20517 App J.pdf [As Published] · 132007.1259

Concept Stormwater Management Plan
Essence of Peregian

 

 

7.0 CONCLUSIONS AND. RECOMMENDATIONS

This report has been prepared generally in accordance with Noosa Council's ‘The Noosa Plan’ Planning Scheme
Policy. Information has been provided on the relevancy of flooding to the site, a stormwater quality management
strategy and a water balance analysis.

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Noosa Council provided documentation that the site has no nominated flood levels associated with it and is not
within an area subject to minimum floor heights. A flood study was not part of the scope of this report.

A Water Quality treatment train has been devised for the proposed subdivision consisting of

e An external bio-filtration basin to treat runoff from the proposed commercial site and external areas being
David Low Way and Peregian Beach Hotel;

e Abio-filtration basin to treat runoff from the internal loop driveway;

e Above ground 3 kL rainwater tanks with internal reuse for toilets and laundry, for each of the 30 beach
shacks;

e Three rainwater tanks that collect roof runoff from the accommodation buildings for irrigation of landscaped
areas in the vicinity of the tank;

e Three Ephemeral Wetlands treating overflows from accommodation building rainwater tanks and ground
level areas surrounding the accommodation buildings;

e Vegetated swales that convey surface runoff to ephemeral wetlands and overflows to discharge points.

The treatment train was modelled using the software program MUSIC and has been demonstrated to achieve
significant pollutant load reductions from treatment of both the developed site and external site catchments. Load
reductions have been compared to water quality objectives as required by neighbouring Maroochy Shire Council.
Load based objectives were applied to this report as concentration targets in the Queensland Water Quality
Guidelines were argued as not appropriate for this development.

The developed scenario (with rainwater reuse measures) water balance model produced average annual runoff
volumes lower than the existing site runoff volumes.

It is recommended that the Concept Stormwater Management Plan be approved and incorporated into the
Operational Works design. Detailed construction drawings for proposed water quality treatment devices will be
submitted with the Operational Works application.

 

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