Attachment F - Engineering Package · MCU22/0171

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6.0 STORMWATER AND DRAINAGE

6.1     Lawful Point of Discharge
The development does not propose to significantly alter the existing site drainage arrangements.
Roof catchments and surface runoff will report to an internal network of pipes discharging to kerb
and channel in Gympie Tce. A small portion of the site will discharge to the rear as surface runoff
but this will be minimal. Both scenarios offer a lawful point of discharge.

6.2     Stormwater Quantity
The proposed development does not increase impervious areas from that of the previous developed
site and is therefore not expected to generate an increase in peak flows. The site is serviced by kerb
and channel and an underground stormwater network in close proximity to the site. It is not
considered that on site detention of stormwater be a requirement accordingly. The site is also
located at the bottom of a wider catchment and any detention of peak flows would likely cause
discharge from the site to coincide with flows from higher in the catchment.

6.3     Stormwater Quality and Reuse
Noosa Plan 2020 9.4.8 Water Quality and Drainage Code AO6.2 suggests that the development is
required to meet water quality objectives. State Planning Policy Appendix 2 Table B however
excluded sites with areas of less than 2500m2. As such no stormwater quality devices (biofiltration
or similar) are proposed. However, if it is determined that water quality treatment is a requirement,
there is sufficient space within the front landscaped area to install a conventional biofiltration basin
(1.5% catchment). There is adequate level differential between the existing kerb invert and
proposed internal surface levels to provide for extended detention and depth of filter media should
this be a requirement. This could be explored further as part of a future Operational Works
development application.

Noosa Plan 2020 9.4.6 Sustainable Building Code AO2.1 determines that a minimum 3kL rainwater
storage be provided for each dwelling for reuse. Rainwater tank location is not currently shown on
the Engineering Drawings, however sufficient space exists within the front driveway and parking
area to install underground tanks as required. Further details will be provided as part of a future
Operational Works development application.



7.0 CONCLUSION

Based on all the information available it is considered that the proposed Dual Occupancy
development at 128 Gympie Tce Noosaville can be readily undertaken with no significant
engineering constraints. The proposal achieves general compliance with The Noosa Plan 2020 and
other relevant standards and codes and is recommended for approval.