Cell Descriptions - South East Natural Resources Management Board

SE13 – Kingston SE
Landforms
This cell extends from Cape Jaffa to Long Beach Road immediately north of Kingston and faces
Lacepede Bay: It is a flat coastal plain.
The features of the modern beach and dunes appear to rely entirely on the extreme low wave
energy of this coastal unit. Deep water swell wave energy is entirely dissipated on the shallow
reefs of Lacepede Bay; Sprigg (1979) maps the ‘Lacepede’ beach, dune and lunette association as
a Pleistocene feature, now drowned by Holocene sea level rise, paralleling the modern beach,
some 8 km offshore. Sediment movement alongshore appears to depend on tidal currents, locally
generated wind waves and storm surges. Subaqueous sand waves arranged transverse obliquely to
the shoreline and extending several hundred metres into the bay, appear to drift slowly from
Cape Jaffa into Lacepede Bay. Where the sand waves attach to the beach pronounced shoreline
protrusions occur, (Short & Hesp, 1984, p.57 and fig.19, p.33). Short attributes the shallows of
Lacepede Bay to the regional upward tilting to the east and calcarenite reefs.
The extensive dune, swamp and lake complex between Cape Jaffa and Kingston has been
formed, following Holocene sea level rise, by sand drifting alongshore into Lacepede Bay: Short
points out that almost all this sand mass is in the form of a series of re-curved spit deposits.
Between and behind sandy spit deposits are swamp and lake deposits, trapped and protected by
the dune ridges. Butchers Gap Drain represents a modern drainage modification of these
naturally poorly drained coastal swamps.
The beaches throughout this cell are of medium to coarse calcareous sands, and the beaches are
reflective with medium beach face angles. Foredunes are stable. As nearshore sand waves migrate
across the bay, beach protrusions will move also, causing local beach accretion and erosion.
Butcher Gap Drain entering Butchers Lake. Photograph Coast Protection Board 2008.
Limestone Coast and Coorong Coastal Action Plan 427