The world's rising sea levels are already affecting the way we build houses in coastal New Zealand.
The Dunedin City Council has just increased the minimum floor level for new houses and extensions. City councillor Kate Wilson says it’s to protect against future events.
“Two things – sea level rising and the surge effect from greater tides,” she says, “they both have a communal effect and an individual effect – it makes some areas more flood-prone, more erosion-prone.”
From now on, floor levels must be between 45cm and 1.2m higher than previously allowed by law. Councils must work to identify possible coastal hazards over at least the next 100 years, and take steps to mitigate the risks.
Gisborne's council says it's constantly reviewing the region’s flood plans. Christchurch City Council has also updated minimum floor levels in some regions, and Auckland's revised plan will be up for public input next March.
But Tim Naish of Victoria Univeristy’s Antarctic Research Centre says when it comes to planning, we are already behind.
“The Dutch have been building dykes for centuries now; we haven't got anything in place." he says. "So even just beginning to think about how either locally or nationally we're going to deal with this problem needs to start now."
In Dunedin around 7000 properties close to coastal areas have some or all of their land below the new minimum floor level.
“There may be an issue while people get their head around what the true effect is,” says Ms Wilson. And they'll have plenty of time to do that.
“They're not in danger immediately – we are required under the Building Act to have a 50-year time frame, so we're looking 50 years out.”
In Dunedin, all building consents submitted from this week will be required to meet the new floor level increases, as will applications currently being processed which are in at-risk areas.