The Challenge

Wallsend near Newcastle in NSW has been the subject of numerous studies into flooding including a catchment wide flood study undertaken by DHI in 2008. In 2014, City of Newcastle engaged SMEC to determine the feasibility of previously nominated flood mitigation options. In turn, SMEC Australia engaged WMS to undertake the modelling component of the project. The primary aim of the proposed works was to reduce the force of flood waters to a point where the risk of collapse would be significantly reduced.

Approach and Outcomes

The first step was to upgrade and recalibrate the 2008 MIKE FLOOD model. Then modelling of five structural mitigation options was undertaken. Each option involved combinations of: bridge widening, bridge removal, channel widening, levee implementation and commercial and residential building demolition.
The options were assessed for feasibility, land use considerations, tangible and non-tangible flood damages by SMEC with input from WMS. The primary outcome of the project was a phased implementation strategy detailing property acquisition, preliminary works, staging of construction/demolition and costings. Recommendations for sources of funding were also provided.