Coastal property owners need to prepare for the impact of rising sea levels on their property. And a new report from the Parliamentary Commissioner for the Environment warns New Zealand must overhaul its preparation for the effect rising seas will have on its coastal cities, towns and properties.

The report, Preparing New Zealand for Rising Seas: Certainty and Uncertainty, shows at least 9000 New Zealand homes lie less than 50 centimetres above spring high tides.

Commissioner Jan Wright says homes, businesses and infrastructure worth billions of dollars have been built on lowlying land close to the coast. In fact, an Insurance Council analysis estimates the replacement cost of assets located between 50 and 150 cms from high tide levels is between $3 billion and $20 billion.

“Rising sea levels will have major impacts in many places. In time, some coastal land will become uninhabitable,” Wright says. “Perhaps the most difficult aspect is the impact on people’s homes, which for many are much more than financial security.”

Effective planning for rising sea levels is difficult and, to date, has been adversarial, but there is time to develop a better approach, she says.

“We must plan for sea level rise, but do it carefully. There are a few cases where action is required soon – for example, restricting greenfield subdivisions in lowlying coastal areas – but in most cases it is more important to do it well than to rush.”

Under the Resource Management Act, councils are responsible for the necessary planning but the report emphasises the Government has to do more to help.

Most of the report’s eight recommendations are aimed at improving the direction and advice government gives to councils on the issue. Early planning and management is key to dealing with the inevitable situation, the Property Council agrees. Chief executive Connal Townsend says councils must be careful when planning as too many overly precautionary restrictions on developments could result in lost opportunities.