Takaka’s flood hazard risk: Open day explains TDC’s finding
Tasman District Council (TDC) is investigating how the Takaka township may be affected in the event of a large flood in the Takaka River.
Commissioning the flood modelling is aimed at providing a greater understanding of what may occur in the town and surrounding rural areas. The information will:
be available to the existing community;
assist with future planning options;
inform an appropriate Civil Defence response.
The results of the modelling will be the subject of a public open day on 18 November at the Takaka Bowling Club to discuss and outline the options available to the community in order to identify the community’s preferred response to the flood hazard risk.
The flood modelling work has been made more affordable due to recent technology advances. TDC has obtained detailed land contour information for the Takaka area through the use of LiDAR, an airborne survey tool that measures the elevation of the land.
Covering the lower Takaka and Motupipi Rivers and their flood plains, the model enables TDC to simulate flood events of different sizes and durations to see what the impacts on the land and built development might be. The model also allows TDC to test different risk management options to see what effect they would have on flood risk in the study area.
The model will provide TDC and Civil Defence groups with valuable information on when and where flooding would close roads. It will also allow advance warnings to be issued to landowners for evacuation of stock or their families, should a large flood event appear imminent.
“Our understanding of the flood risk in Takaka to date has largely been based on anecdotal evidence and photos from previous floods” said Council’s River Scientist Eric Verstappen. “The most recent extreme flood event occurred in July 1983. It had an estimated 1.3% chance of occurring annually (ie an average return period of 75 years).”
“The modelling work gives us information on how a larger 100-year return event might impact on the township and floodplain today, as well as what impact climate change might have in the future.”
TDC’s policy planner Lisa McGlinchey will be using the model outputs to investigate the future development potential for Takaka.
“This is a complex project which involves a whole community – the model will allow us to investigate peoples’ concerns and fully examine the options available so that we can understand the differing impacts on various parties. The initial model results have already raised some interesting questions – it is a valuable tool to have.”
Public Open Day: Friday 18 November 12pm to 6.30pm, Takaka Bowling Club, 17 Hiawatha Lane.
Submitted by TDC
