RFI - Appendix B Civil Engineering Report · MCU22/0038

 12 May 2022



4         STORMWATER
4.1       Flooding

Based on Noosa Shire Council flood mapping, the site is not subject to flooding from any sources.

4.2       Lawful Point of Discharge

The lawful point of discharge for the development site is the existing internal Noosa Civic Shopping
Centre stormwater infrastructure south of the proposed development and the existing stormwater
drainage system along the eastern side of Hofmann Drive. The existing Noosa Civic Shopping
Centre lawful point of discharge is the creek to the south of the site.

4.3       Rainwater Reuse

A rainwater harvesting tank of min 5kL will be included on site to provide water for landscape
watering and internal fixture use. The tank will collect runoff from the new roof area with overflows
directed to the bioretention basin for treatment.

4.4       Site Based Stormwater Management Plan

The aim of the Stormwater Management Plan outlined below is to:

         Prevent or minimise adverse social or environmental impacts from stormwater runoff
          originating from the proposed development.
         Achieve acceptable levels of stormwater runoff quality and quantity.

The Stormwater Management Plan aims to identify Stormwater Quantity and Quality Best
Management Practice for the site and demonstrate that water quantity and quality impacts will be
minimised in receiving waters.

The Stormwater Management Plan outlines the site in two sections, the operational phase and the
construction phase. The operational phase addresses treatment of contaminated runoff from the
developed site by natural methods before discharging into receiving waters whilst the construction
phase of the Stormwater Management Plan addresses erosion and sediment control to prevent
contamination of water sources by stormwater runoff during construction of the site.


4.5       Operational Phase

4.5.1 Proposed Site Drainage

Stormwater runoff from the proposed development will be collected and conveyed in a new
stormwater pit and pipe network prior to discharge to the existing internal infrastructure.

Stormwater runoff from the new roof, carpark, and internal road will be directed to 2 bioretention
basins for stormwater quality treatment.

Stormwater runoff from the landscape areas at the north boundary will remain generally as per
pre-developed conditions, with some re-shaping required to ensure stormwater infrastructure
(swales)remains clear of the proposed building works.


 Excellence with Economy in Engineering                                                                 8
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