Soil/Landform Unit 192

Deep alluvial soils have been derived from alluvial and colluvial sediments from the Barrabool Hills and hills of Waurn Ponds

Area:

98 ha

<0.01% of CMA region

The undulating alluvial plains and drainage depression in the Waurn Ponds areas comprises predominantly Paleogene marine clay with Recent alluvial material and vegetation classes Swampy Riparian Woodland and Grassy Woodland. These deep soils of the Western Plains are mainly alkaline black texture contrast soils. Surface soil horizons are moderate in plant available nutrients, and the deep soils have high water holding capacities. Most areas have been cleared for cropping and grazing, while the uncleared areas support open woodlands. The main land hazards to land use are waterlogging, gully erosion and sodic subsoils.

Hillslopes at Waurn Ponds lead directly to this alluvial valley with deep soils
	Weeds have infested much of the cleared land along the alluvial valley

Component	1	2
Proportion of soil-landform unit	75%	25%
CLIMATE Rainfall (mm)	Annual: 630
Temperature (^oC)	Minimum 10, Maximum 19
Precipitation less than potential evapotranspiration	October–April
GEOLOGY Age and lithology	Paleogene marine clay, Recent clay, sand and gravel
Geomorphology	6.2.5 Alluvium, alluvial terraces, floodplains and coastal plains of the Sedimentary Western Plains
LANDUSE	Uncleared: Nature conservation; water supply Cleared: Cropping; sheep and beef cattle grazing
TOPOGRAPHY Landscape	Alluvial plain
Elevation range (m)	31–83
Local relief (m)	40
Drainage pattern	Dendritic
Drainage density (km/km²)	4.1
Landform	Plains	Drainage lines
Landform element
Slope and range (%)	1 (0–3)	2 (1–5)
Slope shape	Straight	Concave
NATIVE VEGETATION Ecological Vegetation Class	Swampy Riparian Woodland (2.9%) , Grassy Woodland (2.1%)
SOIL Parent material	Clay silt and sand	Clay silt and sand
Description (Corangamite Soil Group)	Alkaline black texture contrast soils (32)	Alkaline black texture contrast soils (32)
Soil type sites	SW88, SW95, OTR492	SW88, SFS20, OTR492
Surface texture	Clay loam	Clay loam
Permeability	Moderate to low	Low
Depth (m)	>2	>2
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS	Texture contrast, moderate to high water holding capacity and nutrient holding capacity in surface soil. Often sodic clay subsoil, hardsetting when dry. Poor to moderate site drainage. High organic matter may alleviate compaction and water logging susceptibility in surface soil.	Texture contrast, moderate to high water holding capacity and nutrient holding capacity in surface soil. Often sodic clay subsoil, hardsetting when dry. Poor to moderate site drainage, subject to inundation. High organic matter may alleviate compaction and water logging susceptibility in surface soil.

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