Article: Speak Easy

Are New Housing Developments  Affected By Rising  Sea Levels?Are New Housing Developments Affected By Rising Sea Levels?

My beautiful wife and I bought a new house in January 2019. One of the factors which persuaded us to choose an elevated house on a good hill was my wife works for Northland’s environmental council, where climate change’s effect on communities is evaluated every day. She told me rising sea levels need to be factored into real estate decisions, and what my wife says goes.

So, then, are new inland housing developments safer than those by the coast?

A January 2019 Newsroom report by Eloise Gibson opines “at some point, banks, insurers, road-builders, pipe-maintainers and the people fixing the electricity wires will probably withdraw from offering their services to the worst-hit (costal flood) neighbourhoods because it won’t be worth the cost of frequent repairs.” This is inspired by ideas coming out of the NZ Planning Institute. I’ve worked for the NZPI –
I know they’re level-headed.

Let’s see what the authorities say, then. Northland Regional Council’s Coastal Erosion Hazard Zone Assessment for Selected Northland Sites, published 14 months ago, says sea level rises before the year 2100 are expected to be a minimum of 0.27m, up to 0.8m by 2100, with an additional sea level rise of 10 mm per year beyond 2100.  NRC’s report notes R G Bell’s 2013 research which recommended that when planning for new activities or developments, higher potential rises of 1.5 to 2 m above the present mean sea level should be considered.

The specific factors making erosion-by-sea worse are one-in-100 year storms, removal of beach sand, concentration of storm water and surface flows down cliff and bank faces, and modification of dune vegetation.

Will the carbon emissions market and more tree planting reverse melting polar ice caps and rising sea levels? Perhaps, though that’lls take time. Meanwhile a combination of real coastal erosion and fear of erosion is having an impact on house prices and insurance, the two of which are intricately connected.

A frequently-cited Journal of Financial Economics article has estimated in the US properties which stand to be flooded after seas rise by just one foot have been selling at a 14.7 percent discount. Whenever unexpectedly large storms flood the land, house prices suffer. Confidence drops. 

Annette Bolton’s May 2018 ESR report ‘Climate Change and Environmental Health’ noted globally the oceans have risen by 20 cm on from 1901 to 2010 and that 9,000 homes are currently less than 0.5m above high spring tide levels, particularly Dunedin, Napier, Lower Hutt, Christchurch, Dunedin and Whakatane.

It’s refreshing, then, to look at the location of new housing developments around Whangarei with less susceptibility to rising waters:
- Kotata Heights is on the south side of the Morningside hill in Whangarei, many
  metres up
- Totara Parklands is very elevated
- A WDC coastal erosion hazard zone review of 2010 found the modifications within Marsden Bay have significantly decreased the risk of coastal erosion in the short to medium term, which is good, considering the report notes the cliffs around One Tree Point are soft and vulnerable to erosion.

The worry/fear/anxiety, ultimately, is all about insurance. A Motu Economic and Public Policy Research paper from 2017 reckons thousands of homes will find it harder and harder to get insurance due to watery bother.

A 2015 report to the Parliamentary Commissioner for the Environment added New Zealand has 43,683 houses within 1.5m of high tide and 8806 within 50cm.

“All insurance policies are one year policies in New Zealand and probably elsewhere,” the report’s author Ilan Noy noted. “So insurance can retreat very quickly from places where they think the risk is too high.”

Insurance, though, for a brand new house in a new development inland? Safe as houses.

Michael Botur has published journalism in NZ Herald, Herald on Sunday, Sunday Star-Times and Mana and he writes a lot of fiction. He moved to Whangarei in 2015 and was ecstatic to be able to afford a house here.

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