Using Resource Condition Limits to Define Groundwater Management Objectives in the Barossa Valley, South Australia

Abstract

Groundwater resources are of vital importance to the iconic Barossa Valley wine producing region in South Australia. This case study outlines a new approach to determining water entitlements for a revision of the Water Allocation Plan that regulates the use of groundwater. Resource managers have been engaging stakeholders in a discussion about resource condition limits in newly defined management areas. This approach is becoming more widely adopted and provides greater transparency in linking rates of groundwater extraction to unacceptable impacts on users, including the environment. In this instance, a numerical flow model has been used to estimate the likelihood that a certain level of pumping will result the condition of the system declining in coming decades beyond a certain state as measured by resource condition indicators such as water levels, groundwater discharge to streams and the ingress of higher salinity groundwater. In management areas where the resource is more vulnerable to short term changes in condition, a more responsive management regime is being developed where allocations can vary on an annual basis. This case study presents a useful prototype for more responsive and participatory management for other regions which face the uncertainties of climate change and increased demand due to economic pressures.