Coastal hazard monitoring

Monitoring Coastal Hazards – Breakwalls

Breakwalls are a common coastal engineering structure for coastal defense or to protect an area for anchorage and marinas. However, during hazardous events, such as, strong swell, overtopping can occur and in effect can turn breakwalls into a serious coastal hazard.

Overtopping can cause risk to life, damage to vessels and infrastructure, as well as the existing structure.

By monitoring coastal structures, coastal engineers can make a clear judgement on the stability, safety and effectiveness of coastal structures. Continuous long-term data sets also support public perception and management outcomes.

CoastalCOMS was approached by GHD to monitor the northern breakwater that joins Muttonbird Island to the mainland at Coffs Harbour in NSW.

This is important monitoring site because the NSW Government has awarded a contract to the Bureau of Meteorology to establish a wave forecasting and overtopping alert notification system (in conjunction with Nat Patterson, Evan Watterson and the SMEC team).

Whilst the Bureau of Meteorology system is meeting the NSW Government immediate needs, there is no option within this system to verify the forecasts. However, the examination of the waverider buoy data and visual cross checks from the CoastalCOMS cameras at Jetty Beach and Park Beach the forecasts can be verified.

The process to verify forecasts

2 X HD CoastalCOMS cameras recorded 3-months of visual cross checks taken daily 5 minutes each side of the high tide.
Video processing was stored within the CoastalCOMS EnviroCOMS System.
Visual data was fused with third-party data including the BOM Automatic Weather Stations, NOAA WW3 and tide predictions.
Automatic reports were generated to streamline data processing and the visualisation of results.

Benefits of the CoastalCOM VMS for coastal monitoring

Aggregate data for optimal visualisation and reporting
A continuous data set in all weather conditions
Saved time with the automatic scheduling of recording data and calibration of physical models
Produced a consistent dataset and visual footage to validate theoretical model

Opportunities for coastal hazard management
Need to apply this service to other coastal projects to validate business benefits
Encourage Governments to use the service so consultants can access a comprehensive data set
Having the system set-up pre, during and post project ensures the full picture can be captured
The system provides value for coastal hazard management, e.g. data is in one place and enables coastal managers / engineers the ability to make a clear judgement on what happened during events (e.g. strong swell) to confirm the value of structures.
Having video data means you can go back and look at when the structure failed and provides coastal engineers with detailed data of the method of failure