Cell Descriptions - South East Natural Resources Management Board

SE15-17 – The Coorong
the dunes across from Marks Point, opposite Mosquito Bay near Gnurlung Point, and near Nine
Mile Point. The native vegetation block at ‘Potters’ also shows a high weed concentration.
There are notable concentrations of ORV activity, on cleared dunes in the south and on lakeside
mudflats in the north of the region; there is seasonal movement of ORVs along the beach south
of Princes Soak Track and into the dunes.
Adaptation to Climate Change: Threats for cells SE15-17
(see also discussion of scenario in Section 4.11
NOTE: the advice below is indicative of likely change and the direction of change, with
implications for ecosystems. Dates, amounts and probabilities cannot be accurately calculated at
this time. Thus advice on flood levels, for example, should not be used in engineering or
development planning.
Climate change
element/ scenario
Combined climate
changes and sea
level rise
throughout this
cell
Sea level rise: 2
2030 : +c.20cm
2070: +c.80cm.
Storms:
Impacts and implications Protect and manage Address landscape
(for this cell) habitat threats issues: fire,
connectivity,
refuges, hydrology
This cell presents a complex
pattern of habitats sensitive
to change.
Create a baseline for
shoreline, dune and lake
change by establishing a
rectified aerial
photographic record at
an appropriate
resolution.
Active dune
management to avoid
escalation of threat.
Establish beach profile
monitoring as baseline
information for coastal
change.
Maintain aerial
photographic record to
track shoreline changes
along the whole shore
(150km).
Monitor lagoon water
quality.
Increase in storm foredune
damage and beach recession.
Beach change will be
affected by the outcrop
Pleistocene calcarenite
revealed by recession.
Increased dune transgression
transports increasing
volumes of sand across the
Younghusband Peninsula
towards the lagoon.
Changes in mudflat and
lagoon conditions resulting
from increased tidal and
groundwater influences.
2030: Occasional storm tide Monitor storm tide
2 Short & Cowell (2009) employ a range of sea level rise projections, from 0.18m to 1.5m over 100 years, to review erosion
of the Coorong shoreline using a Shoreface Translation Model (Cowell et al 2006): they conclude that “Shoreline recession
would be driven by the sea level rise together with sand loss to the dunes, the Murray Mouth flood tide delta and periodically
to storm demand.”
Year
Probability 99% that erosion
will be greater than, m.
Probability 50% that erosion
will be greater than, m.
Probability 1% that erosion
will be greater than, m.
2030 10 28 41
2050 21 67 106
2109 38 152 265
Even the highest projections here (which assume the Younghusband Peninsula is made entirely of sand) would not see a
breaching of the barrier through to the lagoon; however, the model appears limited in its ability to recognise the effect of the
offshore bare rock areas in the north of the region.
Limestone Coast and Coorong Coastal Action Plan 457