Soil/Landform Unit 196

Coastal town of Barwon Downs has experienced a marked population and residential development increase over the last 10 years. The residential development is the primary land use for this unit

Area:

997 ha

0.07% of CMA region

The undulating plains around Barwon Heads provide the most eastern landscape of the Western Plains. The plains fringe the wetlands and river system of the Moolap Sunklands and the Barwon River. The area is derived from a variety of sedimentary sources including sandy calcarenites and coastal dunes. Relief is relatively subdued and reflects the

aeolian

nature of this part of the Bellarine Peninsula. With much of the land cleared for residential or grazing purposes, the land is particularly vulnerable to wind erosion. Soils of the landscape include sandy yellow and/or red texture contrast soils that tend to have alkaline

trends. Soils are prone to high permeabilities in upper sands with restricted flow paths in the subsoil. The nutrient and water holding capacity is low in surface horizons, with sodic subsoils common. Vegetation classes of these coastal plains includes Calcarenite Dune Woodland and Coastal Dune Scrub Mosaic.

The other major land use if for sheep and cattle grazing on cleared land
	Wetlands of the Moolap Sunklands and the Barwon River winding its way towards Barwon Downs

Component	1	2	3
Proportion of soil-landform unit	20%	30%	50%
CLIMATE Rainfall (mm)	Annual: 580
Temperature (^oC)	Minimum 10, Maximum 19
Precipitation less than potential evapotranspiration	October–April
GEOLOGY Age and lithology	Quaternary, Pleistocene; Dune limestone, calcareous quartz sandstone (aeolianite) with interbedded soil layers
Geomorphology	6.2.5 Alluvium, alluvial terraces, floodplains and coastal plains of the Sedimentary Western Plains
LANDUSE	Uncleared areas: Nature conservation including wetlands and coastal dunes Cleared areas: Residential development; sheep and beef cattle grazing
TOPOGRAPHY Landscape	Undulating plains
Elevation range (m)	6–13
Local relief (m)	5
Drainage pattern	Deranged
Drainage density (km/km²)	0.8
Landform	Low rises		Plains
Landform element	Broad low crest	Low mid slopes
Slope and range (%)	2 (1–4)	3 (2–6)	0 (0–1)
Slope shape	Convex	Convex	Straight
NATIVE VEGETATION Ecological Vegetation Class	Calcarenite Dune Woodland (6.7%); Coastal Dune Scrub Mosaic (0.4%)
SOIL Parent material	Alkaline sandy brown, grey or yellow texture contrast soils (10) and minor alkaline sandy red texture contrast soils (12)	Alkaline sandy brown, grey or yellow texture contrast soils (10) and minor alkaline sandy red texture contrast soils (12)	Alkaline sandy brown, grey or yellow texture contrast soils (10) and minor alkaline sandy red texture contrast soils (12)
Description (Corangamite Soil Group)	Calcarenite, sand, silt and clay	Calcarenite, sand, silt and clay	Sand, silt, clay and Calcarenite
Soil type sites	CLRA41, CLRA5, SFS3	CLRA41, CLRA5, SFS3	CLRA41, CLRA5, SFS3
Surface texture	Loamy sand	Loamy sand	Loamy sand
Permeability	High to moderate	Moderate	Moderate to low
Depth (m)	<2	< 2	<2
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS	Texture contrast soils with deep surface and subsurface horizons or deep sands. High permeability in upper soils, restricted in subsoil. Nutirent holding capacity and water holding capacity low in upper soil, but often calcareous particularly subsoil, though generally sodic.	Texture contrast soils with deep surface and subsurface horizons or deep sands. High permeability in upper soils, restricted in subsoil. Nutrient holding capacity and water holding capacity low in upper soil, but often calcareous particularly subsoil, though generally strongly sodic and possibly saline.	Texture contrast soils with deep surface and subsurface horizons or deep sands. High permeability in upper soils, restricted in subsoil. Nutrient holding capacity and water holding capacity low in upper soil, but often calcareous particularly subsoil, though generally strongly sodic and probably saline.

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