Reference Document - Dewatering Management Plan (For Stamping) MCU25/0053 & OPW25/0074

                                                                                                                 ADG Consulting Pty Ltd


                      1        Introduction
                               ADG Consulting Pty Ltd (ADG) was engaged by Seymour Group to prepare a Dewatering Management
                               Plan (DMP) for the proposed residential apartment development within property described as Lot 0 on
                               BUP10936, 7 Noosa Parade, Noosa Heads, Queensland.
                      1.1      Proposed development
                               It is understood the proposed development will comprise a two‐storey building over a single‐level in‐
                               ground basement, extending across the 1,120 m2 site.

                               Based on information provided by Seymour Group, existing ground levels across the proposed basement
                               footprint are approximately RL 2.1 m Australian Height Datum (AHD). Excavations to facilitate the
                               basement construction are proposed to extend to an approximate depth of 2.8 m below existing ground
                               level (bgl), corresponding to an approximate elevation of RL ‐1.1 mAHD (i.e. finished basement floor level
                               of RL ‐0.7 mAHD; allowing for 400 mm raft slab and blinding layer). Localised deeper excavations may be
                               required to facilitate other structural elements (i.e. lift overrun pit, pile caps and footings), where
                               required.

                               During a geotechnical and acid sulfate soil investigation on the site in January 2025, no groundwater was
                               recorded in the drilling of boreholes to the depth of 4.5 mgbl (PTG Consulting, 2025). PTG noted that
                               groundwater levels are expected to fluctuate in response to variations in rainfall and are likely to rise
                               close to the ground surface during periods of heavy or prolonged rainfall. No further recent data has been
                               supplied for review in preparing this DMP, however based on ADG’s experience on nearby sites in the
                               locality in recent years, it is anticipated that groundwater should be expected at or around 0.5 m AHD +/‐
                               0.5 m, depending on tidal and seasonal rainfall conditions. Dewatering will therefore be necessary to
                               allow the basement and other structural elements to be constructed in dry conditions.
                      1.2      Relevant guidelines
                               The DMP was prepared with reference to the following documents:

                                    Australian and New Zealand Guidelines for Fresh and Marine Water Quality 2018. Australian and
                                     New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia
                                     (ANZG, 2018), which supersedes Australian and New Zealand Guidelines for Fresh and Marine Water
                                     Quality, Australian and New Zealand Environment and Conservation Council and Agriculture and
                                     Resource Management Council of Australia and New Zealand (ANZECC/ARMCANZ). 2000.

                                    Environmental Protection (Water & Wetland Biodiversity) Policy 2019. Queensland Government.
                                     2019.

                                    Guidelines for Managing Risks in Recreational Water. Australian Government, National Health and
                                     Medical Research Council (NHMRC). 2008.

                                    Monitoring and Sampling Manual 2018, Version 2 June 2018. Department of Environment and
                                     Science (DES). 2018.

                                    Noosa River environmental values and water quality objectives. Department of Environment and
                                     Science (DES). 2022.

                                    National Environment Protection (Assessment of Site Contamination) Measure 1999, (as amended
                                     May 2013). National Environment Protection Council (NEPC). 2013.

                                    Queensland Water Quality Guidelines 2009, Version 3. The Department of Environment and
                                     Heritage Protection (DEHP). 2013.




                          ADG1777.25 Dewatering Management Plan_Rev0_01.05.25                                                      Page 1




Document Set ID: 23735664
Version: 1, Version Date: 12/05/2025