Summary
This project aimed to improve understanding of groundwater recharge beneath softwood and hardwood plantations in the Green Triangle region and assess whether current groundwater management assumptions accurately reflect plantation water dynamics. The study investigated groundwater responses to a major rainfall event in November 2007 and analysed long-term groundwater monitoring data collected between 2005 and 2019. Researchers examined manual water level measurements, continuous data logger records, rainfall data, and groundwater recharge estimates from observation wells located in and around plantation forests. The findings showed that groundwater recharge does occur beneath plantation forests, including both pine and blue gum plantations, despite the assumption in the Lower Limestone Coast Water Allocation Plan that closed-canopy plantations generate no recharge. Recharge levels varied across locations and were influenced by factors such as rainfall, depth to groundwater, plantation density, roadsides, and firebreaks. The study concluded that groundwater recharge under forests is generally lower than under open pasture but remains significant. It recommended revisiting current water allocation assumptions and expanding groundwater monitoring to support more accurate and adaptive water resource management.
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.
