Summary
This project aimed to improve understanding of how climate variability and climate change influence the groundwater impacts of commercial forestry plantations in South Australia’s Lower Limestone Coast. The study developed climate-driven evapotranspiration models using long-term field measurements from plantation forests and applied them to estimate groundwater extraction and recharge reduction across different climatic conditions, plantation types, and groundwater depths. Researchers assessed how plantation water use varies through the forest rotation and compared modelled groundwater impacts with the “deemed” water use rates currently used for plantation water licensing.
The results showed that groundwater impacts vary significantly across locations and over time, reflecting differences in rainfall, evaporative demand, plantation age, and groundwater accessibility. The modelling indicated that the current deemed rates generally overestimate the groundwater impacts of plantations, particularly as they do not adequately account for groundwater recharge during the early stages of plantation establishment. The project demonstrates that climate-responsive modelling can support more accurate, flexible, and scientifically robust groundwater allocation and management decisions for forestry regions
Acknowledgement of funding
This report was commissioned by the Green Triangle Forestry Hub with funding from the Australian Government, Department of Agriculture, Fisheries and Forestry.
Disclaimer
Reports prepared for Regional Forestry Hubs, and any recommendations contained in the reports, are provided as received by the Hub and are not endorsed positions of the Hub. They do not constitute Australian Government policy.
