Site Based Stormwater Management Plan

EXECUTIVE SUMMARY

Barlow   Shelley   Consulting    Engineers    Pty   Ltd   has   been    commissioned     by
HM Developments Pty Ltd to undertake a Site Based Stormwater Management Plan
(SBSMP) for the proposed Industrial Development on Lot 6 on SP197517, 4 Taylor Court
Cooroy, Queensland. An assessment of the stormwater quantity and quality requirements
has been carried out in accordance with the Noosa Plan (2020) & PSP6 Engineering
Design Standards – Roads, drainage, and earthworks.


Post-developed peak stormwater will discharge from the subject site will be directed to the
underground detention basin situated under the bioretention basin in the lower reaches of
the site at the south-western corner. The detention basin is 94.5m3 in volume and will
ensure non-worsening of stormwater flows to downstream properties, as site discharge will
be mitigated to pre-development characteristics in accordance with the Noosa Plan (2020).


A bioretention basin is proposed to treat stormwater from the proposed development, and
was sized in accordance with the deemed to comply stormwater quality outcome specified
in the SPP (2017), where the bioretention filter area is 1.5% of the contributing catchment
area. The contributing catchment area flowing to the basin is 5,508m2, which requires a
bioretention basin with a filter area of 83m2. The deemed to comply outcome satisfies the
requirements of the P06 of Stormwater quality and protection of receiving waters from the
Noosa Plan (2020).


The Lawful Point of Discharge will be the existing drainage reserve south of the site, where
the site is already provided an existing stormwater drainage outlet to. The Lawful Point of
Discharge meets the requirements of QUDM (2016).