A rising tide of climate change challenges is bubbling up in Karitane Harbour.
The Waikouaiti Coast Community Board is asking for the Dunedin City Council and the Otago Regional Council to devise an integrated management plan for Karitane Harbour.
Board member Andy Barratt said the most significant elements of that plan would consider climate change sea level rises and weather events.
Areas in Waikouaiti and Karitane were in Emergency Management Otago’s red evacuation zone for tsunamis and for sea level rises.
"There is one place on Coast Rd in Karitane where the water does regularly lap over the road, and you can see a bit of surface damage to the road there."
Mr Barratt said he had lived in the area for more than 30 years and there had always been challenges for the harbour.
"The problem is that the river comes down towards the coast, and then it takes a sharp left hand turn as it reaches the harbour."
It was a constantly moving environment and from time to time that had caused problems.
"In the early 2000s, the major problem that it caused here was that it washed away the spit, which is a major protection point for the harbour."
That resulted in stone walls being installed to try to protect the harbour, Mr Barratt said.
A concrete wall by the wharf had to be shored up with large boulders, and a popular walkway that ran from the wharf towards the peninsula was now very seriously damaged.
Water had undermined the pathway and where the sand had collapsed there were exposed holes.
A sewage pipe running under the track had also been affected.
A concrete sleeve had been installed around one part of the pipe but since then other parts of the pipe were now at risk of becoming exposed.
During the flood events last month there was a very fast river flow at the wharf.
" Most people said that it was as fast as they think they'd ever seen," Mr Barratt said.
As a result of that, a large amount of the end of the spit had washed away.
"So the spit now is considerably further back from where it was before."
Two boats lost their moorings and were swept around, ending up on Waikouaiti Beach.
"We've always had flood events, but the expectation is that they are going to be more regular.
"So we think that as part of this plan, we need to look at the flooding that goes on and that we can expect, whether there is any mitigation that can be undertaken to not only deal with issues in the community, but also with the state highway which of course is a major link to Dunedin from the north."
