diagram showing how to work out AHD heights

What is AHD?

AHD stands for the Australian Height Datum, which is the height of a point above mean sea level.

Mean sea level is the average height of the ocean’s surface. In Australia, that level was determined using multiple tide gauges around the country.

The Australian Height Datum is the only national system for height reference. As such, most councils require surveys to be carried out on AHD. It’s also required for new dwellings to determine the height of land relative to the sewerage connection.

Image: Intergovernmental Committee on Surveying and Mapping

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