Stormwater Management Plan -OPW (A) · OPW25/0042

10.0 EXTERNAL CATCHMENTS DRAINAGE ROUTE

The eastern end of the Serenity Close roadway and the existing residential building at
the north-eastern corner of the Settlers Cove site; Macquarie Lodge and Petrie Mansions
were all constructed by RF Thompson Developments during the 1990’s and early 2000’s
predating the Settlers Cove Noosa Residential High Density Environmental Management
Plan (EMP 1) produced by WBM Oceanics Australia.

Current best practice of rainwater infiltration was not adopted for those early
developments and instead stormwater was collected and conveyed to Noosa Inlet via
traditional methods including the existing stormwater line mentioned in Section 2.0.

In accordance with the existing change approval and the previous version of this
report it is proposed that flows from external catchments be re-routed through the
development site on a revised alignment and in a traditional fashion consisting of
minor event flows conveyed underground via piped drainage with a landscaped
major event overland flow path above.


10.1 PIPED FLOWS (< 10 YEAR ARI)

The proposed route for minor event pipework and major event overland flow will be
generally westward from the existing sag point on Serenity Close following the
northern face of the proposed building and the southern extent of ‘quiet pool’
landscaped areas to the Serenity Close cul-de-sac head consistent with approved
architectural drawings.

It is proposed to upgrade existing pipework and headwalls within the road reserve
and pathway in order to cater for the increased catchment area but generally
maintain existing alignments and discharge point.

Notably the nett effect would be to combine the two (2) existing stormwater
discharge points into one with flows from the additional catchment area at the
eastern end of Serenity Close effectively moved around 120m westward.

A proposed sewer diversion will follow a similar route generally parallel to the
stormwater line.

Realigned pipework will be contained within an easement in favour of Council and ,
where sewer is adjacent a shared easement in favour of Council and Unity Water.
Notably the stormwater line passes under elevated structure in two areas, one in the
form of a footbridge and the other hotel units.
It is proposed that volumetric easements will be registered in these areas.

Refer to Engineering Drawings at Appendix A for details.

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A6769/25/SWMP/Rev OpW(A) – Feb 2025                                       Page 19 of 21
SH/PL
                     Brah101 Pty Ltd t/as ALTA PROJECTS