RFI - Engineering Report

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Table of contents
Table of contents .............................................................................................................................. 2
1. Introduction ................................................................................................................................ 3
2. Proposed Development ............................................................................................................. 3
3. Access Road and Intersection ................................................................................................... 4
4. Stormwater Management/Bio-Retention Basin ......................................................................... 5
5. Earthworks................................................................................................................................. 6
6. Water and Sewer ....................................................................................................................... 6
7. Conclusions and Recommendations ......................................................................................... 6
Appendix A – Locality plan ............................................................................................................... 7
Appendix B – Unitywater Infrastructure ............................................................................................ 8
Appendix C – Unitywater Network Planning ..................................................................................... 9




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    1. Introduction

Tod Consulting has been engaged by the JNE Developments Pty Ltd to prepare engineering
drawings and an engineering report in support of a proposed 10 lot residential subdivision
development application to Noosa Shire Council at 25 Pavilion Street, Pomona.

The purpose of this report is to address the engineering infrastructure that will be required to service
the proposed development. This report was complied using information from the following sources:

    •   Site inspection
    •   Dial Before your Dig (DBYD) information
    •   Google Imagery
    •   Detailed Survey provided by Land Surveying Dynamics (LSD)

Existing Property and Features:

The existing property is located at 25 Pavilion Street, Pomona within the Noosa Shire Council local
government area. The total site area is 2.99 Ha and is described as Lot 21 on SP316902. The
location is shown in Appendix A

The site is undeveloped with no existing dwelling. The topography of the site varies from 10-12% at
the eastern end of the block adjacent Pavilion Street to very flat on the western side. The western
section of the lot is subject to flooding. There are existing residential properties to the north and
south of the site.




    2. Proposed Development
The proposed development is for a 10 lot residential subdivision. The proposed lots will be accessed
via a new road intersecting with Pavilion Street and terminating with a “T” shaped turning head. The
plan of development provides for a future road connection to the property to the north which also
has development potential. This would eliminate the need for a further intersection on Pavilion St to
service this site. Swept path diagrams have been provided with the preliminary engineering
drawings to demonstrate a waste collection vehicle can turnaround in the space provided.

As outlined in the Stormwater Management Plan (SWMP) prepared by Peak Urban, the
development will also contain a bio-retention basin to achieve water quality objectives and mitigation
of peak flows. Please review to the SWMP for details.

The development includes water and sewer infrastructure to service each lot, including the balance
parcel (lot 10) which is technically a rural residential lot.




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    3. Access Road and Intersection
The proposed new road intersects with Pavilion Street, which is urban local street generally 8m
wide kerb to kerb with a speed limit of 50kph (general urban unposted limit). The new intersection
is approximately 47 metres south of Tree Street and 68m north of Sandy Street which are both on
the opposite side of Pavilion Street. As such the intersection separation exceeds Councils
minimum requirements as set out in section SC6.7.5(1)(h)(iv)(A) of planning scheme policy 6 –
Engineering Design Standards.

The road reserve boundary is set back 6m from the existing nominal kerb alignment meaning
there is adequate space for a car to stop and see vehicles on Pavilion Street without being
impacted by property fences. The required safe intersection distance (SISD) in each direction for
vehicles exiting the new road, when taken 3-5m back from the nominal kerb line generally meets
the minimum requirements in Austroads Part 4A. The standard design requirements as set out in
table 3.2 for a 60kph design speed is between 114-123m. The visibility to the north is
unobstructed and exceeds 250m. The visibility to the south is slightly impacted by the low crest at
the intersection of Sandy Street and a sag in Pavilion Street approximately 115 south of Sandy
Street in front of No 20 Pavilion Street. The visibility in this direction is approximately 103m
(adjacent to the entry to the caravan park), however it should be noted that given this is an
existing street Extended Design Domain standards can be adopted which would reduce the
visibility requirements to between 81 and 89m. The visibility in this direction exceeds the EDD
sight distance requirements. A site check has confirmed that no clearing of existing vegetation is
required – refer photos below.

Sight Visibility to the South of proposed intersection shown below




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Sight Visibility to the North of proposed intersection shown below




Preliminary design drawings have been prepared showing the new road and intersection. As there
is no truncation on the boundary of the property to the north of the new street the verge width may
not fully comply with Council’s design standards however there will be sufficient space to
accommodate the footpath and ramps to tie into the existing footpath on Pavilion Street.

The swept path for a waste collection vehicle as also be added to the preliminary drawings to
demonstrate there is sufficient room for the WCV to turn around in the proposed turning head
space. Note a NSC standard 10.2 WCV turning path has been used for this purpose.



    4. Stormwater Management/Bio-Retention Basin
Preliminary Drawings have been prepared for the proposed bio-retention basin. The size of the
basin is based on parameters contain in the Stormwater Management Plan prepared by Peak
Urban. Our plans demonstrate that the required bio basin filter area (80m2) and storage volume
can be provided with the allocated space in the plan of development. Please note that we have
generally adopted 1 in 4 batters throughout except for a 1 in 2 batter on the northern side of the
basin. There should be no need for any retaining walls in the bio basin. The outlet from the basin
is directed to the west towards to creek, discharging into the balance area of lot 10.



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    5. Earthworks
The preliminary drawings show proposed earthworks for the site that includes providing level
house pads for future owners to build on. We have shown indicative locations and heights for
retaining walls on the preliminary drawings; however it is planned to minimise the extent of
retaining walls for aesthetic and costs reasons. Full extent of retaining walls will be determined
during the detailed design/Operational Works phase. A typical detail for a concrete sleeper wall
has been included in the preliminary engineering drawings, however it should be noted that as
these are proprietary items they are designed and certified by the supplier/contractors RPEQ.

In order to construct the bio retention basin, it will be necessary to import fill to the site to lift the
blocks and road level above the basin levels. The amount of fill will be refined during the detail
design.



    6. Water and Sewer
There is an existing sewer main traversing the site aligned with the rear of existing
dwellings/properties along Pavilion Street. Noosa A H & I Society Inc (Pomona Show Grounds)
have given their in-principal support to permit the extension of the existing gravity sewer main
within their property to allow the new lots to be fully serviced by a gravity sewer main. Unity Water
have confirmed that if the agreement between JNE Developments Pty Ltd and Noosa A H & I
Society Inc cannot be concluded then Unity Water will permit low-pressure sewer system as an
alternative system. As such we have revised our preliminary engineering drawings to show the
proposed gravity sewer. It should be noted that this sewer line can be extended in the future to
service the development of lots to the north the subject site.

There is an existing 100mm diameter water main along the eastern side of Pavilion Street and a
road crossing to an existing fire hydrant immediately in front on the northern boundary of the site.
A new 100mm diameter main servicing the development will be provided along the new road from
this point. Refer extract from Unitywater infrastructure mapping in Appendix B

Unitywater’s network planning for this site allows for up to 18 dwellings to be established so the
scale of the development is within Unitywater’s network planning forecast. Refer screen shot in
Appendix C.



    7. Conclusions and Recommendations

The preliminary plans along with this report demonstrate that the proposed development can be
serviced and designed to meet Council engineering design standards


Prepared by



Doug Reynolds
RPEQ 9072
TOD Consulting Pty Ltd
18 November 2021




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Appendix A – Locality plan




        Locality Plan (Sourced from Noosa Council interactive mapping)




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Appendix B – Unitywater Infrastructure




              Sourced for Unitywater Infrastructure Mapping

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Appendix C – Unitywater Network Planning




            Sourced for Unitywater Network Planning Mapping




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