Final Engineering services report _62 Lake Macdonald Drive · OPW25/0057

Stormwater flows generally flow to the intersection of Lake Macdonald Drive through a pipe network and overland
flow, the developed case redirects flows via the proposed road corridor with suitable contained road flow capacity up
to and including the 1 % AEP as a minimum.




Figure 5: Flood Hazard / Defined Flood Event
(Image courtesy of Noosa Council Mapping)

3.8.3   Stormwater Network Design

Stormwater design has been undertaken in accordance with the Noosa Plan Engineering Design Standards (2020) and
Queensland Urban Drainage Manual 2017 (QUDM). The design was undertaken utilising 12D design software package
and the rational method to meet the requirements for a minor and major storm event. Refer to Appendix A for the
Operational Works Plans for the proposed stormwater design.

Lots 1 & 2 (Catchment A) will discharge to the existing stormwater network via the proposed bioretention basin. Lot 3
(Catchment B) will discharge to the currently undeveloped Pear Tree Lane reserve and subsequently sheet flow to an
existing drainage reserve (900 SP176968). Refer to Figure 6 for details.

3.8.4   Stormwater Detention Modelling

No hydrologic modelling was undertaken to determine the detention requirements for each residential lot (if any).
The developer(s) of the individual lots must seek approval from Noosa Shire Council for any stormwater detention
infrastructure that may be required to facilitate the development of each lot. Stormwater detention infrastructure
must be contained within the lot that it serves.

3.9     STORMWATER QUALITY

Stormwater quality is to be controlled through the construction of a bioretention basin located on proposed Lot 900.
The bioretention basin will have all piped stormwater flows directed to the basin, discharging to a sediment forebay.

62 Lake Macdonald Drive, Cooroy – Engineering Services Report                                                Page 7
233467 | M24-1037Rpt – Issue A – April 2025