PART Response to Information Request · OPW11/0335

8.0        SEDIMENT AND EROSION CONTROL PLAN


The Noosa River: Environmental Values and Water Quality Objectives state that the
environmental values associated with the Noosa River Wetlands include aquatic ecosystem
protection, and cultural and spiritual values. Because Noosa National Park is a protected area,
these values require a high level of protection (level 1 protection).

However the wetland adjacent to Noosa National Park is a disturbed ecosystem, as indicated
by measured water quality parameters (Table 4-1). The existing caravan park development
appears to be placing pressures on this wetland. The treatment train built for the proposed
Essence of Peregian development is designed to improve the quality of water entering the
wetland, and therefore, the water quality of the wetland. The target water quality objectives of
stormwater entering the wetland are listed in Table 3-1.

During the construction of the Essence of Peregian development, there is a hazard that
disturbed soil might be carried into the wetland by stormwater. In particular, fine sediment
mobilised by stormwater will potentially carry nutrients into the wetland. The likely consequence
of this is increased nutrient availability to weeds, with potential negative consequences for the
adjacent Noosa National Park ecosystem.

Assessment of the Queensland Best Practice Environmental Management Guidelines (DERM,
2009) checklist (Table 8-1), shows that overall there is a high erosion hazard for this site. This
hazard is directly affected by soil type (particularly imported fill on lower slopes), the need to
reshape the ground surface to install structures, and the anticipated duration of site disturbance
being 3 to 6 months. The hazard is greater during the wet season between November and July
when the average monthly rainfall is expected to be above 100 mm.

Table 8-1: Factors Contributing to Erosion Hazard
                                          Erosion Hazard Assessment Form
 Controlling Factor                                                           Points                             Score
 Average Slope of Whole Site                                                      1                                  1
 Soil type being disturbed                                                     2 or 5                             3 or 6
 Anticipated duration of site disturbance                                         5                              8 or 11
  Erosive rainfall risk during site disturbance                     1 between Aug - Oct;
                                                                                                             9 or up to 13
                                                                    2 between Nov - Jul.
 Off-site sediment control (downslope of soil
                                                                                  0                          9 or up to 13
 disturbance)
  Run-off entering the site                                                       0                          9 or up to 13
  Extent of site disturbance                                                      2                         11 or up to 15
 Total Score                                                                  11 -15                    High Erosion Risk

By implementing sediment and erosion controls, it is possible to moderate the erosion hazard.
This includes protective covering of disturbed soils (particularly on erosion prone parts of the
landscape, and when rain is expected), scheduling work to avoid the highest rainfall risk period,
installing upslope diversion of runoff away from soil disturbance, and installing purpose built
sediment control traps down-slope of the soil disturbance.

The SECP has identified construction site best practices for managing sediment erosion and
control. A daily site check-list will be used to ensure that building contractors are cognizant of
and performing the required management actions. This check-list is attached in Appendix C.



©2012 Simmonds & Bristow Pty Ltd                         Contrast Constructions                           J-1 005-310 - 13 January 2012
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SCEMP_Scanlon Property Group_V3 0 ta_120113.doc                                                                           Page 13 of 24