16-001014-02A (Ultimate SCMMP)

2.2       CONSTRUCTION PHASE / ESTABLISHMENT
Outlined below are the proposed procedures and methodology for the construction and operational establishment of the
Central WQCP proposed as part of Stage 2 of the development. Performance indicators for managing mosquitos and
cyanobacterial blooms have also been specified. Procedure and methodology has been based on Water By Design’s,
Construction, and Establishment Guidelines: Swales, Bioretention Devices, and Wetlands (2010) and Healthy Waterways
WSUD Technical Design Guidelines for South East Queensland (2006).

2.2.1     GENERAL MANAGEMENT

Construction of the development and the following building works on allotments has the potential to mobilise large
quantities of sediment in runoff. For WQCPs to perform as designed there is a need to protect the planting and vegetation
during this phase of the development. It is proposed to follow a staged installation procedure for the WQCP generally in
accordance with Option 2 of Table 4.4 and Section 4.7.2 of Water By Design’s Construction and Establishment
Guidelines (2011). A summary of the methodology is presented below:

1)   Civil Works Functional Installation – the WQCP will be constructed in two phases. Phase 1 is to use the WQCP areas
     as a temporary sediment basin during construction. In Phase 2 once the majority of the construction works have
     been completed, earthworks and shaping to create the layout and functional elements of the WQCP will be
     undertaken. Bulk earthworks (e.g. forming of the macrophyte zones, high‐flow bypass and surrounds, considering
     future allowances for topsoil) and installation of functional elements (e.g. rock protection, inlet pipes and headwalls,
     trash racks, maintenance accesses, outlet pit and pipe, and bypass weirs) shall be undertaken as per the
     methodology detailed in Section 4.9.3 in the Construction and Establishment Guidelines (2011).

2) Building Phase Construction – The WQCP is to be maintained as a temporary sediment basin during the building
   phase of the upstream catchment. Establishment of macrophyte zones and other vegetation areas is to be delayed
   until 80% of upstream catchment development has been completed.

3) Landscape / Operational Establishment – When 80% of the proposed upstream catchment development is complete,
   the ultimate WQCP configuration is to be established and vegetated in accordance with Section 4.9.3 of the
   Construction and Establishment Guidelines (2011).
During the establishment of vegetation bird control is essential to prevent excess vegetation damage. Maintaining this
densely vegetated separation between the shore and deeper water is a key issue to preventing the birds concentrating in
one area and eroding the foreshore as they move from the land to the water.
During the construction phase, inspections should be carried out every month and immediately following storm events.
The construction inspection checklist, which is included in Appendix A, shall be completed and records of the inspection
shall be kept.

2.2.2     MOSQUITOES

Free draining surface areas are a critical performance indicator in managing mosquitoes during the construction phase.
Therefore standard construction measures will ensure that surfaces are free draining and no isolated shallow pool areas
are formed in the stormwater infrastructure or adjacent to the WQCP.

While mosquito fish are effective for controlling mosquito larvaue, some species (i.e. Gambusia spp.) may adversely
impact frog and native fish populations. Coppock and Erskine (1997) have found that native Fire‐tailed Gudgeons
(Hypseleotris galii) are successful predators of mosquito larvae and should be seeded into the pond before Gambusia
can establish. Their introduction into a constructed WQCP is only viable if a reasonable quality of oxygenated water can
be established. Insectivorous birds should be encouraged to keep control over adult mosquito populations.

2.2.3     CYANOBACTERIAL BLOOMS

General construction performance indicators are to be followed as per Section 2.2.1 above.




16-001014-02A | SMCMP | PALM LAKE RESORTS                         COOROY RETIREMENT COMMUNITY, TRADING POST
                                                                                              ROAD, COOROY                 |5