Home / Environment / Australia's Forests Drink Groundwater Dry
Australia's Forests Drink Groundwater Dry
14 Sep
Summary
- Plantations reduce rainfall reaching groundwater in South Australia.
- Groundwater recharge reduced by up to 83% under plantations.
- Wetlands decline as shallow groundwater levels drop.
South Australia's Lower South East, part of the Green Triangle region, is experiencing significant pressure on its groundwater system. Decades of land conversion to commercial forestry, including extensive softwood and hardwood plantations, have led to reduced rainfall reaching groundwater reserves. Where water tables are shallow, these plantations directly consume underground water.
Assessments indicate a substantial decrease in groundwater recharge beneath plantations, with reductions estimated at 78% for hardwood and 83% for softwood forests compared to former dryland agricultural landscapes. This water usage by approximately 103,000 hectares of softwood and 43,000 hectares of hardwood plantations affects about 32% of the region's allocable groundwater.
The direct impact on water availability has led to a decline in the condition of groundwater-dependent wetlands, such as the Ramsar-listed Bool and Hacks lagoons. These vital ecosystems, relying on shallow groundwater, are highly vulnerable to even small declines. The situation is compounded by overallocation of groundwater resources, with current levels deemed unsustainable for the future, especially with changing climate conditions.
