BG&E was appointed to undertake a flood immunity study, options analysis, and business case for the main street of Rosewood on the outskirts of Ipswich, to improve flood immunity and road safety.

The first stage of the project was problem definition – to confirm whether a flooding problem still existed following recent upgrades to the upstream retention basin and mining leases, or if the issue had transformed into a drainage problem.

BG&E worked with Ipswich City Council and TMR technical specialists to update the Council’s flood model, incorporating recent changes and recalibrating it using gauge data and BOM information. The updated model confirmed a flood problem still exists – though not in the primary catchment.

The second stage of the project involved developing a long list of options to address the confirmed flooding issues and identified safety concerns through the main street.

These were discussed in a strategic merit test workshop with key stakeholders and three options were selected for refinement.

The three short listed options were assessed in a multi criteria analysis with an initial assessment refined in a collaborative workshop with key stakeholders including Ipswich City Council, TMR Project Delivery, and TMR Engineering and Technology (hydraulics, pavements and active transport).

BG&E is delivering the business case for the preferred option, undertaking sufficient design and hydraulic modelling to inform a P90 cost estimate to enable TMR to make an informed decision on whether to fund the preferred option for delivery.