Dewatering Management Plan · OPW24/0032

                                                                                            ADG Consulting Pty Ltd


2    Site characteristics
2.1 Property description
     The site is described as Lot 145 on N21859, and is situated at 38 Mossman Court, Noosa Heads,
     Queensland. The site is understood to be currently occupied by a multistorey dwelling (Nearmap Imagery,
     10 September 2021) which is planned to be demolished. The site is irregular in shape and has an area of
     607 m2. The site locality is shown in Figure 1, Appendix A.
2.2 Surrounding environment
     The surrounding environment and land use is described briefly in Table 1.

     Table 1 Surrounding land use and environment

              Direction                                              Environment

                North             Mossman Court, then residential development, then Noosa River.

                 East             Residential development.

                South             Noosa River, then reserve area, then residential development.

                West              Residential development, then Noosa River.


2.3 Topography
     The site and surrounding land is considered to be generally level, with the site gently sloping towards the
     Noosa River from the north to the south, southeast. Surface elevations range from 2.20 m to between
     1.62 and 1.25 m AHD. Refer to Appendix C (Preliminary Concept Design ‐ Site/Survey Plan, 2021).
2.4 Geology & soils
     The surface geology at the site is mapped as being Anthropocene aged gravel, sand and silt; man‐made
     deposits generally associated with land‐fill or mining (tailings, dumps and rehabilitated areas). The
     dominant rock type is identified as volcanic and metamorphic as reference through the detailed surface
     geology (accessed via Queensland Globe online, 6 October 2021).

     The Acid Sulfate Soils (ASS) mapping layer 1:100,000 Redcliffe to Teewah categorises the site as ‘SDL’ or
     ‘Acid Sulfate on Disturbed Land’, indicating that the site is likely to contain acid sulfate soils (and potential
     exists that partial or full treatment may have been undertaken), however limited field investigation has
     been performed in this area (accessed via Queensland Globe online, 6 October 2021).
2.5 Hydrogeology
     A search of groundwater bores licensed by DRDMW was conducted by ADG on 6 October 2021. The
     search identified no licensed bores within a 500 m radius of the site. A map showing the bore search area
     is provided in Appendix B.

     Based on the local geology and topography, and the site’s proximity to the Noosa River, the inferred
     groundwater flow is to the south. Groundwater beneath the site is likely to be hydraulically connected to
     the river, therefore saline groundwater conditions are anticipated, and additional saltwater intrusion is
     likely to occur during dewatering.




ADG1304.21 Dewatering Management Plan_Rev0_08.10.21                                                             Page 3