Improving Adelaide’s Groundwater Management for Managers & Decision Makers

This free webinar will provide participants with an overview of the outcomes of a recent study on the groundwater resources of the Adelaide Plains. The webinar will focus on the used multi-methodology approach, in particular the regional groundwater modelling and scenario analysis. Please note that this webinar will run: 3.30-4.30pm AEDT (Adelaide time). For AEST the time is 4.00 pm - 5.00 pm.

Change my region
Change my timezone

Sessions

No sessions found.

Description

Groundwater is a strategic and vital resource in South Australia playing a crucial role in sustaining a healthy environment, as well as supporting industries and economic development. In the Adelaide metropolitan region ten different aquifer units have been identified, extending to more than 500 m below sea level. Although salinity within most of these aquifers is variable, water suitable for commercial, irrigation and/or potable use is predominantly found in the deeper Tertiary aquifers. Major industries, market gardeners, golf courses, and local councils are highly dependent on this resource. Despite recent rapid expansion in managed aquifer recharge, little is known about the sources and ages of Adelaide’s groundwater.

The study focuses on three important knowledge gaps:

1. Does groundwater flow from the Adelaide Hills into the sedimentary aquifers on the plains?

2. What is the potential for encroachment of seawater if groundwater extraction increases?

3. How isolated are the different aquifers, or does water leak from one to the other?

A multi-tool approach has been used to improve the conceptual understanding of groundwater flow processes; including the installation of new groundwater monitoring wells, an extensive groundwater sampling campaign (chemistry and environmental tracers), and development of a regional scale numerical model rigorously tested under different scenario conditions. The model allowed quantification of otherwise hardly quantifiable quantities such as flow across fault zones and through aquitards. Scenario modelling allowed analysis of the water resources status up to 2100. This includes several development scenarios (current or increased/decreased extraction rate) as well as taking into account outputs from climate change predictions and potential increase of MAR. The modelling results show that the regional groundwater system is severely stressed. The main aquifers provide water from storage, which is replenished by water from formations with decreasing storage above and below the main aquifers. The salinity distribution along the coastline is shown not to be simply an equilibrium situation with an intruded seawater wedge extending inland. Tertiary aquifers can still contain old freshwater near the coast, and in deeper layers a hypersaline brine has been identified, which could constitute a previously-overlooked source of salinity. This study is the first comprehensive investigation of the groundwater resources within the Adelaide environment and supports strongly integrated water management of the resource.

Presenters:

Professor Okke Batelaan – Flinders University
Okke Batelaan is a Strategic Professor hydro(geo)logy, School of the Environment, Flinders University. Professor Batelaan has extensive research experience and a publication record in hydrogeology, shallow groundwater hydrology and modeling, recharge-discharge estimation and modeling, urban hydrology and distributed modelling, ecohydrology and impacts of landuse and climate change on groundwater systems. He is editor-in-chief of Journal of Hydrology: Regional Studies and MDPI-Hydrology. He wass coordinator of the Goyder Institute for Water Research project ‘Assessment of Adelaide Plains Groundwater Resources’.

Dr. Etienne Bresciani – Flinders University

Dr Bresciani is a hydrogeologist specialized in regional groundwater modelling. His main research focuses on the development of modelling tools and strategies for the investigation of groundwater flow and groundwater-surface water interaction at the regional scale. After graduating from a Ph.D. in Earth Sciences at the University of Rennes 1 (France) in 2011, he joined the NCGRT at Flinders University as a post-doctorate fellow in 2012. Since then he participated in a number of research projects including the Goyder project for the Assessment of Adelaide Plains Groundwater Resources.