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:

European settlement:

Development of irrigation

Table: the recent use of the groundwater resource

Ware usePresent
(Megalitres)
1984
(Megalitres)
Irrigation:  
Unconfined aquifer
141 000200 000
Confined aquifer
32 00037 000
Public water supply7 7008 800
Stock supplies17 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 pasture150
Pasture seed production500
Dairying750
Potato growing800
White wine grapes3500
Red wine grapes5000
Paper and pulp mill6000

DEVELOPING PROBLEMS WITH THE GROUNDWATER SYSTEM

Recognition of developing problems

Subsurface drainage of pollutants:

Engineering & Water Supply Department:

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

Water Resources Acts of 1976 and 1990

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:

Mechanisms:

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:

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.

AreaYear proclaimed
Padthaway1975
Tatiara1984
Naracoorte Ranges1986
Comaum-Caroline1986
Lacepede-Kongorong1997
Tintinara-Coonalpyn1999 (put under restriction)

General policies:

THE FUTURE OF GROUNDWATER MANAGEMENT

Major issues:

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.