a $1.5 million airborne geophysicssurvey was completed in January 2002. The surveywill provide information on the extent of salt-affectedsoil up to 100 metres below the surface in key regionsof the State (Riverland, South East and Mid North).This will be used to help determine which areas of theState should be targeted for remedial action.

For more information on programs andinitiatives see the State of the Environment 2003Supplementary Report.

CASE STUDY – Tungkillo Landcare GroupIn 1998 the Tungkillo Landcare Group established a project to rehabilitate land that was significantly affectedby dryland salinity. The local community was involved in on-ground actions to intercept saline groundwater,primarily through revegetating affected areas. This whole-of-community involvement was one of the keycomponents that ensured the success of the project.

The original aim of the project was to revegetate 120 hectares of degraded, salt affected land. At the endof the project in 2002, 132 hectares of native vegetation had been successfully established. A network ofsites to monitor groundwater levels has also been established and tests will be conducted on an ongoingbasis to assess the status of groundwater levels.

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References

Barnett, S.R. (2000). Extent and Impacts of DrylandSalinity in South Australia. Report for the National Landand Water Resources Audit. Adelaide, Department forWater Resources.

Barnett, S., Yan, W., Watkins, N.L., Woods, J.A. andHyde, K.A. (2002). Murray-Darling Basin Salinity Audit –Groundwater modelling to predict future dryland saltloads to the River Murray in South Australia. SouthAustralia. Department for Water Resources. ReportDWR 2001/017.

Government of South Australia (2001). South AustralianDryland Salinity Strategy. Prepared by the PrimaryIndustries and Resources SA for the Soil ConservationCouncil of South Australia. Adelaide, PIRSA.

National Land and Water Resources Audit (NLWRA)(2001). Australian Dryland Salinity Assessment 2000:extent, impacts, processes, monitoring andmanagement options. National Land and WaterResources Audit on behalf of the Commonwealthof Australia.

Further information

Cooperative Research Centre for Plant-BasedManagement of Dryland Salinitywww1.crcsalinity.com/index.asp

National Land and Water Resources Auditwww.nlwra.gov.au/atlas

Salt Control SAwww.saltcontrolsa.com


Land UseTrends

• Residential land use: INCREASING in semi-

urban regions with resulting pressures on

biodiversity, water resources and

agricultural land.

• Change from relatively low intensity land

use (such as grazing) to higher intensity

uses (such as viticulture and plantation

forestry): INCREASING in some regions.

• Awareness and acknowledgement of site

contamination: INCREASING, since the

State of the Environment Report 1998 there

have been significant advances in our

knowledge and understanding of site

contamination.

Goal

Land use decision-making processes and land useallocations at all levels of Government meet the overallgoal of ecologically sustainable development and arebased on a consideration of all land values and uses,while avoiding fragmentation, duplication, conflict andunnecessary delays.National Strategy for Ecological SustainableDevelopment, 1992


The major land uses in South Australia are livestockgrazing on native pastures (46% of the State1),conservation and natural environments (42% of theState), and dryland agriculture, which includes thegrowing of crops and the grazing of livestock onmodified pastures (10% of the State). Land use inareas closer to towns and settlements is generallymore intensive, involving greater modification to thenatural environment. Generally, the more intensivethe land use, the greater the potential impact onthe environment.

If a particular land use is not compatible with thenature of the land – its soils, water and vegetation –and if ongoing management of the land does not takeinto consideration these factors in the long term,significant environmental, social and economicproblems can occur.

While at the State level land use tends to remainrelatively stable due to the limitations imposed byrainfall and soil type, at the smaller, regional scale landuse can show distinctive changes over time. Someland use changes can have a potentially significantimpact on the environment, especially if it involves achange from a relatively low intensity use to a higherintensity use, or one involving a more sensitive use

(although not all changes in land use impactdetrimentally on the environment).

Over the last decade for example, the areaoccupied by vineyards in South Australia has grownconsiderably, increasing by 150% between 1994 and2002. The area of commercial plantation forestry isalso set to increase, particularly in the lower SouthEast and the Mount Lofty Ranges. If managedinappropriately, these land uses can place greaterpressure on water resources, biodiversity and soils incomparison, say, to grazing, a land use which theseactivities often replace. Similarly, increasing residentialdevelopment in the Mount Lofty Ranges is placingadditional pressure on the environmentally sensitiveMount Lofty Ranges Watershed and replacing some ofour most highly productive agricultural land, whichprovides great economic benefit to the State (albeittown growth in the Mount Lofty Ranges Watershed atleast is restricted by urban containment boundaries).

Problems can also occur if new land uses are notcompatible with past land uses. Building houses onland that was once used for industrial purposes, suchas a foundry or tannery for example, can lead toproblems associated with soil and water pollution andhave implications for human health and well being.The use of agricultural pesticides can also cause sitecontamination on a broader, more diffuse scale. Ourlow level of pesticide application rates by worldstandards means that this is not likely to be generally asignificant problem in Australia or South Australia,however, we currently do not have enough informationon pesticide types in use, where the use is occurringor at what application rates to be certain.

See also chapters on Soil Erosion and Acidity;Population and Urban Form; Water Quality;Dryland Salinity; and Health of the Marine and

Coastal Environment.

1 Land use cover has not yet been estimated for the wholeState (see Map 4.2). These figures reflect values based onthe current mapping coverage.

LAND USE

Piccadilly ValleyPhoto: Kym Nicolson

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CONDITION INDICATOR

• Current land use in South Australia(reported on in the State of the EnvironmentReport 1998)

This provides an indication of current land usesand a baseline against which to assess changeover time.

PRESSURE INDICATORS

• Land use change (reported on in the Stateof the Environment Report 1998)

Land use change is a direct measure of potentialpressure on the environment.• Site contamination (reported on in the State

of the Environment Report 1998)Site contamination provides an indication ofpotential pressure on water, soil, biodiversityand human health.

FindingsMaking progressA Planning Strategy for Adelaide’s outer metropolitan areas is being developed. The Planning Strategy for thisarea – the Inner Region Planning Strategy (encompassing Fleurieu Peninsula, Barossa, Central Hills, NorthernAdelaide Plains) – will place priority on protecting the Mount Lofty Ranges Watershed, protecting biodiversitycorridors and productive rural land, and minimising conflicts between land use and the environment.

The Planning Strategy for Metropolitan Adelaide introduces the concept of an ‘urban containmentboundary’ which aims to protect viable agricultural land and clearly divide residential land from rural land uses.The Planning Strategy for the Inner Region will also include the concept of ‘urban containment boundaries’ forsome rural towns.

Since the development of the National Environment Protection (Assessment of Site Contamination)Measure in 1999 we now have a nationally consistent approach to assessing site contamination. This and otherinitiatives have influenced the manner in which the Environment Protection Authority records and reports onissues associated with site contamination.

There is an increasing awareness of environmental issues in the wine, forestry, mining, dairy and otherindustries and many are developing Environmental Management Systems. This is resulting in improved landmanagement practices.

A Code of Practice for the use of pesticides in South Australia is to be released in 2003/04. This willbe linked with the Environment Protection (Water Quality) Policy which will ensure compliance withregulatory requirements.

The State Government’s plan for rehabilitation of the lower Murray irrigated dairy pastures should see animprovement in land management practices for this region.

Attention requiredCurrent planning and development controls do not routinely take into account the cumulative impact of landuse change on natural resources at regional or catchment levels.

The Mount Lofty Ranges are undergoing rapid urbanisation, which is leading to concerns about thesustainability of the region’s natural resources and the potential loss of valuable, highly productive agriculturalland. The introduction of urban containment boundaries should go some way to addressing this issue.

Site contamination continues to cause environmental and human health concerns. Recent contaminationissues (such as at Birkenhead and the Port Stanvac Oil Refinery) have placed a high priority on amendingcurrent legislation to ensure that site contamination is adequately addressed and managed in South Australia.

What more should we be doing?The Environment Protection Authority recommends that:4.5 A legislative and policy framework is developed that integrates natural resource management with the

land use planning system. This should include the incorporation of land capability and suitabilityassessments into planning and development controls at all levels, and consider the cumulative impact ofland use change.

4.6 The environmental impact assessment process and its administration is reviewed as a matter of priority.4.7 If a development proposal involves a significant change in land use this should trigger a strategic

assessment of that development proposal in relation to its potential environmental, social andeconomic impacts.

4.8 All proposed major developments in the Mount Lofty Ranges Watershed that have the potential tocause significant environmental harm should be subject to an environmental risk assessment beforereceiving approval.

4.9 High priority is given for legislative reform to ensure that site contamination is adequately recognised,considered and addressed.



CONDITION INDICATOR: Current landuse in South Australia

The State of the Environment Report 1998 indicatedthat information on land use was either very old orincomplete, making it difficult to identify trends. Sincethen the Land Use and Management Mapping ofSouth Australia Program, conducted by theDepartment of Water, Land and BiodiversityConservation, has developed land use maps for mostagricultural regions2 of the State using a GeographicInformation System. This provides valuable informationto assist in the identification and management of awide range of natural resource management issues.

The information can also be used to analyse landuse across the State. Map 4.2 shows major land usesin South Australia.3 This indicates that land use inSouth Australia is dominated by primary productionand conservation/natural environments.

Conservation and natural environmentsOf the land that has been mapped, conservation andnatural environments covers around 40,300,801hectares or 42% of the State. The majority of this landuse occurs in the Far North.

This broad land use category is subject to arelatively low level of human impact. Specific landuses include National Parks and Wildlife (NPW)Reserves, Aboriginal lands (e.g. the Pitjantjatjara

Map 4.2: Major land use across South AustraliaBased on Australian Land Use and Management (ALUM) version 4 Classifications

SOURCE: DWLBC

lands), protected landscapes, defence and naturereserves. National Parks and Wildlife Reserves occupyaround 53% of this broad land use category (see alsochapter on Native Vegetation).

It is important to recognise the conservation ofnatural environments as a legitimate land use. Otherland uses can impinge on the effectiveness ofconservation reserves to maintain ecologicalprocesses and conserve biodiversity. In particular,conservation areas adjacent to agricultural andresidential land uses can be affected by pressure fromweeds, feral animals and farm chemicals. The potentialimpact of other land uses on conservation areas islowest in the Far North of the State, where such areastend to be large and other land uses of relatively lowintensity (see following section).

Production from relatively naturalenvironmentsThis broad land use category occupies the largestproportion of South Australia at around 46%(43,691,966 hectares) of all land that has beenmapped. Land in this category is generally subject torelatively low levels of human impact.

2 See the State of the Environment 2003 SupplementaryReport for regional land use maps.3 At the time of writing land use maps were still beingprepared for a portion of the Murray-Darling Basin andthe region immediately north of Morgan. A land use mapis not available for the metropolitan area.

LAND USE

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The major land use is grazing on native pasturesin the Rangelands region. Sheep grazing dominatessouth of the dingo fence and cattle grazing north of thedingo fence.

Over-stocking and grazing by rabbits in the pasthas led to the degradation of vegetation and soilerosion in many regions. Recovery in some areas isslow, despite de-stocking due to a series of poorseasons. The establishment of a detailed leaseassessment program in 1989 under the Pastoral LandManagement and Conservation Act 1989 requiresregular assessments of land condition (including nativevegetation) and estimates of its ability to supportstock. This has helped to improve land management inthe region over the last decade or so (see also chapteron Native Vegetation).

Production from dryland agricultureand plantationsThis broad land use occupies around 10% of the State(10,005,366 hectares) and is based on dryland farmingsystems, where the majority of native vegetation hasbeen cleared. Specific land uses include stock grazing,cropping, plantation forestry and a wide range ofhorticultural production. South Australia has 33% ofthe nation’s barley growing area and 15% of thenation’s wheat growing area (ABS, 2003).

Agricultural land uses have significantly changedAustralia’s and South Australia’s landscape. However,land and crop management practices are improving inmany regions as a consequence of farmer education.Soil loss associated with agricultural land use in SouthAustralia for example has reduced considerably overthe last 50 years and continues to decline directly asthe result of better land management practices (seechapter on Soil Erosion and Acidity).

Forestry plantations occupy around81,500 hectares of land in South Australia. Themajority of this (82%) occurs in the ‘Green Triangle’around Mount Gambier. The majority of the restoccurs in the Mount Lofty Ranges (12%) and in theMid North (4.5%). Most forestry plantations in SouthAustralia consist of softwood (mostly pinus radiata),however, there is an increasing trend towards theestablishment of hardwood plantations, mostly ofeucalyptus species. This reflects the higher economicreturns from hardwood, which are better suited toAustralian conditions (Hamblin, 2001). Forestry SAalso manages 24,000 hectares of native forestreserves. These have multiple-use objectivesincluding recreation and conservation.

There are concerns that growth of the forestryindustry, particularly in the lower South East,Mount Lofty Ranges and the Middle River catchmenton Kangaroo Island, could have a potential impacton regional water resources (see PRESSURE

INDICATOR: Production from dryland agriculture

and plantations).Forestry management practices have improved

significantly over the last 10 years (see What are we

doing about it?).

Irrigated agriculture and plantationsThis land use occupies around 0.2% of the State(222,307 hectares) and consists of irrigatedhorticulture, viticulture and pastures. These uses can

place greater pressures on the environment than lessintensive agricultural uses such as cropping andgrazing. In particular, irrigated crops can place greaterpressures on surface and groundwater resources dueto higher water demand.

There are around 4850 hectares of flood

irrigated dairy pastures along the lower River Murraystretching approximately 80 kilometres betweenMannum and Wellington. The drainage of irrigationwater from the dairy pastures has been cause forconcern over a number of years, particularly in termsof implications for water quality in the River Murray.Monitoring by the EPA indicates that the levels offaecal bacteria exceed national guidelines for drinkingwater and recreational use at Tailem Bend, due largelyto pollution from irrigated dairy pastures (see chapteron Water Quality). A major program to rehabilitate thelower Murray dairy pastures was announced by theState Government in 2003 (see What are we doing

about it?).The establishment of vines across the State is an

increasing trend, an issue also identified in the State ofthe Environment Report 1998. This is largely beingdriven by the buoyant wine industry. As an example,the area planted to vines in the Riverland regionincreased by 18% between 1988 and 2001 and, in theMount Lofty Ranges, the area occupied by vinesincreased by over 100% between 1993 and 1999.South Australia has 42% of the nation’s grapevines byarea (ABS, 2003). In 2002 this amounted to around66,456 hectares (www.phylloxera.com.au).

The environmental management of viticulture hasimproved significantly over the last few years (seeWhat are we doing about it?).

Intensive usesIntensive land uses occupy 1.3% of land in SouthAustralia. These uses involve high levels ofinterference with natural processes and are generallyassociated with human settlements. Specific landuses include urban and rural residential development,mining, transport and communication, manufacturingand waste treatment and disposal.

South Australia is a highly urbanised state, with73% of the population living in Adelaide (ABS, 2003). Incomparison, only 46% of Queenslanders live inBrisbane because of the more regionalised nature ofsettlement in that State.

The Adelaide metropolitan area continues tospread into the Mount Lofty Ranges. This expansion isgenerally (but not always) into areas that werepreviously used for grazing, cropping or horticulture.This is having a number of adverse effects includingthe loss of biodiversity, decreasing water quality andthe loss of prime agricultural land. Residential living isalso increasing significantly along the South Australiancoastline as a greater number of people seek a morerelaxing lifestyle in closer proximity to the beach. Thisissue is considered in more detail in the chapter onHealth of the Marine and Coastal Environment.

Mining occupies only a very small proportion ofthe State. Major products include copper (which has thehighest value of any mined commodity in the State),gold, iron, gypsum, granite, oil, gas, coal, uranium andopals. These are all non-renewable resources.

Blue Gum plantationPhoto: Forestry SA

Vineyard irrigationPhoto: Arthur Mostead, courtesyMurray-Darling Basin Commission


Recent changes in land use and land accessclassifications have reduced mining access to someareas of the State (for example in the GammonRanges National Park). However, this is offset bySouth Australia’s early (1988), innovative and large-scale progressive refinement of multiple land use aspracticed in the State’s extensive 10,601,000 squarekilometre network of Regional Reserves, whichprovide conservation protection to sensitive areas,while allowing resource exploration and developmentunder strict management control. The recentannouncement by the Premier of a protective regimefor the Ramsar listed (International WetlandConvention) Coongie Lakes in the State’s Far North, aninitiative of the conservation movement, thepetroleum industry and the Government, is a clearindication of the realistic potential for a balancedapproach to both conservation and development inSouth Australia.

The impact on the environment associated withmining has been significantly reduced in recent years.This has been driven largely from within the industry,which is now considered one of the mostenvironmentally aware land users of any sector inAustralia (Hamblin, 2001).

PRESSURE INDICATOR: Land usechange

Broad land use categories across the State tend toremain relatively stable over time; however, there aresmall-scale changes evident in some regions and forsome particular types of land use that show distinctivetrends. Land use change issues in South Australia forwhich there is data available include:• increasing residential development in the Mount

Lofty Ranges;• the increase in area planted to grape vines;• impact of plantation forest land use on

water resources.The issues associated with these changes in land

use are discussed in more detail in the following sections.

Increasing residential development inthe Mount Lofty RangesPrevious State of the Environment Reports forSouth Australia (1993 and 1998) have highlighted theexpansion of Adelaide into the Mount Lofty Ranges as amajor pressure on rural and semi-rural land uses in theregion. This issue continues to cause concern in 2003.

Analysis of land use in the region in 1993 (Map4.3) and 1999 (Map 4.4) shows that during this periodthere was a 105% increase in rural residential living

from 9029 hectares in 1993 to 18,536 hectares in1999. During this time there was a decline in the areaoccupied by field crops (declined by 61%) andvegetables (declined by 62%).

The Environment Protection Authority (EPA) hasexpressed concerns about the environmental impactof increasing housing developments in the MountLofty Ranges particularly in the Mount Lofty RangesWatershed4.

If all vacant allotments in the region were to bebuilt upon, it would mean a 25% increase in thenumber of houses in this environmentally sensitiveregion (Watershed Protection Office pers. comm.).

There are concerns that insensitive housingdevelopments will lead to the further loss of nativevegetation, exacerbation of bushfire risks to housingand human life, and increasing degradation ofwater quality.

A development risk assessment study conductedby the EPA in early 2003 in the Crafers, Stirling,Aldgate and Bridgewater area found that 22% of the350 vacant allotments inspected should not bedeveloped for housing purposes due to significant siteconstraints. These included land close towatercourses, land covered in native vegetation andland that is prone to flooding and/or water logging.

Another concern associated with increasingresidential development in the Mount Lofty Ranges isthe encroachment of housing onto land that is ideallysuited to primary production. Currently, DevelopmentPlans do not differentiate rural areas on the basis oftheir importance for primary industry.

The region has significant advantages andopportunities for some agricultural enterprisesincluding access to reclaimed water, proximity tolabour, markets and freight facilities and, for somehorticultural crops, favourable climatic and soilconditions not found elsewhere in South Australia. Thefurther loss of these areas to residential developmentpotentially represents the loss of a valuable resourceto the State.

Irrigated agriculture and plantationsOne of the most significant changes in land use overthe past decade has been an increase in the area

occupied by vineyards, often with an associated lossof grazing or cropping land (although in the Riverlandregion vines are replacing citrus and stonefruit crops).

The total area of vineyards in South Australiaincreased by 150% between 1994 and 2002, from26,584 hectares to 66,456 hectares(www.phylloxera.com.au). South Australia has 40% ofthe nation’s vineyard area (ABS, 2003).

Figure 4.3 shows the total area planted tovineyards in the State’s major established grape-growing districts before 2000 and in 2002. All areashave shown growth. The Adelaide Hills shows thehighest rate of growth, with an increase of 38% in thearea planted.

There has also been a significant increase in thearea of grapevines planted in relatively new grapegrowing regions. Of all grape-growing areas in theState, these have shown the highest rate of growthover recent years. For example, the area of vines inthe Fleurieu Peninsula region (outside of McLaren Valeand Langhorne Creek) increased by 61% between2000 and 2002 (from 630 hectares to 1032 hectares)and the area of vines planted in Wrattonbully on theLimestone Coast (excluding Padthaway and theCoonawarra) increased by 70% between 2000 and 2002(Pylloxera and Grape Industry Board, pers. comm.).

Where viticulture is replacing dryland farmingactivities, this development may place strong

4 The Mount Lofty Ranges Watershed is a managementarea regulated under the Environment Protection Act 1993to protect water supplies to metropolitan Adelaide.

LAND USE

Ade

laid

e P

lain

s

Note: Riverland includes Renmark, Berri,Barmera and Waikerie.

SOURCE: PHYLLOXERA & GRAPE INDUSTRY BOARDOF SOUTH AUSTRALIA (www.phylloxera.com.au)

Figure 4.3: The area of vineyards inmajor grape-growing regions ofSouth Australia – pre–2000 & 2002

Hect

ares

(000

’s)

Pre–2000

2002

0

2

4

6

8

10

12

14

16

18

20

Ade

laid

e H

ills

McL

aren

Val

e

Lang

horn

e C

reek

Bar

ossa

/Ede

n V

alle

y

Riv

erla

nd

Cla

re

Coo

naw

arra

Pad

thaw

ay

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4 Land Resources

Map 4.3 Land use in the Mount Lofty Ranges – 1993SOURCE: DWLBC

GoolwaGoolwa

Cape JervisCape Jervis

StrathalbynStrathalbyn

Mount BarkerMount Barker

Land Use Classes, 1993

Accommodation

Rural Residential Accommodation

Landscape/Seascape/Consvn Rec Area

Outdoor Recreational Area (Sports)

Meat Product Manufacturing

Wine Manufacturing

Livestock (Grazing)

Dairy Cattle

Horses

Field Crops

Horticulture

Horticulture − Berry Fruit

Horticulture − Row Crops (Vegetables)

Vine Fruit

Forest Plantation

Aquaculture

Mining or Extractive Industries

Protected Area

Native Veg

Water Storage (Reservoir/Dam/Water Tower/Tank)

Sewage

Cemetery

Govt Admin/Defence Services

Marina

Rubbish Dump

Major Road


LAND USE

Map 4.4: Land use in the Mount Lofty Ranges – 1999SOURCE: DWLBC

GoolwaGoolwa

Cape JervisCape Jervis

StrathalbynStrathalbyn

Mount BarkerMount Barker

Land Use Classes, 1999

Accommodation

Rural Residential Accommodation

Landscape/Seascape/Consvn Rec Area

Outdoor Recreational Area (Sports)

Meat Product Manufacturing

Manufacturing

Livestock (Grazing)

Dairy Cattle

Horses

Field Crops

Field Crops − Irrigated Agriculture

Root Vegetable Crops

Vegetable Crops

Horticulture

Vine Fruit

Improved Pastures nec

Forest Plantation

Aquaculture

Mining or Extractive Industries

Protected Area

Native Veg

Water

Water Storage (Reservoir/Dam/Water Tower/Tank)

Sewage

Airport/Airstrip

Army Base

Cemetery

Culture & Recreation Services

Education

Marina

Rubbish Dump

Major Road

94

4 Land Resources

demands on water in areas that are already developedto their sustainable limit. These include the MountLofty Ranges and the Clare and Barossa Valleys (seechapter on Water Use). The development of cropsrequiring irrigation will place pressure on existingsources of water and increase demand for water fromthe River Murray unless reclaimed water is utilised.

Production from dryland agricultureand plantationsPlantation forestry can have a significant impact onregional water resources. Plantation forests interceptand use more rainfall than traditional agricultural landuses. Hence a change of land use to plantation

forest can reduce the surface water yield from

catchments, leading to reduced stream flow,reduced groundwater recharge and the creation ofchanges and pressures on water dependentecosystems. In addition to the potentialenvironmental consequences, in areas where theavailable water resources are approaching theallocation limit or are already fully allocated, anyreduction in the availability of water resources mayimpact on existing users of that resource.

This situation potentially exists in a number ofregions within South Australia, notably the lowerSouth East, the Mount Lofty Ranges and Middle Rivercatchment on Kangaroo Island. An increase in forestryin some locations in the Mount Lofty Ranges may alsoaffect some threatened species and ecologicalcommunities, in particular the Swamps of the FleurieuPeninsula5, the Mount Lofty Ranges Southern EmuWren and the plant species Euphrasia collina ssp.osbornii (Osborns Eyebright) and Prasophyllum frenchii(Maroon Leek Orchid).6

The issue of increasing forestry development isconcerning resource managers in other regionsthroughout Australia, and policy options for managingthe impact that plantation forestry has on waterresources, as part of the catchment water budget, arebeing considered nationally through the NaturalResources Management Ministerial Council (foractions in South Australia see What are we doing

about it?).

PRESSURE INDICATOR:Site contamination

The National Environment Protection (Assessment ofSite Contamination) Measure (1999) definescontamination as ‘... the condition of land or waterwhere any chemical substance or waste has beenadded at above background level and represents, orpotentially represents, an adverse health orenvironmental impact’.

Site contamination is usually associated withprevious land uses that involved the disposal ofchemicals and wastes, or the intensive use ofchemicals. These land uses may occur in urban or ruralareas. The number of sites affected by contaminationin South Australia is largely unknown.

Site contamination went largely unacknowledgeduntil the 1980s, when regional contamination aroundplaces such as Port Pirie and localised contaminationfrom former industrial land uses were recognised.At the same time, contamination was also beingrecognised due to urban consolidation and thetransformation of older, inner-city sites, which hadpreviously been used for industrial purposes, into

Vineyards in the Mount Lofty RangesPhoto: Kym Nicolson

5 The Swamps of the Fleurieu Peninsula are listed as a critically endangered ecological community under the EnvironmentProtection and Biodiversity Conservation Act 1999.6 These species are listed as nationally endangered under the Environment Protection and Biodiversity Conservation Act.

CASE STUDY – Examples of site contamination incidents in South AustraliaOver the last few years there have been a number of site contamination incidents in South Australia that haveattracted public attention. The following sites are now either fully remediated or are undergoing furtherinvestigation and monitoring.

Northern Islington Railyards

Activities involved with the railyards left a legacy of waste contaminated with asbestos and heavy metal locatednext to residential housing. The site has now been fully rehabilitated for use as a community recreation area.

West Lakes

In 2000 investigations by the EPA revealed that 191 properties in the West Lakes development had higher thannormal levels of cadmium present in the soil as a consequence of the dispersal of sewage sludge prior to thehouses being built. The EPA, in collaboration with the Department for Human Services, issued an informationbooklet that provided information to residents in affected areas to minimise as far as practical potentialexposure to sludge-affected soils. The Department of Administrative and Information Services, on behalf of theGovernment, is continuing to provide assistance to residents in the affected areas with specific measuresaimed at managing this issue.

Birkenhead

In June 2003 concerns were raised over contaminated soil on a former gas storage site, now occupied byhousing trust properties. Tests indicated that the soil contained a range of toxic substances including polycyclicaromatic hydrocarbons and cyanide. This was mostly below the ground surface. At the time of writing theresidents had been relocated and further investigations and assessments were due to commence.


residential areas. This conversion from industrial tosensitive uses (such as residential development) is amajor issue associated with site contamination.

The types of activities that can lead to sitecontamination include industrial and some commercialland uses; the disposal of wastes and chemicalsubstances; accidental spillage of wastes andchemical substances; leakage during plant operation,storage or transportation; the spreading of sewagesludge; and the use of pesticides.

An emerging issue in relation to sitecontamination in South Australia relates to the publiclyannounced ‘mothballing’ of the Port Stanvac Oil

Refinery. Existing environment protection

legislation is totally inadequate to manage the site

contamination issues known to exist at this site.

Pesticide useThe use of pesticides (including insecticides,herbicides, fungicides and growth promotants) hasbrought us significant benefits in terms of greatlyincreased world food security, the control of diseaseand the provision of high quality food at a reasonableprice. However, there is increasing awareness of theimpact that pesticide use can have on theenvironment and the importance of environmentallyfriendly and sustainable agricultural production.

The use of pesticides has the potential to causecontamination of soil and water on a wider, morediffuse level than contamination associated with aspecific industry, which tends to be more confined.On the whole, Australia uses much lower levels ofpesticides than many other countries. This has lead tothe marketing of Australian produce as ‘cleanand green’.

The level of contamination of water and soilresources via pesticide application in South Australia isnot currently known in detail. Analysis of results fromthe EPA’s groundwater monitoring program indicatesthat the herbicides atrazine and simazine weredetected in low levels in groundwater samples takenfrom the South East in 1999, 2000 and 2001. In 1997herbicide application associated with forestrymanagement practices resulted in the contaminationof the Warren, South Para and Barossa reservoirs andsource waters in the Mount Lofty Ranges Watershed.These herbicides remained at detectable levels insource waters for around 18 months. Subsequent tothis, forestry management practices were reviewedand improved.

In 2000 South Australia experienced a major locustplague. To control the insects, around 505,000 hectaresof land was sprayed with insecticides betweenSeptember and December 2000. Follow-up monitoringindicated that no residual pesticides were found inwater samples collected from the area (EPA, 2001).

There is relatively little understanding of thebehaviour of pesticides in Australian soils. A total of227 properties in South Australia had livestock thattested above risk levels for organochlorine chemicals(i.e. above half the Australian Maximum Residue Limit)during the organochlorine crisis of the late 1980s.Now, only 29 properties remain with sources thatpose a possible risk to livestock. All of these propertieshave their risk effectively controlled by auditable

Property Residue Management plans conducted byPrimary Industries and Resources South Australia.

Our low level of pesticide use by world standardsis reflected in the level of pesticides detected in foodsamples. Of 274,000 food analyses done in theNational Residue Survey during 2000-01, there was99.97% compliance in grain and horticulture, 99.98%in meat and 100% in fish samples in terms of ensuringthat any pesticides detected were below allowableMaximum Residue Limits (AATSE, 2002).

What impact does land use and landuse change have?

If a particular land use is not compatible with thenature of the land and its soil, water and biodiversityresources, significant environmental, social andeconomic effects may occur. These include:Increased pressure on water resources. The currenttrend in land use away from relatively low intensityagricultural uses to more intensive uses means thatgreater pressures are being placed on surface andgroundwater resources, which in some areas arealready being used above estimated sustainable limits(e.g. the Mount Lofty Ranges and Northern AdelaidePlains). There are also greater demands being made onwater from the River Murray to irrigate vineyards andother high water use crops, particularly in the Barossaand Clare valleys. This will have implications for theenvironment and water quality, which in turn mayaffect economic productivity.

The proposed expansion of commercial forestryin the lower South East has implications for thesustainability of groundwater resources in the region,which provide a major water supply for many uses.

Stormwater run-off and pollution from theincreasing intensification of urban land uses in theMount Lofty Ranges, if not managed appropriately, willthreaten water quality in what are Adelaide’s mostimportant water catchments. It also has the potentialto impact on Adelaide’s marine environment as thestormwater is discharged to sea.Loss of highly productive agricultural land. Highvalue agricultural land is gradually being converted tonon-agricultural land uses as residential developmentexpands in Adelaide’s outer metropolitan areas. Highvalue agricultural land in South Australia is relativelyscarce and its loss to residential and other uses willultimately have an impact on the economy as a result ofreduced productivity. This is also causing someproducers to relocate elsewhere (or leave the industry)resulting in social disruption to families andcommunities and additional transport costs to bringproduce from further afield to markets orprocessing plants.Clearance of native vegetation. Clearing nativevegetation to make way for housing development inthe Mount Lofty Ranges has the potential tosignificantly affect the region’s biodiversity, wherealready only around 15% of the original nativevegetation remains.Site contamination of urban areas. The costsassociated with ‘cleaning up’ site contamination canbe large, often costing millions of dollars. There are

Chemical sprayingPhoto: Arthur Mostead courtesyMurray-Darling Basin Commission

KEY FACTS

• The number of sites affected

by contamination in South

Australia is unknown.

LAND USE

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4 Land Resources

also economic and social costs associated withrelocating affected communities. Site contaminationalso poses an immediate and long term hazard tohuman health and the environment, particularlygroundwater.The use of pesticides. In South Australia this is atsuch a level that it is unlikely to have a significantimpact on the environment. Potential effects includethe pollution of rivers, streams, groundwater and soilresources. Animals and humans can be affected byeating food contaminated by pesticides, drinkingcontaminated water, breathing in contaminants orabsorbing them through the skin.


The Development Act 1993, Development

Regulations 1993, the Planning Strategy andCouncil Development Plans provide the legal andstrategic framework that controls land use acrossthe State.

A comprehensively updated Planning Strategy

for Regional South Australia and a selectivelyupdated Planning Strategy for Metropolitan

Adelaide7 were released in January 2003. Theseacknowledge the importance of integrating naturalresource management with land use planning and theconsideration of land capability in the planning andassessment process.

In recognition of the importance and uniquecharacteristics of Adelaide’s inner regional areas aPlanning Strategy for the Inner Region is beingdeveloped. This will encompass the Northern AdelaidePlains, Barossa, Central Hills and the SouthernFleurieu and will place priority on minimising conflictsbetween land use and the environment.

The Planning Strategy for Metropolitan Adelaideintroduces the concept of an urban containment

boundary which defines the physical extent ofAdelaide’s urban growth and, in so doing, clearlydivides residential land from rural land in order toprevent inherent land use conflicts. This is considereda major positive development.

In October 2002 the State Governmentannounced a review of the current Hills Face Zone8

policies to achieve a coordinated and effectiveapproach to controlling future land development. Thereview will be completed by late 2003.

In July 2003 the Development Regulations

were amended to require the referral of all newhousing development applications (including thosethat propose to replace an existing house) in theMount Lofty Ranges Watershed to the EPA. The EPAwill have the power to direct the Council orDevelopment Assessment Commission to eitherrefuse the development application or imposeconditions on the development approval.

Primary Industries and Resources SA has initiatedthe Designated Primary Industry Areas (DPIA)

program to identify significant primary productionareas that are at risk from residential development.Following incorporation into the Planning Strategy, it isintended that DPIAs be reflected in Local GovernmentDevelopment Plans.

The Mount Lofty Ranges Catchment Program

(MLRCP) and the Mount Lofty Ranges WatershedProtection Office are complementary programs thataddress land use issues. The MLRCP involves threelevels of Government and focuses on communityinvolvement to address land use issues, while theWatershed Protection Office was established by theEPA to provide technical support to landholders andorganisations operating in the Mount Lofty Ranges,focusing on water quality.

There have been a number of initiatives over thelast five years that have significantly improved ourknowledge and understanding of site contamination.The most significant of these is the National

Environment Protection (Assessment of Site

Contamination) Measure, which came into effect inDecember 1999, to ensure a nationally consistentapproach to the assessment of site contamination. InOctober 1995, the EPA endorsed the use of VictorianEPA appointed Environmental Auditors

(Contaminated Land) as appropriate persons toprovide vendors, developers and financial institutionswith a high degree of certainty that a site is suitablefor a proposed use. The State of the EnvironmentReport 1998 indicated that 25 Site Audit Reports hadbeen completed since 1995. Up to May 2003, a totalof 380 Site Audit Reports have been undertaken. Thisconsiderable increase reflects the trend for planningauthorities, developers and landowners to comply withEPA recommendations for the use of auditors.

A Code of Practice for the use of pesticides in

South Australia is to be released some time in 2003/04. This is linked with the Environment Protection(Water Quality) Policy.

A series of Agricultural Sustainability

Indicators have been developed to monitor andevaluate the progress of South Australia’s agriculturalindustries towards achieving the goals of sustainableagriculture (PIRSA, 1999). Further work is continuing torefine these indicators.

The Environmental Management Systems

(EMS) in Agriculture Taskforce was established in2003 to support implementation in South Australia ofAustralia’s National Framework for EnvironmentalManagement Systems in Agriculture. The Taskforcewill create awareness of the Framework amongstakeholders and establish partnerships withstakeholders to identify EMS in agriculture issues anddevelop relevant systems to monitor, address, informand resolve EMS issues.

Many industries are now developing

environmental management systems and standardsin acknowledgement of the importance of protectingthe environment. These include the forestry, wine,dairy and mining industries.

The forestry industry has developed anAustralian Forestry Standard (October 2002), andforest management certification has emerged inresponse to the challenges of forest conservation and

7 A more comprehensive update of the Planning Strategyfor Metropolitan Adelaide has commenced.8 The Hills Face Zone was introduced into South AustralianPlanning Policy in 1962.


LAND USE

sustainable forest management. EnvironmentalManagement Guidelines for Plantation Forestry inSouth Australia were jointly developed in 1997 byindustry and Government, to provide a code ofpractice for forest industries. The Mount Lofty

Ranges Forestry Working Group (MLRFWG)

released a briefing to the NRM Committee on thepotential environmental impact of commercial forestrydevelopment in the Mount Lofty Ranges in June 2003.

As mentioned previously, the impact of plantationforestry on water resources is of concern nationallyand policy options are being considered through theNatural Resources Management Ministerial Council.Here in South Australia, a specific proposal is beingdeveloped under the Water Resources Act 1997 tomanage the impact of expansion of the lower SouthEast plantation forest estate on sustainablemanagement of regional groundwater resources.

The agricultural and horticultural industries aredeveloping Environmental Management Systems

that incorporate a wide range of natural resourcemanagement issues. For example, in 2002 theAustralian wine industry released its EnvironmentStrategy (SAWBIA, 2002). This provides a frameworkto guide the industry towards the adoption ofecologically sustainable management practices in allaspects of industry operations.

Management of the Lower Murray dairy

swamps is set for improvement following theannouncement by State Government of a majorrehabilitation program in the area that seeks toimprove land management practices and reduce waterpollution in the river. The dairy industry, through itsDairySA Regional Action Plan, aims to adoptsustainable management practices that include a 50%reduction in nitrogen and phosphorus loadings indrainage waters (NLWRA-DRDC, 2001).

Over the last decade the mining industry hasmade significant improvements to its environmentalmanagement. The Petroleum Act 2000 contains moreeffective environmental protection objectives thanearlier legislation in South Australia. Under the Act aStatement of Environmental Objectives is requiredfor all regulated activities. This must contain over-arching objectives that conform to the nationalstrategy for Ecologically Sustainable Development. TheAct also establishes a Public Environmental

Register, which ensures there is transparency andaccountability in decision-making processes.

Since 1972 quarry operators have been requiredto pay a royalty on all materials produced. The StateGovernment places 50% of this royalty into theExtractive Areas Rehabilitation Fund which is usedfor rehabilitation projects. Over the period 1997 to2002, a total of 248 projects have been funded with anexpenditure of nearly $7.8 million from the fund. TheMining Act 1971 is currently undergoing review. It isexpected that as part of this review, matters relating toenvironmental provisions will be strengthened. Formore information on programs and initiatives see theState of the Environment 2003 Supplementary Report.

References

Australian Academy of Technological Sciences andEngineering (AATSE) (2002). Pesticide use in Australia.AATSE, Victoria. www.atse.org.au

Australian Bureau of Statistics (ABS) (2003). SouthAustralia at a glance. ABS Catalogue No. 1306.4.

Environment Protection Authority (EPA) (2001).Assessment of the impact of insecticide spraying ofAustralian plague locusts. EPA, Adelaide.

Hamblin, A. (2001). Land, Australia State of theEnvironment Report 2001 (Theme Report), CSIROPublishing on behalf of the Department of theEnvironment and Heritage, Canberra.

NLWRA-DRDC (2001). Sustaining our DairyResources – Dairying for Tomorrow. National Land andWater Resources Audit and Dairy Research andDevelopment Corporation. DRDC, Melbourne

Primary Industries and Resources SA (1999).Agricultural Sustainability Indicators for regions ofSouth Australia. PIRSA, Adelaide.

South Australian Wine and Brandy IndustryAssociation (SAWBIA) (2002). Sustaining Success.The Australian Wine Industry’s Environmental Strategy.South Australian Wine and Brandy IndustryAssociation Inc., Adelaide.

Further information

Environment Protection Authoritywww.epa.sa.gov.au

Mount Lofty Ranges Catchment Programwww.mlrcp.sa.gov.au

Phylloxera and Grape Industry Board of South Australiawww.phylloxera.org.au/statistics

Planning SAwww.planning.sa.gov.au

Gawler quarry site prior to rehabilitationPhoto: PIRSA

Gawler quarry site on completion ofearthworks and tree plantingPhoto: PIRSA

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4 Land Resources

Soil Erosionand AcidityTrends

• Extent of acid soils and rates of soil

acidification in South Australia:

INCREASING and will continue to increase

unless the level of remedial action is

significantly increased.

• Rates of soil loss to water and wind erosion

in South Australia: SLOWLY DECLINING but

unsustainable levels of soil loss still occur

during extreme weather events.

Goal

To recognise that degradation of the land has occurredto a significant extent and that some degradation isstill occurring, and that Government, industry and thecommunity at large must work together to prevent orminimise further degradation and rehabilitatedegraded land ...

... to ensure that conservation of land becomesan integral part of land management practice, and thatland is used within its capability.Soil Conservation and Land Care Act 1989


Since European settlement, the condition of our soil hasbeen significantly changed by land managementpractices such as vegetation clearance, grazing,cultivation, the introduction of exotic flora and fauna andthe application of fertilisers, herbicides and pesticides.

Soil erosion and increasing soil acidity are two ofthe most significant problems that have resulted fromagricultural land management practices. Soil loss andacidification permanently reduce the productivecapacity of agricultural lands, and can adversely affectwater resources and biodiversity.

Erosion occurs when soil particles are washed orblown from one site to another. Soil erosion resultsfrom a complex interaction of climatic conditions, soiltype, topography and land management practices.

Soil loss due to wind or water erosion does occurin undisturbed natural environments, but usually atrelatively low rates. The rate of soil loss from land usedfor agriculture is usually many times higher than thenatural rate. Large erosion events occur when extremerainfall or winds act on loose soil that is inadequatelyprotected by standing vegetation or plant residues.

Many soils are naturally acidic. Agricultureincreases the rate of acidification through processesassociated with the use of nitrogen fertilisers, growinglegume crops and pastures, and the export of basiccations from the soil in agricultural products. Stronglyacid soils are likely to exhibit nutrient deficiencies and/or toxicities that can severely reduce plant production.In turn, these systems are likely to contribute more towater table rise and dryland salinity.

Rates of soil acidification and the area of affectedland continue to increase in most agricultural areas,while rates of soil erosion have declined somewhat,although not nearly to a level that will ensure longterm sustainability.

The majority of information presented in thisreport has been sourced from a report (in preparation)on soil condition by the Department of Water, Landand Biodiversity Conservation using data collectedfrom October 1999 to October 2002. This provides thefirst data in what will be an ongoing assessment ofsoil condition. The soil loss information takes a riskassessment approach rather than directmeasurement, as it is technically difficult and would bevery costly to measure actual soil loss. Change in riskis used as a surrogate for actual soil loss on theassumption that over time, any change in risk willcorrespond to an equivalent change in the rate of soilloss. The soil acidity information is estimated indirectlyusing models that incorporate soil type, climate andproduction systems, and levels of lime use.

See also chapters on Dryland Salinity; andLand Use.


PRESSURE INDICATORS

• The area of agricultural land at risk ofwind and water erosion (new indicator)

This indicates the areas at risk from erosion.Increased rates of erosion can have a negativeeffect on water quality in streams and rivers.These areas require special managementmeasures to avoid unacceptable soil loss.• The area of land at risk from soil acidity

(new indicator)This indicates the areas at risk from significantsoil acidification.

RESPONSE INDICATOR

• Land and crop management practices(reported on in the State of the EnvironmentReport 1998)

The adoption of conservation-based landmanagement practices is an indirect measure ofthe sustainability of farming systems.


PRESSURE INDICATOR: The area ofagricultural land at risk of wind erosion

The State of the Environment Report 1998 did notreport comprehensively on soil loss due to wind erosionbecause there was no reliable information available.However, recent work by the Department of Water,Land and Biodiversity Conservation (DWLBC) hasprovided three years worth of data that enables anassessment to be made of the key areas of the Statethat are at risk from losing soil due to wind erosion. It istechnically very difficult to measure actual loss so a riskassessment approach is taken as a surrogate measure.

Bare soil, resulting from drought,excessive tillage or overgrazing, can besusceptible to erosionPhoto: Giles Forward, Rural Solutions SA

Sand drift, a feature of wind erosionresulting from strong winds andexposed soilPhoto: Giles Forward, Rural Solutions SA

Water erosion of soil. Scenes like thisare becoming rarer as landholdersadopt sustainable land managementpracticesPhoto: M. Young, Rural Solutions SA


SOIL EROSION AND ACIDITY

FindingsMaking progressWhile there is little substantive data to objectively quantify changes in the incidence or magnitude of soil lossdue to wind or water erosion, it is certain that soil loss associated with agricultural land use has reducedconsiderably over the past 50 years and continues to decline as a result of improved crop and landmanagement practices.

Using indirect, semi-quantitative approaches, rates of soil loss due to water erosion in the worst affectedareas of the mid and upper north of South Australia are estimated to have improved on average by at least90% since the first half of the twentieth century. However, even these lower rates of loss are in manyinstances greater than rates of soil formation. Significant soil loss still occurs periodically, usually because ofintense, localised storms.

Over the last decade there has been a more integrated approach to soil conservation and sustainable soilmanagement issues. This is due largely to an expansion in the roles and responsibilities of Soil ConservationBoards in the 1990s in combination with the growing community landcare movement and an increase in theavailability of funding to tackle land condition issues via programs such as the Natural Heritage Trust.

Attention requiredEven though improved land management practices have led to a reduction in the amount of soil lost due toagricultural land use, the drought of 2002/03 has demonstrated that large areas of the State are still vulnerableto high levels of erosion as a result of cropping and grazing practices and severe climatic events.

Accelerated soil acidity is now emerging as a major issue – rates of acidification have increasedsignificantly over recent years with increases in the productivity, extent and intensity of cropping, andincreased pasture productivity. The rate of application of lime to acid soils is still considerably less than isrequired to balance the annual soil acidification rate.

What more should we be doing?The Environment Protection Authority recommends that:4.10 There should be improved understanding of the underlying technical, economic and social reasons why

adoption of improved land management practices remains inadequate in many areas, together with thedevelopment of methodologies and investment strategies that address the key issues identified.

4.11 Monitoring of soil and land condition should be conducted on an ongoing basis to assess the impact ofland management practices on erosion risk and the condition of acid soils.

There are about 10.2 million hectares of arableagricultural land (as opposed to non-arable areas suchas lakes and conservation parks) in South Australia andapproximately 2.43 million hectares (23.8%) of thishave a moderate to high susceptibility to wind erosiondue to their sandy soil types. The majority of this areais on the Eyre Peninsula and in the Murraylands andSouth East (Map 4.5).

Even soils containing more clay can sometimesbe susceptible to wind erosion if they are cultivated orgrazed excessively, although the quantity of soil loss israrely in the same order as for sandy soils.Approximately 3.51 million hectares (34%) of arableagricultural land is in this lower risk category of winderosion potential, the majority of which (1.68 millionhectares) occurs on the Eyre Peninsula.

While comparable quantitative erosion riskinformation does not exist prior to 1999, there is littledoubt that rates of soil loss are now significantly lowerthan even a decade ago for comparable climaticconditions. The reasons lie in improved landmanagement practices.

However, the amount of soil loss in some areas,notably parts of the Murraylands and Eyre Peninsula, isstill at an unsustainable level whenever seriouslyadverse seasonal conditions occur, such as highfrequency wind events during extended dry spells.

PRESSURE INDICATOR: The areaof agricultural land at risk ofwater erosion

The State of the Environment Report 1998 did notreport comprehensively on soil loss due to watererosion because there was no reliable informationavailable. However, as indicated for wind erosion,recent work by DWLBC has provided three yearsworth of data that enables an assessment to be madeof the key areas of the State that are at risk fromlosing soil due to water erosion.

Approximately 780,000 hectares (or 7.6%) ofarable agricultural land in South Australia have amoderate to high inherent susceptibility to watererosion, and require special management measures toavoid unacceptable soil loss.

The key factors that predispose this land to watererosion are soil type and land slope. The Mount LoftyRanges and Northern and Yorke Peninsula AgriculturalDistricts have the greatest proportion of landsusceptible to water erosion with 307,000 hectares(39% of the State’s total area at risk) and 265,000hectares respectively at risk (Map 4.6). The SouthernEyre Peninsula has around 119,000 hectares of land atrisk from water erosion.

Raised dust, a feature of wind erosionresulting from strong winds andexposed soilPhoto: M. Young, Rural Solutions SA

Applying lime in a vineyardPhoto: Brian Hughes, Rural Solutions SA

KEY FACTS

• 23.8% (2.43 million hectares) of

agricultural land in South

Australia is moderately to

highly susceptible to wind

erosion. Most of this area is on

the Eyre Peninsula and in the

Murraylands and South East.

• For many areas of the State

rates of soil loss are now

significantly lower than even

a decade ago. The reasons

lie in improved land

management practices.

100

4 Land Resources

Map 4.5: Distribution of land susceptible to wind erosion in South AustraliaSOURCE: DWLBC, IN PREP.

A further 2.4 million hectares of agricultural landhave a moderately low susceptibility to water erosion.These areas are particularly at risk during extremerainfall events. Around 41% of this land (997,000hectares) occurs in the Northern and Yorke PeninsulaAgricultural Districts.

PRESSURE INDICATOR: The area ofland at risk from soil acidity

Soil acidity is relatively widespread across SouthAustralian agricultural land, although at a smaller scalethan in most other States.

Accelerated acidity due to agricultural activitieshas already caused a decline in productivity, to datemostly under improved legume pastures in higherrainfall areas. However, it is now emerging as a majorissue because rates of acidification have increased

significantly along with increases in the productivityand intensity of cropping.

Extensive soil survey data collected by theDWLBC provides an indication of the areas currentlysusceptible to soil acidity.

Approximately 1.9 million hectares of arableagricultural land (10%) have moderate to highsusceptibility to degradation due to increasing soilacidity. This is land with soils that are neutral or acidic,have low clay content, no free lime and relatively highrainfall and production levels. Many of these soils arealready showing production losses to some extent.

The South East region has the largest area of landsusceptible to degradation by soil acidity at around684,000 hectares – 36% of the State’s total area at risk.This is followed by the Mount Lofty Ranges with406,000 hectares susceptible to acidity and theNorthern and Yorke Peninsula Agricultural Districts with343,000 hectares susceptible to soil acidity (Figure 4.7).

Crop sown into retained stubble with noprior tillage, is well protected from erosionPhoto: Giles Forward, Rural Solutions SA



Map 4.6: Distribution of land susceptible to water erosion in South AustraliaSOURCE: DWLBC, IN PREP.

What impact will deteriorating soilcondition and soil loss have?

Some of the environmental, social and economiceffects associated with deteriorating soil condition andsoil loss are outlined below to illustrate the broadersignificance for sustainability.Poor plant growth and reduced water use.

Increased acidity can lead to poor plant growth andwater use as a result of nutrient deficiencies orimbalances and/or induced aluminium or manganesetoxicity. In turn, systems with low crop and pasturewater use are likely to contribute more to water tablerise and dryland salinity.Degradation of watercourses. Water erosion cancause off-site degradation of watercourses, swamps,estuarine areas and the marine environment due tosiltation and increased nutrient levels.

Damage to infrastructure. Wind erosion can causedamage to buildings and other infrastructure, plant andequipment as well as the significant cost of removingsoil from roads. The severe dust storm on EyrePeninsula in 1988 required the District Council ofFranklin Harbour to spend an additional $250,000 onroad maintenance (Williams & Young, 1999).Impact on human health. Wind-blown dust isimplicated in the occurrence of asthma and associatedhealth problems.Productivity decline. Soil acidification has causedproductivity decline in some areas, predominantly thehigher rainfall areas, namely the South East, KangarooIsland and southern Mount Lofty Ranges. On veryacidic soil, productivity can be reduced by more than50%. The annual average cost (in terms of loss inagricultural productivity) of clay and organic materiallost from South Australia’s agricultural land due to

Contour banks used on sloping land tocontrol water erosionPhoto: Rural Solutions SA

102

4 Land Resources

wind erosion has been estimated at about $2.80 perhectare per annum, or a total loss of $6.2 million perannum (Payne, 1998). These are partial cost estimatesas they are based on the value of lost nutrients only –total costs may be higher.Impact on rural communities. Landholders cansuffer long term economic losses due to reducedproductivity, and/or have the additional cost ofrehabilitating degraded areas. Loss of farm income hasa direct impact on local and State economies.Atmospheric pollution Dust storms result inatmospheric pollution and may disrupt the way inwhich people go about their lives in both rural andurban areas because of reduced visibility and thenuisance of airborne dust. Low visibility increases therisk of road accidents and disrupts air travel.


RESPONSE INDICATOR: Land and cropmanagement practices

Improved land and crop management practices havegone some way to improving soil condition over thelast 50 years, although the rate of adoption ofsustainable land management practices is still not asextensive as it should be.

Soil acidification – the application of agricultural

liming materials

Within conventional agricultural systems, the onlypractical way of balancing the acidification caused byagriculture is by applying liming materials. Monitoringthe use of lime provides an indirect measure of theextent to which farmers have recognised the need toaddress soil acidification problems.

Rates of lime use have risen substantially sincethe mid-1990s, but only landholders in the MountLofty Ranges and the South East appear to beapplying enough lime to balance annual acidificationrates (Figure 4.4). There are still very large areas ofland that are continuing to acidify to damaging levels.

Despite the relatively low cost of lime in SouthAustralia in comparison to other States, cost is oftencited by farmers as a key barrier to its use.

Erosion and changes in farming practices

Awareness that erosion is a significant landmanagement issue is growing among land managers.Around 40% of current land managers across theState recognise that wind erosion is a serious issue intheir districts; a level of concern that appears tocorrelate with the degree of erosion risk. Only around19-23% of land managers across the State recognisethat water erosion is a serious land managementissue. This may be due to the very long periods (20years or more) between severe water erosion events.

The adoption of improved land managementpractices is contributing to the reduction in soil lost toerosion. These include direct drill sowing, where theonly cultivation occurs at sowing, and no-till sowing,where the seed is placed in a narrow slot in the soil tominimise soil disturbance.

Increasingly farmers are using seedingimplements that can sow without the needfor prior cultivation or stubble removalPhoto: Mary-Anne Young,Rural Solutions SA

In 2002 the greatest proportion of land managersusing direct drill techniques to some extent occurredon the Eyre Peninsula (at 60%) with the lowest rateoccurring in the Murraylands (30%), a region that isparticularly vulnerable to wind erosion. The greatestproportion of land managers using no-till techniques tosome extent in 2002 were in the Mount Lofty Ranges/Kangaroo Island region (40%) and the Eyre Peninsula(39%) and the lowest proportion were in theMurraylands (21%).

Programs and policyThe Soil Conservation and Land Care Act 1989 isthe primary statutory basis for sustainable soilmanagement in South Australia. The Act provides forthe establishment of District Soil Conservation

Boards that are responsible for developing andimplementing strategies for sustainable land use atthe local level and for promoting awareness andunderstanding of soil conservation issues in the localcommunity. There are currently 27 Soil ConservationBoards that cover most of the State.

The Land Condition Monitoring Program, runby the DWLBC, commenced in 1999. Whileinformation collected by the Program does not providea direct measure of the amount of soil lost in any givenevent or period, it aims to determine long termchanges in the risk of wind and water erosion and soilacidity resulting from changes in land managementpractices. This information will be used to help informland management strategies across the State.

Over the last decade a large number ofcommunity groups have been involved in improvingthe management of our natural resources. At any time,there are about 300 active landcare groups across theState, most of them in agricultural districts. Landcareprojects range from salinity and erosion control tobushland management and the development ofsustainable farming technologies.

Also over the past decade, millions of native

trees, shrubs and grasses have been established

on agricultural lands across South Australia. This highlevel of interest and commitment to revegetation fromindividual landowners and community groups reflectsan increased awareness of land degradation issuesand a willingness to work to prevent further damageand rehabilitate degraded lands.

See chapter on Native Vegetation for furtherinformation on revegetation activity. For moreinformation on programs and initiatives see the Stateof the Environment 2003 Supplementary Report.

KEY FACTS

• The direct, on-site cost of the

loss of one millimetre of

topsoil from cropping land due

to water erosion is estimated

at about $80 per hectare.

• The rate of lime application in

most agricultural regions is

still significantly lower than is

required to balance the annual

soil acidification rate.

• Progress towards sustainable

management of erosion risk in

susceptible areas relies upon

the increased adoption of

improved land management

practices.

Eyre

Pen

insu

la

Figure 4.4: Estimates of the amountof lime required to balance theannual acidification rate and totallime used in 1998/99–2001/02 byagricultural region

Lim

e (0

00’s)

tonn

es

SOURCE: DWLBC, IN PREP.

Total Lime Required

Lime Used 1998/99

Lime Used 1999/00

Lime Used 2000/01

Lime Used 2001/02

0

10

20

30

40

50

60

Nor

ther

n an

dYo

rke

Pen

insu

la

Mur

rayl

ands

Mou

nt L

ofty

Ran

ges

Kan

garo

o Is

land

Sou

th E

ast

70



Map 4.7: Distribution of arable land susceptible to induced soil acidification in South AustraliaSOURCE: DWLBC, IN PREP.

References

Department of Water, Land and BiodiversityConservation (DWLBC) (in preparation). Report on thecondition of agricultural land in South Australia. ReportNo. 1. Department of Water, Land and BiodiversityConservation, South Australia.

Payne, R. (1998). Soil Condition. Land Management,PIRSA (unpublished report).

Williams, P. and Young, M. (1999). Costing Dust. Howmuch does wind erosion cost the people of SouthAustralia? Final Report. Policy and Economic ResearchUnit, CSIRO Land and Water.

Further information

Department of Water, Land and BiodiversityConservationwww.dwlbc.sa.gov.au

Primary Industries and Resources SAwww.pir.sa.gov.au

National Land and Water Resources Auditwww.ea.gov.au/land/nlwra/index.html

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