Hydrologic Soil Groups (HSG) of NSW

This map provides an estimation of Hydrologic Groups of soils in NSW according to the four class system (A-D)

• A — soils having high infiltration rates, even when thoroughly wetted and consisting chiefly of deep, well to excessively-drained sands or gravels. These soils have a high rate of water transmission and have low water run-off potential.

• B — soils having moderate infiltration rates when thoroughly wetted and consisting chiefly of moderately deep to deep, moderately fine to moderately coarse textures. These soils have a moderate rate of water transmission.

• C — soils having slow infiltration rates when thoroughly wetted and consisting chiefly of soils with a layer that impedes downward movement of water, or soils with moderately fine to fine texture. These soils have a slow rate of water transmission.

• D — soils having very slow infiltration rates when thoroughly wetted and consisting chiefly of clay soils with a high swelling potential, soils with a permanent high water table, soils with a claypan or clay layer at or near the surface, and shallow soils over nearly impervious material. These soils have a very slow rate of water transmission.

The map uses the best available soils mapping coverage and was derived from a lookup table system linking a Hydrologic Group class to a particular soil type using the Great Soil Group (GSG) classification. Each dominant GSG has been assigned a Hydrologic Soil Group.

The classification is based on the United State's Hydrologic Soil Group system published within the National Engineering Handbook (2007).

Online Maps: This dataset can be viewed using eSPADE (NSW’s soil spatial viewer), which contains a suite of soil and landscape information including soil profile data. Many of these datasets have hot-linked soil reports. An alternative viewer is the SEED Map; an ideal way to see what other natural resources datasets (e.g. vegetation) are available for this map area.

Reference: Department of Planning, Industry and Environment, 2021, Hydrologic Soil Groups of NSW, Version 4.5, NSW Department of Planning, Industry and Environment, Parramatta.