This layer provides the boundaries of the Groundwater Catchments of Victoria and is a product of the NWC funded Secure Allocations, Future Entitlement (SAFE) Project. The Groundwater Catchments (GC) have been developed to provide complete coverage of Victoria while considering the following: (1) Reflect aquifer systems and groundwater movement; and, (2) Align with physical (i.e. surface water) and administrative boundaries where appropriate. The GCs are aligned within Victoria’s Groundwater Basins (GB). Boundaries that related directly or in-directly to the physical characteristics of groundwater resources included groundwater flow divides, surface water flow divides, topographic divides, and geological structural features that influence aquifer extent and groundwater flow direction. Administrative boundaries directly linked to the management of groundwater resources include: The Victorian State Boundary (Water Act (1989); WSPA: Water Supply Protection Area (formally declared under provisions of the Act); GMA: Groundwater Management Area (described and lodged as a plan with the Central Plan Office); RWC: Rural Water Corporation administration areas - Grampians Wimmera Mallee Water (GWMWater), Goulburn Murray Water (GMW), Lower Murray Water (LMW) and Southern Rural Water (SRW); and MDBA: Murray Darling Basin Authority (Federal Water Act (2007)). The description of water resource management is often described in terms of surface water and groundwater. In reality, the two resources are connected; however there are differing degrees of interconnection depending on the groundwater system and location within the surface water catchment. In preparing the Groundwater Catchments (GC), surface water catchments were directly considered. The key surface water boundaries considered are: Victorian Sustainable Diversion Limits (SDL) Catchment boundaries; Bureau of Meteorology (2011) Surface Water Basins (Australian Hydrological Geospatial Framework, product suite v2 2011); Victorian Surface Water Basin Catchment (Australia’s River Basin, 1997); and, Geoscience Australia (500 sqkm) National Nested Catchment.

This dataset representst Victoria’s Groundwater Management Areas (GMAs) Where groundwater has been intensively developed in Victoria, or has the potential to be developed, Groundwater Management Areas (GMAs) are established and the Permissible Consumptive Volume (PCV) is progressively set. Monitoring of the groundwater resource in these areas is undertaken by the Department of Sustainability and Environment through the State Groundwater Monitoring Network. Water levels and the amount of water allocated to groundwater users in the areas are closely monitored.

## **Abstract** This dataset and its metadata statement were supplied to the Bioregional Assessment Programme by a third party and are presented here as originally supplied. DEPI originally engaged GHD to develop seamless 3D aquifer surfaces for the Victorian Aquifer Framework (VAF). The seamless mapping of aquifers across the state provides the fundamental framework for groundwater resource management, underpins development of a revised management structure for Victoria (the Secure Allocation Future Entitlement project funded by the National Water Commission) and contributes to the data needs of the Bureau of Meteorology National Groundwater Information System (NGIS). The original dataset was produced by GHD in 2012 using (in part) data provided by Southern Rural Water Corporation and Goulburn-Murray Water Corporation. It has been subsequently amended by Hocking et al and SKM in 2013. ## **Dataset History** A number of key input datasets were sourced as part of the process to derive the 3D aquifer surfaces. These datasets included: The DEPI State-wide Stratigraphic Database (SSD); The National Groundwater Information System (NGIS) database containing groundwater borehole location information as well as lithological and stratigraphic information; Raster layers previously produced for Southern Rural Water (SRW) by SKM and GHD in 2009; The crystalline basement surface provided by the former Department of Primary Industries (DPI); Outcrop 1:250,000 scale geological mapping compiled by the former Geological Survey of Victoria, DPI; A state-wide 100m Digital Elevation Model (DEM) based on the DEPI 20m DEM. This was used to represent the natural surface; Data generated using DEPI's state-wide ecoMarkets groundwater modelling package to assist with the definition of key layers of the major Cainozoic aquifers; Latrobe Valley Coal Model which was used to provide a framework for the hydro-stratigraphy of the wet Gippsland Basin; Rasters of the top elevation of the major aquifer systems covering the Kiewa, Ovens, Goulburn-Broken and Loddon and Campaspe catchments; Data extracted from the Basin in a Box, the Murray Basin Hydrological Map Series and the Murray-Darling Basin Groundwater Status 1990-2000: Summary Report; Airborne magnetic data publicly available from raster data published by the former Geological Survey of Victoria, DPI. Once the input data had been compiled, the VAF 3D surfaces were developed by lfollowing a number of key steps, summarised below: (1) Contours as polylines and aquifer extents as polygons were extracted from previous mapping surfaces; (2) Outcrop points attributed with values from the DEM were created; (3) Based on the state-wide stratigraphic database, the contours and extents were refined or created; (4) A top elevation raster was interpolated using contours, outcrop points and bore data then replacing outcrop areas with the DEM; (5) The aquifer thickness was then checked in GIS by comparing layers against each other and assessing for cross-overs and negative thickness; (6) The input data was then revised and bore data, contours, and aquifer extents modified as required due to errors in the thickness; (7) If there were subsequent issues identified such as overlaps between aquifers, mismatches between bores and resulting layers, then the process was revised by returning to Step (3); (8) If the layers were matching well, then extent points were created to smooth layers at the edges; (9) A top elevation raster was generated again using contours, outcrop points, extent points and bore data; (10) The aquifer thickness was checked again, and if significant issues were identified, then the process returned back to Step (3) for further iteration; (11) Further modifications were applied to remove negative thicknesses and to provide minimum thickness of overburden; (12) Top and bottom elevation rasters were then generated at 100m pixel resolution to form the final dataset. In generating each of the layers, a number

Purpose: Management of Groundwater resources in Western Australia. Groundwater Resources stored in WRIMS (Water Resource Information Management System). The intersection of groundwater Subareas with Aquifer boundaries (usually) define groundwater Resources, which are the units used by the DWER to manage environmentally sustainable limits of extraction for groundwater resources. For the purposes of groundwater resource management, the state of Western Australia is divided into groundwater areas proclaimed under the Rights in Water and Irrigation Act. These groundwater areas are further subdivided into groundwater subareas. The subareas are not proclaimed under the Rights in Water and Irrigation Act, but are administrative boundaries used to manage the extraction and licensing of groundwater resources. Groundwater Resources in this dataset are not always the intersection of a Subarea with an Aquifer. Additionally, the Groundwater Areas stored in WRIMS do not accurately reflect the official gazetted Groundwater Area boundaries. A program is currently underway (Sept 2005) to review both Groundwater Resource and Groundwater area boundaries. Please contact the data steward for more information.

Surface Water Management Areas for Western Australia were derived in consultation with the regional offices, geometry is based on hydrographic subcatchments. Regional Department of Environment officers identified areas of similar management requirements to define boundaries. Management areas will be used for licencing and administrative purposes. Purpose: The Surface Water Management Area data was developed in order to give a clear understanding of surface water availability and to provide management tools to make good water allocation and natural resources management decisions. Dataset was formally known as Surface Water Management Areas (DOW-020)