Original source · versioned page text
Attachment 3 - Revised Engineering Report (rec. 7.04.2025) MCU24-0165 & OPW24-0222
Original PDF page 1, section 1. The text section number identifies this passage in the reader.
Engineering Report incl. Stormwater Management 5 School Street, Pomona, QLD Arcos Project: 240628
See the original
The page text is free to read. Viewing or downloading an original file needs an account.
Log in to see the originalLog in to download the original file
The download may take up to a minute.
Full text of sections 2 to 22 (of 32)
Section 2
Attention: Rowan Anderson 15 November 2024
C/- N/A Arcos Project: 240628
By Email Rev 0
AG-240628-RPT-C-01
Engineering Report incl. Stormwater Management
5 School Street,
Pomona, QLD
Document Control
Version Date Details Prepared Checked Approved
0 15/11/24 For Approval HR GM LS
1 05/03/25 IR response JCL GM LS
Director
Lachlan Swann B.Eng (Civ) (Hons), CPEng, RPEQ, NER, MIEAust
[email protected]
For and On Behalf of Arcos Group
E [email protected]
W arcosgroup.com.au
A 177C Brisbane Road, Mooloolaba, QLD, 4557
Section 3
ABN 51 640 311 842
CONTACT
arcosgroup.com.au
OFFICES
Sunshine Coast | Brisbane | Gold Coast
Contents
1 Introduction ...................................................................................................................................... 4
2 Proposed Development ................................................................................................................... 5
3 Access ............................................................................................................................................. 5
3.1 Road Classification & Driveway Type ........................................................................................ 5
3.2 Parking ....................................................................................................................................... 5
3.3 Sight Distances .......................................................................................................................... 5
3.4 Vehicle Turn Paths ..................................................................................................................... 5
4 Earthworks ....................................................................................................................................... 6
5 Stormwater Management ................................................................................................................ 6
5.1 Existing Catchment .................................................................................................................... 6
5.2 External Catchments .................................................................................................................. 7
5.3 Lawful Point of Discharge .......................................................................................................... 8
5.4 Flooding ..................................................................................................................................... 8
5.5 Stormwater Quantity Management ............................................................................................ 9
5.5.1 General .............................................................................................................................. 9
5.6 Stormwater Quality Management .............................................................................................. 9
5.6.1 Construction Phase ........................................................................................................... 9
5.6.2 Operational Phase ........................................................................................................... 11
5.7 Stormwater Quality Asset Maintenance ................................................................................... 15
5.7.1 Maintenance Schedule .................................................................................................... 15
6 Service Provisions ......................................................................................................................... 16
6.1 Water Supply & Fire Servicing ................................................................................................. 16
6.2 Sewer ....................................................................................................................................... 16
6.3 Waste Collection ...................................................................................................................... 16
6.4 Communications & Electrical ................................................................................................... 16
7 Conclusion ..................................................................................................................................... 17
LIMITATIONS ........................................................................................................................................ 18
Appendix A – Stormwater Management Drawings ............................................................................... 19
Appendix B – Site Survey ..................................................................................................................... 20
Appendix C – Flood Search Certificate ................................................................................................. 21
15 November 2024 Page 3
Section 4
ABN 51 640 311 842
CONTACT
arcosgroup.com.au
OFFICES
Sunshine Coast | Brisbane | Gold Coast
1 Introduction
Arcos Unit Group Pty Ltd (Arcos) has been commissioned by Rowan Anderson to prepare this
Engineering Report and drawings as part of a combined MCU & OPW development application with
Noosa Shire Council (NSC). The subject site is described as Lot 14 on RP35096 with a site area of
1,868 m2. A site locality plan is presented in Figure 1 and zone mapping showing conservation lots in
Figure 2. The residential development will be located at 5 on School Street, Pomona, Queensland.
Subject Site
FIGURE 1: SITE LOCALITY (SOURCE: QUEENSLAND GLOBE)
FIGURE 2: ZONE MAPPING (SOURCE: NSC MAPPING)
The site currently has a single storey dwelling and a shed located in the front half of the lot. There is
native vegetation at the rear of the lot which backs onto a densely vegetated environmental
management and conservation freehold lot (22 Rifle Street, Lot 1 on RP35098) and a drainage channel
on the side of Rifle Street.
15 November 2024 Page 4
Section 5
ABN 51 640 311 842
CONTACT
arcosgroup.com.au
OFFICES
Sunshine Coast | Brisbane | Gold Coast
This report addresses engineering considerations such as access, site works, servicing provisions, and
stormwater quality and quantity requirements for site-based stormwater management.
2 Proposed Development
The proposed works consists of a 9-unit multi-residential development, with access from School Street.
The proposed dwelling configuration is shown on the design drawings comprising of 2 x 3 bedroom and
7 x 2 bedroom attached dwellings.
3 Access
3.1 Road Classification & Driveway Type
Access to the development is provided via a concrete crossover in accordance with Council and IPWEA
requirements fronting School Street. Internal shared driveway comply with minimum widths set out in
AS2890.1 for off street car parking.
TABLE 1 – ROAD & DRIVEWAY TYPE
Description Standard
School Street (Existing) Minor Distributor
Shared Access/Driveway 2 lane general wide heavy duty crossover. Internal driveway
generally 1 lane width with passing opportunities and apron width to
garage entrances.
The frontage road classification only requires footpath to one side. Assessment of the surrounding path
network shows existing paths to the West and East of the subject site are located on the opposite side
of the road. Therefore no frontage paths have been provided for the development. The frontage will be
provided with kerb and channel and standard verge arrangements to meet Council road classification
requirements as shown on the drawings.
3.2 Parking
Based on the proposed dwelling types, a total of three (3) off-street visitor parking spaces have been
provided within the development site in accordance with the NSC Transport and Parking Code. Each
on-site parking space has been designed to accommodate forward entry in a single manoeuvre for B85
vehicles and up to a three-point manoeuvre for B99 vehicles, with the exception of visitor park 3, which
is generally reverse entry only.
3.3 Sight Distances
The development provides internal sight visibility along the shared driveway. The frontage road speed
is not posted and therefore a default posted speed of 50km/h has been adopted, requiring a minimum
sight distance of is 69m. Access sight distance has been assessed and achieved in accordance with
AS2890.1 ‘other than domestic’ requirements, being 3 or more dwellings.
3.4 Vehicle Turn Paths
Vehicle turn paths have been checked for the site layout and access as shown by the vehicle tracking
plans. B85 and B99 vehicles are shown to access each of the garages and proposed car parks. Internal
Service Vehicles are not required.
15 November 2024 Page 5
Section 6
ABN 51 640 311 842
CONTACT
arcosgroup.com.au
OFFICES
Sunshine Coast | Brisbane | Gold Coast
4 Earthworks
The existing site grades away from School Street sloping towards the drainage channel towards the
rear of the lot. The internal site levels range between 89.2m AHD to 91.1m AHD, with the high point
located in the north-western corner of the site.
The site is predominantly nominated for filling works to achieve compliance with flood levels, therefore
retaining walls have been proposed along the site boundary as detailed on the design drawings.
All cutting and filling are to be carried out in accordance with AS3798 Guidelines on Earthworks for
Commercial and Residential Developments. Any site filling required will be from site spoil (subject to
Geotechnical Investigation), provided it meets the requirements of AS3798 and is placed with controlled
compaction.
Impacts of proposed earthworks on overland flow conditions will not adversely affect adjacent or
downstream properties. Proposed earthworks will not encroach on adjacent properties or affect the
function of stormwater catchments external to the site.
All construction activities, including Erosion and Sediment Control (ESC) methods, would be managed
under the control measures of a Construction Environmental Management Plan (CEMP) for the
development site. The CEMP and ESC plans would be prepared for submission with the future
application for Operational Works Approval.
5 Stormwater Management
5.1 Existing Catchment
The existing site catchment drains to the rear into the environment management and conservation lot
(22 Rifle Street). A drainage channel is located south of this lot along Rifle Street which conveys flows
from the west to a culvert structure east of the development site. The subject do not directly drain to
this channel due to a high bund on the development side of the channel, however, flows generally head
easter towards Creek Street and other environmental management and conservation lots. The wider
catchment conditions are shown in Figure 3.
FIGURE 3: EXISTING STORMWATER NETWORK (SOURCE: NSC MAPPING)
15 November 2024 Page 6
Section 7
ABN 51 640 311 842
CONTACT
arcosgroup.com.au
OFFICES
Sunshine Coast | Brisbane | Gold Coast
The drainage channel and culvert structure at Rifle Street is shown in the following figures.
FIGURE 4: RIFLE STREET DRAINAGE CHANNEL, FROM POMONA CONNECTION ROAD LOOKING EAST
FIGURE 5: RIFLE STREET DRAINAGE CHANNEL, FROM RIFLE STREET CULVERT NEAR CREEK STREET
LOOKING WEST
5.2 External Catchments
Flows within School Street are directed East through a shallow open grass swale in the verge as shown
in Figure 6. Lots to the West appear to drain directly south towards Rifle Street. The proposed
development is not considered to change the conditions of this catchment with the point of discharge
remaining consistent in the developed case for these adjacent lots.
It is noted that future development of adjacent lots will result in surface levels being raised to match the
subject site adhering to minimum floor levels required by the 1% AEP flood event + freeboard.
15 November 2024 Page 7
Section 8
ABN 51 640 311 842
CONTACT
arcosgroup.com.au
OFFICES
Sunshine Coast | Brisbane | Gold Coast
FIGURE 6: SCHOOL STREET GRASS VERGE, EAST OF THE SUBJECT SITE LOOKING WEST TO POMONA
CONNECTION ROAD
5.3 Lawful Point of Discharge
The existing lawful point of discharge is the southern boundary of the lot where runoff water exits the
lot as sheet flow into 22 Rifle Street. It is proposed that this lawful point of discharge is maintained post
development which is compliant with Section 3.9.1 requirements of QUDM. Pipe flows are proposed
direct to the drainage channel in Rifle Street with surface flows beyond the minor storm discharging to
22 Rifle Street conservation lot.
5.4 Flooding
The site is not identified to be impacted by flooding inundation event as per NSC Flood Hazard Overlay
Mapping as shown in Figure 7. Whilst the subject lot is not identified to be affected by the flood extents,
consideration of the surrounding flood conditions has been made as the adjacent lot to the south is
shown to be inundated during flood events. A flood search certificate was obtained which indicated that
the Defined Flood Event being the 1% AEP Climate Change flood level is 90.3m AHD. The building
levels have been designed to be above this minimum FFL (DFE +0.3m Freeboard).
15 November 2024 Page 8
Section 9
ABN 51 640 311 842
CONTACT
arcosgroup.com.au
OFFICES
Sunshine Coast | Brisbane | Gold Coast
FIGURE 7 - SITE FLOOD HAZARD OVERLAY MAPPING
5.5 Stormwater Quantity Management
5.5.1 General
Due to the increase in impervious area for the development, it is expected that stormwater runoff peak
flow will increase. As such, consideration of the peak flow increase to the surrounding system and
properties is to be considered and managed.
The natural drainage reserve at the rear of the lot which acts as the lawful point of discharge is expected
to be flooded during peak storm events based on flood mapping. This existing drainage channel is sized
such that additional flows received from the subject lot would be accepted by the channel without
resulting in negative impacts to the wider network.
The site is located very close to the receiving waterway, Cooroorah Creek, that experiences significant
flooding all the way along the creek to Six Mile Creek and beyond in major flood events. Providing
detention to this site, particularly for larger rainfall events would likely cause adverse effects due to the
coinciding peak flows.
The transport corridor will not be impacted by runoff from the proposed works of the subject site with
the lawful point of discharge being located at the rear of the lot, and surface grading to the drainage
channel.
Therefore, it is proposed that no stormwater detention is to be provided for the subject site as it would
have a negligible effect on the site and wider catchment.
In accordance with the sustainable building code each unit will be fitted with a 3kL rainwater re-use
tank. Tanks will be located as per architectural design drawing and connected to a minimum of 50% of
roof area. Refer to hydraulic consultant drawings for internal plumbing design.
5.6 Stormwater Quality Management
5.6.1 Construction Phase
The site's management is important in ensuring water quality standards are achieved during the
construction phase. Implementing best practice Erosion and Sediment Control techniques is imperative
to managing the runoff quality affected by construction works.
15 November 2024 Page 9
Section 10
ABN 51 640 311 842
CONTACT
arcosgroup.com.au
OFFICES
Sunshine Coast | Brisbane | Gold Coast
Best practice measures shall be utilised during the construction phase to minimise the potential impacts
of the pollutants mentioned above. Detailed Erosion and Sediment Control Management Plans should
be developed in conjunction with the Operational Works design prior to construction works commencing
in accordance with the International Erosion Control Association (IECA) - "Best Practice Erosion and
Sediment Control (BPESC) document" and overseen by a Certified Professional in Erosion and
Sediment Control (CPESC) or Registered Professional Engineer Queensland (RPEQ).
Through their principal contractor, the developer shall be responsible for ensuring that temporary
sediment and erosion controls are installed and maintained correctly.
5.6.1.1 Pollutants
The pollutants that would typically be generated during the construction of the proposed development
are outlined in Table 2.
TABLE 2: TYPICAL CONSTRUCTION PHASE POLLUTANTS
Pollutant Source
Litter Paper, construction packaging, food packaging, cement bags, offcuts
Sediment Unprotected exposed soils and stockpiles during earthworks and building
Hydrocarbons Fuel and oil spills, leaks from construction equipment
Toxic Materials Cement slurry, asphalt prime, solvents, cleaning agents, wash waters e.g.
from tile works)
Ph Altering Acid sulphate soils, cement slurry
Substances
5.6.1.2 Potential Impacts
Construction activities can have a potential impact on water quality. Removal of vegetation, earthworks
and changes to drainage patterns can result in erosion and sediment being washed into waterways.
This can impact the physical-chemical parameters of the receiving water, the decline in the health of
aquatic ecosystems, and overall aesthetics. The potential impacts on the development site's
surrounding receiving waters will be minimised during the construction phase with typical measures
outlined below. These measures should be adequately detailed on erosion and sediment control plans
as part of the development's Operational Works application.
5.6.1.3 Performance Objectives
The amount of runoff traversing and discharging from the site while under construction should be kept
to a minimum. This will restrict soil erosion and mobilisation of sediments and pollutants through and
off the site. During the construction phase, stormwater runoff at discharge points shall comply with the
objectives detailed in QLD SPP (July 2017).
5.6.1.4 Control Measures
The following are typical treatment measures that should be implemented before the commencement
of any construction works. Detailed erosion and sediment control procedures shall be based on the
erosion and sediment control plans lodged at the Operational Works phase.
5.6.1.5 Maintenance
Maintenance of erosion and control treatment measures (such as sediment fences) will be undertaken
if it is observed that they have not been properly installed or the capacity of the measure falls below
75%.
5.6.1.6 Minimise Disturbance Area
Clearing of land is to be minimised to areas planned to be actively under construction in the near term
(e.g. within the next 3-6 months).
15 November 2024 Page 10
Section 11
ABN 51 640 311 842
CONTACT
arcosgroup.com.au
OFFICES
Sunshine Coast | Brisbane | Gold Coast
5.6.1.7 Stabilise Disturbed Areas
Provide temporary stabilisation of disturbed soils whenever active construction is not occurring on a
portion of the site. Provide permanent stabilisation during finish grade and landscape the site.
5.6.1.8 Protect Slopes and Channels
Safely convey runoff from the top of the slope and stabilise temporary and permanent channel crossings
as quickly as possible and ensure that increases in runoff velocity caused by the project do not erode
the channel.
5.6.1.9 Diversions of Upslope Runoff
Upslope runoff should be diverted away from areas of exposed soil to prevent the contamination of
clean runoff. This may be achieved by installing tightly abutting sandbags, creating a 'sandbag
perimeter bank' to divert flow.
5.6.1.10 Sediment Fences and Inlet Protection
Delineate site perimeter to prevent disturbing areas outside the project limits. Sediment fences should
be installed around the perimeter of works to ensure contaminated runoff is filtered and sediment is
trapped before leaving the site. Sandbags or geofabric should also be placed around/over existing
stormwater inlets/grates throughout the site to filter any contaminated runoff before entering the existing
piped stormwater network.
5.6.1.11 Retain Sediment
Retain sediment-laden waters from disturbed, active areas within the site.
5.6.1.12 Stabilised Vehicle Entry/Exit Point
A stabilised entry/exit point should be constructed to minimise the transport of sediment off-site. All
vehicles entering and leaving the site must use this designated entry/exit point.
5.6.1.13 Stockpiles
Stockpile locations should be identified before the commencement of works. Ideally, they should be
located in a flat area at least 15m from any water body or stormwater inlet. Sediment fences should be
installed downslope of all erodible stockpiles, and upslope protection measures should be used (i.e.
sandbags or sediment fence) to divert runoff in the event of rain. At the end of each working day,
stockpiles should be covered with geofabric if rain or high winds are forecast.
5.6.1.14 Street Sweeping
Ensure that local roads are swept as required. This will minimise the potential for sediment tracked onto
the road to be washed into the stormwater system. If there is a large quantity of sediment being tracked
onto the surrounding streets, the stabilised entry/exit point may need to be raked or reinforced with rock
treatment to provide more effective sediment removal for vehicles.
5.6.1.15 Erosion Control Matting and Permanent Stabilisation
Exposed areas onsite should be permanently stabilised (i.e. with turf) as the construction works
progress. Erosion control matting or mulching should be used as a temporary measure to stabilise
exposed areas before permanent stabilisation can be undertaken.
5.6.1.16 Monitoring
Monitoring and recording of the performance of the drainage control devices are to be undertaken in
accordance with local government requirements. It is further recommended that the proposed
construction works be undertaken during periods of dry weather to reduce the potential for sediment to
be transported off-site during construction.
5.6.2 Operational Phase
The State Planning Policy states that stormwater management design objectives do not apply for
developments smaller than 2500m2, with the site being smaller than this size.
15 November 2024 Page 11
Section 12
ABN 51 640 311 842
CONTACT
arcosgroup.com.au
OFFICES
Sunshine Coast | Brisbane | Gold Coast
However, AO6.2 of NSC Water Quality and Drainage code indicates that all developments must achieve
water quality objectives and must use natural processes wherever possible. Therefore natural treatment
through a bio basin system has been adopted and designed in the following sections.
5.6.2.1 MUSIC Modelling
MUSIC (MUSICX by eWater), a pollutant export modelling program, has been used to model the
expected pollutant loads generated by each catchment within the development and the effectiveness
of WSUD treatment options selected.
5.6.2.2 Catchment Approach
The MUSIC model is based on a split catchment approach, modelled as various catchments
representing the different surface types in accordance with the guidelines and available site information.
Split catchment surface information was informed by taking measurements of the site layout in
accordance with HLW guidelines and are shown in Table 3.
TABLE 3: ADOPTED AREA & PERCENT IMPERVIOUS – URBAN RESIDENTIAL
Surface Type Area (ha) Percent of Site (%) Percent Impervious
(%)
Roof 0.096 51 100
Driveway 0.043 23 80
Ground 0.049 26 30
5.6.2.3 MUSIC Meteorological Data
Weather data from Cooroy station 40059 was used for the MUSIC analysis. The 10-year climate period
was selected from 01/01/1973 to 31/12/1983 in accordance with HLW guidelines. The rainfall and
evapotranspiration data with a 6-minute time step, was used in the model.
Input parameters for the rainfall-runoff, source nodes and treatment devices were also obtained from
the guidelines. The following parameters were selected based on urban residential development.
5.6.2.4 Rainfall-Runoff Parameters
The rainfall-runoff parameters listed in Table 3.7 of MUSIC guidelines were used in the model. The
parameters recommended by the guideline are as shown in Table 4.
15 November 2024 Page 12
Section 13
ABN 51 640 311 842
CONTACT
arcosgroup.com.au
OFFICES
Sunshine Coast | Brisbane | Gold Coast
TABLE 4: RECOMMENDED RAINFALL-RUNOFF PARAMETERS
Parameter Urban Residential
Rainfall threshold (mm) 1
Soil storage capacity (mm) 500
Initial storage (% capacity) 10
Field capacity (mm) 200
Infiltration capacity - Coefficient a 211
Infiltration capacity - Exponent b 5.0
Initial depth (mm) 50
Daily recharge rate (%) 28
Daily baseflow rate (%) 27
Daily deep seepage rate (%) 0
5.6.2.5 Pollutant Export Parameters
The pollutant export parameters for split catchment land use was adopted for MUSIC modelling and
are shown in Table 5.
TABLE 5: POLLUTANT EXPORT PARAMETERS – SPLIT CATCHMENT URBAN RESIDENTIAL LAND USE
Flow Type Surface Type Total Suspended Total Total Nitrogen
Solids (TSS) Phosphorous (TN)
(Log10 mg/L) (TP) (Log10 mg/L)
(Log10 mg/L)
Mean Std Mean Std Mean Std
Dev Dev Dev
Baseflow Roof N/A N/A N/A N/A N/A N/A
concentration
parameters Road Reserve 1.00 0.34 -0.97 0.31 0.20 0.20
Ground 1.00 0.34 -0.97 0.31 0.20 0.20
Stormflow Roof 1.30 0.39 -0.89 0.31 0.26 0.23
concentration
parameters Road Reserve 2.43 0.39 -0.30 0.31 0.26 0.23
Ground 2.18 0.39 -0.47 0.31 0.26 0.23
5.6.2.6 MUSIC Model Layout
The model node arrangement shown in Figure 8 has been adopted and is representative of the
proposed development.
15 November 2024 Page 13
Section 14
ABN 51 640 311 842
CONTACT
arcosgroup.com.au
OFFICES
Sunshine Coast | Brisbane | Gold Coast
FIGURE 8: WATER QUALITY TREATMENT TRAIN & AREAS
15 November 2024 Page 14
Section 15
ABN 51 640 311 842
CONTACT
arcosgroup.com.au
OFFICES
Sunshine Coast | Brisbane | Gold Coast
.
5.6.2.7 MUSIC Model Results
The model's minimum load-based pollutant reduction efficiencies are achieved, shown in Table 6, and
in accordance with the QLD SPP (July 2017), Table B: Post Construction Phase - stormwater
management design objectives.
TABLE 6: MUSIC MODEL RESULTS
Parameter Required Load Music Results Result
Reduction
Total Suspended Solids (TSS) 80% 82.2% Compliant
Total Phosphorous (TP) 60% 73.6% Compliant
Total Nitrogen (TN) 45% 52.3% Compliant
Gross Pollutants >5mm 90% 100% Compliant
5.7 Stormwater Quality Asset Maintenance
Vegetation plays an important role in the healthy and effective operation of the bioretention basin.
Maintenance in the initial establishment period (up to two years) is crucial to the ongoing performance
of the bioretention basin, where weed removal and re-planting may be required.
There are several typical maintenance elements for bioretention basins, as follows:
• Routine inspection of the bioretention basin profile to identify any obvious areas of increased
sediment deposition, scouring from storm flows, rill erosion of the batters from lateral inflows,
damage to the profile from vehicles and clogging of the bio-retention basin (evident by a 'boggy'
filter media surface);
• Routine inspection of inflows systems, overflow pits and under-drains to identify and clean any
areas of scour, litter build-up and blockages;
• Removal of sediment where it is smothering the bio-retention basin vegetation;
• Where a sediment forebay is adopted, removal of accumulated sediment.
• Repair any damage to the profile resulting from scour, rill erosion, or vehicle damage by
replacing appropriate fill (to match onsite soils) and revegetating.
• Regular watering/irrigation of vegetation until plants are established and actively growing; and
• Removal and management of invasive weeds (herbicides should not be used);
Routine inspections shall be undertaken on the bioretention after every significant rainfall event (30mm
or more of rainfall within a 24 hr period) or on a three-monthly basis within the first two (2) years during
the establishment of the planting media. After that, inspections can be reduced to a six (6) monthly
basis.
The following minimum requirements for inspection should be undertaken:
• Check for a build-up of sediment at pipe inlet/outlet structures, and remove as required;
• Check all concrete structures for damage and deterioration;
• Check for the build-up of vegetation matter on the bioretention basin surface and removal of
the excess build-up to ensure minimal blockage to filter media;
• Check health of planting and ensure establishment has occurred;
• Check bioretention basin during rainfall events to ensure stormwater is filtering through media
and operating according to the design intent.
5.7.1 Maintenance Schedule
Outlined below in Table 7 are the recommended maintenance schedules for the treatment types.
15 November 2024 Page 15
Section 16
ABN 51 640 311 842
CONTACT
arcosgroup.com.au
OFFICES
Sunshine Coast | Brisbane | Gold Coast
TABLE 7: STORMWATER QUALITY ASSETS MAINTENANCE SCHEDULE
Stormwater Asset Maintenance Frequency Tasks
Bioretention Basin Three-monthly inspections & Repair erosion, clean litter and
after major storm events (2 sediment, control weeds
years)
Repair erosion, clean litter and
Yearly & after major storm sediment, control weeds
events
6 Service Provisions
6.1 Water Supply & Fire Servicing
The development is to be serviced by connection to existing water mains along the development
frontage within School Street. Due to the depth of the lot, the development is not adequately serviced
by existing street hydrants, therefore on-site private hydrants will be required subject to hydraulic design
details. A master water meter and fire service will be required as shown on the design drawings.
6.2 Sewer
An existing DN160 PE sewer main traverse’s the lot in the south western corner. The site will be
connected to the existing network by upgrading the property connection to a DN150 as shown on the
design drawings. An abandoned buried sewer main is shown to dissect the development site in the rear
of the lot and will remain in place.
6.3 Waste Collection
An enclosed area for 360L bin storage location is provided for the development site, with bins being
manually handled to the road reserve on collection days. The Waste Collection Vehicle will temporarily
park adjacent the kerb, clear of the driveway access whilst servicing.
6.4 Communications & Electrical
Details of electrical supply and communication infrastructure and services proposed for the
development site are outside the scope of this report. However, we understand that supply to the
development can be provided via the existing communications and electrical network.
15 November 2024 Page 16
Section 17
ABN 51 640 311 842
CONTACT
arcosgroup.com.au
OFFICES
Sunshine Coast | Brisbane | Gold Coast
7 Conclusion
This Engineering Services Report has been prepared to provide a review and information on the
engineering requirements to support the proposed development application at 5 School Street,
Pomona.
The following requirements have been reviewed as part of this report:
• Suitable access is provided from School St via an upgraded access.
• Vehicles can safely manoeuvre internal shared driveways and on-site parking.
• A flood search has been obtained to determine the minimum floor levels requirements and
freeboard for the site.
• Stormwater quantity has been assessed and on-site detention requirements is considered
unnecessary for reasonings provided;
• Stormwater quality objectives have been achieved by application of a bio-retention basin;
• The site is currently serviced by the existing water and sewerage network and augmentations
to connections will be provided to meet the development requirements.
In summary, this report shows that the development site can be adequately serviced, and provision
made as currently shown and in further detailed design for this development to be in accordance with
Council's code requirements.
15 November 2024 Page 17
Section 18
ABN 51 640 311 842
CONTACT
arcosgroup.com.au
OFFICES
Sunshine Coast | Brisbane | Gold Coast
LIMITATIONS
Arcos Unit Group Pty Ltd (Arcos) has prepared this document for the project described on the title page
for the client's exclusive use. The document is specific to this particular project and for the purposes as
described within the document. The document cannot be used for any other project on the same site or
other sites or relied upon by a third party. Any party relying upon this document beyond its exclusive
use and purpose as stated above, and without the express written consent of Arcos, does so entirely
at its own risk and without recourse to Arcos for any loss or damage. Arcos has necessarily relied upon
information provided by the client and/or their agents.
The required detailed design for the service infrastructure will be subject to the conditions (if any),
attached to the Development Approval provided by Council and any nominated referral agencies.
The advice given in this document is based upon the assumed conditions and data outlined herein. The
relevance and accuracy of advice given are directly affected by variations in the information supplied
and open source information relied upon.
This document must be kept in its entirety, read in full and understood. Interpretations or conclusions
made by others unless supported by an expressed written statement, interpretation, outcome or stated
within this document cannot be the responsibility of Arcos.
This document or parts of it should not be used as part of a specification or design for a project without
prior review and agreement by Arcos.
15 November 2024 Page 18
Section 19
ABN 51 640 311 842
CONTACT
arcosgroup.com.au
OFFICES
Sunshine Coast | Brisbane | Gold Coast
Appendix A – Stormwater Management Drawings
15 November 2024
Section 20
EXISTING LEGEND
SUBJECT PROPERTY BOUNDARY
4.00 MAJOR CONTOUR
SCHOOL STREET MINOR CONTOUR
SEWER MAIN (QUALITY LEVEL)
1
SEWER MAIN ABANDONED
SP275888 WATER MAIN
U/G TELECOMMS
O/H ELECTRICITY
STORMWATER
FENCE
20.000 SURFACE LEVEL
90
91.2
.9
A/1 91.0 PROPOSED LEGEND
DWELLING
91.2
.1
91
STORMWATER PIPE
50.00 MAJOR CONTOUR 0.1m INTERVAL
1 MINOR CONTOUR 0.5m INTERVAL
90.6
91.1
SP316907 FLOW DIRECTION
SUBSOIL DRAIN
91.1
A/2
B/1 UNIT A UNIT B
FFL 91.10 FFL 91.10
C/1
91.0 C/2
NOTES:
91.1
A/3
90.6
1. FOR GENERAL & STORMWATER NOTES REFER DRG C-011
2. PROVIDE ROOF WATER CONNECTION STUBS TO FIELD INLETS TYPICAL
90.9
90.9
3. FOR BIO-BASIN SECTION DETAILS REFER TO DRG C-402
B/2 4. FOR STORMWATER LONGSECTIONS REFER TO DRG C-431
90.9
FFL 90.60
90.8
UNIT D
FFL 90.90 E/1
A/7
UNIT C
FFL 90.90 2
90.2
21 SP316907
90.7
14
P5015 RP35096 A/4 UNIT F
FFL 90.80 CP 900x900 GRATED PIT WITH
.5
INTERNAL HIGH FLOW WEIR
90.3
90
SP316907 BYPASS REFER TO DETAIL A
UNIT E E/2
22 FFL 90.80
CONCRETE FOREBAY (1.0 x 3.0)
90.5
P5015 90.8
GENERALLY IN ACCORDANCE WITH
90.7
IPWEA STD DRG DS-075
90.4
UNIT J D A/8
90.4
FFL 90.70
A/5 402
D/1 E/3
E
AC
RF
SU 3
I O
B 89. 7
ENSURE SURFACE IS E/4 RL
90.3
FREE DRAINING TO REAR
90
.6
90.4
90.3
90.2
90.1
A/9 4
90.0
89.5
89.9
89.8
BIO-RETENTION BASIN
89.7
89.6
89.5
89.4
89.3
UNIT H
89.2
90.2
20m2 FILTER AREA
89.1
89.0
88.9
FFL 90.60
REFER TO DETAIL DRG C-402
C
.6
A/6 89.65
UNIT G 90 402 89.68
FFL 90.60 89.89
.9 89.95 89.75
89
A/7 89.78
0.0
.19
90
90.10
90.5
Filename: C:\PROJECTS\240628 - MUL RES - 5 SCHOOL STREET, POMONA\3.0 CAD\DRAWINGS\OPW\240628-OPW-C-401.DWG
A/8 1
RP35098
A/10
90.4
90.3
90.2
A/9
90.1
90.0
89.9
89.8
89.7
89.6
89.5
89.4
89.3
89.2
89.1
89.0
88.9
Last Plotted: 2025-03-09
300mm THICK ROCK PROTECTION, d50 = 150mm
OVER GEOTEXTILE MATERIAL
Last saved by: JOSHLAVERS(2025-03-09)
A/10
North Point Scale Horiz. Datum Client Consultant Project Drawing
LOCAL Drawn JCL Project No. Drawing No. Rev No.
ROWAN ANDERSON MULTI RESIDENTIAL DEVELOPMENT STORMWATER & BIO-RETENTION BASIN
0m 1.25 2.5 Design
B
JCL
Vert. Datum OPPERATIONAL WORKS - CIVIL PLAN 240628 OPW-C-401
A1 1:50 AHD
0m 0.625 1.25 5 SCHOOL STREET Check GM
B IR RESPONSE 4.03.25 LS RL Datum POMONA, QLD, 4568 Approved Approved Date Signed Sheet
A1
A1 1:25 CIVIL | STRUCTURAL | GEOTECHNICAL
A FOR APPROVAL 10.12.24 LS COPYRIGHT © All rights reserved.
SUNSHINE COAST | BRISBANE | GOLD COAST LACHLAN SWANN 21.11.24 Status FOR APPROVAL
Revision Description
This work is copyright and cannot be reproduced
Size
Rev Date Approved or copied in any form without the prior consent www.arcosgroup.com.au | ABN 51 640 311 842 RPEQ 21223
Section 21
POOL FENCE TO OR EQUIVALENT
TO BIO-BASIN EDGE TYPICAL
VEHICLE BOLLARDS
RP BDY
DESIGN SURFACE
3.00
FALL RL 90.47 FALL
RL 90.13
RL 89.73
1.14
EXISTING SURFACE
INLET PIPE
RL 88.89
CORE FILLED BLOCK RETAINING WALL CONCRETE FOREBAY & ROCK 1.50
TO BASIN WHERE SPECIFIED TYPICAL GENERALLY IN ACCORDANCE WITH
IPWEA STD DRG DS-075
RETAINING WALL DEPTH TO
EXTEND FOR FILTER MEDIA
SECTION C
SCALE 1:50 301
EXISTING SEWER MAIN
MAKE GOOD ALL AREAS DISTERBED BY
CONSTRUCTION ACTIVITIES AS PER LANDSCAPE
DESIGN OTHERWISE TOPSOIL & TURF
INSTALL GROUTED RICK PROTECTION GROUTED ROCK WEIR OVERFLOW DESIGN SURFACE
RP BDY
AROUND SIDES/BACK OF HEADWALL
FALL
RIFLE STREET
1% AEP(CC) RL 90.30 EXISTING SURFACE
INLET
INSTALL FLAP GATE FOR
CONTRACTOR TO MAKE GOOD BACKFLOW PREVENTION
FOR ANY CHANNEL DISTURBANCE
0.4% MIN
1.65
LOCALLY SHAPE OUTLET TO CHANNEL INVERT
INSTALL 300mm THICK ROCK PROTECTION,
d50 = 150mm OVER GEOTEXTILE MATERIAL
SECTION D
SCALE 1:50 EXISTING SEWER MAIN
301
900x900 FEILD INLET
SUBSOIL CLEAN OUT POINT A
EXTENDED DETENTION 900x900 GRATED INLET PIT
DEPTH 300mm
INLET PIPE
IMPERMEABLE LINER CONCRETE PAVEMENT
500mm FILTER MEDIA
LOW FLOW
4EY (1IN3 MONTH) FLOW 42L/s
100mm TRANSITION LAYER
0.15
200mm DRAINAGE LAYER
LOW FLOW
Filename: C:\PROJECTS\240628 - MUL RES - 5 SCHOOL STREET, POMONA\3.0 CAD\DRAWINGS\OPW\240628-OPW-C-402.DWG
OUTLET PIPE
INTERNAL CONCRETE WEIR
HIGH FLOW BYPASS
RIGID SLOTTED PIPES AT 0.5% FALL
TYPICAL DETAIL - BIO-RETENTION FILTER MEDIA
Last Plotted: 2025-03-09 6:19 PM
SCALE 1:25
A HIGH FLOW BYPASS
SECTION A - A
SCALE 1:25
NOTE: DETAIL A
SCALE?
Last saved by: JOSHLAVERS(2025-03-09)
1. BASIN BASE TO GRADE AT MIN 0.5% -
2. BASINS TO BE CONSTRUCTED IN ACCORDANCE WITH IPWEA STD DRG WSUD 001-004
3. PLANTING IN ACCORDANCE WITH LANDSCAPE DRAWINGS AND SPECIFICATIONS
4. BIO-RETENTION TO BE IN ACCORDANCE WITH HEALTHY LAND & WATER
BIO-RETENTION TECHNICAL DESIGN GUIDELINES (OCT 2014) NOTES:
1. FOR GENERAL & ROADWORKS/DRIVEWAY NOTES REFER DRG C-011.
North Point Scale Horiz. Datum Client Consultant Project Drawing
LOCAL Drawn JCL Project No. Drawing No. Rev No.
ROWAN ANDERSON MULTI RESIDENTIAL DEVELOPMENT BIO-RETENTION BASIN
Design
B
JCL
Vert. Datum OPPERATIONAL WORKS - CIVIL SECTIONS & DETAILS 240628 OPW-C-402
AHD
5 SCHOOL STREET Check GM
B IR RESPONSE 4.03.25 LS RL Datum POMONA, QLD, 4568 Approved Approved Date Signed Sheet
A1
CIVIL | STRUCTURAL | GEOTECHNICAL
A FOR APPROVAL 10.12.24 LS COPYRIGHT © All rights reserved.
SUNSHINE COAST | BRISBANE | GOLD COAST LACHLAN SWANN 21.11.24 Status FOR APPROVAL
Revision Description
This work is copyright and cannot be reproduced
Size
Rev Date Approved or copied in any form without the prior consent www.arcosgroup.com.au | ABN 51 640 311 842 RPEQ 21223
Section 22
A/10
A/1
A/2
A/3
A/4
A/5
A/6
A/7
A/8
A/9
STRUCTURE NAME
STD FIELD INLET
STD FIELD INLET
STD FIELD INLET
STD FIELD INLET
STD FIELD INLET
STD FIELD INLET
STD FIELD INLET
STD FIELD INLET
STRUCTURE DESCRIPTION
DEFLECTION
HEADWALL
600x600
600x600
600x600
600x600
600x600
600x600
600x600
600x600
NOTES:
1. FOR GENERAL & STORMWATER NOTES REFER DRG C-011.
PIT SIZE
REFER TO IPWEA DS-050
0-1.0 DEPTH 600mm x 600mm
1-1.5 DEPTH 600mm x 900mm
0-2.0 DEPTH 900mm x 900mm
2.0 GREATER STANDARD MH WITH
APPROVED INLET
PIPE SIZE (mm) 225 225 225 225 300 373 373 373 373
PIPE CLASS & TYPE PP SN8 PP SN8 PP SN8 PP SN8 PP SN8 PP SN8 PP SN8 PP SN8 PP SN8
PIPE GRADE (%) 1.32% 0.61% 0.55% 0.63% 0.50% 0.76% 0.40% 0.40% 0.36%
PIPE SLOPE (1 in X) 75.7 164.6 182.4 159.6 200.0 131.8 250.0 250.0 280.3
FULL PIPE VELOCITY (m/s) 0.14 0.19 0.84 0.93 0.84 0.77 0.93 0.93 0.96
NORMAL DEPTH VELOCITY (m/s) 1.10 0.92 1.31 1.40 1.46 1.86 1.53 1.53 1.48
PIPE FLOW (cumecs) 0.006 0.008 0.034 0.037 0.059 0.084 0.101 0.101 0.105
CAPACITY FLOW (cumecs) 0.075 0.051 0.048 0.051 0.099 0.218 0.158 0.158 0.149
DATUM RL 82.000
HGL IN PIPE &
90.617
90.610
90.502
90.499
90.505
90.514
90.413
90.405
90.419
90.341
90.241
90.234
90.154
90.158
90.166
90.082
90.083
90.097
90.009
90.005
89.918
89.900
89.910
89.817
89.800
WSE IN STRUCTURE
NATURAL SURFACE LEVEL
90.588
90.451
90.123
90.090
90.044
89.915
89.925
89.854
90.103
INVERT LEVEL 89.007
90.550
90.430
90.410
90.340
90.260
90.200
90.180
90.100
89.948
89.890
89.870
89.780
88.974
88.965
88.965
88.921
88.895
88.860
88.860
Filename: C:\PROJECTS\240628 - MUL RES - 5 SCHOOL STREET, POMONA\3.0 CAD\DRAWINGS\OPW\240628-OPW-C-430.DWG
DEPTH TO INVERT
-0.026
0.541
0.523
0.543
0.498
0.578
0.528
0.548
0.498
0.649
0.646
0.666
0.703
1.509
1.531
1.531
0.000
0.147
0.147
SETOUT LEVEL
91.090
90.950
90.830
90.720
90.590
90.530
90.480
90.490
90.030
89.500
Last Plotted: 2025-03-05
-13.566 N
-24.978 N
-35.887 N
-47.793 N
-57.789 N
-63.976 N
-66.346 N
-72.007 N
-80.409 N
10.927 E
11.228 E
12.833 E
13.676 E
18.288 E
24.330 E
14.211 E
13.994 E
-4.482 N
4.629 E
9.695 E
SETOUT COORDS
Last saved by: JOSHLAVERS(2025-03-05)
9.089m 11.525m 10.941m 12.768m 11.680m 11.860m 2.380m 10.943m 9.812m
CHAINAGE
20.614
31.555
44.323
56.003
67.863
70.244
81.187
90.999
0.000
9.089
LINE A
North Point Scale Horiz. Datum Client Consultant Project Drawing
LOCAL Drawn JCL Project No. Drawing No. Rev No.
ROWAN ANDERSON MULTI RESIDENTIAL DEVELOPMENT STORMWATER
0m 12.5 25 Design
B
JCL
Vert. Datum OPPERATIONAL WORKS - CIVIL LONGITUDINAL SECTIONS 240628 OPW-C-431
A1 1:500 AHD
0m 1.25 2.5 5 SCHOOL STREET Check GM
B IR RESPONSE 4.03.25 LS RL Datum POMONA, QLD, 4568 Approved Approved Date Signed Sheet
A1
A1 1:50 CIVIL | STRUCTURAL | GEOTECHNICAL
A FOR APPROVAL 10.12.24 LS COPYRIGHT © All rights reserved.
SUNSHINE COAST | BRISBANE | GOLD COAST LACHLAN SWANN 21.11.24 Status FOR APPROVAL
Revision Description
This work is copyright and cannot be reproduced
Size
Rev Date Approved or copied in any form without the prior consent www.arcosgroup.com.au | ABN 51 640 311 842 RPEQ 21223
The text continues on section 23.