The History of Groundwater Management in the South East of South Australia - Towards Achievable Sustainability?

Ludovic Schmidt, Department for Environment, Heritage and Aboriginal Affairs, South Australia

ABSTRACT

Since European settlement began in the area in the middle of the 19th Century, land use practices have had a considerable impact on the hydrological cycle in the region and on the quality of the groundwater. The removal of more than 90% of native vegetation and its replacement with shallow rooted crops and plantation forestry have greatly altered recharge patterns. Comprehensive surface drainage schemes have also been implemented over most of the region. Point-source and diffuse-source contamination of groundwater from the surface has occurred. Salinisation of groundwater has resulted from the mobilisation of salts in the unsaturated zone and from irrigation-induced concentration of salts.

Legislative controls on the use of groundwater were first introduced in the late 1960s. Legislation has progressively moved from treating groundwater as a commodity in isolation to recognising the groundwater as part of the broader environment. There was little recognition and consideration given initially to the role of groundwater in the broader environment. Management has also moved from being reactive to being proactive, from trying to fix up problems after they have occurred to trying to prevent problems from developing.

Current legislation aims for ecologically sustainable development, but pressures for economic development, vested interests and political reality will make this difficult to achieve. New legislation allows for the empowerment of local communities in management of the groundwater resource, reducing the direct influence of political pressure and centralised government. The major challenges faced are in defining sustainability and then developing and implementing policies which achieve it in the face of numerous competing pressures.

THE HISTORY OF USE OF THE GROUNDWATER

Aboriginal use:

• Coastal and inland springs
• Sinkholes, caves

European settlement:

• Cave Gardens, Englebrecht Cave and Umpherstone Cave were the first water supplies for Mount Gambier.
• Blue Lake has been the main public water supply for the greater Mount Gambier area since 1883.
• Development of town water supplies across the region from groundwater bores, in both the upper unconfined aquifer and the lower confined aquifer.
• Gouldens Waterhole and Little Blue Lake, for example, were modified to allow stock access for drinking water.

Development of irrigation

• Early history; very limited irrigation due to the difficulty of extracting the large volumes of groundwater required.
• Rapid expansion from 1950s onwards due to the development of new technology such as turbine pumps, travelling irrigators and centre-pivot irrigators.

Table: the recent use of the groundwater resource

Ware use	Present (Megalitres)	1984 (Megalitres)
Irrigation:
Unconfined aquifer	141 000	200 000
Confined aquifer	32 000	37 000
Public water supply	7 700	8 800
Stock supplies	17 000

Available resource (estimated 'sustainable' yield):

Upper unconfined aquifer: 863 000 Ml
Lower confined aquifer: ~ 100 000 Ml

Economic value of the resource

Total farm gate value of irrigated products in 1997 was $100 million. The value added per megalitre of water use varies by a factor of about 40 between different uses.

Table: value added per megalitre (Ml) allocated for irrigation

Product	$/Ml
Meat from pasture	150
Pasture seed production	500
Dairying	750
Potato growing	800
White wine grapes	3500
Red wine grapes	5000
Paper and pulp mill	6000

DEVELOPING PROBLEMS WITH THE GROUNDWATER SYSTEM

• Altered recharge patterns due to vegetation changes, increasing or decreasing the recharge rates, which affect the hydrological equilibrium of the groundwater systems.
• The removal of native vegetation has also led to salinisation of the groundwater in some areas due to the increased flushing of salts stored in the soil profile resulting from the increased recharge rates.
• Extensive surface drainage of the region has also altered the hydrological equilibrium.
• Irrigation resulting in changes in groundwater levels and increases in salinity levels due to evapo-transpiration and flushing of salt from the soil profile.
• Changes in nutrient cycles from highly efficient natural ecosystems to relatively inefficient farming systems

Recognition of developing problems

Subsurface drainage of pollutants:

• Department of Mines reports in 1930s and 1940s
• Mil Lel and other cheese factories, underground disposal of effluent
• Sewage disposal in Mount Gambier, directly into sinkholes or bores, or via septic tanks
• Rubbish disposal into sinkholes and landfills

Engineering & Water Supply Department:

• pollution reports in 1970s identifying some sources
• closure of town water supply bores near Mount Gambier in 1970s due to nitrate and bacterial contamination
• nitrate in the Blue Lake, increased in the 1970s but has stabilised since

Salinisation of groundwater in the Padthaway and Tatiara areas was first investigated in the 1970s and 1980s.

Diffuse source contamination of groundwater from land management practices was first recognised in the late 1970s. This is the major source (about 90%) of nitrate contamination to the groundwater, especially in the lower South East region.

HISTORICAL LEGISLATION

Underground Waters Preservation Act 1969

• Mainly concerned with trying to bring in controls on water level changes resulting from use of groundwater.

Water Resources Acts of 1976 and 1990

• Use of water resources committees, with a majority of private members, to advise the Minister via the South Australian Water Resources Council on how the resource should be managed.
• Objects of Water Resources Act 1990:
  
  • Recognition of water resources as one of the most important natural resources and that it is a limited resource
  • Mentions sustainability, water in the environment and preservation of ecosystems
  • Covers both water quality and water quantity issues

There were, however, poorly defined mechanisms in the Act on how these objects would be achieved.

CURRENT LEGISLATION

Groundwater (Border Agreement) Act 1985

Provides a mechanism for limited cross-border management of the groundwater resource between Victoria and South Australia. Sets the Permissible Annual Volumes (sustainable yield) for zones within 20 km of State border.

The committee and the technical working group set up under this legislation has developed much of the technical basis of groundwater management in the whole region. This has also been widely adopted as the basis for groundwater management in other parts of South Australia and in Victoria.

Water Resources Act 1997

Object:
A clear statement of the fundamental elements of ecologically sustainable development - the use and management of resources in such a way that those who rely on those resources today will reap the best environmental, social and economic gain from them, whilst not compromising the ability of future generations to reap those same benefits.

Principles: Council of Australian Governments (CoAG) agreement on the reform of the water industry:

• Institutional separation of water resource managers and water users
• Water 'pricing' - user pays to recognise the economic value of the resource
• Water allocations and entitlements recognised as tradeable property rights separate from land titles
• Water for the environment - allocations must be made for environmental requirements.

Mechanisms:

• Local management planning focussed on catchment-based areas and the knowledge and experience of local communities
• Strong strategic direction from central Government

Environment Protection Act 1993

Objects:
Based strongly on the principles of ecologically sustainable development.

Principles:
Based on the Intergovernmental Agreement on the Environment, and national policies set by the National Environment Protection Council.

Mechanisms:

• Authorisations - licences, exemptions, works approvals
• Orders to prevent and clean up pollution
• Policies - codes of practice, area management plans, guidelines

HISTORY OF GROUNDWATER MANAGEMENT

Until recently, management has been largely reactive, with regulation and active management only brought in once serious problems have developed with the resource, such as severe salinisation or over-extraction. The proclamation of the Lacepede-Kongorong area in 1997 has been the first attempt to bring in pro-active management, to manage the development of the resource in order to prevent problems from developing in the first place.

Area	Year proclaimed
Padthaway	1975
Tatiara	1984
Naracoorte Ranges	1986
Comaum-Caroline	1986
Lacepede-Kongorong	1997
Tintinara-Coonalpyn	1999 (put under restriction)

General policies:

• Licence required to take water for all major uses
• Permissible Annual Volume based on the long-term annual vertical recharge to the upper, unconfined aquifer
• An area-based, rather than volumetric, allocation system is used
• Allocations granted to existing users at the time of proclamation
• Water trading - permanent and temporary, limited to local management areas and subject to a hydrogeological assessment
• Hydrogeological assessment required of all applications for new allocations and for transfers to determine the impacts on the resource and on other users of the resource
• Irrigation Development and Management Programs are required for all new developments to ensure the water allocation is developed and used

THE FUTURE OF GROUNDWATER MANAGEMENT

Major issues:

• Salinisation of groundwater from irrigation, and mobilisation of salts stored in the soil profile due to increased recharge resulting from removal of native vegetation
• The major limiting factor on the future use of the groundwater, especially for irrigation, will be increasing salinity and environmental water needs, rather than the volume of water available
• Diffuse-source groundwater contamination from the intensification of agriculture and other land uses
• Defining and meeting environmental requirements for groundwater
• efining sustainable limits on groundwater use and the trade-offs involved
• Reducing the influence of politics and vested-interest groups, and increasing the input of scientific knowledge in groundwater management decisions
• The lag between the technical information available and the information needed for good decision-making.
• Integrating groundwater management with surface water management and broader natural resource management - towards integrated natural resource management
• Integration of natural resource management with economic management - internalising the costs of environmental management. Can we really achieve user pays? There is very strong resistance to this from those with vested economic interests, probably because they are not able to pass this cost on to the consumers of goods produced from the use of natural resources. Mechanisms are needed so that the full costs of the use and management of natural resources are reflected in the prices paid by the ultimate consumers of the resource or products derived from it.

CONCLUSIONS

This quote from Dr John Williams, Deputy Chief of CSIRO Land and Water, encapsulates the issues we face in management of land and water resources:

"Our rural production has been built by drastically changing the nature and seasonal patterns in the water and nutrient cycles of the continent. Our present systems are not sustainable because they leak water and nutrients. We desperately need solutions to plug the leaks and capture both water and nutrients for productive use"

Current legislation aims for ecologically sustainable development, but pressures for economic development, vested interests and political reality will make this difficult to achieve.

New legislation allows for the empowerment of local communities in management of the groundwater resource, reducing the direct influence of political pressure and centralised government. The major risk is that these local community groups can be 'hijacked' by vested interest groups, especially if the groups are political appointees.

Historically, groundwater management has moved from an engineering focus to the current 'economic rationalist', economic-commodity-based focus. Future management needs to fully recognise and adopt a broader, environmental-ecological focus, with economic and engineering factors being considered within this over-riding context.

The major challenges faced are in defining sustainability and then developing and implementing policies that achieve it in the face of numerous competing pressures.