NZ urged to act on rising sea levels

The Commissioner's latest report Preparing New Zealand for rising seas: Certainty and Uncertainty identified at least 9000 New Zealand homes that lie less than 50cm above spring high tides.

There was no doubt that sea levels were rising and it was certain the frequency of coastal flooding would increase as sea level rises, Dr Wright said.

Areas of low-lying coastal land that at present flood during storms or king tides will experience more frequent and severe flooding.

In some cases the rising sea will increase the duration and extent of river floods, such as the flooding that occurred in Whanganui earlier this year.

These projections are based on the longest historic records of sea levels in New Zealand, measured on tide gauges at the ports of Auckland, Wellington, Christchurch (Lyttelton), and Dunedin.

The report focused on the impact on New Zealanders and their communities from sea level rise and made eight recommendations to the Minister for the Environment Nick Smith, the Minister of Conservation Maggie Barry and to finance minister Bill English.

As part of those recommendations it looked at the role local and central government played in the planning processes for settlements, and what needed to be considered in the future.

While the world needed to act urgently on reducing greenhouse gas emissions - through which the Earth warms and contributes to rising sea levels - Dr Wright did not believe the same urgency applied to the planning needed to prepare for the rise.

"Haste can be counter-productive," she said.

However, there were aspects that needed to be considered immediately, including granting of consents for greenfields development.

"We now see building new suburbs on land prone to liquefaction in much of the country as foolish. We should see allowing new subdivisions on vulnerable coastal land as equally foolish."