Flood Mapping and Options Assessment for the Taitarakihi Creek
The urbanised lower portion of the Taitarakihi Creek catchment in Timaru is prone to flooding, with significant flood events occurring in 1986, 2000 and 2012.
A comprehensive, fully integrated 1D – 2D hydraulic model was constructed using Tuflow to analyse flood levels and flood mitigation options in the catchment. Both State Highway 1 and the Main Trunk Railway line cross the lower Taitarakihi Creek, and the culvery structures at these points were determined to be critical hydraulic components during flood flows.
The modelling of mitigation options therefore focused on improving the capacity of these components, as well as providing flood storage in the upper catchment. The modelling analysis found that the most effective measure was to upgrade the culvert beneath the Main Trunk Railway line.
- Hydraulic analysis
- Risk assessment
- Flood mitigation options