Evaluation of dairy effluent management options using multiple criteria analysis.

Area of Science:

• Environmental Science
• Agricultural Management
• Water Quality

Background:

• Dairy farming in the Lower Murray River region historically used flood irrigation, returning effluent to the river.
• Effluent contained nutrients, salts, and microbial contaminants, causing environmental, health, and tourism issues.
• Existing practices posed significant challenges to water quality and ecosystem health.

Purpose of the Study:

• To evaluate various management options for dairy effluent in the Lower Murray River.
• To apply a structured decision-making framework for complex environmental policy.
• To identify a sustainable solution balancing environmental, social, and economic factors.

Main Methods:

• Utilized Multiple Criteria Analysis (MCA), a framework for integrating diverse objectives.
• Assessed 11 distinct dairy effluent management options.
• Evaluated options against 6 predefined criteria, including environmental, social, and economic considerations.

Main Results:

• The MCA model identified partial rehabilitation of dairy paddocks as the optimal solution.
• This approach involved converting remaining land to alternative agricultural uses.
• The selected option aimed to mitigate the negative impacts of dairy effluent.

Conclusions:

• The South Australian Government adopted the MCA-recommended strategy for dairy effluent management.
• Incentives are now provided to dairy farmers for infrastructure upgrades or industry transition.
• The study provides a successful case of applying MCA to resolve regional environmental challenges.