Managed aquifer recharge for agriculture in Australia – History, success factors and future implementation

Managed aquifer recharge (MAR) is the intentional recharge of water to aquifers for subsequent recovery or environmental benefit. MAR can potentially increase security of water in drought more economically than new dams, can augment existing dams with higher efficiency storage (less evaporation), augment brackish groundwater desalination schemes, and facilitate conjunctive use of surface and groundwater resources. In Australia in 2023, there are currently 10 known operational MAR schemes used to increase agricultural activity in varying stages of development, providing a total capacity of ∼ 70 × 106 m3/year. A review of these Australian MAR schemes identified several general principles which are more likely to lead to successful implementation, including: an ongoing demand for water for high value agriculture; availability of water for recharge; a suitable aquifer for storage with the capacity to store water for recovery and use; a suitable location for the MAR scheme typically in areas of low topographic relief; and the organisational capability, institutional arrangements and supportive policies to operate the scheme sustainably and economically. If MAR schemes are to be developed to support agricultural activity in Australia, site identification, project design, economic viability, and community and regulator consultation within an investment prospectus will be required. Operational demonstration schemes in a variety of agricultural settings will encourage wider adoption. Supportive policy development is required to ensure sustainable and equitable ongoing operation of MAR to support irrigated agriculture and for drought resilience.