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Groundwater Modelling

In 2007 ecoMarkets initiated a state-wide program to develop groundwater models for each of Victoria's ten Catchment Management Areas. Now completed these groundwater models give Ensym the ability to assess the impacts of land use change and water use change on groundwater regimes and stream aquifer interaction at the catchment scale.

A staged approach was adopted during the development of each groundwater model. The initial phase involved the conceptualisation and development of a multi-layered steady state groundwater model. The second phase involved the refinement and expansion of the phase one outputs which lead to the construction of a multi-layered transient groundwater model.

The development of each groundwater model had to conform to the following minimum specifications:

  • Finite difference gridding at a maximum of 200 metre cell size; - Multi-layer groundwater model (representing major geological units) consistent with existing models;
  • Common boundary conditions and consistent aquifer parameters with adjacent models (as arising from the state-wide groundwater modelling workshop outlined below);
  • A normalised (scaled) RMS of less than 5 per cent for steady-state based on matching mapped depth to watertable;
  • A normalised (scaled) RMS of less than 10 per cent for the transient model based on matching mapped depth to watertable, sub-catchment baseflow and groundwater hydrograph responses for selected and agreed groundwater monitoring bores;
  • A calibration period of no less than 10 years;
  • A sensitivity analysis to assess the variability of modelled outputs to variations in key model input parameters;
  • Catchment groundwater water balance error of less than 2 percent;
  • All catchment water balance features to be considered and reported;
  • The source and a statement of quality of all input data sets to be reported;
  • At least 500 groundwater monitoring observation bores used for calibration (if > 500 present);
  • Model domain represents the entire extent of the catchment management area, and
  • The steady-state and transient groundwater recharge layers developed and provided by DSE are to be incorporated unaltered into each model unless demonstrated to be erroneous.;

At the end of each phase the models were independently reviewed in accordance with the Murray Darling Basin Authorities Groundwater Modelling Guidelines (Middlemis, 2001) which is Australian best practice guideline for groundwater flow modelling, including review and appraisal.

The review process was conducted via direct informal communication between developer and reviewer in conjunction with five structured workshops, held at key stages of the groundwater models development, including:

  • Informal review workshop - following collation of all relevant data sets and development of preliminary aquifer conceptualisation
  • State-wide groundwater modelling workshop - Carried out post preliminary conceptualisation to ensure consistency between model areas
  • Phase 1 model review workshop - Formal presentation of the final aquifer conceptualisation and a calibrated steady-state multi layered groundwater model for review.
  • Phase 2 model review workshop - Formal presentation of the calibrated Phase 2 transient multi layered groundwater model and report for review.
  • Final State-wide groundwater modelling workshop - Presentation of the final groundwater model to DSE and Rural Water Authorities, including discussion on the development, review process and model limitations.

Each of the model development reports are available for download below (Warning. Large file size)

For more information on the EcoMarkets groundwater models please contact: This e-mail address is being protected from spambots. You need JavaScript enabled to view it

North East - developer Hocking et al, reviewer Parson Brinkerhoff

Goulburn Broken - developer Hocking et al, reviewer SKM

North Central - developer Hocking et al, reviewer Parson Brinkerhoff

Mallee - developer Aquaterra, reviewer Australian Water Environments

Wimmera - developer Hocking et al, reviewer Aquaterra

East Gippsland - developer GHD, reviewer Parson Brinkerhoff

West Gippsland - developer GHD, reviewer Parson Brinkerhoff

Port Phillip and Western Port - developer GHD, reviewer Aquaterra

Glenelg Hopkins - developer SKM, reviewer URS

Last Updated on Thursday, 22 March 2018 00:56

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