Upper King River managed aquifer recharge investigations

Project overview

Managed aquifer recharge (MAR) is the intentional recharge of water into groundwater aquifers for subsequent recovery or environmental benefit. It can improve water security and provide a drought reserve, as water stored underground won’t evaporate like water stored in surface dams.

An investigation is underway to test whether a site in the Upper King River in the Katherine region of the Northern Territory could be suitable for MAR. In 2019-20, this region had suffered 3 consecutive below average wet seasons and the underlying Katherine Tindall Limestone Aquifer did not recharge. This led to reduced water allocations for many licence holders in the region.

A MAR scheme could provide greater water security in this region by helping to ensure water is available even after poor recharge seasons.

The project is part of a staged program based on an established Australian framework for developing MAR schemes.

Goals of the assessment

The project aims to test whether the selected site is suitable for MAR. It will consider whether a MAR scheme can provide ongoing water security to agricultural groundwater licence holders in the eastern areas of the Katherine Tindall Limestone Aquifer.

The assessment will:

• establish constructive relationships with key stakeholders (leaseholders, Traditional Owners and industry groups)
• develop baseline water quality datasets for the Upper King River and underlying Tindall Limestone Aquifer to determine suitability and potential water treatment requirements for a MAR scheme
• assess the hydrogeological suitability of the study site for the development of a MAR scheme
• assess the surface water flow characteristics of the Upper King River to determine water availability and timing of potential offtake and injection
• assess the existing legislative, regulatory and policy limitations for developing a MAR scheme at the site
• complete the first 2 stages of CSIRO’s MAR risk assessment framework and make recommendations for a future pilot program as the third stage.

The project will also address knowledge gaps regarding:

• surface water available to be injected into the aquifer
• performance of injection bores used to add water to the aquifer
• understanding of the aquifer’s geology and how water will move through the system
• water quality of the source water and the water in the aquifer, to understand how compatible they are
• possible policy constraints for MAR in the selected location.

About the Upper King River

The Upper King River is in the Daly catchment and has seasonal flows.