NSW site data into Civil 3D and QGIS: a setup checklist

Setting up a NSW site for early design means assembling four things: a ground surface (contours or a DEM), the lot boundaries from the cadastre, the right coordinate system, and the planning context from the NSW Planning Portal and the section 10.7 certificate. Get those in order before the first design model and the rest of the job runs clean. This checklist walks the steps for Sydney, Newcastle, Wollongong and regional NSW, with the formats each dataset comes out in so you load the correct file the first time.

Stage 1: Set the coordinate system first

Do this before you import anything. A surface loaded on the wrong zone lands kilometres from the cadastre.

• Pick the MGA2020 zone for the site. Most of NSW west of about Cobar is Zone 54; the coast, Sydney, Newcastle and Wollongong sit in Zone 55; the far east corner near the Victorian border can fall into Zone 56. Check which zone the site is in before you set the drawing.
• Use GDA2020, not GDA94. NSW survey data is now published on GDA2020. Mixing GDA94 and GDA2020 data shifts features by roughly a metre. The coordinate system guide covers how MGA2020, GDA94 and AHD fit together.
• Set heights to AHD. NSW elevation data is in the Australian Height Datum. Confirm your surface reads real reduced levels, not ellipsoidal heights.
• Match the project zone in Civil 3D or the project CRS in QGIS to the same MGA2020 zone before loading data.

Stage 2: Bring in the ground surface

Choose contours or a raster DEM depending on what you are doing. For early set-up and desktop review, a DEM is lighter; for a design surface, contours build a cleaner TIN. The contours or DEM article compares the two.

• Contours come as DXF, Shapefile, GeoPackage or KMZ. Load the DXF straight into Civil 3D as a surface from contour data. In QGIS or ArcGIS, use the Shapefile or GeoPackage.
• DEM / raster elevation comes as a GeoTIFF. Import it as a surface from a DEM in Civil 3D, or add it as a raster layer in QGIS and ArcGIS.
• TIN surfaces come out in DXF only. Load them directly as a surface.
• Imagery, where available, comes as a georeferenced JPG plus a KMZ overlay. Use it for context, not for measurement.
• Check the contour interval suits the terrain. The flat alluvium around the Hawkesbury-Nepean reads well at tight intervals; the sandstone ridges of the northern beaches or the Illawarra escarpment behind Wollongong need to be read at a coarser interval so the lines stay legible. The contour interval guide explains how to choose.

Stage 3: Add the cadastre and lot boundaries

The NSW cadastre gives you the lot shape, so your surface and your design sit inside the correct boundary.

• Load lot boundaries as DXF, Shapefile, GeoPackage or KMZ. The cadastre into CAD and GIS article covers the three vector formats.
• Confirm the Lot/DP against the title. NSW lots are identified by lot and deposited plan, for example Lot 12 DP 1234567. Read the label against the contract or title so you have the right parcel.
• Treat the cadastre as approximate. Digital cadastre boundaries can differ from a surveyed boundary by metres, especially in older subdivisions. It scopes the desktop review; it is not a boundary survey and is not a mark-out for design to the title line.

Stage 4: Pull the planning context

Early site set-up is not just the surface. The planning layers tell you what the ground has to carry.

• Check the LEP zone and overlays on the NSW Planning Portal Spatial Viewer. The Spatial Viewer walkthrough shows how to read zoning, flood, bushfire prone land and heritage for an address.
• Read the section 10.7 planning certificate for hazards the mapping flags, including flood, landslip, acid sulfate and mine subsidence around the Newcastle and Lake Macquarie coalfields. See how to read a section 10.7 certificate for ground hazards.
• Note the geology early. Shale in Sydney's western growth corridors weathers to reactive clay, while the Hawkesbury Sandstone suburbs are often close to benign. The ground surface alone will not tell you this; the published mapping will.
• Keep a clipped, dated set. Export each layer clipped to the site extent so your model carries only the data for this lot, with a record of when it was pulled.

Before the first design model

Line the four up and check they overlay: surface, cadastre, coordinate system and planning context. If the lot boundary sits over the contours and the levels read as AHD, you are set to model.

To get all four for a NSW address in one clipped, dated download, export site data for any address or see a sample export.

LayeredGeo lets you download site data for Queensland, New South Wales, Victoria, South Australia, the ACT and Tasmania - contours, cadastre and more - in DXF, Shapefile, GeoPackage, KMZ and raster formats, ready for Civil 3D, QGIS and ArcGIS.

About this article. Published by LayeredGeo. It is general information about how property and ground conditions are assessed in Australia, not engineering, planning, legal or financial advice, and it is not specific to any property. Check anything that matters against the source dataset or a suitably qualified professional before you rely on it. If you spot something wrong, tell us at hello@layeredgeo.com.au and we will fix it.

← All articles