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Slope Stability Report
SLOPE STABILITY RISK
ASSESSMENT REPORT
Site Address: Lot 22 on CP908656 (No.24)
Comet Drive, Sunrise Beach Qld 4567
Client: Brighton Homes Queensland
Project Job No. GEO219297‐B
Date: 15th of September, 2022
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TABLE OF CONTENTS 1.0 INTRODUCTION 2.0 SCOPE AND METHOD OF INVESTIGATIONS 2.1 Qualifications of Responsible Firm ................................................................................................. 3.0 PROPOSED DEVELOPMENT 4.0 OVERVIEW 4.1 Regional Setting and Site Description ............................................................................................. 4.2 Regional Geology ............................................................................................................................ 5.0 GEOTECHNICAL SITE INVESTIGATION 5.1 Fieldwork......................................................................................................................................... 5.2 Subsurface Conditions .................................................................................................................... 5.3 Groundwater ................................................................................................................................... 6.0 SLOPE STABILITY ASSESSMENT 6.1 Stability Assessment Findings ......................................................................................................... 6.2 Desktop Assessment Findings ......................................................................................................... 6.3 Hazard Identification ....................................................................................................................... 6.4 Qualitative Risk Assessment ........................................................................................................... 7.0 COMMENT & RECOMMENDATIONS 7.1 Development................................................................................................................................... 7.2 Development Constraints ............................................................................................................... 7.3 Earthworks ...................................................................................................................................... 7.4 Foundations .................................................................................................................................... 7.5 Drainage .......................................................................................................................................... 7.6 Erosion Control & Landscape .......................................................................................................... 8.0 COMPLIANCE CERTIFICATION 9.0 CONCLUSION APPENDICES Appendix A – Soil Profiles and Laboratory Results Appendix B – Landslide Frequency Analysis Appendix C – Site Photographs Appendix D – Site Maps Appendix E – Qualitative Terminology for use in assessing risk to property Appendix F – Stability of Retaining Structures Appendix G – Hillside Construction
Page 3
1.0 INTRODUCTION
This report presents the results of a geotechnical assessment of stability investigation carried out by
STA Consulting Engineers at Lot 22 on CP908656 (No.24) Comet Drive, Sunrise Beach Qld 4567.
2.0 SCOPE AND METHOD OF INVESTIGATIONS
The aim of this report is to assess the potential risk of slope instability or Landslide risk for the
proposed residential development in its existing and post developed state.
It must be noted that this report reflects the results of a qualitative risk assessment only and is not
to be seen as a slope stability analysis or design report, nor is it intended to quantify a geotechnical
factor of safety or certify the design as provided by the client.
The methodology adopted by STA Consulting Engineers in order to determine the Landslide risk for
this site is obtained incorporating the following criteria :‐
Guidelines developed by the Australian Geomechanics Society (AGS), Landslide Risk
Management, Volume 42 No.1, March 2007.
Landslide Frequency Assessment in accordance with the report “A Method of Zoning
Landslide Hazards”, prepared by MacGregor and Taylor 2001.
A review of existing Hazard mapping (where available), aerial photographs and various
published information to assist in identifying past activity.
2.1 Qualifications of Responsible Firm
This report is prepared by a Registered Professional Engineer of Queensland (RPEQ) specialising in
geotechnical engineering.
3.0 PROPOSED DEVELOPMENT
It is understood the proposed development is to involve the demolition and removal of the
established residential dwelling from the 631.45 square metre allotment. The proposed new
construction is to be positioned largely to the area of the original construction as per the attached
siting plan (refer) appendix D with a nominated off‐set distance of 6.0 metres OMP from the front
Northern boundary, 1.5 metres OMP from the Eastern side boundary, 3.03 metres OMP from the
Southern side boundary, and 8.62 metres from the Western boundary. From the preliminary
information provided, the new construction is to comprise of a double storey, brick veneer structure
supported by slab on ground.
Finished platform levels had not been provided, however upon removal of the existing residence, it
is assumed for the purpose of this report that earthworks are to involve further cut and filling of the
site for the purpose of obtaining desired ground levels and to create a level building platform.
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4.0 Overview
4.1 Regional Setting and Site Description
The site under review is identified as being an established residential type allotment 632 square
metres in overall area, regionally located approximately 3.0 kilometres South East of Noosa Heads
and approximately 1.0 kilometre West of the the coast. The block is positioned within an established
development constructed in the late 1980’s, early 1990’s and is bounded by similar, established
residential type properties. The established residence comprises of a single storey, slab on ground
construction with an in‐ground swimming pool to the North West. The property is landscaped
incorporating gardens and shrubs.
The general topography comprises of the undulating, low rounded hills parabolic sand dunes formed
between the coast to the East and Lake Wyeba to the West.
Fig. 1. Topographic Map – Qld Globe, Queensland State Government.
4.2 Regional Geology
Reference to the Department of Natural Resources, Mines and Energy electronic series indicates
that the site is underlain by (Qpd/2) Quartz Sand; parabolic sand dunes of the Pleistocene age.
Fig. 2 ‐ Regional Geology ‐ Department of Natural Resources, Mines and Energy, QLD State Government.
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5.0 GEOTECHNICAL INVESTIGATION
5.1 Fieldwork
Three (3) bore holes were undertaken across the site using a mechanical push tube to a maximum
depth of 1.5 metres. Dynamic Cone Penetrometer (D.C.P) tests were undertaken at the time of the
site investigation. The bore holes were drilled using solid flight augers fitted with a steel ‘V’ shaped
bit or tungsten carbide bit.
An authorised representative from STA Consulting Engineers set out the bore holes locations from
existing site features, directed sampling and logged bore hole profiles. Engineering logs of the bore
holes are presented in Appendix A, together with Explanation Sheets defining the terms and symbols
used in the preparation of the logs.
5.2 Subsurface Conditions
The sequence encountered by the bore holes typically included a medium dense to dense sand for
the extent of the test holes undertaken. Uncontrolled fill comprising of a silty sand was identified in
test hole # 3 only. The following table is a summary of the subsurface profiles observed:‐
Bore Hole Summary
Bore Uncontrolled Fill (m) Silty Sand (m) Sand (m) Termination Depth
Hole # (m)
BH # 1 ‐ 0.0 ‐ 0.2 0.2 – 1.5 1.5 m
BH # 2 ‐ 0.0 ‐ 0.2 0.2 – 1.5 1.5 m
BH # 3 0.0 – 0.8 ‐ 0.8 – 1.5 1.5 m
5.3 Groundwater
Groundwater was not identified at the time of the subsurface investigation. It must be noted that
ground moisture and ground water depths are typically influenced by climatic conditions and the
permeability of the soils observed and may vary with seasonal change.
6.0 SLOPE STABILITY ASSESSMENT
6.1 Stability Assessment Findings
At the time of the site assessment, the following observations were made:‐
Topographically the site is positioned on the upper slopes of the undulating dune surface.
The predominate land shape is Planar.
The natural unaltered slope is considered moderate with a general cross fall sloping from the
North East to the South West, estimated at approximately 7 to 8 degrees.
From visual assessment only, it appears cut and fill earthworks had been conducted to
accommodate the existing residence.
The site is connected to the mains storm water and sewer networks, therefore all outflows
are to be directed to these mains..
No ground water or surface water seepage was observed, nor was any vegetation such as
reeds/ sedge grasses typically associated with wet areas identified.
No tension cracks were observed on or across the slope within the vicinity of the site.
Hummocky or bulging soils were not identified on or at the base of the slope within the
vicinity of the site.
Page 6
The site is surrounded by a mix of existing residential construction including predominately
slab on ground type construction. From visual inspection only, all appear to be performing as
intended.
Indicators of instability from surrounding man‐made structures were not identified. This
includes but is not limited to signs of rotation or stress in existing swimming pools, retaining
walls, fence posts the performance of existing structures etc....
6.2 Desktop Assessment Findings
A review of historical imagery has been undertaken. No indicators of past landslip activity or
instability on or surrounding the nominated building sites could be identified from these
images.
Fig. 3 – Image Era ~ 1987 QImagery, Qld State Government
With reference to the Landslide Hazard Overlay interactive mapping by the Noosa Shire
Council we have identified the site as having Moderate Hazard areas.
Fig. 4 – Landslide Hazard Overlay – Noosa Shire Council Interactive Maps.
Page 7
6.3 Hazard Identification
A Hazard is defined as a condition with the potential for causing an undesirable consequence (the
landslide).
The hazard assessment given in this report is consistent with the procedures outlined in the report,
“A Method of Zoning Landslide Hazards” by MacGregor and Taylor, 2001. The following major site
features have been considered in determining a likelihood estimate or Frequency Analysis in turn, the
potential Hazard of the site in order of undertaking the final risk assessment for the proposed building
zone and immediate surrounds :
‐ The Natural Slope Angle ‐ The Natural Slope Shape/ Formation
‐ Local Area Geology ‐ Material Strength
‐ Concentration of Surface Water ‐ Evidence of Groundwater
‐ Evidence of Past Forms of Instability
From the results of studies undertaken by SMEC in similar terrain a correlation between relative
frequency and potential Hazard Rating has been determined as presented in the following table :‐
The following summarises the relative frequency calculation adopted following the guidelines of the
Landslide susceptibility analysis form extracted from the document ‘Landslide Susceptibility
Assessment Report’ for the City of Gold Coast, SMEC, August 2011. The complete form can be found
in appendix B;
Feature Description Risk Level
Natural Surface Slope 5 to 15 degrees Moderate
Slope Shape Planar/ Undulating Moderate
Site Geology Sedimentary Rock Moderate
Soil Conditions Residual > 3.0 m High
Evidence of Groundwater None apparent Low
Fill Height Less than 1.0 m Moderate
Cut Height Between 1.0 to 3.0 m Moderate
Slope of Cut Face Less than 30° Low
Material in Cutting Soil Very High
Cut Slope Support Timber Retaining Wall High
Concentration of Surface Water Upper Slope Moderate
Waste Water Disposal Fully Sewered Moderate
Stormwater Disposal All Stormwater Piped to Street Drainage Low
Evidence of Instability No Sign of Instability Low
As an opinion, the hazard for the nominated building location and surrounds of such is provisionally
outlined below:‐
Applied Relative Frequency Hazard Rating
0.68 Moderate
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6.4 Qualitative Risk Assessment
With reference to the Australian Geomechanics Society (AGS) ‘Landslide Risk Management Guideline
2007’, as per Section 8.0 ‘Risk Assessment’, the main objectives of risk evaluations is usually to decide
whether to accept or treat the risks and to set priorities. The ‘Tolerable Risk’ criteria are usually
imposed by the regulator (local Authority), unless agreed otherwise.
The AGS guidelines define ‘Risk’ as a measure of probability and severity of an adverse effect to health,
property or the environment. Risk is often estimated by the product of probability and consequences.
In these guidelines risk is further defined as;
a) For Life Loss, the annual probability that the person most at risk will lose his or her life taking
account of the landslide hazard and the temporal spatial probability and vulnerability of the
person.
b) For property loss – the annual probability of the consequence or the annualised loss taking
account of the elements at risk, their temporal spatial probability and vulnerability.
A qualitative assessment involves an analysis which uses word form, descriptive or numeric rating
scales in order to describe the magnitude of potential consequences and the likelihood that those
consequences will occur. The Risk evaluation involves making judgements about the significance and
tolerability of the estimated risk. Evaluation may involve comparison of the assessed risks with other
risks or with risk acceptance criteria related to finance, loss of life or other values.
A qualitative landslide risk has been calculated taking into consideration the applied hazard rating and
the intended development as described by the client. It must be noted, the residual risk level
determined is conditional on the risk mitigation measures as outlined in Sections 7.0 of this report
being fully implemented and maintained for the expected life of the structure.
The elements considered within the risk assessment are as follows:
The intended/ proposed buildings and associated outbuildings.
Persons or Occupants on site.
As per the AGS guidelines, Qualitative Terminology used in assessing likelihood, consequence and risk
is presented in the following tables;
Likelihood Indicative Annual Description
Probability
Barley Credible 10‐6 The event is inconceivable or fanciful over the design life.
Rare 10‐5 The event is conceivable but only under exceptional
circumstances over the design life
Unlikely 10‐4 The event might occur under adverse conditions over the
design life.
Possible 10‐3 The event could occur under adverse conditions over the
design life.
Likely 10‐2 The event will probably occur under adverse conditions over
the design life.
Almost Certain 10‐1 The event is expected to occur.
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The potential implications for the associated risk level are outlined within the table below:‐
Risk Level Implications
VH (Very High Risk) Unacceptable without treatment. Extensive detailed investigation and
research, planning and implementation of treatment options essential to
reduce risk to Low; may be too expensive and not practical. Work likely to cost
more than the value of the property.
H (High Risk) Unacceptable without treatment. Detailed investigation, planning and
implementation of treatment options required to reduce risk to Low. Work
would cost a substantial sum in relation to the value of the property.
M (Moderate Risk) May be tolerated in certain circumstances (subject to regulator’s approval)
but requires investigation, planning and implementation of treatment options
to reduce the risk to Low. Treatment options to reduce to Low risk should be
implemented as soon as practicable.
L (Low Risk) Usually acceptable to regulators. Where treatment has been required to
reduce the risk to this level, ongoing maintenance is required.
VL (Very Low Risk) Acceptable. Manage by normal slope maintenance procedures.
Note: The implications for a particular situation are to be determined by all parties to the risk assessment and may depend
on the nature of the property at risk; these are only given as a general guide.
The table below outlines our qualitative assessment of landslide risk for the development site.
Hazard Likelihood Consequence Assessed Comments
to Property Risk
1. Shallow failure Rare due to the gentle gradients of the
through the Rare Minor Very Low natural slope and to the extent of
residual soils on development including retaining walls
slopes <15 º adjoining the site. The consequence of
such instability would be Minor with
the resultant risk being Very Low.
2. Failure of the This has been assigned as possible due
existing timber Possible Insignificant Very Low to the wall being of timber
retaining walls to construction and the limited lifespan
the Northern and expected for timber walls. The
Eastern boundary consequence of failure would be
lines. insignificant with the resultant risk
being Very Low. Note, the design and
construction details of these walls had
not been supplied, therefore have not
been independently verified by STA.
The stability/ integrity of the existing
retaining walls remains the
responsibility of the owner/ builder
and design engineers.
3. Deep seated failure Whilst the consequence of such a
within the residual Barely Major Very Low failure would be major, the likelihood
soil profile or Credible is barley credible due to relatively
weathered rock. gentle gradients and absence of
evidence of instability of such nature.
The resultant risk is Very Low.
On the basis of the qualitative risk assessment of likelihood and consequence presented in the table
above, the risk of the area assessed is determined as ‘Very Low’. This level of risk is acceptable;
manage by normal slope maintenance procedures.
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7.0 COMMENT & RECOMMENDATIONS
The area of the proposed structure has been defined as Very Low Risk providing the following
recommendations are implemented, managed and maintained for the expected life of the structure
:‐
7.1 House Design
As indicated by the client, the proposed development is to involve the demolition and removal of
the established residential dwelling from the 631.45 square metre allotment. The proposed new
construction is to be positioned largely to the area of the original construction as per the attached
siting plan (refer) appendix D with a nominated off‐set distance of 6.0 metres OMP from the front
Northern boundary, 1.5 metres OMP from the Eastern side boundary, 3.03 metres OMP from the
Southern side boundary, and 8.62 metres from the Western boundary. From the preliminary
information provided, the new construction is to comprise of a double storey, brick veneer structure
supported by slab on ground.
Finished platform levels had not been provided, however upon removal of the existing residence, it
is assumed for the purpose of this report that earthworks are to involve further cut and filling of the
site for the purpose of obtaining desired ground levels and to create a level building platform.
STA Consulting Engineers are satisfied that a construction type as described above is
considered suitable for this site providing the following recommendations outlined are
implemented and maintained for the life of the structure.
7.2 Earthworks
Retain the existing natural contours wherever possible.
Where the removal of trees or existing structures is undertaken the voids created by their
removal, must be over excavated, back filled and compacted with suitable material.
All earthworks to be carried out in accordance with the requirements of Australian Standard
AS 3798 Guidelines on Earthworks for Commercial and Residential Developments.
Cuts ‐ Minimise depth.
Support cut batters with engineered retaining walls or profile to an appropriate slope. For this
site, exposed cut batters are to be profiled no greater than the following :‐
Safe Batter Profile Angles (up to 1.0 metres in height)
Material Temporary Permanent
Non-cohesive Soils 1V : 2H 1V : 2H
Drainage measures MUST be installed immediately up slope and behind all cut batters
including those retained to capture both surface and subsurface water movements and divert
waters to a suitable, controlled outflow below and clear of the building envelope. All drains
must be maintained for the life of the structure.
No excavation is to be undertaken within the zone of influence of any existing structure on or
adjoining the site (including retaining walls, sewer and storm water infrastructure etc..) unless
it can be shown that measures have been implemented to protect the stability of these
structures during and after construction. This should be determined by the design engineer.
Page 11
Fills ‐ Minimise height.
Support filled batters with engineered retaining walls or profile to an appropriate slope. For
this site, exposed fill batters are to be profiled no greater than the following :‐
Safe Batter Profile Angles/ Heights
Material Temporary Permanent Maximum Unsupported
Batter Height
Uncontrolled Fill 1V : 2H 1V : 4H 1.0 m
Engineered Controlled Fill 1V : 1H 1V : 2H 2.0 m
Note: The safe batter profile angles given are for un‐surcharged batters only.
Strip vegetation, topsoil and key/ bench the natural slope prior to filling. Fill is not to be simply
placed onto sloping surfaces greater than ~ 7 degrees.
Use clean fill materials and compact to engineering standards. Fill should be placed in
maximum 200 mm deep layers and be compacted to a minimum of 95 % Standard Maximum
Dry Density for cohesive (clay) material or 70 ‐ 90 % Relative Density for non‐cohesive (sand)
materials.
Structural filled batters should be over constructed by filling beyond the required final batter
face and cut back/ trimmed enabling machines to adequately compact the entire fill batter.
The finished platform must not slope towards the filled embankment which will allow water
to flow/ cascade over the exposed face. Ponding water on the platform must also be
avoided.
Consideration must be given to ensure that no surcharge loading from proposed filling is
imposed onto any existing infrastructure (including retaining walls, sewer and storm water
infrastructure etc..) unless it can be shown that measures have been implemented to
protect the stability of these structures during and after construction. This should be
determined by the design engineer.
7.3 Foundations
Footings should be founded within the medium dense to dense sand profile. This is to be
determined by the designing engineer.
The design engineer should consider the location of the existing swimming pool and
retaining walls to ensure that no additional surcharge is imposed on these structures as a
result of the proposed development.
On site foundation inspections including footing, slab & retaining walls must be undertaken
by a suitably qualified and experienced Geotechnical Engineer.
7.4 Drainage
The control of surface and subsurface water is critical to the overall performance of this site. All
surface and subsurface water must be captured and directed off site via a suitable outflow. Water
MUST not be left to pond on site, nor is water to be left to cascade over any cut or fill batter. Some
basic guidelines include but are not limited to:‐
Surface
Provide drains at the top of all cut and fill slopes, including those retained.
Discharge under controlled conditions (i.e. pipe) to the street drainage.
Provide and maintain general falls within drains to prevent blockage by siltation.
Line spoon drains to minimise the infiltration of surface water and make drains flexible
where possible.
Page 12
Subsurface
Provide filters around all subsurface drainage.
Provide appropriate drainage behind ALL retaining structures.
Use flexible pipelines with access for long‐term maintenance.
Prevent the inflow of surface water.
Waste Water & Storm water
The site is connected to the mains sewer and storm water systems. All outflows are to be
directed to these mains.
Storage tanks should be watertight and adequately founded. Overflows are to be piped to
the existing storm water system.
7.5 Erosion Control & Landscape
Control erosion as this may lead to instability.
Slope protection measures shall be carried out on exposed batters in order to mitigate the
development of stability and erosion issues. These works shall be carried out in a timely
fashion after the batter is exposed.
Re‐vegetate exposed with shrubs, grasses and ground covers preferably with plants
indigenous to the local area.
Page 13
8.0 COMPLIANCE CERTIFICATION
For final building approvals, a compliance certificate may be required by the local authority to assess
that the relevant slope aspects of the development have been constructed in accordance with the
recommendations contained within this report.
In the event that a this certificate is required and as good practise in general, site inspections by STA
Consulting should be carried out at various stages of the development. This shall include, as a
minimum:
1. Site preparation works prior to building construction. This may include inspection on
topsoil stripping, cut and fill batters (temporary and/or permanent), drainage
measures etc.. This inspection would enable the identification of areas of
geotechnical concerns at the early stage of development.
2. Work Completion. This inspection is expected to assess the compliance with the
recommendations in this report and advise if further works are needed.
Inspections pertaining to footings, slab, retaining walls etc.. should be carried out
separately to the above inspections.
It should be noted, STA Consulting reserves the right to decline a request for a compliance inspection
and subsequent certification on the basis we have not undertaken staged site inspections as outlined
above.
9.0 CONCLUSION
In conclusion, it is our considered opinion, from a geotechnical viewpoint that the site is suitable for
the proposed residence that had been indicated by the client at the time of writing this report.
This recommendation is subject to the implementation of the measures specified within this report.
On site foundation inspections including footing, slab & retaining walls must be undertaken by a
suitably qualified and experienced Engineer.
Thank you for entrusting us with this work, if we can be of any further assistance in this matter,
please let us know.
For and on behalf of
STA Consulting Group Pty Ltd
Digitally signed by STA Consulting Engineers
DN: c=AU, st=Queensland, l=Brisbane, o=STA
Consulting Engineers, cn=STA Consulting
Engineers, [email protected]
Robin Cao BEng Justin J Williamson
MIEAust CPEng NPER RPEQ 12198 A.D. Civil Eng. Cert. Mining Eng
Page 14
APPENDICES [OCR of page images] APPENDICES
Page 15
APPENDIX A Soil Profile and Laboratory Results [OCR of page images] APPENDIX A Soil Profile and Laboratory Results
Page 16
Project Job No. ES219297
Bore Log Sheet
Bore Hole # 1 Bore Hole # 2 Bore Hole # 3
Project Job No. ES219297-B
Client: Brighton Homes Queensland Drill Method: Push Tube Drill Method: Push Tube Drill Method: Push Tube
D.C.P blows/ 100 mm
D.C.P blows/ 100 mm
D.C.P blows/ 100 mm
Sample Location
Sample Location
Sample Location
Depth (m)
Depth (m)
Depth (m)
Groundwater
Groundwater
Groundwater
SOIL DESCRIPTION SOIL DESCRIPTION SOIL DESCRIPTION
Extent of Fill
Extent of Fill
Extent of Fill
Graphic Log
Graphic Log
Graphic Log
N'q (kPa )
PP Value
PP Value
PP Value
N'q (kPa)
N'q (kPa)
Symbols
Symbols
Symbols
0 (SM) silty SAND, fine to med. sands
0 (SM) silty SAND, fine to med. sands
0 (SM) silty SAND - FILL, fine to med. sands
(Grey), Dry and Loose (Grey), Dry and Loose (Grey), Dry and Loose
(SP) SAND, fine to med. sands 2
(Grey White), Dry to Moist and Medium Dense (SP) SAND, fine to med. sands 1
0.5 0.5
(Grey White), Dry to Moist and Medium Dense 0.5
2
2
3
4
(SP) SAND, fine to med. sands 4
1.0 1.0 1.0 (Grey White), Dry to Moist and Medium Dense 5
Dry to Moist & Medium Dense to Dense 5
Dry to Moist & Medium Dense to Dense 6
Dry to Moist & Medium Dense to Dense
1.5 1.5 1.5
END END END
2.0 2.0 2.0
2.5 2.5 2.5
3.0 3.0 3.0
3.5 3.5 3.5
4.0 4.0 4.0
4.5 4.5 4.5
5.0 5.0 5.0
Bore Hole Terminated - 1.5 m Bore Hole Terminated - 1.5 m Bore Hole Terminated - 1.5 m
Terms :-
D.C.P.:- Dynamic Cone Penetrometer Note : kPa value is allowable bearing pressure caculated in accordance
N'q:- Allowable Bearing Capacity (kPa) with paper 'Determination of allowable bearing pressure under small structures'
PP:- Pocket Penetrometer Strength (kPa) by M.J Stockwell (June 1977)
U.T.P:- Unable to Penetrate
Slope Direction
STA CONSULTING ENGINEERS Client
Brighton Homes Queensland
Site Address
Lot 33 No.24 COMET DRIVE SUNRISE BEACH 4567
Brisbane (Eight Mile Plains) (07) 3071 7444 Gold Coast (07) 3071 7444 Newcastle (02) 4032 6450
email: [email protected] webpage: www.staconsulting.com.au PO Box 3220 LOGANHOLME 4129
Page 17
Project Job No. ES 219297
Site Sketch ( Not to Scale )
(All Dimensions Shown are Approximate Only)
Retaining Wall Laboratory Test Results
Sample Location:- N/A
6m Depth of Sample:- N/A
Retaining Wall
GENERALLY LEVEL Liquid Limit:- N/A
3m
Linear Shrinkage:- N/A
Shed
2. N/A
Retaining Wall
Iss:-
Classification by characteristic surface movement as per AS2870-2011
SITE CLASSIFICATION SYMBOLS DESIGN Y'S RANGE GENERALISED DESCRIPTION
Existing House (Guide Only)
Retaining Wall
7m
Most sand and rock sites with little or no ground movement from
'A' 0 < Ys
moisture changes.
Existing Established
Dwelling Slightly reactive clay sites, which may experience only slight ground
'S' 0 < Ys < 20
3m movement from moisture changes
Moderately reactive clay or silt sites, which may experience moderate ground
'M' 20 < Ys < 40 movement from moisture changes
3.
Highly reactive clay sites, which may experience high ground movement
8m 'H1' 40 < Ys < 60 from moisture changes
1. Highly reactive clay sites, which may experience very high ground movement
1m 'H2' 60 < Ys < 75 from moisture changes
Extremely reactive clay sites, which may experience extreme ground
'E' Ys > 75 movement from moisture changes
Problem sites which generally have soils associated with uncontrolled fill,
Existing Swimming Pool 'P' N/A abnormal moisture conditions (trees), soft or collapsing soils, landslip etc..
For classes M, H1, H2 and E this further classification may be required, based
Driveway '- D' N/A on the depth of expected moisture change. Applied to sites with deep-seated
moisture changes characteristic of dry climates and corresponding to a design
depth of suction change (Hs), equal to or greater than 3 metres.
Test Methods: AS1289 3.1.2 (liquid limit), 3.4.1(linear shrinkage), 7.1.1(shrink-swell)
STREET
Note - Tree heights (Ht) nominated are
approximate and do not represent the
potential mature height of the tree.
STA CONSULTING ENGINEERS Client
Brighton Homes Queensland
Site Address
Lot 33 No.24 COMET DRIVE SUNRISE BEACH 4567
Brisbane (Eight Mile Plains) (07) 3071 7444 Gold Coast (07) 3071 7444 Newcastle (02) 4032 6450
email: [email protected] webpage: www.staconsulting.com.au PO Box 3220 LOGANHOLME 4129
Page 18
APPENDIX B Landslide Frequency Analysis [OCR of page images] APPENDIX B Landslide Frequency Analysis
Page 19
GEOLOGY: (Qpd/2) Quartz Sand
Location: Lot 22 on CP908656 (No.24) Comet Drive, Sunrise
Beach Qld 4567
1. Natural Surface Slope 8. Slope of Cut Face
Area Level Factor
Area Level Factor
x Less than 30 Degrees L 0.5
Less than 5 degrees L 0.1
Between 30 and 45 VH 1
x Between 5 and 15 M 0.5
Degrees
Degrees
Between 45 and 60 VH 1.5
Between 15 and 30 M 0.8
Degrees
degrees
Greater than 60 VH 3
Between 30 and 45 H 1.2
Degrees
degrees
More than 45 Degrees M 0.8
9. Material in Cutting
Area Level Factor
2. Slope Shape
Area Level Factor High Strength Rock L 0.5
Crest or ridge L 0.7 Medium Strength Rock L 1
Planar/ Convex M 0.9 Low Strength Rock M 1.2
x
Rough/ Irregular M 1.2 Very Low Strength Rock H 1.5
and Soil
Concave H 1.5
x Soil VH 2
3. Site Geology
Area Level Factor 10. Cut Slope Support
Area Level Factor
Volcanic Extrusive Rock H 1.1
Concrete Wall L 0.5
x Sedimentary Rock M 1
Crib Wall M 0.9
Low Grade Metamorphic M 1
Rock Gabion Wall M 1
High Grade Metamorphic L 0.9 Rock Wall H 1.5
Rock Timber Wall H 2
x
Volcanic Intrusive Rock M 1
Unsupported H 2
4. Soils
Area Level Factor 11. Concentration of Surface Water
Area Level Factor
Rock at Surface VL 0.1
Ridge L 0.7
Residual Soil < 1m deep L 0.5
Crest M 0.8
Residual Soil 1 - 3m deep M 0.9
x Upper Slope M 0.9
x Residual Soil > 3m deep H 1.5
Mid Slope H 1.2
Colluvial Soil < 1m deep H 1.5
Lower Slope H 1.5
Colluvial Soil 1 - 3m deep VH 2
Colluvial Soil > 3m deep VH 4
12. Wastewater Disposal
Area Level Factor
5. Fill Height
Area Level Factor x Fully Sewered M 1
None L 0.9 Onsite Disposal - M 1.2
Surface
x Less than 1.0 m M 1.1
Onsite Disposal - Soak H 1.5
Between 1.0 m and 3.0 m M 1.3 Pit /Trench
Between 3.0 m and 6.0 m H 1.7
Greater than 6.0 m VH 2.5 13. Stormwater Disposal
Area Level Factor
6. Evidence of Groundwater x All Stormwater Piped to L 0.7
Area Level Factor Street Drainage
Rainwater Tank with M 1
x None Apparent L 0.7
Overflows
Minor Moistness M 0.9 Stormwater Discharge H 1.5
Generally Wet H 1.5 on Site
Subsurface Springs VH 3
14. Evidence of Instability
Area Level Factor
7. Cut Height
Area Level Factor x No sign of instability L 0.8
None (Go to section 11) L 0.9 Soil Creep H 1.2
Less than 1.0 m M 1.1 Minor Irregularity VH 2
Between 1.0 m and 3.0 m M 1.3 Major Irregularity VH 5
x
Between 3.0 m and 6.0 m H 1.7 Active Instability VH 10
Greater than 6.0 m VH 2.5
Page 20
Summary
1 Natural Surface Slope M 0.5 Relative Frequency Hazard Rating
2 Slope Shape M 0.9 < 0.2 Very Low
3 Site Geology 0.2 - 0.6 Low
M 1.0 0.6 - 2.0 Moderate
4 Soils H 1.5 2.0 - 6.0 High
5 Fill Height M 1.1 >6 Very High
6 Evidence of Groundwater L 0.7
7 Cut Height M 1.3 Relative Frequency = 0.68
8 Slope of Cut Face L 0.5
9 Material in Cutting VH 2.0 Hazard Rating = Moderate
10 Cut Slope Support H 2.0
11 Concentration of Surface Water M 0.9 *The numerical factor allocation to these site features are based on
12 Wastewater Disposal judgement and experience observed at time of assessment.
M 1.0
13 Stormwater Disposal L 0.7
14 Evidence of Instability L 0.8
9 Relative Frequency M 0.68
(1x2x3x4x5x6x7x8x9x10x11x12x13x14)
Page 21
APPENDIX C Site Photographs [OCR of page images] APPENDIX C Site Photographs
Page 22
Fig.5. View South East towards site. Fig.6. View North East towards site. [OCR of page images] Fig.5. View South East towards site. Fig.6. View North East towards site.
Page 23
Fig.7. View East across Northern aspect of established residence. Fig.8. Existing retaining wall to Northern boundary.
Page 24
APPENDIX D Site Maps - Aerial Image - Preliminary Siting Plan [OCR of page images] APPENDIX D Site Maps Aerial Image Preliminary Siting Plan
Page 25
Fig. 9. Aerial Image – Qld Globe, Queensland State Government. [OCR of page images] Fig. 9. Aerial Image - Qld Globe, Queensland State Government.
Page 26
Site Calculations SITE AREA EXISTING FLOOR AREA PROPOSED AREA 631.98m 0.00m2 315.37m 0424950253 COPYRIGHT STATEMENT DESCRIPTION This plan always remains the copyright of designer & shall not be used other than for the project work intended without written authority. No part may be produced by any other exclusive right be exercised . : 5 A without permission legal enforcement will be taken on copyright infringement Site Plan Generated DISCLAIMER This is not an official document, and may not comply with current laws or industry standards. You should make your own enquiries and seek independent advice from relevant industry professionals before acting or relying on the contents of this document. W.M Cilent Emall Sales Person Wayne Moodie Phone [email protected] PROPERTY DETAILS 24 Comet Dr, Sunrise Beach, QLD 4567, Australia Lot/DP; 33/CP908656 Gent Phone SHEET NAME Site Plan DESIGN Aurora 35 SCALE: 1-900 MAR JOB NO: 313800 SHEET NO: REV NO: 4 2a INAI2N29
Page 27
APPENDIX E Qualitative Terminology for use in assessing Risk to Property [OCR of page images] APPENDIX E Qualitative Terminology for use in assessing Risk to Property
Page 28
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Page 29
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Page 30
AUSTRALIAN GEOGUIDE LR7 (LANDSLIDE RISK) [LANDSLIDE RISK | Concept of Risk Risk is a familiar term, but what does it really mean? It can be defined as “a measure of the probability and severity of an adverse effect to health, property, or the environment.” This definition may seem a bit complicated. In relation to landslides, geotechnical practitioners (GeoGuide LR1) are required to assess risk in terms of the likelihood that a particular landslide will occur and the possible consequences. This is called landslide risk assessment. The consequences of a landslide are many and varied, but our concerns normally focus on loss of, or damage to, property and loss of life. Landslide Risk Assessment Some local councils in Australia are aware of the potential for landslides within their jurisdiction and have responded by designating specific ‘landslide hazard zones". Development in these areas is often covered by special regulations. If you are contemplating building, or buying an existing house, particularly in a hilly area, or near cliffs, go first for information to your local council. Landalide ri i jertak & geotechnical practitioner. it may involve visual inspection, geological mapping, geotechnical investigation and monitoring to identify: * potential landslides (there may be more than one that could impact on your site) the likelihood that they will occur the damage that could result the cost of disruption and repairs and the extent to which lives could be lost. Risk assessment is a predictive exercise, but since the ground and the processes involved are complex, prediction tends to lack precision. If you commission a landslide risk assessment for a particular site you should expect to receive a report prepared in accordance with current professional guidelines and in a form that is acceptable to your local council, or planning authority. Risk to Property Table 1 indicates the terms used to describe risk to property. Each risk level depends on an assessment of how likely a landslide is to occur and its consequences in dollar terms. "Likelihood" is the chance of it happening in any one year, as indicated in Table 2. "Consequences" are related to the cost of repairs and temporary loss of use if a landslide occurs. These two factors are combined by the geotechnical practitioner to determine the Qualitative Risk. TABLE 2: LIKELIHOOD Likelihood Annual Probabil Almost Certain 1:10 7:10, 000 Rare 1:100,000 The terms "unacceptable", "may be tolerated", etc. in Table 1 indicate how most people react to an assessed risk level. However, some people will always be more prepared, or better able, to tolerate a higher risk level than others. Some local councils and planning authorities stipulate a maximum tolerable level of risk to property for developments within their jurisdictions. In these situations the risk must be assessed by a geotechnical practitioner. If stabilisation works are needed to meet the stipulated requirements these will normally have to be carried out as part of the development, or consent will be withheld. TABLE 1: RISK TO PROPERTY Qualitative Risk | Significance - Geotechnical engineering requirements Very high | VH | Unacceptable without treatment. Extensive detailed investigation and research, planning and implementation of treatment options essential to reduce risk to Low. May be too expensive and not practical. Work likely to cost more than the value of the property. High H Unacceptable without treatment. Detailed investigation, planning and implementation of treatment options required to reduce risk to acceptable level. Work would cost a substantial sum in relation to the value of the property. May be tolerated in certain circumstances (subject to regulator's approval) but requires investigation, planning and implementation of treatment options to reduce the risk to Low. Treatment options to reduce to Low risk should be implemented as soon as possible. Moderate M Usually acceptable to regulators. Where treatment has been needed to reduce the risk to this cos | | tevel, ongoing maintenance is required. Very Low | VL | Acceptable. Manage by normal slope maintenance procedures.
Page 31
AUSTRALIAN GEOGUIDE LR7 (LANDSLIDE RISK) Risk to Life Most of us have some difficulty grappling with the concept of risk and deciding whether, or not, we are prepared to accept it. However, without doing any sort of analysis, or commissioning a report from an "expert", we all take risks every day. One of them is the risk of being killed in an accident. This is worth thinking about, because it tells us a lot about ourselves and can help to put an assessed risk into a meaningful context. By identifying activities that we either are, or are not, prepared to engage in we can get some indication of the maximum level of risk that we are prepared to take. This knowledge can help us to decide whether we really are able to accept a particular risk, or to tolerate a particular likelihood of loss, or damage, to our property (Table 2). In Table 3, data from NSW for the years 1998 to 2002, and other sources, is presented. A risk of 1 in 100,000 means that, in any one year, 1 person is killed for every 100,000 people undertaking that particular activity. The NSW data assumes that the whole population undertakes the activity. That is, we are all at risk of being killed in a fire, or of choking on our food, but it is reasonable to assume that only people who go deep sea fishing run a risk of being killed while doing it. It can be seen that the risks of dying as a result of falling, using a motor vehicle, or engaging in water- related activities (including bathing) are all greater than 1:100,000 and yet few people actively avoid situations where these risks are present. Some people are averse to flying and yet it represents a lower risk than choking to death on food. Importantly, the data also indicate that, even when the risk of dying as a consequence of a Particular event is very small, it could still happen to any one of us any day. If this were not so, no one would ever be struck by lightning. Most local councils and planning authorities that stipulate a tolerable risk to property also stipulate a tolerable risk to life. The AGS Practice Note Guideline recommends that 1:100,000 is tolerable in newly developed areas, where works can be cared out as part of the development to limit risk. The tolerable level is raised to 1:10,000 in established areas, where specific landslide hazards may have existed for many years. The distinction is deliberate and intended to prevent the concept of landslide risk management, for its own sake, becoming an unreasonable financial burden on existing communities. Acceptable risk is usually taken to be one tenth of the tolerable risk (1:1,000,000 for new developments and 1:100,000 for established areas) and efforts should be made to attain these where it is practicable and financially realistic to do so. TABLE 3: RISK TO LIFE Risk (deaths per Activity/Event Leading to Participant per Death year) (NSW data unless noted) 1:1,000 Deep sea fishing (UK) TE, |a sei, roe wae * ultralight flying (Canada) 4:23,000 Motor vehicle use 1:30,000 Fall 1:70,000 Drowning 1:180,000 Fire/burn 1:660,000 Choking on food 1:1,000,000 Scheduled airlines (Canada) 1:2,300,000 Train travel 1:32,000,000 Lightning strike More information relevant to your particular situation may be found in other AUSTRALIAN GEOGUIDES: GeoGuide LR1 - Introduction GeoGuide LR2 - Landslides GeoGuide LR3_ - Landslides in Soil GeoGuide LR4 = - Landslides in Rock GeoGuide LR5 - Water & Drainage GeoGuide LR6 - Retaining Walls GeoGuide LR8 - Hillside Construction GeoGuide LRO - Effluent & Surface Water Disposal GeoGuide LR10 - Coastal Landslides GeoGuide LR11 - Record Keeping The Australian GeoGuides (LR series) are a set of publications intended for property owners; local councils; planning authorities: developers; insurers; lawyers and, in fact, anyone who lives with, or has an interest in, a natural or engineered slope, a cutting, or an excavation. They are intended to help you understand why slopes and retaining structures can be a hazard and what can be done with appropriate professional advice and local council approval (if required) to remove, reduce, or minimise the risk they represent. The GeoGuides have been prepared by the jcty. a specialist technical society within Engineers Australia, the Australian Geomechanics Society, national peak body for all engineering disciplines in Australia, whose members are professional geotechnical engineers and engineering geologists with a particular interest in ground engineering. The GeoGuides have been funded under the Australian governments” National Disaster Mitigation Program.
Page 32
APPENDIX F Stability of Retaining Structures [OCR of page images] APPENDIX F Stability of Retaining Structures
Page 33
Stability of Retaining Structures
Geotechnical stability of all proposed retaining structures must be carried out against sliding, overturning and global
slope instability. The retaining structures must also be stable against bearing capacity failure (or excessive base
settlements). Moreover, the retaining structure itself must be adequately designed against any potential structural
failures such as flexural failure or shear failure.
B
Pa=Active earth pressure
Pp=Passive earth
pressure
O
Fig. 7: Typical retaining structure and the lateral earth pressure distributions
Figure 7 shows a typical retaining structure including lateral earth pressure distributions. The retained soil behind
the retaining structure will exert active lateral earth pressure if the retaining structure allows some lateral
movement; otherwise lateral earth pressure at rest (Ko condition) should be used during design and stability
assessments. The soil in front of the wall will cause passive earth pressure, as shown in Fig. 7.
All development applications involving retaining structures must assess the geotechnical stability and factor of
safety against the following:
a) Sliding caused by the active earth pressure and resistance by passive earth pressure and frictional force at the
base the retaining structure;
b) Overturning about the toe (point O in Fig. 7) as a result of driving moment caused by the active earth pressure
and resisting moment caused by the passive earth pressure, the self‐weight of the retaining structure and weight of
the retained soils behind the structure; and
c) Global slope instability considering a large slip circle passing through the underneath of the retaining structure
and the retained soils.
The stability assessment shall ensure that all retaining structures will achieve a factor of safety (FOS) > 1.5 against
sliding, overturning and global slope instability.
Referenced “Geotechnical Stability Assessment Guidelines JUNE 2007: Version 1.0 Gold Coast City Council” Section
5.2 Page 19.
Page 34
APPENDIX G Hillside Construction [OCR of page images] APPENDIX G Hillside Construction
Page 35
AUSTRALIAN GEOGUIDE LR8 (CONSTRUCTION PRACTICE)
Sensible development practices are required when building on hillsides, particularly if the hillside has more than a low
risk of instability (GeoGuide LR7). Only building techniques intended to maintain, or reduce, the overall level of landslide
risk should be considered. Examples of good hillside construction practice are illustrated below.
EXAMPLES OF GOOD HILLSIDE CONSTRUCTION PRACTICE
ae
Surface water interception drainage —,
Watertight, adequately sited and founded roof water storage
tanks (with due regard for impact of potential leakage)
Flexible structure
Roof water piped off site or stored
On-site detention tanks, watertight and adequately
founded. Potential leakage managed by sub-soil
“= Pier footings into rock
*“—Subsoil drainage may be
required in slope
\ Cutting and filling minimised in development
“= Sewage effluent pumped out or connected to sewer.
Tanks adequately founded and watertight. Potential
leakage managed by sub-soil drains
~ Engineered retaining walls with both surface and ~
subsurface drainage (constructed before dwelling)
@ Ags (2007)
‘Soe algo AGS (2000) Appendix J
WHY ARE THESE PRACTICES GOOD?
Roadways and parking areas - are paved and incorporate kerbs which prevent water discharging straight into the
hillside (GeoGuide LR5).
Cuttings - are supported by retaining walls (GeoGuide LR6).
Retaining walls - are engineer designed to withstand the lateral earth pressures and surcharges expected, and include
drains to prevent water pressures developing in the backfill. Where the ground slopes steeply down towards the high
side of a retaining wall, the disturbing force (see GeoGuide LR6) can be two or more times that in level ground.
Retaining walls must be designed taking these forces into account.
Sewage - whether treated or not is either taken away in pipes or contained in properly founded tanks so it cannot soak
into the ground.
Surface water - from roofs and other hard surfaces is piped away to a suitable discharge point rather than being allowed
to infiltrate into the ground. Preferably, the discharge point will be in a natural creek where ground water exits, rather
than enters, the ground. Shallow, lined, drains on the surface can fulfil the same purpose (GeoGuide LR5S).
Surface loads - are minimised. No fill embankments have been built. The house is a lightweight structure. Foundation
loads have been taken down below the level at which a landslide is likely to occur and, preferably, to rock. This sort of
construction is probably not applicable to soil slopes (GeoGuide LR3). If you are uncertain whether your site has rock
near the surface, or is essentially a soil slope, you should engage a geotechnical practitioner to find out.
Flexible structures - have been used because they can tolerate a certain amount of movement with minimal signs of
distress and maintain their functionality.
Vegetation clearance - on soil slopes has been kept to a reasonable minimum. Trees, and to a lesser extent smaller
vegetation, take large quantities of water out of the ground every day. This lowers the ground water table, which in tum
helps to maintain the stability of the slope. Large scale clearing can result in a rise in water table with a consequent
increase in the likelihood of a landslide (GeoGuide LR5). An exception may have to be made to this rule on steep rock
slopes where trees have little effect on the water table, but their roots pose a landslide hazard by dislodging boulders.
Possible effects of ignoring good construction practices are illustrated on page 2. Unfortunately, these poor construction
Practices are not as unusual as you might think and are often chosen because, on the face of it, they will save the
developer, or owner, money. You should not lose sight of the fact that the cost and anguish associated with any one of
the disasters illustrated, is likely to more than wipe out any apparent savings at the outset.
ADOPT GOOD PRACTICE ON HILLSIDE SITES
Page 36
AUSTRALIAN GEOGUIDE LR8 (CONSTRUCTION PRACTICE)
EXAMPLES OF POOR HILLSIDE CONSTRUCTION PRACTICE
Unstabilised rock topples and travels dawnsiope
‘Vegetation removed ——
‘Steep unsupported cut fails
Discharges of roofwaler soak away rather than
conducted offsite of to secure storage for re-use
‘Structure unable to tolerate
setternent and cracks:
Poorly compacted fill setties
unevenly and cracks pool
Inadequate walling unable
to support fill
inadequately
supported cut fails
Saturated \
slope fais — z ~ Dwelling not founded in
’ bedrock
Absence of subsoil drainage
within fill
Loose, saturated fill slides and
possibly flows downslope
—— Ponded water enters slope and activates landslide
(@ Ags @oor)
NS hie eal Gee DOE Pees chet cise doo ‘Bee alse KIS (2000) Appendix
WHY ARE THESE PRACTICES POOR?
Roadways and parking areas - are unsurfaced and lack proper table drains (gutters) causing surface water to pond and
soak into the ground.
Cut and fill - has been used to balance earthworks quantities and level the site leaving unstable cut faces and added
large surface loads to the ground. Failure to compact the fill properly has led to settlement, which will probably continue
for several years after completion. The house and pool have been built on the fill and have settled with it and cracked.
Leakage from the cracked pool and the applied surface loads from the fill have combined to cause landslides.
Retaining walls - have been avoided, to minimise cost, and hand placed rock walls used instead. Without applying
engineering design principles, the walls have failed to provide the required support to the ground and have failed,
creating a very dangerous situation.
A heavy, rigid, house - has been built on shallow, conventional, footings. Not only has the brickwork cracked because
of the resulting ground movements, but it has also become involved in a man-made landslide.
Soak-away drainage - has been used for sewage and surface water run-off from roofs and pavements. This water
soaks into the ground and raises the water table (GeoGuide LR5). Subsoil drains that run along the contours should be
avoided for the same reason. If felt necessary, subsoil drains should run steeply downhill in a chevron, or herring bone,
pattern. This may conflict with the requirements for effiuent and surface water disposal (GeoGuide LR9) and if so, you
will need to seek professional advice.
Rock debris - from landslides higher up on the slope seems likely to pass through the site. Such locations are often
referred to by geotechnical practitioners as "debris flow paths”. Rock is normally even denser than ordinary fill, so even
quite modest boulders are likely to weigh many tonnes and do a lot of damage once they start to roll. Boulders have
been known to travel hundreds of metres downhill leaving behind a trail of destruction.
Vegetation - has been completely cleared, leading to a possible rise in the water table and increased landslide risk
(GeoGuide LR5).
DON'T CUT CORNERS ON HILLSIDE SITES - OBTAIN ADVICE FROM A GEOTECHNICAL PRACTITIONER
More information relevant to your particular situation may be found in other Australian GeoGuides:
e GeoGuide LR1 - Introduction « GeoGuide LR6 - Retaining Walls
e GeoGuide LR2 - Landslides @ GeoGuide LR7 - Landslide Risk
* GeoGuide LR3 - Landslides in Soil * GeoGuide LR - Effiuent & Surface Water Disposal
© GeoGuide LR4 - Landslides in Rock GeoGuide LR10 - Coastal Landslides
2 _GeoGuide LR5__- Water & Drainage « _GeoGuide LR11 - Record Keeping
The Australian GeoGuides (LR series) are a set of publications intended for property owners: local councils; planning authorities:
developers; insurers; lawyers and, in fact, anyone who lives with, or has an interest in, a natural or engineered slope, a cutting, or an
excavation. They are intended to help you understand why slopes and retaining structures can be a hazard and what can be done with
appropriate professional advice and local council approval (if required) to remove, reduce, or minimise the risk they represent. The
GeoGuides have been prepared by the Australian Geomechanics Society. a specialist technical society within Engineers Australia, the
national peak body for all engineering disciplines in Australia, whose members are professional geotechnical engineers and engineering
geologists with a particular interest in ground engineering. The GeoGuides have been funded under the Australian governments’
National Disaster Mitigation Program.