This project involved options analysis and concept planning to develop a number of options to provide improved flood evacuation and repatriation time while addressing isolation issues for North Bundaberg residents during major Burnett River flood events. 

 

HIG were engaged by DLGRMA to investigate a raised roadway that would span between the existing Tallon Bridge northern abutment and the Roundabout on Bundaberg – Gin Gin Road.

 

Multiple options were investigated including single and dual lane viaduct both east, west and online of the existing roadway with different configurations of on and off ramps with various connections to the existing road network.

 

A major constraint of the project was to provide a solution that would limit the closure time of the Tallon Bridge during construction, as the only other connection across the Burnett River is the Burnett Traffic Bridge which has weight restrictions. Also, the capacity would be an issue as seen following the 2013 flood event when the Tallon Bridge was closed temporarily due to a failure in the northern abutment.

 

Impact to flood conditions was also a very important aspect as the new structure would need to have little impact in terms of afflux and velocities. The flow conditions through this North Bundaberg area during major Burnett River flood events when the water breaks the banks is complex and a new flood model was created to ascertain the impacts of the proposed options. Discussions were had to share information between this project and the house buyback scheme that was being undertaken in parallel as the viaduct option to be progressed may change the flood conditions and directly impact buyback requirements.

 

Technical components of the project included viaduct design, on and off ramp design, pedestrian and cycleway retrofitted to the existing Tallon Bridge with connection to existing infrastructure, intersection configurations, lighting, drainage, pavement design and PUP relocation.  The design also considered visual amenity, Crime Prevention through Environment Design, connectivity, community expectation and value creation.