Kinsley Group was engaged by Downer EDI Works to facilitate feature survey works and hydraulics and hydrology studies for two bridge structures located along ARTC rail corridors. The investigation associated with the Condah Reservoir Overflow Bridge was commissioned by Downer EDI Works due to the proposed bridge replacement works. Downer EDI Works wanted assurance that the proposed open area beneath the bridge structure was capable of supporting water flows in a 1 in 100 year storm event. Hydraulic modelling of the proposed culvert structure to replace the bridge was undertaken using HEC-RAS and the flood impacts were assessed for the 10 year, 20 year, 50 year and 100 year ARI events.

The investigation associated with the Fiery Creek Bridge was to establish if one of the 10No. ARMCO pipes associated with the structure could be filled-in due to the poor structural integrity of the pipe without adversely impacting on the ability of the overall structure to support a 1 in 100 year storm event. Hydraulic modelling of the proposed culvert structure to replace the bridge was undertaken using HEC-RAS and the flood impacts were assessed for the 1 year, 2 year, 5 year 10 year, 20 year, 50 year and 100 year ARI events to determine the impact of sealing one of the ARMCO pipes.