FAQs
Did the flood study investigate the recent roads works along Solitary Islands way at Blackadder Creek?
Yes, the flood studies scope was amended to include the analysis of the recent road works along Solitary Islands way at Blackadder creek and the new Highway to investigate whether flood behaviour may be been altered.
Is the consultant independent and did they conduct the Corindi River flood study for RMS?
WMAwater is independent and has been engaged by council to complete the technical components of this flood study.
WMAwater has been providing independent review advice to RMS on the pacific highway for over 10 years. The RMS commissioned flood study post 2013 flood was undertaken by SKM/Jacobs, not WMAwater. WMAwater was engaged to independently review the original Blackadder Creek safety works, the proposed modifications by SKM/Jacobs and the associated modelling. To ensure that observed flood behaviour of the 2013 flood was collected appropriately, WMAwater representatives accompanied SKM/Jacobs and RMS staff during the data collection phase.
In 2015 WMAwater was appointed by Department of Planning as the independent hydrologist for the Woolgoolga to Ballina Pacific Highway upgrade. This role is independent of RMS and involved the independent review of the major river models ensuring they meet industry best practice.
WMAwater was selected by council to undertake this flood study as they had intrinsic knowledge of the catchment from these independent reviews when compared to other consultants. The flood study was also be reviewed by councils flood engineers and by the councils floodplain risk management committee.
Was the same flood model from the RMS Corindi River flood study be used?
No, WMAwater developed a brand new flood model for this flood study. The flood model developed for the RMS flood study completed by SKM/Jacobs only modelled in detail a small portion of the catchment near the Pacific Highway alignment. The new model developed for this study will include Upper Corindi, and also be extended down to the river mouth at Red Rock. The new model utilised the latest digital elevation data available for the catchment, and was calibrated to the recent February 2020 flood event utilising all the information gathered during the data collection stage of the project. This ensures that the flood model reproduces the locally observed flood behaviour as closely as possible.