Approvals Application Supporting Material · MCU26/0084

                                               Noosa Harbour & Las Rias Foreshore Management Works
                                                 OFFICIAL



Analysis of historical aerial imagery and bathymetric change demonstrates that the foreshore area
adjacent to the site has migrated southward since at least 2019 due to the evolution and infilling of sand
shoals to the northwest of the site (Figure 2.3). This migration has resulted in a progressive constriction
of the channel width adjacent to the foreshore, increasing tidal current velocities in close proximity to
the shoreline.

Previous modelling undertaken for the lower Noosa River indicates that peak tidal velocities occur on
the flood tide, with velocities historically in the order of 0.5 m/s (See Figure 3.1). The observed reduction
in channel cross‑section adjacent to the site is likely to have increased both flood and ebb tide
velocities, thereby increasing erosion pressure on the foreshore and reducing the capacity for placed
sand to settle and be retained.




Figure 3.1 Water velocity and water level in the foreshore area adjacent to the Site from 20
December 2018 to 27 December 2018 (adapted from BMT, 2025 – Figures 2.5)
The interaction of elevated tidal currents with vessel traffic closer to the shoreline has further
contributed to localised sediment loss, particularly during periods of high-water levels and energetic
flow conditions. As a result, the site experiences chronic erosion, and recent nourishment campaigns
have proven unable to maintain a stable beach buffer in isolation.

The proposed groynes, nourishment works, and revetment wall repairs have been designed to respond
directly to the localised coastal process drivers at the site. The groynes are low‑profile, shore‑normal
structures intended to locally interrupt sediment transport, reduce nearshore wave energy, and promote
retention of nourished sand within discrete sand compartments.

© BMT 2026
004024 | 001 | 00                                    14                                       10 August 2026