Soil/Landform Unit - Wattle Creek covered plain

Alluvial plains in the distance, east of Navarre

Area: 7277 ha

0.31% of CMA region

Flats and gentle slopes in the upper Wimmera River catchment around Navarre are part of the Dissected Western Uplands sequence of terraces and floodplains (2.1.7). These flats, gentle slopes and drainage lines are fed from the Navarre to the north and the Pyrenees Ranges to the east and lead into the Wimmera River

alluvial

complex as it moves out of the uplands onto the older alluvial plains. Flats are dominant with gentle slopes, moderate to gentle upper footslopes, drainage lines and terrace flats also. Soils are predominantly red texture contrast soils (

Chromosols

), with sodic brown, yellow and grey texture contrast soils (

Sodosols

) particularly in the poorer drained positions. Sheet, rill and gully erosion are land degradation issues given the texture contrast nature of the soil, especially where the subsoil is

sodic

and exposed. This unit is used for grazing (sheep, beef cattle), with occasional dryland cropping and viticulture. Vegetation communities recorded include Heathy Dry Forest, Creekline Grassy Woodland, Plains Woodland, Riparian Woodland, Alluvial Terraces Herb-rich Woodland and Swampy Riparian Woodland.

Gentle slopes near Moonambel looking towards Pyrenees Ranges
	Crops on gentle slopes beneath Blue Mount

Component	1	2	3	4	5
Proportion of soil-landform unit	10%	30%	45%	5%	10%
CLIMATE Rainfall (mm)	Annual: 575
CLIMATE Rainfall (mm)	Annual: 575
Temperature (^oC)	Minimum 8, Maximum 20
Precipitation less than potential evapotranspiration	October–April
GEOLOGY Age and lithology	Quaternary fluvial silt, sand & minor gravel (Shepparton Fm); Cambrian marine sandstone, siltstone & biotite schist (St Arnaud Group)
GEOLOGY Age and lithology
Geomorphology	2.1.7 Terraces and floodplains of the Dissected Western Uplands
LANDUSE	Uncleared areas: Water supply; nature conservation Cleared areas: Sheep and beef cattle grazing; dryland cropping; viticulture
LANDUSE
TOPOGRAPHY Landscape	Alluvial plains and valleys
TOPOGRAPHY Landscape	Alluvial plains and valleys
Elevation range (m)	197–365
Local relief (m)	5–7
Drainage pattern	Dendritic
Drainage density (km/km²)	1.9
Landform	Footslopes	Alluvial plains
Landform element	Moderate to gentle upper footslopes	Gentle slopes	Flats	Terrace flat	Drainage lines
Slope and range (%)	8 (5-20)	4 (2-10)	1 (0-2)	2 (0-7)	2 (0-5)
Slope shape	Convex	Straight	Straight	Straight	Concave
NATIVE VEGETATION Ecological Vegetation Class	Plains Woodland (38.9%), Creekline Grassy Woodland (18.5%), Grassy Woodland/Alluvial Terraces Herb-rich Woodland Mosaic (18.5%), Riparian Woodland (7.4%), Other (14.8%)
NATIVE VEGETATION Ecological Vegetation Class
SOIL Parent material	In situ marine sandstone, siltstone and biotite schist, fluvial gravel, sand and silt	Fluvial gravel, sand and silt	Fluvial gravel, sand and silt	Fluvial gravel, sand and silt	Alluvial gravel, sand and silt
SOIL Parent material		Fluvial gravel, sand and silt	Fluvial gravel, sand and silt	Fluvial gravel, sand and silt	Alluvial gravel, sand and silt
Description (Corangamite Soil Group)	Sodic and non-sodic, yellow and brown texture contrast soils (5) and sodic and non-sodic, brown and red texture contrast soils (6)	Red texture contrast soils (10) and yellow and brown gradational and texture contrast soils (11)	Red texture contrast soils (10) and sodic brown, yellow and grey texture contrast soils (12)	Red texture contrast soils (10)	Sodic brown, yellow and grey texture contrast soils (12)
Soil type sites	DOAGW15, WLRA141, WLRA142,	DOAGW17, DOAGW2, WLRA66	DOAGW17, DOAGW2, DOAGW12	DOAGW17, DOAGW2, LP80	DOAGW12, WLRA144, WLRA145, WLRA148
Surface texture	Sandy clay loam	Loamy sand	Loam, fine sandy (heavy)	Sandy loam	Loam, fine sandy (heavy)
Permeability	Moderate	Moderate	Moderate - slow	Moderate - high	Slow
Depth (m)	> 2	> 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 subsoils are exposed. Topsoil may be susceptible to acidification.	Lighter surface susceptible to sheet and rill erosion and compaction. Subsoil susceptible to gully erosion where exposed. 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 and exposed. Lighter variants are well drained. Upper soil susceptible to acidification.	Light soil surface susceptible to sheet and rill erosion and compaction. Subsoil susceptible to rill and gully erosion where sodic. Lighter soil variants are well drainage. Upper soil 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. Upper soil susceptible to acidification.

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