Callide Coalfield Crossing Drainage Study and Flood Mitigation Assessment
Client
Aurizon
Flood impact assessment on an existing rail crossing site to identify possible mitigation works to minimise flood impacts on adjacent properties.
Background
Callide Coalfield level crossing had previously been raised without an assessment of overland flooding impacts on adjacent properties. A retrospective assessment was required to confirm any flooding impacts related to the raising the level crossing, and to identify possible mitigation works to minimise flood impacts on adjacent properties.
Solution
We compared flood impacts of the existing crossing and the proposed raised crossing to assess flood impacts and recommend any additional works required. To evaluate flood impacts we developed a hydrologic model (WBNM) of the catchment and a 2D hydraulic model (TUFLOW) of the floodplain, hydraulic structures and the rail embankment, prior to and after raising the crossing. We assessed the flood impacts for a range of design flood events from 50% to 2% Annual Exceedance Probability, and documented the model development, results and recommendations.
Outcomes
The outcomes of this study informed discussions with land holders regarding the mitigation works required to minimise the impact of flooding.