Attachment 5A - Noosa Landfill RRA Flood Assessment

Noosa Landfill RRA Flood Assessment



3 BASE CASE MODELLING
Base case flood modelling has been undertaken with the site in its existing condition.

3.1    Hydraulic Model Software
Hydraulic modelling has been carried out using TUFLOW HPC software developed by BMT WBM
in Brisbane. TUFLOW HPC is a 1D / 2D finite volume numerical model that is used to simulate
hydrodynamic flow in rivers, floodplains and urban catchments. It is widely used in Australia and
overseas.

TUFLOW HPC version 2020-10-AA_64_iSP has been used for this investigation.

3.2    Topography
Model topography is defined using a 2D fixed grid with a 3m cell size. TUFLOW’s Sub Grid
Sampling with a 1m grid size has also been applied to enable the 3m cells to better reflect ground
levels.

Model topography levels are based on Noosa Council’s 2015 Aerial LiDAR Survey (ALS) external
to the site. The landfill site is represented using 2020 LiDAR collected by a drone. Where
necessary local adjustments have been made to ensure key features such as road embankments
are correctly represented in the model.

Model ground levels in the vicinity of the site are shown on Image 3-2.




J00352R1V2                                                                                     3