Development Application Part 2 of 2 - Plans 7 Banksia Avenue Noosa Heads · OPW10/2120

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                                                                                    Job No. DE10/061




      •   The fill used in the construction of the flat platform must be compacted to at least 70%
          Density Index to form "Controlled Fill" in accordance with AS. 2870 "Residential Slabs
          and Footings") and A.S. 3798-2007 "Guidelines on Earthworks for Commercial and
          Residential Developments".

      •   Fill slopes should be no steeper than 2.5(H):1(V) and be over-constructed and trimmed
          back to ensure compaction in the outer zones. Slopes cut into the natural soil should
          also be no steeper than 2(H):1(V).

      •   All cut and fill batters must be vegetated at a minimum or otherwise suitably stabilised
          as soon as possible after construction to minimise the potential for surface scouring and
          erosion. Geotextile sheeting in conjunction with planting provides additional support
          against erosion events and should also be considered, especially in high surface flow
          areas.

      •   Existing vegetation should be retained where practical.

      •   All upslope surface runoff must be redirected away from the cut and fill batters and
          house platform to minimise the potential for instability within the batters and damage to
          the building footings.

      •   If retaining walls are to be constructed they must be designed to have a long-term factor
          of safety of at least 1.5 with respect to global stability as well as internal stability, which
          includes sliding, rotational and overturning movements. Retaining walls must also
          incorporate adequate internal drainage behind the walls to limit the potential for wall
          failure due to the buildup of groundwater pressures directly behind the wall.

      •   All surface runoff and roof water must be discharged into stormwater systems, not over
          the ground surface. Alternatively roof water can be discharged into water tanks located
          to the side or downslope of the house for storage.

      •   All storage tank overflow water must be piped to the nearest controlled drainage area
          well downslope of the house or into the stormwater system. Uncontrolled discharge to
          the hill slope is not recommended.

If the above recommendations outlined in Section 6.0 are followed, the risk to property can be
assessed as "Low to Moderate", which is acceptable if continuously managed by the slope
maintenance procedures listed above.


7.0       LIMITS OF INVESTIGATION

Recommendations given in this report are based on information supplied regarding the
proposed development in conjunction with the findings of the investigation. Any change in
development type or in development location may require additional testing and/or make
recommendations invalid.

Every reasonable effort has been made to locate test sites so that bores are representative of
the soil conditions within the area to be investigated. The Client should be made aware
however, that this assessment has been based on limited site data using small diameter
boreholes. In some cases, soil conditions can change dramatically over short distances,
therefore even careful exploration programmes may not locate all the variations. If soil
conditions differing from those shown on the log sheet are encountered during construction, this
office should be advised immediately.




Ref: 148586 DEQ Consulting Engineers Pty Ltd                            MORRISON GEO TECHNIC