Coastal f indings help community make better land decisions
Coastal hazard findings by the National Institute of Water and Atmospheric Research (Niwa) for the Waitaki District across 20, 50, 100 and 500 years have been presented to Otago Regional Council.
Coastal erosion has been calculated for the length of the Waitaki district coast, with no new erosion hotspots identified. However, more than 60 per cent of the coast in the Waitaki district is shown to be retreating at a rate of 15 centimetres a year or more, with continued erosion rates expected at the present hotspots of Katiki Beach, Beach Road, Kakanui, North Oamaru, Hampden, Kaika and Karita settlements. Flooding due to storm surge or sea level rise has been mapped for Oamaru, Kakanui, Hampden and Moeraki for timeframe scenarios at each site. Areas mostly affected by inundation are Oamaru Harbour and Kakanui Estuary.
ORC director engineering, hazards and science Dr Gavin Palmer said the report improves understanding of future coastal hazards, erosion and inundation in the Waitaki District due to climate change. ‘‘Niwa found that while erosion is widespread, the flooding only applies to relatively small parts of the district, mostly Kakanui Estuary and Oamaru Harbour.’’
Palmer said the report would help the community make better decisions on future land use. ‘‘We are working with the Waitaki District Council by providing technical support in understanding the risk to coastal areas, so they can apply it to their planning processes. We are taking into consideration the new Ministry for the Environment guidance on preparing for coastal change and providing learnings from other councils around how to adopt coastal reports with the inclusion of affected communities,’’ he said.