1.1.6 Surface water – groundwater interactions


The near-surface groundwater flows in the Sydney Basin bioregion are described within their geological settings. Groundwater flows in the central and eastern portion move laterally across different scales, from local to regional, and in general discharge into surface water bodies and rivers. In the north-west part of the bioregion the landscape is more rugged and incised, with local-scale flows driven by topography. Watercourses are net gaining with respect to groundwater under natural conditions.

Previous work in the vicinity of mines and borefields provides insight into natural and disturbed flow behaviour. Hydrological investigations of undisturbed streams and hanging swamps indicate that local, perched groundwater tables are the primary source of baseflow sustaining these surface features, and have little connection to deeper, larger-scale groundwater systems. Where a disturbance creates a linkage between flow scales and geological units, water flows are observed to be away from the surface, reducing baseflow and groundwater discharge.

Last updated:
21 January 2019
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