Foreshore Assessment of Shoreline Change and the Impact of Waves on Lake Macquarie

about 1 year ago
Marks point belmont south

The Foreshore Assessment of Shoreline Change and the Impact of Waves on Lake Macquarie study presents an assessment of the recession, and run-up and overtopping hazard at four estuarine foreshore localities across Lake Macquarie, with Marks Point/Belmont South forming the primary study location.

The study also provides a discussion on the geomorphology and coastal processes at each location. The recession hazard has been assessed at a first pass level by applying a slight variation of Lake Macquarie Council’s ‘eShorance’ methodology for a range of sea level scenarios, with this output in the form recession hazard maps.

A necessary initial step in preparing adaptation plans is determining the potential extent or severity of the hazards which will change the nature of the Lake’s fringes. The recent floodplain management process of the Lake Macquarie waterway (WMA Water, 2012a, WMA Water, 2012b) derived the design depths and extents of extreme flooding within Lake Macquarie. However, changes around the foreshores are not limited to extreme flood levels. Other processes which require further consideration are:
  • enhanced foreshore flooding due to the additional impact of wind waves resulting in run-up and overtopping of the foreshore above the inundation water level. Some limited analysis of run-up is available in (WMA Water, 2012b), but more detail is necessary at the local scale to enable effective planning; and
  • the response (typically recession) of the unconsolidated foreshore to sea level rise.
The aim of the present study was to develop a methodology for analysing these hazards then demonstrate its application to the Belmont South Marks Point Local Adaptation Plan.

Appendix C of the report presents an Overtopping Design Study for Marks Point and Belmont South Shores in which overtopping rates for Marks Point to Belmont South shorelines (i.e. the primary study site) have been estimated for range scenarios to determine the ideal crest elevation for three typical shoreline protection designs used on Lake Macquarie’s foreshore.

If you would like more information on the report or how it relates to the Marks Point and Belmont South Local Adaptation Plan please contact the project team at council@lakemac.com.au or through "who's listening" in the right navigation panel.


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