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Soils on Older Consolidated Sediments

Orb - Ordovician Gently Dissected | Org - Ordovician Plain | Orr - Ordovician Hills (North) | Ors - Ordovician Steep Hills

Orb - Ordovician Gently Dissected

Ordovician hills (moist)This unit represents 0.9% of the survey area and covers approximately 1.9 km2. It is mainly part of the catchment to White Swan Reservoir in the western part of the Shire. The unit is mostly covered with a good stand of messmate and narrow-leafed stringybark but blue gum and broad-leafed peppermint are present. One of the major uses is protection of the Ballarat water supply

COMPONENT
1
2
3
Proportion %
10
85
5
CLIMATE (Average)
Rainfall mm

750 - 780
*Temperature C
Average annual 120C
*Seasonal growth limitations
Temperature less than 10C May - September
GEOLOGY
Age, growth

Ordovician, slates and sandstones
TOPOGRAPHY
Landscape

Slightly dissected plains
Elevation (range) m
421
Local relief (av.) m
10
Drainage pattern
Dendritic
Drainage density km/km2
3.9
Land form
Rolling plains
Position on land form
Crest
Long gentle slopes
Drainage line
Slope (av.) ,%, slope shape
1-2; Convex
2-7; Straight
1-2; Concave
NATIVE VEGETATION
Structure
Woodland
Open forest
Dominant species
E. obliqua, E. radiata, E. dives
E. viminalis, E. obliqua, E. globulus
E. ovata, E. obliqua, E. globulus
SOIL
Parent material

In-situ weathered rock

In-situ weathered rock

Alluvium, clays, silts sands and gravels
Description
Shallow stony red gradational soils
Mottled yellow, red gradational soils
Mottled yellow and red gradational soils
Surface texture
Gravelly loamLoamy clayClay loam
Permeability
High
Moderate-high
Moderate-low
Depth (av.) in
0.6
1
2
LAND USE
Forestry with some grazing
SOIL DETERIORATION
Critical land features

Hard setting surfaces, dispersibility

Hard setting surfaces

Moderate dispersibility, poorly drained site,

hard setting surfaces
Processes
Overland flow
Overland flow
Overland flow
Forms
Sheet and rill erosion, compaction
Sheet and rill erosion, gully erosion,
compaction
Gully erosion
* Ballan figures

LAND UNIT: Ordovician hills (moist)COMPONENT: 1-Crests – Shallow stony gradational soilsMAP SYMBOL: Orb 1

CAPABILITY OF THE LAND TO SUPPORT VARIOUS ACTIVITIES
CAPABILITY OF THE LAND TO SUPPORT SUBDIVISION
ACTIVITY
RATING
MAJOR LIMITING FEATURES OF THE LAND
SUBDIVISION
TYPE
RATING
MAJOR LIMITING ACTIVITIES
Building houses
Fair
Depth to rock (moderate hardness); stoniness.Urban (sewered)
Poor
Shallow excavations; (otherwise-fair: building houses; secondary roads).
Absorption fields
Poor
Too stony; depth of soil.
Small Farmlets
4 ha
Poor
Small farm dams; absorption fields - effluent; (otherwise fair: access tracks; gravel roads; building houses).
Secondary roads
Fair
Depth to rook (moderate hardness); stoniness.
Large Farmlets
16 ha
Poor
Small farm dams; absorption fields - effluent; (otherwise-fair: access tracks; building houses).
Gravel roads
Fair
Stoniness
Bush Blocks
4 ha.
Poor
Absorption fields - effluent; clearing for house
sites and access tracks.
Access tracks
Fair
Stoniness; erosion of surface.
Shallow excavations
Poor
Depth to rock (moderate hardness); stoniness.
Small farm dams
Poor
Depth to rock; stoniness; catchment requirements.
Sewerage lagoons
Poor
Depth to rook.
Topsoil - Quality
Poor
Stoniness.
- Removal
Very poor
Very thin layer; stones.
- Resowing
Poor
Infertile shallow subsoil; stoniness; slope.
Sand - Quality
Very poor
No sand.
- Operation
Gravel - Quality
Fair
Variable: clay content; stoniness.
- Operation
Fair to poor
Erodible soils; slope.
Grazing
Poor
Shallow stony soils of low moisture holding capacity and low fertility.
Cultivation
Very poor
Very shallow, stony soils - not cultivated.
Clearing
Poor
Slow revegetation - sheet erosion
EFFECT OF SUBDIVISION OF THE LAND ON TOWN WATER SUPPLY
URBAN:Due to the poor soils, it will be difficult to quickly re-establish vegetation to protect earthworks. There will be a considerable risk of silt loss during development especially if clearing is required.
FARMLET:Erosion of gravel roads and tracks will be the main source of turbidity and siltation from farmlet subdivisions.
Note: This unit is normally uncleared and if cleared, supports low stocking rates. Higher rates or badly managed stock can lead to overgrazing and therefore sheet erosion.
Failure of septic absorption fields because of the shallow stony soils and steep slopes will be a risk. Percolation rates may be very rapid, but the lack of soil depth and high rock fragment content will hinder soil treatment of effluent. If this component is included in a subdivision, it would be better if it formed part of a large block which also contained areas of better land.
BUSH BLOCK:As for farmlets, effluent absorption and erosion of roads and tracks will be the main continuing hazards. However, clearing for the construction of roads, tracks and house sites will be a risk during the development stage. The steep slopes and shallow stony soils will make safe planning and construction extremely difficult.

LAND UNIT: Ordovician hills (moist)COMPONENT: 2 - Long gentle slopes-mottled yellow gradational soilMAP SYMBOL: Orb 2

CAPABILITY OF THE LAND TO SUPPORT VARIOUS ACTIVITIES
CAPABILITY OF THE LAND TO SUPPORT SUBDIVISION
ACTIVITY
RATING
MAJOR LIMITING FEATURES OF THE LAND
SUBDIVISION
TYPE
RATING
MAJOR LIMITING ACTIVITIES
Building houses
0-15% Fair
Erosion during construction; dispersible clay; low to moderate shrink-swell.Urban (sewered)
0-15% Fair
Building houses; secondary roads.
Absorption fields
Fair
Variable percolation rates; imperfect soil drainage; perched temporary watertables.Small Farmlets
4 ha
Fair
Absorption fields-effluent; building houses; gravel roads; access tracks; clearing- if required).
Secondary roads
0-12% Fair
12-20% Poor
Risk of erosion during construction.
Slope for construction.
Large Farmlets
Fair
Absorption fields-effluent; building houses; access tracks; (and clearing if required).
Gravel roads
Fair to poor
Risk of erosion to surface, batters and drains.Bush Blocks
4 ha.
Fair
Absorption fields-effluent; building houses; gravel roads; access tracks; clearing for construction.
Access tracks
Fair to poor
Risk of erosion to surface and drains
Shallow excavations
0-8% Good
8-15% Fair
Slope - machinery operation.
Small farm dams
Good
Sewerage lagoons
2-8% Fair
8-15% Poor
Slope for construction
Topsoil - Quality
Fair
Hard setting.
- Removal
Poor
Thin layer.
- Resowing
poor
Infertile, easily eroded sub-soil.
Sand - Quality
Very poor
No sand.
- Operation
Gravel - Quality
Poor
Gravel deposits rare.
- Operation
Fair
Slope - erosion risk.
Grazing
Fair
Hard-setting structureless topsoil; impermeable clay.
Cultivation
Poor
Slope; hard setting structureless topsoil.
Clearing
Fair
Silt loss prior to pasture establishment.
EFFECT OF SUBDIVISION OF THE LAND ON TOWN WATER SUPPLY
URBAN:Although much of this land is rated fair for urban development, erosion and silt loss during development will be a considerable hazard to the water quality. The hazard will be increased if clearing is required (much of the land is forested). Land disturbance guidelines should be observed.
FARMLETS:Erosion of batters, drains and surfaces of gravel roads; access tracks and construction sites will be a major source of dispersible clay and silt. Correct planning and construction will be required to minimise this hazard. High silt loss can be expected if clearing is required. Also the impermeable clay often results in perched watertables. Effluent disposal by absorption fields is likely to cause problems, especially on the lower slopes near drainage lines.
BUSH BLOCK:As for farmlets, erosion of roads, tracks and cleared areas is a potential problem.
NOTE: Soil drainage under forest is generally somewhat better than for cleared areas. Absorption fields will probably function a little better.

LAND UNIT: Ordovician hills (moist)COMPONENT: 3 – Drainage lines-mottled yellow/red gradational soilMAP SYMBOL: Orb 3

CAPABILITY OF THE LAND TO SUPPORT VARIOUS ACTIVITIES
CAPABILITY OF THE LAND TO SUPPORT SUBDIVISION
ACTIVITY
RATING
MAJOR LIMITING FEATURES OF THE LAND
SUBDIVISION
TYPE
RATING
MAJOR LIMITING ACTIVITIES
Building houses
Poor to very poor
Soil drainage; surface flows (very poor in flood risk areas).Urban (sewered)
Poor to very poor
Building houses; secondary roads; shallow excavations.
Absorption fields
Very poor
Soil drainage - seasonal and permanent watertables; percolation rate.Small Farmlets
4 ha
Very poor
Soil absorption fields - effluent; access tracks (otherwise poor: building houses; gravel roads).
Secondary roads
Poor
Soil drainage; some flood risk; surface flows; erosion during construction.Large Farmlets
Very poor
Soil absorption fields - effluent; access tracks (otherwise-poor: building houses).
Gravel roads
Poor
Soil drainage; surface flows; erosion during construction; erosion of drains and surface.Bush Blocks
4 ha
Very poor
Soil absorption fields - effluent; access tracks (otherwise-poor: building houses; gravel roads).
Access tracks
Very poor
Soil drainage; surface flows; erosion of surface and drains.
Shallow excavations
Poor
Soil drainage.
Small farm dams
Fair to good
Variable material for embankment.
Sewerage lagoons
Poor
Flood prone; proximity to watercourse.
Topsoil - Quality
Good
Thin layer.
- Removal
Fair
Surface flows.
- Resowing
Poor
Severe erosion risk.
Sand - Quality
Poor
Quality variable.
- Operation
Poor
Poor drainage; surface flows; erosion risk.
Gravel - Quality
Poor
Quality variable.
- Operation
Poor
Poor drainage; surface flows; erosion risk.
Grazing
Fair
Soil drainage; pugging of soil; possible gully erosion.
Cultivation
Very poor
Surface flow; fallow wash - rilling; sheet and gully erosion.
Clearing
Poor
Surface flow; topsoil wash prior to pasture establishment.
EFFECT OF SUBDIVISION OF THE LAND ON TOWN WATER SUPPLY
URBAN:Due to the poor drainage and risk of high velocity floods, much of the land is not capable of supporting urban subdivision without extensive drainage works. However, any development within these drainage lines is likely to contribute significantly to turbidity and silt loads, particularly during construction.
FARMLET:Although this unit may be included as part of a farmlet block, it is essential that buildings, access and effluent disposal should be excluded from it. Clearing will involve a serious risk of erosion.
BUSH BLOCK:As with farmlets, this unit may be included as part of a bush block, as long as housing access and effluent disposal areas are excluded from this unit.

Orr - Ordovician Hills (North)

Ordovician hills (north)This unit represents 18.5% of the survey area and covers a total area of 38.2 km2. It is predominantly forested and in public ownership in the north eastern part of the Shire. Part of the unit has been cleared and is used for grazing with occasional crops as part of the pasture improvement. A large part of the area has been converted to softwood plantation. Most of the catchment to Korweinguboora Reservoir is in this unit and careful management of the land is required to protect the water supply

COMPONENT
1
2
3
4
Proportion %
20
15
60
5
CLIMATE (Average)
Rainfall mm

760 - 1000
*Temperature C
Average annual 12oC
*Seasonal growth limitations
Temperature less than 100C May - September
GEOLOGY
Age, growth

Ordovician, slates and sandstones and Quaternary basalt
TOPOGRAPHY
Landscape
Hills at northern end of Shire
Elevation (range) m
670
Local relief (av.) m
45
Drainage pattern
Dendritic
Drainage density km/km2
5.9
Land form
Hills
Position on land form
Crest & steep slopes
Slopes with deep soil
Slopes with shallow soil
Drainage line
Slope (av.) ,%, slope shape
5-20 ; Convex
3-8 ; Straight
3-8 ; Straight
1-4 ; Concave
NATIVE VEGETATION
Structure

Open forest
Dominant species
E. radiata, E. dives, E. rubida,
E. obliqua
E. viminalis, E. obliqua, E. radiata,
E. rubida
E. obliqua, E. radiata, E. rubida,
E. dives, E. viminalis
E. ovata,. E. obliqua, E. rubida,
E. radiata
SOIL
Parent material

In-situ weathered rock
In-situ weathered rock

In-situ weathered rock

Alluvium, colluvium clay, silt, sand and gravel
Description
Shallow stony brown gradational soil
Red gradational soil, fine structure
Yellow gradational soil, fine structure
Brown gradational soil
Surface texture
Gravelly loam
Clay loam
Clay loam
Clay loam
Permeability
High
High
Moderate-high
Moderate
Depth (av.) in
1.5
2
1
2
LAND USE
Soft wood plantations, some grazing, cropping
SOIL DETERIORATION
Critical land features

Steep slopes
Slopes

Slopes

Moderate permeability, dispersibility
Processes
Overland flow, leaching
Overland flow, leaching
Overland flow, leaching
Overland flow, subsurface,
water logging
Forms
Sheet & rill erosion, nutrient decline
Sheet erosion, nutrient decline
Sheet & rill erosion, nutrient decline
Gully erosion, compaction
* Ballan figures

LAND UNIT: Ordovician hills (north)COMPONENT: 1 – Crests – shallow stony gradational soilsMAP SYMBOL: Orr 1

CAPABILITY OF THE LAND TO SUPPORT VARIOUS ACTIVITIES
CAPABILITY OF THE LAND TO SUPPORT SUBDIVISION
ACTIVITY
RATING
MAJOR LIMITING FEATURES OF THE LAND
SUBDIVISION
TYPE
RATING
MAJOR LIMITING ACTIVITIES
Building houses
Poor
Slope; depth to rock (moderate hardness).Urban (sewered)
Poor
Building houses; secondary roads; shallow excavations.
Absorption fields
Poor
Slope; depth to rook; stoniness.Small Farmlets
4 ha
Very poor
Small farm dams; (otherwise-poor: absorption fields - effluent; building houses; gravel roads; access tracks; clearing; resowing).
Secondary roads
Poor
Slope; depth to rook (moderate hardness).Large Farmlets
16 ha
Very poor
Small farm dams; (otherwise-poor: absorption fields - effluent; houses; access tracks; clearing resowing).
Gravel roads
Poor
Slope; depth to rook; erosion of drains and batters.Bush Blocks
4 ha.
Poor
Absorption fields - effluent; building houses; gravel roads; access tracks; clearing (for house sites and access).
Access tracks
Poor
Slope; depth to rock; stoniness; erosion of surface and batters.
Shallow excavations
Poor
Slope; depth to rook (moderate hardness).
Small farm dams
Very poor
Slope; depth to rook.
Sewerage lagoons
Very poor
Slope; depth to rock
Topsoil - Quality
Poor
Very stony soil.
- Removal
Poor
Thin layer.
- Resowing
Poor
Slope; poor quality shallow soils-erosion.
Sand - Quality
Very poor
No sand.
- Operation
Gravel - Quality
Variable
Slope; poor quality shallow soils-erosion.
- Operation
Poor
Grazing
Fair
Shallow stony soil; low fertility and moisture holding capacity; poor pastures.
Cultivation
Very poor
Shallow stony soils.
Clearing
Poor
Shallow stony soil; low fertility; slow pasture regeneration; sheet erosion.
EFFECT OF SUBDIVISION OF THE LAND ON TOWN WATER SUPPLY
URBAN:Due to the poor soils, it will be difficult to quickly re-establish vegetation to protect earthworks. There will be a considerable risk of silt loss during development especially if clearing is required.
FARMLET:Erosion of gravel roads and tracks will be the main source of turbidity and siltation from farmlet subdivisions.
Note: This component is normally uncleared and if cleared, supports low stocking rates. Higher rates or badly managed stock can lead to overgrazing and therefore sheet erosion.
Failure of septic absorption fields because of the shallow stony soils and steep slopes will be a risk. Percolation rates maybe very rapid, but the lack of soil depth and high rock fragment content will hinder soil treatment of effluent. If this component is included in a subdivision, it would be better if it formed part of a large block which also contained areas of better land.
BUSH BLOCK:As for farmlets, effluent absorption and erosion of roads and tracks will be the main continuing hazards. However, clearing for the construction of roads, tracks and house sites will be a risk during the development stage. The steep slopes and shallow stony soils will make safe planning and construction extremely difficult.

LAND UNIT: Ordovician hills (north)COMPONENT: 2 – Slopes – deep red gradational soilsMAP SYMBOL: Orr 2

CAPABILITY OF THE LAND TO SUPPORT VARIOUS ACTIVITIES
CAPABILITY OF THE LAND TO SUPPORT SUBDIVISION
ACTIVITY
RATING
MAJOR LIMITING FEATURES OF THE LAND
SUBDIVISION
TYPE
RATING
MAJOR LIMITING ACTIVITIES
Building houses
Good
Urban (sewered)
Good
Absorption fields
Good
Small Farmlets
4 ha
Fair
Small farm dams.
Secondary roads
Good
Large Farmlets
16 ha
Fair
Small farm dams.
Gravel roads
Good
Bush Blocks
4 ha.
Good
Access tracks
Good
Shallow excavations
Good
Small farm dams
Fair to poor
Percolates rapidly.
Sewerage lagoons
Poor
Slope; percolates too rapidly
Topsoil - Quality
Fair
Good
- Removal
Poor
Thin layer.
- Resowing
Fair
Slope, infertile subsoil-sheet erosion
Sand - Quality
Very poor
No sand
- Operation
Gravel - Quality
Poor
Gravelly areas are rare.
- Operation
Good
Grazing
Very good
Cultivation
Good to fair
Slope-sheet and rill erosion, fertilizer requirements.
Clearing
Good
Slope-erosion during pasture establishment.
EFFECT OF SUBDIVISION OF THE LAND ON TOWN WATER SUPPLY

URBAN FARMLET and BUSH BLOCK:
The main limitation of this unit is that it generally occurs in small areas each of only a few hectares or less) associated with component 3 (yellow gradational soils). Bore holes are required to differentiate these two components. The yellow soils are poorer than the red gradational soils, and are far more erosion prone when exposed. They are also far more common (the ratio of yellow to red soils is approximately 4:1 although this varies).
Thus a subdivision is likely to contain both soil types, with the yellow soil being far more common. Therefore, the limiting features of component 3 must be considered when planning a subdivision.
On individual blocks, the red soil will be far better than the yellow for effluent absorption and worse than the yellow for dams because of its higher percolation rate.

LAND UNIT: Ordovician hills (north)COMPONENT: 3 – Slopes – Mottled yellow gradational soilMAP SYMBOL: Orr 3

CAPABILITY OF THE LAND TO SUPPORT VARIOUS ACTIVITIES
CAPABILITY OF THE LAND TO SUPPORT SUBDIVISION
ACTIVITY
RATING
MAJOR LIMITING FEATURES OF THE LAND
SUBDIVISION
TYPE
RATING
MAJOR LIMITING ACTIVITIES
Building houses
0-15% Fair
15+% Poor
Erosion during construction, dispersible clay, low to moderate shrink-swell.Urban (sewered)
Fair to poor
Building houses; secondary roads.
Absorption fields
Fair
Variable percolation rate; imperfect drainage temporary watertables, esp. on cleared land.Small Farmlets
4 ha
Fair
Absorption fields-effluent; building houses; gravel roads; access tracks; clearing - if required
Secondary roads
0-12% Fair
12+% Poor
Dispersible clay; erosion during construction.Large Farmlets
16 ha
Fair
Absorption fields-effluent; building houses; access tracks; (and clearing if required).
Gravel roads
Fair to poor
Risk of erosion of batters and drains.Bush Blocks
4 ha
Fair
Absorption fields-effluent; building houses; gravel roads; access tracks; clearing for construction.
Access tracks
Fair to poor
Risk of erosion of surface and drains.
Shallow excavations
Good
Seasonal drainage problems.
Small farm dams
Good
Sewerage lagoons
Fair
Slope-construction.
Topsoil - Quality
Fair
Too clayey, hard setting.
- Removal
Poor
Thin layer.
- Resowing
Poor
Infertile, easily eroded subsoil layers.
Sand - Quality
Very poor
No sand.
- Operation
Gravel - Quality
Poor
Gravel deposits rare.
- Operation
Fair
Erosion risk.
Grazing
Good to fair
Hard setting structureless topsoil, impermeable clay, overgrazing will cause a high risk of erosion.
Cultivation
Poor
Hard setting structureless topsoil, impermeable clay, high risk of erosion.
Clearing
Fair
Slow pasture establishment, shallow, low fertility topsoil, erosion prior to pasture establishment.
EFFECT OF SUBDIVISION OF THE LAND ON TOWN WATER SUPPLY
URBAN:Although much of this land is rated fair for urban development, erosion of the Boils will be a considerable hazard to water quality during development and construction. The hazard will be increased if clearing is required (many areas of this land system remain under forest). Land disturbance guidelines should be observed to minimise pollution by erosion of construction sites.
FARMLETS:Erosion of batters, drains and surfaces of gravel roads and tracks will be a major source of silt and dispersible clay. Correct planning and construction would be required to minimize this hazard. Many areas would require clearing for farmlets. High silt loads can be expected prior to pasture establishment.

Also the impermeable clay commonly causes perched watertables especially in cleared land. Effluent disposal by soil absorption will cause problems especially on lower slopes and near drainage lines.
BUSH BLOCKS:As for farmlets, erosion of roads and tracks is a potential problem. Also, clearing for access and building sites will be additional hazard.
NOTE: soil drainage under forest is generally somewhat better than for cleared areas, especially on upper and mid slopes.

LAND UNIT: Ordovician hills (north)COMPONENT: 4 – Slopes – Drainage line – brown gradational soilsMAP SYMBOL: Orr 4

CAPABILITY OF THE LAND TO SUPPORT VARIOUS ACTIVITIES
CAPABILITY OF THE LAND TO SUPPORT SUBDIVISION
ACTIVITY
RATING
MAJOR LIMITING FEATURES OF THE LAND
SUBDIVISION
TYPE
RATING
MAJOR LIMITING ACTIVITIES
Building houses
Poor to very poor
Soil drainage; surface flows (very poor in flood risk areas).Urban (sewered)
Poor to very poor
Building houses; secondary roads; shallow excavations.
Absorption fields
Very poor
Soil drainage-seasonal and permanent watertables; percolation rate.Small Farmlets
4 ha
Very poor
Absorption fields - effluent; access tracks; gravel roads; building houses.
Secondary roads
Poor
Soil drainage; some flood risk; surface flows; erosion during construction.Large Farmlets
16 ha
Very poor
Absorption fields - effluent, access tracks; building houses.
Gravel roads
Poor to very poor
Soil drainage; surface flows; erosion during construction; erosion of drains and surface.Bush Blocks
4 ha.
Very poor
Absorption fields - effluent; access tracks; gravel roads; building houses.
Access tracks
Very poor
Soil drainage; surface flows; erosion or surface and drains.
Shallow excavations
Poor
Soil drainage.
Small farm dams
Fair to good
Variable material for embankment.
Sewerage lagoons
Poor
Flood prone; proximity to watercourse.
Topsoil - Quality
Good
Thin layer.
- Removal
Fair
- Resowing
Poor
Surface flows; impermeable poor subsoil; severe erosion risk.
Sand - Quality
Poor
Quality variable.
- Operation
Poor
Poor drainage; overland flows; severe erosion.
Gravel - Quality
Poor
Quality-variable.
- Operation
Poor
Poor drainage; overland flows; severe erosion.
Grazing
Fair
Soil drainage; pugging of soil; possible gully erosion (some areas flood).
Cultivation
Very poor
Surface flows; fallow wash - rilling; sheet and gully erosion.
Clearing
Poor
Surface flows; topsoil wash prior to pasture establishment.
EFFECT OF SUBDIVISION OF THE LAND ON TOWN WATER SUPPLY
URBAN:Due to the poor drainage and risk of high velocity floods, much of the land is not capable of supporting urban subdivision without extensive drainage works. However, any development within these drainage lines is likely to contribute significantly to turbidity and silt loads, particularly during construction.
FARMLET:Although this unit may be included as part of farmlet blocks, it is essential that buildings, access and effluent disposal should be excluded from this unit. Clearing will involve a serious risk of erosion.
BUSH BLOCK:As with farmlets, this unit may be included as part of abash block, as long as housing access and effluent disposal areas are excluded from this unit.

Ors - Ordovician Steep Hills

Ordovician steep hillsThis unit represents 7.9% of the survey area or 16.4 km2 and contains the most hazardous land in the Bungaree Shire. Most of the steepest hills have fortunately been left forested which is the most suitable land use for this unit. Some of the gentler parts have been cleared for grazing. The unit can be distinguished from other Ordovician units by the characteristic steep slopes and soils not influence by volcanic dykes

COMPONENT
1
2
3
4
Proportion %
45
CLIMATE (Average)
Rainfall mm

660 - 710
*Temperature C
Average annual 12oC.
*Seasonal growth limitations
Temperature less them 10 C May - September
GEOLOGY
Age, growth

Ordovician; slates and sandstones
TOPOGRAPHY
Landscape
Hilly areas throughout the Shire
Elevation (range) m
425
Local relief (av.) m
65
Drainage pattern
Dendritic
Drainage density km/km2
7.6
Land form
Hill
Position on land form
Southern slope
Northern slope
Drainage line
Crest
Slope (av.) ,%, slope shape
15 ; Straight
15 ; Straight
3 ; Concave
3 ; Convex
NATIVE VEGETATION
Structure
Tall open forest
Open forest
Dominant species
E. obliqua, E. ovata, E. radiata, E. viminalis
E. dives, E. obliqua, E. viminalis, E. radiata
E. radiata, E. viminalis E. obliqua
E. obliqua, E. dives, E. viminalis, B. radiata
SOIL
Parent material

In-situ weathered rock
In-situ weathered rock

Alluvium, clay, silt, sand, gravel

In-situ weathered rock
Description
Mottled yellow and red gradational soil, fine structure
Mottled yellow and red gradational soil, fine structure
Black gradational soil, variable)
Shallow stony red gradational soil
Surface texture
Fine sandy loam
Fine sandy loam
Clay loam
Gravelly loam
Permeability
High
High
Moderate-low
High
Depth (av.) in
1
1
0.5
LAND USE
Mainly forestry, grazing
SOIL DETERIORATION
Critical land features
Steep slopes, hard setting surfaces
Steep slopes, hard setting surfaces
Moderate permeability, hard setting surfaces, dispersibility
Moderate elopes, hard setting surfaces
Processes
Overland flow
Overland flow
Overland flow, subsurface flow, waterlogging
Overland flow
Forms
Sheet and rill erosion
Sheet and rill erosion, compaction
Gully erosion, compaction
Sheet and rill erosion compaction
* Ballan figures

LAND UNIT: Ordovician steep hillsCOMPONENT: 1 – Southern slopes – mottled red/yellow gradational soilsMAP SYMBOL: Ors 1

CAPABILITY OF THE LAND TO SUPPORT VARIOUS ACTIVITIES
CAPABILITY OF THE LAND TO SUPPORT SUBDIVISION
ACTIVITY
RATING
MAJOR LIMITING FEATURES OF THE LAND
SUBDIVISION
TYPE
RATING
MAJOR LIMITING ACTIVITIES
Building houses
0-15% Fair
15+% Poor
Slope and erodible soils-erosion during construction.Urban (sewered)
0-15% Fair
15+% Poor
Building houses; secondary roads (development stage).
Absorption fields
Poor
Slow percolation rate (variable); slope affecting layout and operation.Small Farmlets
4 ha
Poor
Absorption fields - effluent; small farm dams; access tracks; gravel roads.
Secondary roads
0-15% Fair
Slope & erodible soils-erosion during construction.Large Farmlets
Poor
Effluent absorption; farm tracks; (clearing).
Gravel roads
Poor
Erosion of table drains and batters due to the slope and erodible clay.Bush Blocks
4 ha.
Poor
Absorption fields -effluent; gravel roads; access tracks; clearing for house sites and access.
Access tracks
Poor
Erosion of drains; batters and surfaces due to elope and erodible clay.
Shallow excavations
Fair
Depth to rock (soft to moderately hard).
Small farm dams
0-10%Fair
10+%
Slope-construction; depth of material.
Slope.
Sewerage lagoons
Poor
Slope - construction.
Topsoil - Quality
Fair
Structureless; hard setting
- Removal
Poor
Thin layer
- Resowing
Very poor
Slope; infertile erodible sub-soil
Sand - Quality
Very poor
No sand
- Operation
Gravel - Quality
Poor
Gravel deposits rare
- Operation
Poor
Slope - erosion risk
Grazing
Good to fair
Soil erodibility; low fertility; and poor structure.
Overgrazing causes sheet erosion. Slope; poorly structured, erodible topsoil.
Cultivation
Very poor
Cultivated soil can be easily eroded on these slopes.
Clearing
Poor
Slope-erodibility of the soil and difficulty of establishing pasture.
EFFECT OF SUBDIVISION OF THE LAND ON TOWN WATER SUPPLY
URBAN:Unless special management techniques are employed, dispersible clay and silt from development sites will severely affect the water supply.
FARMLETS:Percolation tests indicate a large variability for the success of effluent absorption in these soils. The average rate of absorption is slow. This together with the gradient of the land increases the risk of pollution from failing absorption trenches.
Also, silt and dispersible clay will be common pollutants due to the elopes and the erodible soils. Gravel roads, tracks and existing erosion are likely to be the main sources of these pollutants although overgrazing may contribute. Clearing will be another potential source of sediment due to difficulties in establishing good pasture cover quickly - Note: large areas still remain forested because of the slopes, hazard of erosion and poor pasture production.
BUSH BLOCKS:As above, effluent disposal, gravel roads and tracks will be main sources of pollution. Clearing for house sites and access will be an additional source of sediment unless correctly managed.

LAND UNIT: Ordovician steep hillsCOMPONENT: 2 – Northern slopes – mottled yellow gradational soilsMAP SYMBOL: Ors 2

CAPABILITY OF THE LAND TO SUPPORT VARIOUS ACTIVITIES
CAPABILITY OF THE LAND TO SUPPORT SUBDIVISION
ACTIVITY
RATING
MAJOR LIMITING FEATURES OF THE LAND
SUBDIVISION
TYPE
RATING
MAJOR LIMITING ACTIVITIES
Building houses
0-15% Fair
15+% Poor
Slope and erodible soils - erosion during construction.Urban (sewered)
0-15% Fair
15+% Poor
Building houses; secondary roads (development stage).
Absorption fields
Poor
Slow percolation rate (variable); slope affecting layout and operation.Small Farmlets
4 ha
Poor
Absorption fields-effluent; small farm dams; access tracks; gravel roads; (clearing - very poor).
Secondary roads
0-15% Fair
15+% Poor
Slope & erodible soils-erosion at construction.Large Farmlets
16 ha
Poor
Absorption fields-effluent; small farm dams; access tracks; (clearing -.very poor).
Gravel roads
Poor
Erosion of table drains and batters due to the slope & erodible clay.Bush Blocks
4 ha.
Poor
Absorption fields-effluent; gravel roads; access tracks; clearing for house sites and access.
Access tracks
Poor
Erosion of drains, batters & surface due to slope and erodible clay.
Shallow excavations
Fair
Depth to rook (soft to moderately hard).
Small farm dams
0-10% Fair
10+% Poor
Slope - construction; depth of material.
Slope
Sewerage lagoons
Poor
Slope - construction
Topsoil - Quality
Fair
Structureless; hard setting
- Removal
Poor
Thin layer
- Resowing
Very poor
Slope; infertile erodible sub-soil
Sand - Quality
Very poor
No sand
- Operation
Gravel - Quality
Poor
Gravel deposits rare
- Operation
Poor
Slope - erosion risk
Grazing
Fair
Soil erodibility; low fertility; and poor structure. Overgrazing causes sheet erosion.
Cultivation
Very poor
Slope; poorly structured; erodible topsoil.
Cultivated soil can be easily eroded on these slopes.
Clearing
Very poor
Slope; erodibility of the soil and difficulty of establishing pasture.
EFFECT OF SUBDIVISION OF THE LAND ON TOWN WATER SUPPLY
URBAN:Unless special management techniques are employed, dispersible clay and silt from development sites will severely affect the water supply.
FARMLETS:Percolation tests indicate a large variability for the success of effluent absorption in these soils. The average rate of absorption is slow. This together with the gradient of the land increases the risk of pollution from failing absorption trenches.
Also, silt and dispersible clay are common pollutants due to the elopes and the erodible soils. Gravel roads, tracks and existing erosion are likely to be the main sources of these pollutants although overgrazing will contribute. Clearing will be another major potential source of sediment due to difficulties in establishing good pasture cover quickly. Soils are poorer than those on the southern slopes (component 1).
BUSH BLOCKS:As above, effluent disposal, gravel roads and tracks will be the main sources of pollution. Clearing for house sites and access will be an additional source of sediment unless correctly managed.

LAND UNIT: Ordovician steep hillsCOMPONENT: 3 – Drainage line – black gradational soils (variable)MAP SYMBOL: 3

CAPABILITY OF THE LAND TO SUPPORT VARIOUS ACTIVITIES
CAPABILITY OF THE LAND TO SUPPORT SUBDIVISION
ACTIVITY
RATING
MAJOR LIMITING FEATURES OF THE LAND
SUBDIVISION
TYPE
RATING
MAJOR LIMITING ACTIVITIES
Building houses
Poor to very poor
Soil drainage; surface flows (very poor in flood risk areas).Urban (sewered)
Poor to very poor
Building houses; secondary roads; shallow excavations.
Absorption fields
Very poor
Soil drainage - seasonal and permanent watertables; percolation rate.Small Farmlets
4 ha
Very poor
Absorption fields-effluent; access tracks; (otherwise poor: house foundations; roads)
Secondary roads
Poor
Soil drainage; some flood risk; Surface flows; erosion during construction.Large Farmlets
16 ha
Very poor
Absorption fields - effluent; access tracks (otherwise - poor: house foundations; roads
Gravel roads
Poor
Soil drainage; surface flow; erosion during construction; erosion of drains and surface.Bush Blocks
4 ha.
Very poor
Absorption fields - effluent; access tracks (otherwise-poor: house foundations; roads)
Access tracks
Very poor
Soil drainage; surface flow; erosion of surface and drains.
Shallow excavations
Poor
Soil drainage.
Small farm dams
Fair to good
Variable material for embankment
Sewerage lagoons
Poor
Flood prone; proximity to watercourse.
Topsoil - Quality
Good
Thin layer.
- Removal
Fair
Surface flows.
- Resowing
Poor
Infertile sub-soil; severe erosion.
Sand - Quality
Variable
- Operation
Poor
Poor drainage; surface flows; severe erosion risk.
Gravel - Quality
Variable
Poor drainage; surface flows; severe erosion risk.
- Operation
Grazing
Fair
Soil drainage; pugging of soil; possible gully erosion.
Cultivation
Very poor
Surface flow; fallow wash - rilling; sheet and gully erosion.
Clearing
Very poor
Surface flow; topsoil wash prior to pasture establishment.
EFFECT OF SUBDIVISION OF THE LAND ON TOWN WATER SUPPLY
URBAN:Due to the poor drainage and risk of high velocity floods, much of the land is not capable of supporting urban subdivision without extensive drainage works. However, any development within these drainage lines is likely to contribute significantly to turbidity and silt loads, particularly during construction.
FARMLET:Although this unit may be included as part of farmlet blocks, it is essential that buildings, access and effluent disposal should be excluded from this unit. Clearing will involve a serious risk of erosion.
BUSH BLOCK:As with farmlets, this unit may be included as part of bush blocks as long as housing access and effluent disposal areas are excluded from this unit.

LAND UNIT: Ordovician steep hillsCOMPONENT: 4 – Crests – Shallow stony red gradational soilsMAP SYMBOL: Ors 4

CAPABILITY OF THE LAND TO SUPPORT VARIOUS ACTIVITIES
CAPABILITY OF THE LAND TO SUPPORT SUBDIVISION
ACTIVITY
RATING
MAJOR LIMITING FEATURES OF THE LAND
SUBDIVISION
TYPE
RATING
MAJOR LIMITING ACTIVITIES
Building houses
Fair
Depth to rock (moderate hardness); stoniness.Urban (sewered)
Poor
Shallow excavations (otherwise - fair: building houses; secondary roads)
Absorption fields
Poor
Too stony; shallow soil.Small Farmlets
4 ha
Poor
Small farm dams; grazing; clearing; absorption fields - effluent; (otherwise-fair: building houses: gravel roads; access tracks)
Secondary roads
Fair
Depth to rook (moderate hardness); stoniness.Large Farmlets
16 ha
Poor
Small farm dams: grazing; clearing; absorption fields - effluent: (otherwise - fair: building houses; access tracks).
Gravel roads
Fair
StoninessBush Blocks
4 ha.
Poor
Effluent absorption; clearing for house sites; access tracks.
Access tracks
Fair
Stoniness; erosion of surface.
Shallow excavations
Poor
Depth to rock (moderate hardness); stoniness.
Small farm dams
Poor
Depth to rock; stoniness; catchment requirements
Sewerage lagoons
Poor
Depth to rook
Topsoil - Quality
Poor
Stoniness
- Removal
Very poor
Thin stony layer
- Resowing
Very poor
Depth to rook; infertile stony sub-soil
Sand - Quality
Very poor
No sand
- Operation
Gravel - Quality
Fair
Variable quality; clay content; stoniness
- Operation
Fair
Erodible soils; slope
Grazing
Poor
Shallow stony soils of low moisture holding capacity and low fertility
Cultivation
Very poor
Very shallow; stony soils - not cultivated
Clearing
Very poor
Very slow revegetation - sheet erosion; very poor pasture production.
EFFECT OF SUBDIVISION OF THE LAND ON TOWN WATER SUPPLY
URBAN:Due to the poor soils and dispersible clays it will be difficult to quickly re-establish vegetation to protect earthworks. There will be a considerable risk of silt loss during development.
FARMLET:Failure of septic absorption fields because of the shallow stony soils will be a hazard. Percolation rates maybe very rapid, but the lack of soil depth and high rock fragment content will hinder soil treatment of effluent. Erosion of gravel roads and tracks will be the main source of turbidity and siltation from farmlet subdivisions.
Note: this unit is normally uncleared and if cleared supports low stocking rates. Excess or badly managed stock can lead to overgrazing and therefore sheet erosion. Clearing will involve a serious risk of erosion-large areas remain uncleared because of poor pasture production and erosion risk.
BUSH BLOCK:As for farmlets, effluent absorption and erosion of reads and tracks will be the main continuing hazards. However, clearing for the construction of roads, tracks and house sites will be a very serious risk during the development stage. Bush block subdivision would require special planning and management to minimise pollution of the water supply.

Org - Ordovician Plain

Ordovician plainThe balance of the Ordovician material falls into a slightly dissected plain mainly in the northern parts of the Shire. The unit represents 17.7% of the survey area and covers 36.5 km2. It is mainly used for grazing although increasingly used for cereal cropping. Parts of this unit falling within the Ballarat water supply catchments are in public ownership and forested with pine plantations.

COMPONENT
1
2
3
Proportion %
10
85
5
CLIMATE (Average)
Rainfall mm

30 - 760
*Temperature C
Average annual 12C
*Seasonal growth limitations
Temperature less than 1000 May - September
GEOLOGY
Age, growth

Ordovician, slate & sandstone
TOPOGRAPHY
Landscape

Slightly dissected plains
Elevation (range) m
421
Local relief (av.) m
10
Drainage pattern
Dendritic
Drainage density km/km2
3.9
Land form
Rolling Plain
Position on land form
Crest
Long gentle slope
Drainage line
Slope (av.) ,%, slope shape
1-3 ; Convex
3-9 ; Straight
1-3 ; Concave
NATIVE VEGETATION
Structure

Woodland

Open forest
Dominant species
E. obliqua, E. radiata
E. viminalis E. obliqua
E. ovata, E. obliqua
SOIL
Parent material

In-situ weathered rock

In-situ weathered rock
Alluvium-clay, silt, sand and gravel
Description
Shallow stony red gradational soil
Mottled yellow, red duplex soil
Mottled yellow & red gradational soil
Surface texture
Gravelly loam
Loamy clay
Clay loam
Permeability
High
Moderate-low
Low-moderate
Depth (av.) in
0.6
1
2
LAND USE
Grazing with some forestry and cropping (cereal)
SOIL DETERIORATION
Critical land features

Hard setting surfaces, dispersibility

Hard setting surfaces

Moderate dispersibility, poorly drained site, hard setting surfaces
Processes
Overland flow, leaching of salts
Overland flow, leaching of salts
Overland flow, accumulation of salts
Forms
Sheet and rill erosion, compaction
Sheet and rill erosion, gully erosion, compaction
Salting, gully erosion
* Ballan figures

LAND UNIT: Ordovician plainCOMPONENT: 1 – Crests – Shallow stony red gradational soilsMAP SYMBOL: Org 1

CAPABILITY OF THE LAND TO SUPPORT VARIOUS ACTIVITIES
CAPABILITY OF THE LAND TO SUPPORT SUBDIVISION
ACTIVITY
RATING
MAJOR LIMITING FEATURES OF THE LAND
SUBDIVISION
TYPE
RATING
MAJOR LIMITING ACTIVITIES
Building houses
8-15% Fair
15+% Poor
Depth to rock of moderate hardness; stoniness.Urban (sewered)
Poor
Shallow excavations (otherwise-fair: building houses and secondary roads).
Absorption fields
Poor
Stoniness; depth of soil.Small Farmlets
4 ha
Poor
Small farm dams; absorption fields – effluent (otherwise fair: access tracks; gravel roads; building houses).
Secondary roads
8-12% Fair
12-20% Poor
Depth to rock of moderate hardness; stoniness.
Slope-construction.
Large Farmlets
16 ha
Poor
Small farm dams; absorption fields-effluent (otherwise fair: access tracks and building houses).
Gravel roads
8-12% Fair
12-20% Poor
Stoniness.
Slope-erosion & damage.
Bush Blocks
4 ha.
Poor
Absorption fields-effluent: clearing for house sites and access tracks.
Access tracks
8-12% Fair
12-20% Poor
Stoniness; erosion of surface.
Slope - erosion & damage.
Shallow excavations
Poor
Depth to rock of moderate hardness stoniness.
Small farm dams
Poor
Depth to rook; stoniness; catchment requirements.
Sewerage lagoons
Poor
Depth to rock.
Topsoil - Quality
Poor
Stoniness.
- Removal
Very poor
Thin stony layer.
- Resowing
Very poor
Infertile erodible subsoil; slope - erosion.
Sand - Quality
Very poor
No sand.
- Operation
Fair
Gravel - Quality
Fair
Variable: clay content; stoniness.
- OperationErodible soils; slope
Grazing
Fair
Shallow stony soils of low moisture holding capacity and low fertility.
Cultivation
Very poor
Very shallow; stony soils - not cultivated.
Clearing
Poor
Slow revegetation - sheet erosion.
EFFECT OF SUBDIVISION OF THE LAND ON TOWN WATER SUPPLY
URBAN:Due to the poor soils and dispersible clays, it will be difficult to quickly re-establish vegetation to protect earthworks. There will be a considerable risk of silt lose during development.
FARMLET:Erosion of gravel roads and tracks will be the main source of turbidity and siltation from farmlet subdivisions.
NOTE: this component normally supports low stocking rates. Higher rates or badly managed stock can lead to overgrazing and therefore sheet erosion.
Failure of septic absorption fields because of the shallow stony soils will be a major hazard. Percolation rates may be very rapid but the lack of soil depth and high rock fragment content will hinder the treatment of the effluent.
BUSH BLOCK:As for farmlets, effluent absorption and erosion of roads and tracks will be the main continuing hazards. However, clearing for the construction of roads, tracks and house sites will be a very serious risk during the development stage. Bush block subdivision would require special planning and management to
minimise pollution of the water supply.

LAND UNIT: Ordovician plainCOMPONENT: 2 – Long gentle slopesMAP SYMBOL: Org 2

CAPABILITY OF THE LAND TO SUPPORT VARIOUS ACTIVITIES
CAPABILITY OF THE LAND TO SUPPORT SUBDIVISION
ACTIVITY
RATING
MAJOR LIMITING FEATURES OF THE LAND
SUBDIVISION
TYPE
RATING
MAJOR LIMITING ACTIVITIES
Building houses
0-8% Good
8-15% Fair
Erosion during construction; some shrink-swell.
Slope - erosion & construction problems.
Urban (sewered)
Fair
Building houses; secondary roads.
Absorption fields
Fair
Variable percolation rates; imperfect drainage; temporary water tables - esp. on cleared landSmall Farmlets
4 ha
Fair
Absorption fields-effluent
building houses; gravel roads; access tracks).
Secondary roads
0-8% Good
8-15% Fair
Risk of erosion during construction.
Slope - construction and erosion problems.
Large Farmlets
16 ha
Fair
Absorption fields - effluent; building houses; access tracks.
Gravel roads
Fair
Risk of erosion of batters; drains and surface.Bush Blocks
4 ha.
Fair
Absorption fields - effluent; building houses; gravel roads; access tracks.
Access tracks
Fair
Risk of erosion of surface and drains; soil drainage.
Shallow excavations
Good
Some seasonal drainage problems.
Small farm dams
Good
Sewerage lagoons
Fair
Slope-construction.
Topsoil - Quality
Fair
Too clayey; very hard-setting..
- Removal
Poor
Thin layer
- Resowing
Poor
Sand - Quality
Very poor
No sand.
- Operation
Gravel - Quality
Poor
Gravel deposits are rare or thin layer.
- Operation
Good
Grazing
Good
Soil fertility; impermeable clayey B horizon; hard setting topsoil.
Cultivation
Fair
Impermeable clayey B horizon; hard setting structureless topsoil; erosion.
Clearing
Fair
Soil loss prior to pasture establishment.
EFFECT OF SUBDIVISION OF THE LAND ON TOWN WATER SUPPLY
URBAN:Although the slopes are gentle, the soil is erodible and impermeable. Bare surfaces shed water readily. The clay, which partially disperses, is easily transported. Unless Land Disturbance guidelines are followed during development, moderate turbidity & silt loads can be expected in the runoff.
FARMLET:Erosion of batters, drains and surfaces of gravel roads and tracks in subdivisions will be a moderate source of silt and clay. The silt loss can be minimised by correct planning, construction and maintenance.
Also, the impermeable clay, commonly causes perched watertables, especially in cleared land. Effluent disposal by soil absorption will cause problems, especially on lower slopes and near drainage lines.
BUSH BLOCK:As for farmlets. However, clearing for house sites and access will be an additional potential source of silt and clay in the runoff. Soil drainage will generally be somewhat better in uncleared upper and mid slopes.


LAND UNIT: Ordovician plainCOMPONENT: 3 – Drainage line – mottled yellow/red gradational soilsMAP SYMBOL: Org 3

CAPABILITY OF THE LAND TO SUPPORT VARIOUS ACTIVITIES
CAPABILITY OF THE LAND TO SUPPORT SUBDIVISION
ACTIVITY
RATING
MAJOR LIMITING FEATURES OF THE LAND
SUBDIVISION
TYPE
RATING
MAJOR LIMITING ACTIVITIES
Building houses
Poor to very poor
Soil drainage surface flows (very poor in flood risk areas).Urban (sewered)
Poor to very poor
House foundations; secondary roads; shallow excavations.
Absorption fields
Very poor
Soil drainage - seasonal and permanent watertables; percolation rate.Small Farmlets
4 ha
Very poor
Absorption fields - effluent; access tracks (otherwise poor: building houses and gravel roads).
Secondary roads
Poor
Soil drainage; some flood risk; surface flows; erosion during construction.Large Farmlets
16 ha
Very poor
Absorption fields - effluent; tracks (other. wise- poor: building houses).
Gravel roads
Poor
Soil drainage; surface flows; erosion during construction; erosion of drains and surface.Bush Blocks
4 ha.
Very poor
Absorption fields - effluent; access tracks (otherwise- poor: building houses and gravel roads).
Access tracks
Very poor
Soil drainage; surface flows; erosion of surface and drains.
Shallow excavations
Poor
Soil drainage.
Small farm dams
Fair to good
Variable material for embankment.
Sewerage lagoons
Poor
Flood prone; proximity to watercourse (otherwise: good).
Topsoil - Quality
Good
Thin layer.
- Removal
Fair
- Resowing
Poor
Surface flows; impermeable subsoil; severe erosion risk.
Sand - Quality
Variable
Generally poor quality.
- Operation
Poor
Poor drainage; surface flows; severe erosion risk.
Gravel - Quality
Variable
Generally poor quality.
- Operation
Poor
Poor drainage; surface flows; severe erosion risk.
Grazing
Fair
Soil drainage; pugging of soil; possible gully erosion.
Cultivation
Very poor
Surface flow; fallow wash - rilling; sheet and gully erosion.
Clearing
Poor
Surface flow; topsoil wash prior to pasture establishment.
EFFECT OF SUBDIVISION OF THE LAND ON TOWN WATER SUPPLY
URBAN:Due to the poor drainage and risk of high velocity floods, such of the land is not capable of supporting urban subdivision without extensive drainage works. However, any development within these drainage lines is likely to contribute significantly to turbidity and silt loads, particularly during construction.
FARMLET:Although this unit may be included as part of farmlet blocks, it is essential that buildings, access and effluent disposal should be excluded from this unit. Clearing will involve a serious risk of erosion.
BUSH BLOCK:As with farmlets, this unit may be included as part of bush block, as long as housing access and effluent disposal areas are excluded from this unit.
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