Nuisance Inundation at Selected South East Australian Estuary Sites

Mr Dave Hanslow1

1Nsw Office Of Environment And Heritage, Dangar, Australia


Global sea levels are rising and likely to have an increasing impact on coastal communities over the coming decades and centuries. NSW communities are known to be highly vulnerable to sea level rise with exposure greatest in low lying areas adjacent to estuaries. Increasing extent and frequency of inundation is likely to be one the more obvious impacts of sea level rise.

The potential impact of sea level rise on coastal infrastructure and communities is known to be partially dependent on the magnitude of current tide range and sea level extremes. The smaller the tide range and magnitude of extremes the greater the potential impact of sea level rise. In several places internationally, the impacts of sea level rise are already evident through increasing frequency of inundation of low-lying areas -so called ‘nuisance inundation’ or ‘sunny day flooding’.

In this study we examine the occurrence of tidal inundation at selected estuary sites in NSW. We combine observations of local inundation, high resolution digital elevation data with local tide gage data to identify thresholds for nuisance inundation at selected estuary sites. These thresholds are linked with the inundation of streets and foot paths. We explore changes in the frequency of inundation to date and examine the likely implications of relatively modest amounts of sea level rise on the frequency of inundation.


Dave is the senior team leader for the coastal and marine science team at the NSW office of Environment and Heritage