Since the founding of Groundwater Logic in April 2015, we have completed projects for a range of private and public sector clients, examples of which are outlined below.

Water Supply and Natural Resource Management

Baseflow Characterisation and Stream Depletion Risks (2015-current)

Client:  GHD / Victorian Department of Environment, Land and Water Planning (DELWP).

GHD and Groundwater Logic developed and implemented a rigorous, efficient and cost-effective method for quantifying groundwater-surface water interactions (baseflows) across thirteen Victorian river basins, and assessing ecological and equitability risks of groundwater and surface water usage to these interactions. The method involves quantification of groundwater discharge to streams using a geochemical (electrical conductivity (EC)) mass balance approach, at both the catchment scale upstream of gauges, and at the reach-scale between gauges. A digital filter is subsequently trained to the baseflow estimates of the EC mass balance, to produce a continuous estimated baseflow time series for the entire gauge record. The project involved a thorough assessment of uncertainty, was reviewed by five independent reviewers, and has been applied to more than sixty Victorian stream gauges.

GHD and Groundwater Logic recently completed a validation process for three Gippsland rivers, utilising detailed radiometric and major ion surface water and groundwater surveys from Monash University. We are currently undertaking field verification of the method for three rivers in Gippsland.

Technical Review of GDE Wetland Quantification Project (2015)

Client: Department of Environment, Land, Water & Planning (DELWP)

Independent technical review and evaluation of the underlying methods used in DELWP's and Jacobs' "Assessment of ecological impacts to groundwater dependent wetlands from water extraction" project. This project aimed to prepare a cost-effective method for determining and identifying the potential impacts of water extraction on the environmental values of groundwater dependent wetlands in Victoria. Groundwater Logic was engaged to provide an assessment of the project with reference to the Australian Groundwater Modelling Guidelines (Barnett et al., 2012), and whether the deliverables (a report and spreadsheet tool) were fit for purpose.

Menindee Lakes Phase 2 Groundwater Modelling (Ongoing)

Client: Jacobs

Groundwater Logic is currently sub-contracted to Jacobs to provide technical support for the development of a numerical groundwater flow model of the Menindee Lakes area, NSW. The model, being developed for WaterNSW, will be used to investigate a potential potable groundwater supply to Broken Hill. The model is being developed in MODFLOW-USG, using a quadtree mesh. Uncertainty analysis will be carried out using PEST.

Anglesea Borefield Project: Sustainable Yield Assessment (2015)

Client: GHD / Barwon Water

Barwon Water investigated and developed the Anglesea Borefield, an urban groundwater supply, between 2007 and 2010, in response to severe water shortages at that time. Development of the borefield was supported by a series of field and desktop investigations, including integrated numerical modelling of groundwater and surface water flows to provide a tool for assessing potential borefield impacts. One of the highest impact risks identified was the potential to impact the ecology of the Anglesea Swampland. Subsequently GHD assisted Barwon Water in proposing groundwater level management triggers to protect the swamplands.

In Barwon Water's Water Supply Demand Strategy 2012, they had included 7,000 ML/year to be available from the Anglesea Borefield. The objective of this project was to assess the implications of the swampland triggers for the potential future borefield yield. Groundwater Logic utilised the integrated groundwater-surface water model, developed by Chris Nicol whilst employed by GHD, to assess this under a range of climate change scenarios and with reference to continued operation or cessation of Alcoa's Anglesea coal mine. Limited uncertainty analysis was also undertaken.

Dewatering and Environmental Impact Assessments

Groundwater Flow Model - Open Cut Coal Mine (2015-16)

Client: SRK / Glencore

Groundwater Logic developed a numerical model that is to be used to assess water management issues and the potential mining-related effects on surface water and groundwater water resources around an existing open cut coal mine. The model was developed in MODFLOW-USG using a Voronoi mesh constructed using AlgoMesh. It was designed to simulate historical underground mine workings, open cuts now used for water storage, actively mined open cuts and spoil and tailings disposal areas, in addition to surface water systems. MODFLOW-USG's Time-Variant Materials package was used to simulate pit backfilling and fracturing above underground workings. mod-PATH3DU was used for particle tracking. The model was calibrated using manual and automated methods (PEST), using a range of observation types including heads, head differences, dry and artesian bores, seepage locations, and qualitative information on mine water inflows.

Technical Support and Guidance

Latrobe Valley Regional Model Update Support (2015-current)

Client: GHD

Groundwater Logic is currently engaged to provide technical support to GHD staff in updating the MODFLOW-USG model maintained by the Latrobe Valley Regional Monitoring Committee. This model is used to simulate coal mine depressurisation and land subsidence effects throughout the Latrobe Valley. Chris is providing technical advice on model re-design, and implementing PEST for model calibration to groundwater level and subsidence data.

General Modelling Support

Client: HydroSimulations (2015)

Groundwater Logic was engaged to provide technical support and guidance to HydroSimulations staff in building and calibrating a groundwater flow model of the Galilee Basin using MODFLOW-USG for Geoscience Australia. Due to the large basin and model extent, an unstructured grid was employed to enable fine detail in areas of interest without compromising model run times and file sizes. Groundwater Logic has also provided ad-hoc support on two other groundwater flow models, which have been developed by HydroSimulations for the purpose of assessing the effects of coal mines on groundwater and surface water systems.

Custom Model Processing Utility Development

MODFOW-USG Pressure Head Cross-Section Tool (2015)

Client: HydroSimulations

Groundwater Logic was engaged to develop a Python / GIS tool for semi-automated extraction, contouring and plotting of hydrogeological (head and pressure head) cross-sections from unstructured MODFLOW-USG models. Commercial Graphical User interfaces for unstructured models are not yet sufficiently developed to provide such plotting capabilities. The developed tool extracts and contours modelled head and/or pressure head data from any number of models, model output times and cross section locations, and plots ancillary features such as mine infrastructure locations, and model layers/geology.