8. Volume 5 - Stormwater Management Plan

                                          LAMBERT & REHBEIN
                                             ENGINEERS • MANAGERS • SCIENTISTS




Stormwater quality during the construction phase of the development should be addressed in an
Erosion and Sediment Control Plan. The plan should address construction phase erosion and
sediment control issues in accordance with the Institute of Engineers Australia (Qld) Erosion and
Sediment Control Guidelines. The Erosion and Sediment Control Plan should also be in
accordance with Noosa Council guidelines.

4.2.2   OPERATIONAL PHASE

During the operational phase of the development, the following impacts have been identified in
relation to stormwater runoff and water quality of the receiving waterways:

•       Potential exists for gross pollutants, which include human derived litter, coarse sediment
        and vegetation, to affect the drainage capacity of stormwater systems. Gross pollutants
        may physically affect the downstream waterway habitats and organisms such as
        entangling birds and aquatic animals. Gross pollutants are also typically unsightly and
        reduce the visual amenity of the site;
•       Sediment can become mobilised by stormwater as suspended solids from the erosion of
        exposed soil areas, un-mulched garden beds, sediment deposited on car park and
        hardstand areas by vehicles and by atmospheric deposition of sediment. Suspended
        solids can be used as a transport medium resulting in nutrients and heavy metals making
        their way into waterways. Suspended solids can block stormwater systems leading to
        local flooding and can also affect receiving waterways physically through smothering
        aquatic flora and fauna; and
•       Nutrients can enter waterways in stormwater runoff through many sources including
        detergents used in car washing, fertilizers from landscaping and lawn areas, nitrous
        oxide deposition from vehicle exhausts, and organic waste. High nutrient levels can lead
        to eutrophication of the receiving waterways resulting in algal blooms (toxic in some
        cases) and excessive macrophyte growth.
Implementation of the appropriate Stormwater Quality Improvement Devices (SQIDs) would
ensure that stormwater discharge from the site would adhere to Noosa Council’s requirements
and objectives.

4.3     STORMWATER QUALITY ASSESSMENT
The potential impact and effectiveness of the proposed SQIDs was assessed using MUSIC
Version 6.1.0. MUSIC is a software tool that simulates stormwater runoff quality from different
sources and the effectiveness of SQIDs.




 Ref: B16239CR002                                       - 11 -                      Stormwater Management Plan
                                                                                 Noosa Energy Centre - Noosaville