2019-12-16 GC Agenda - Item 5 - Attachment 1 - Noosa Spit Shoreline Erosion Management Plan-Part 2

7.0 Summary
The 2019 swath bathymetry and backscatter survey was a success in terms of providing very
detailed information about riverbed features within the catchment and the offshore area
around the entrance to the Noosa River. The data should assist the current modelling efforts
for bank erosion, and future promotional presentations for the general Noosa public.
Although a quantitative assessment of the 2010 SBES survey and the 2019 swath bathymetry
survey wasn’t possible, the qualitative comparison between the 2010 charts and 2019
contours looks good. The 2019 contours extracted from the swath bathymetry align nicely
with the contours in the 2010 charts in test areas presumed to be free of substantial
deposition or erosion.
The backscatter data acquired with the bathymetry data should be useful for future programs
planned by the Noosa Council. A small section of the data was presented in this report but
more exists across all of the survey area. Possible uses of the data include seabed
characterisation (regional and local), identification of features within the river (e.g., debris,
rock areas, etc.), and monitoring of slips/slides along the banks of the river.
Although other techniques might be adopted for regional surveying of the river in the future
(e.g., drone-based Lidar or Satellite Derived Bathymetry) the acoustically derived data that is
a part of this survey provides a highly detailed snapshot in time of the current Noosa River
state. As such, it will be invaluable for future monitoring efforts. The detailed imagery should
also be of interest to the Noosa public and AI will continue to assist the Noosa Council in
generating products that might illustrate the work conducted here.




23                             Noosa Council - Noosa River Survey                      20.06.2019