Sea Level Rise Flooding Risks Assessed

Today I went along to the first attempt by Thames-Coromandel Council to engage with the public relating to its Shoreline Management Plan proposals.  It was a very low-key broad brush presentation which is to be expected I suppose when the whole three-year scheme is just kicking off.

Hopefully this low key event is not representative of the intensive  research, risk and vulnerability assessment which needs to occur by coastal hazard experts if there is to be meaningful outreach to the community.

As if to emphasise the need for that in-depth risk assessment, the day before NIWA presented a New Zealand wide assessment of the impact of sea level rise on both coastal flooding and fluvial/pluvial (river/estuary) flooding it has just undertaken.

There is an excellent summary of the presentation in this Eloise Gibson article in Newsroom.

The data presented is almost entirely at a regional level so it is not yet possible to drill down into the potential impacts of sea level rise on local communities.  That level of detail will have to await the publication of the complete data set in December 2019.

But even at a regional level it is clear that the impacts on Hauraki and Thames-Coromandel of sea level rise will be severe.  Bear in mind when viewing the following slides that “Waikato” essentially means the coastline between Waitakaruru and Kopu, the Thames-Coromandel coastline, and the sparsely populated West Coast of the North Island around Raglan.  Note also how Hauraki District gets a special mention as being at extreme risk in terms of productive land and roads exposed to sea level rise.











The 2015 risk assessment NIWA carried out for the Parliamentary Commissioner for the Environment confirmed that in terms of numbers of building and replacement value in the zone of 0.5 m of sea level rise – Thames is in the top 10 of the most at-risk towns and cities in New Zealand.


It will be fascinating to see how Thames and other Thames Coromandel communities fared when this more accurate risk assessment of both coastal and river/estuary flooding and sea level rise is published later this year.