Swmp

EXECUTIVE SUMMARY

Barlow Shelley Consulting Engineers (Aust) Pty Ltd has been commissioned by AJG
Property Development Trust to undertake a Site-Based Stormwater Management Plan
(SBSMP) for the proposed Mixed Use Multi-story development at Lot 157 on RP88772 at
2 Bottlebrush Avenue, Noosa Heads, Queensland.


An assessment of the stormwater quantity was performed to demonstrate the comparison
between the existing and developed case peak stormwater flow rate discharging from the
property. It was found the 1-Year, 10-Year, and 100-Year ARI (63%, 10%, & 1% AEP)
design storms were comparable between both existing and developed case. The post-
developed site will discharge stormwater at peak flow rates comparable to the existing
case. This is attributed to the relatively high existing fraction impervious value, and the
comparable scale of the development.


In the existing case, the entire site drains to the kerb and channel on Noosa Drive. The
proposed development will formalize the existing lawful point of discharge by piping the
roofwater to a newly constructed kerb inlet pit on Noosa Drive. A small portion of ground
will fall to the street.


An assessment of the stormwater quality requirements has been carried out in accordance
with the Noosa Council Planning Scheme 2020. The proposed development site is less
than the prescribed threshold for stormwater quality treatment, therefore the development
is exempt from meeting stormwater quality treatment objectives. The development will be
provided with alternative stormwater quality management, being sloped hardstand surfaces
to landscaped areas where possible. Stormwater runoff will generally be buffered by
landscaped areas prior to discharge to Noosa Drive.


The proposed development will discharge stormwater to a Lawful Point of Discharge being
a newly constructed kerb inlet pit on Noosa Drive, in accordance with QUDM (2016).