PRW in the Lockyer Valley
The SEQ Water Strategy 2010 indicated that up to 32,000 megalitres per year of recycled water would be made available for rural production in the Lockyer Valley when not required to supplement Wivenhoe Dam. The Lockyer Valley has both a high intensity of agricultural enterprise and a complex hydrogeology. Provision of recycled water in an environmentally sound and socially equitable manner requires a good understanding of the likely influences including the hydrogeological response.
The estimation of sustainable groundwater yields can be performed using numerical groundwater models, but relies on the results of a metering program quantifying abstraction rates by irrigators. Currently, only part of the Lockyer Valley is metered for groundwater use, leading to considerable uncertainty regarding the influence of agriculture on groundwater levels and conditions. Extension of the metering effort is in progress.
This project aimed to provide a scientific basis for the sound delivery of purified recycled water (PRW) to the Lockyer Valley. The research delivered methodologies to improve water delivery using aquifer storage, while recognising concerns over common pool access. Our research questions included:
- How can robust quantifications of sustainable yield considering evolving metering programs?
- What are the optimum patterns for importing recycled water into the Lockyer Valley?
- What is the impact of climate change on the Locker Valley water system?
- What is the anticipated response of soils, creek bed sediments and aquifers to the use of Purified Recycled Water in the Lockyer?
- To what extent can the Lockyer Valley aquifer serve as a buffer in the SEQ Water Grid?
Key Publications and Outputs
A literature review was undertaken. Fieldwork was undertaken to assess potential impacts of PRW on soils and salinity and to define water demand and irrigation practices. A numerical groundwater model was created and used for simulations and assessment of yields.
- Technical Reports 60 and 103 address aspects of the project.
- Conference papers listed on the Alliance website
- Proceedings of the Alliance Science Forums
The knowledge generated in this project will be directly relevant to the SEQ water supply strategy. It will inform the sustainable management of recycled water use and overall water balance in the Lockyer Valley. In addition, it provides a framework for assessing the impacts of using fit-for-purpose recycled waters for irrigation in other regions across Australia.
CSIRO Water for a Healthy Country Flagship
Ph: +61 2 6246 4565