Attachment 7C - Flora and Fauna Survey Assessment_Noosa Landfill - Revision 3

                                                                                      Native Foresters



Induration can potentially occur at depth or near to the surface. Induration can be laterally
and vertically variable. The presence of an indurated layer is of hydrogeological significance
as it can act as a semi-confining layer influencing groundwater flows, hydraulic connectivity
and aquifer storage. The transitional environments between the Land Zone 5 and Land
Zone 3 ecosystems may or may not exhibit induration and there is potential for merging of
confined deep aquifers and unconfined shallow aquifers at the interface between the two
land zones.

Uncertainty regarding the presence of coffee rock/organic hardpans may be addressed by
soil profile data from bore holes excavated along the eastern tip boundary (in particular Bore
16 which lies to the near west of areas of known Swamp Crayfish/Wallum Froglet habitat)
and from areas further east in close proximity to Swamp Crayfish/Wallum Frog habitat.

Should the presence of a layer of coffee rock or organic hardpan underlying shallow
groundwater east of the tip be confirmed, excavation works along the eastern tip boundary
should not exceed the depth of this material.

3.5.3 Rainwater infiltration and changes in water quantity

Construction of new cells and the installation of impervious cover over all cells has the
potential to reduce localised recharge of groundwater to the near east of the landfill and
increase the amount of rainwater (previously infiltrated to the landfill and directed to the STP
via leachate) flowing to the drainage lines at SW4 and SW5 (Refer to Appendix B). Total
flows will increase because larger catchment areas will be redirected to those points.
Whether the reduction in infiltration and groundwater recharge will have a significant impact
on ground water levels in areas of nearby Swamp Crayfish and/or Wallum Froglet requires
further investigation and hydrological modeling of the following:

    i.        the behaviour of ground water east of the tip (including fluctuations in
              groundwater levels related to rainfall);
    ii.       the amount, intensity, frequency and duration of rain;
    iii.      groundwater recharge and discharge rates; and
    iv.       evapotranspiration.

With respect to increased/intermittent surface flows to the drainage lines, it is considered
likely that peak flows can be mitigated, however total volumes and flow frequency will
increase. Resultant impacts on habitat condition and vegetation community structure are
discussed in section 4.1.




Noosa Landfill & Resource Recovery Centre – Fauna and Flora Assessment – Revision 3
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