Swmp

5.2         Construction Phase

Sediment generated during the construction phase shall be controlled in accordance with a site-specific
Erosion and Sediment Control (ESC) Plan and kept on site throughout construction. A detailed ESC
should be documented by a suitable experienced professional prior to works commencing on site.

The SPP (DILGP, 2017) Appendix 2 – Stormwater Management Design Objectives Table A: Construction
phase – stormwater management design objectives outlines design objectives for construction phase
requirements for stormwater quality.



The following design manuals are to be implemented prior to any construction commencing.

      -   SPP Appendix 2, Table A

      -   IECA Principles of Construction site ESC

      -   Water By Design ESD Factsheet Suite




5.3         Operational Phase


We are proposing to use a combination of active and passive stormwater treatment measures. Active
measures will include a bio-retention basin and a water storage tank for re-use and passive measures
via gross pollutant inserts into stormwater pits within paved areas that receive runoff from areas prone
to gross pollutants.



5.3.1      Water Quality Objectives
Water quality objectives for outlined in the Noosa Plan 2020 (PO6 of the water quality & drainage code)
and are displayed in Table 5.1. These reductions are achieved by adopting best practice techniques in
accordance with the abovementioned guidelines.

                              Table 5.1: Minimum Mean Annual Load Reductions

                POLLUTANT / ISSUE                    MINIMAL MEAN ANNUAL LOAD REDUCTIONS

      Total Suspended Solids (TSS)                                     80%

      Total Phosphorous (TP)                                           60%

      Total Nitrogen (TN)                                              45%

      Gross Pollutants (GP)                                            90%



5.3.2      Proposed Treatment Measures
Implementing the water quality objectives for the site as mentioned above and to ensure that on-site
stormwater management facilities can be economically maintained, it was deemed the most appropriate
method for treatment is the inclusion of a small bio-retention basin. Roof and surface runoff will be
collected via an internal drainage network and directed to the on-site bio retention basin prior to the
lawful point of discharge.

 SCG Consulting engineers                             8                      SCG Ref: 33094(SWM).Rev A