Soil/Landform Unit - Howard Creek plains

Upper catchment for Howard Creek. Note the abundant vineyards occupying the footslopes of the Pyrenees Ranges

Area: 6523 ha

0.28% of CMA region

and colluvial plains that supply significant surface and subsurface volumes to the Wimmera River include the Howard Creek plains in the south-east of the Wimmera CMA region. Part of the Dissected Western Uplands, the plains include a suite of colluvial footslopes and alluvial floodplains of mainly sodic (

Sodosols

) and non-sodic yellow texture contrast soils (

Chromosols

). These soils can be extremely prone to gully and tunnel erosion where subsoils are exposed. Soil surfaces can be

hardsetting

and vulnerable to sheet and rill erosion where insufficient ground coverage exists. Land use has changed largely with viticulture now well established up the Howard Creek valley on colluvial footslopes while grazing and cereal cropping also exist. Woodlands are the dominant native vegetation community present, including Creekline Grassy Woodland, Grassy Woodland and Plains Woodland. Grassy Woodland/Alluvial Terraces Herb-rich Woodland Mosaic has also been recorded.

View over Howard Creek as it passes through Landsborough
	Plains east of Joel South with slight undulations

Component	1	2	3	4
Proportion of soil-landform unit	5%	30%	55%	10%
CLIMATE Rainfall (mm)	Annual: 580
CLIMATE Rainfall (mm)	Annual: 580
Temperature (^oC)	Minimum 8, Maximum 20
Precipitation less than potential evapotranspiration	October–April
GEOLOGY Age and lithology	Quaternary silt, sand and minor gravel (Shepparton Formation); Neogene gravel, sand and silt; Quaternary fluvial gravel, sand and silt; Cambrian marine sandstone, siltstone and biotite schist (St Arnaud Group)
GEOLOGY Age and lithology
Geomorphology	2.1.5 Cainozoic landscapes of the Dissected Western Uplands
LANDUSE	Uncleared areas: water supply; nature conservation Cleared areas: dryland cropping; sheep grazing; viticulture; residential development; water supply
LANDUSE
TOPOGRAPHY Landscape	Undulating and dissected plains
TOPOGRAPHY Landscape	Undulating and dissected plains
Elevation range (m)	205–326
Local relief (m)	3–5
Drainage pattern	Dendritic
Drainage density (km/km²)	1.4
Landform	Long broad footslopes (Howard Creek 2 & 3)		Alluvial floodplains (Howard Creek 1)
Landform element	Moderate footslope	Gentle footslope	Alluvial flat	Drainage line
Slope and range (%)	5 (3-10)	2 (1-3)	0 (0-1)	0 (0-1)
Slope shape	Concave	Linear	Straight	Concave
NATIVE VEGETATION Ecological Vegetation Class	Grassy Woodland/Alluvial Terraces Herb-rich Woodland Mosaic (38.0%), Creekline Grassy Woodland (23.7%), Plains Woodland (22.6%), Other (7.9%)
NATIVE VEGETATION Ecological Vegetation Class
SOIL Parent material	Colluvial and alluvial gravel, sand and silt	Colluvial and alluvial gravel, sand and silt	Alluvial gravel, sand and silt	Alluvial gravel, sand and silt
SOIL Parent material	Colluvial and alluvial gravel, sand and silt	Colluvial and alluvial gravel, sand and silt	Alluvial gravel, sand and silt	Alluvial gravel, sand and silt
Description (Corangamite Soil Group)	Sodic and . -sodic, yellow and brown texture contrast soils (5)	Sodic and non-sodic, yellow and brown texture contrast soils (5)	Yellow and brown gradational and texture contrast soils (11) and sodic brown, yellow and grey texture contrast soils (12)	Sodic brown, yellow and grey texture contrast soils (12)
Soil type sites	DOAGW15	DOAGW15	WLRA66, WLRA63, DOAGW12	DOAGW12, WLRA144, WLRA145, WLRA148
Surface texture	Sandy clay loam	Sandy clay loam	Sandy loam	Loam, fine sandy (heavy)
Permeability	Moderate	Moderate	Moderate	Moderate
Depth (m)	> 2	> 2	> 2	> 2
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS Critical land features, processes, forms	Hardsetting and soft surfaces susceptible to sheet and rill erosion even on gentle slope due to impeding layer (clay or hardpan). Subsurface soil and upper subsoil susceptible to compaction, and also gully erosion where sodic and deep. Topsoil may be susceptible to acidification.	Hardsetting and soft surfaces susceptible to sheet and rill erosion even on gentle slope due to impeding layer (clay or hardpan). Subsurface soil and upper subsoil susceptible to compaction, and also gully erosion where sodic and deep. Topsoil may be susceptible to acidification.	Lighter surface susceptible to sheet and rill erosion and compaction, especially with low organic matter. Subsoil susceptible to rill and gully erosion where sodic, deeper and sloping terrain. Lighter variants are well drained.	Lighter surface susceptible to sheet and rill erosion and compaction, especially with low organic matter. Subsoil susceptible to rill and gully erosion where sodic, deeper and sloping terrain. Lighter variants are well drained. Upper soil susceptible to acidification.

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