Dewatering Management Plan

                                                                                         ADG Consulting Pty Ltd


3    Previous investigations
     This DMP is based on site and locality specific information sourced from the following information
     provided to ADG by SCG Consulting Engineers and/or otherwise sourced by ADG:
             Site Classification Report, Proposed Residence 11 Ravenwood Drive, Noosa Heads. Global Testing,
              August 2016, Ref: 16/0686.
             Foundation Design Report, Lot 1 9 Ravenwood Drive, Noose Heads. STA Consulting Engineers,
              September 2016, Ref: ES137382‐B.
             River Oasis, Preliminary Concept, design plan set. Chris Clout Design. 4 February 2025 (Refer
              Appendix C).
     It is noted that dilapidation reports for surrounding structures and services are proposed to be
     undertaken prior to commencement of construction and dewatering, however are to be provided to
     Council separately from this DMP.

     A brief discussion of relevant soil and groundwater conditions is provided below.
3.1 Global Testing 2016
     A Site Classification Investigation was undertaken at the site in August 2016 by Global Testing (Global) to
     assess the soil suitability for slab and footing establishment associated with a previously proposed
     development. ADG notes the relevance of this report is limited due to the age of the report, and fact that
     the site was developed with a residential premises including basement carparking in 2018, which has
     since been demolished as of October 2024.
3.1.1 Soils
     A total of two boreholes (BH1 and BH2) were drilled to 3.5m in depth. Shallow fill material encountered
     comprised brown, fine to coarse grained medium‐dense sands to between 0.0m and 2.0m in depth.
     Underlying fill materials comprised similar material with increasing moisture (saturated) from 2.1m to
     the termination depths of 3.5m in both boreholes. Global makes mention that the encountered fill was
     likely placed a significant number of years prior and that the site may be underlain with deep settling
     marine clays.
3.1.2 Groundwater
     Groundwater was intercepted in both boreholes (BH1 to BH2) at approximately 2.1m below the ground
     surface at the time of the investigation (July 2016). No analysis of ground water was conducted as part
     of the investigation. No steady groundwater levels were obtained, however given the site location and
     highly permeable soils, groundwater levels are anticipated to be directly influenced by tidal variation in
     the canal (adjacent to site). ADG notes the relevance of this report is limited due to the age of the report,
     and fact that the site was developed with a residential premises including basement carparking in 2018,
     which has since been demolished as of October 2024. It is also noted that no acid sulfate soil (ASS)
     investigation was undertaken alongside the soil classification investigation for the site.

     Therefore, as part of the groundwater monitoring program, untreated groundwater will be sampled as
     part of the pre‐discharge monitoring (and then as required) to detect any potential in‐situ oxidation of
     potential ASS, and potential contingencies such as reinjection of groundwater to minimise oxidation will
     be recommended if required.
3.2 STA Consulting Engineers 2016
     A Site Investigation was undertaken on the adjacent site at 9 Ravenwood Drive by STA Consulting
     Engineers (STA) in September 2016. A total of two boreholes (BH1 and BH2) were drilled to between 2.0m
     and 2.6 m in depth. Subsurface material encountered comprised brown, orange‐brown, medium‐dense
     to dense silty sands to between surface level and termination depths in all boreholes.

     No groundwater seepage was indicated on the bore log sheets provided however the subsurface material
     was logged as being wet from approximately 1.6m in depth in both boreholes.

ADG1786.25 Dewatering Management Plan_Rev0_20.02.25                                                         Page 4