In 2020, Cairns Regional Council commissioned WMS to undertake a flood impact assessment (FIA) for the proposed Jalarra Park detention basin. WMS teamed up with civil engineering firm Dryside Engineering to deliver the FIA and detailed design of the basin. The objective of this study was to reduce the frequency of flooding on downstream properties while designing a drainage asset that complemented the existing nature of the park.
WMS updated the hydrologic and hydraulic models to ARR 2019. Numerous basin iterations were run to determine the optimum dimensions of the basin and outlet structure configuration. The implementation of the detention basin showed significant reductions to downstream flooding for both the frequent and infrequent events.
The hydraulic modelling results were used to size scour protection and complete the design ready for construction.
A landscape plan was produced which maintained the existing vegetation and included an upgraded walking path and benches to improve park facilities for residents. WMS also provided Council with landscape sketches and advice for the community consultation sessions which resulted in positive feedback regarding the proposed basin.