Reference Documents - Stormwater Management Plan & Waste Management Plan - MCU26/0040, OPW26/0066 & RAL26/0013 (As Published)

EXECUTIVE SUMMARY
An assessment of the stormwater quality and quantity requirements has been carried out
for the proposed development at 18 Taylor Court, Cooroy, in accordance with the Noosa
Shire Council Planning Scheme Policy (PSP).


The project involves the construction of 54 industrial tenancies, each with a gross floor area
ranging from 120 to 370m². The key stormwater management components include a
combined bioretention and detention basin.


Stormwater quality modelling, conducted using MUSIC software, confirms that the proposed
treatment train will meet the required pollutant export removal targets. A bioretention basin
with a filter area of 210 m² will provide adequate treatment to meet the pollutant export
removal targets in the Noosa Shire Council Planning Scheme and QLD SPP (2017).


Stormwater runoff volumes from the pre- and post-development catchment were modelled
with a Watershed Bounded Network Model (WBNM) using the initial and constant loss
method as per the Australian Rainfall and Runoff (ARR) and Queensland Urban Drainage
Manual (QUDM 2016) guidelines. The proposed 472m³ detention basin is sufficient to
attenuate total post-development peak flows from the site to pre-development levels for all
design storm events up to and including the 1% AEP + CC event.


The drainage strategy directs the majority of runoff to the southeast lawful point of discharge
(LPOD1). At this location, runoff from LPOD1 is both treated and attenuated before being
released into the adjacent stormwater reserve, ensuring that increases in runoff do not
cause actionable nuisance to surrounding properties. A smaller, separate catchment
discharges to the northeast lawful point of discharge (LPOD2), where flows travel east
toward Taylor Court. This discharge is negligible, with a maximum flow of 29 L/s during a
1% AEP event. The overall approach is fully compliant with the requirements of Clause 3.9
in QUDM (2016).