The famed Castlepoint lighthouse and reef will soon become an island as the lagoon would be flooded if sea levels rise by less than 1m. PHOTO/FILE

Castlepoint to Castle Island

GIANINA SCHWANECKE
gianina.schwanecke@age.co.nz

Rising sea levels may force residents out and drastically alter Wairarapa’s low-lying coastal areas, according to a new climate change map produced by Greater Wellington Regional Council.

The modelling tool shows the impact of climate change and rising sea levels across the Wellington region and along the Wairarapa coastline by the turn of the next century.

Scientists estimate the sea level rise by the end of the century will likely be from 0.3m to 1.3m.

A 2.4m increase is considered physically possible but an extreme value reading.

The modelling tool allows residents to better understand how the region might be impacted and whether their own homes or properties might be affected by rises from zero to five metres.

Worst hit will be the South Wairarapa region, with just a 1m sea level rise expected to cover roads, farmland and homes near lakes Onoke and Wairarapa.

The extreme projection of a 2.5m sea level rise would prove even more devastating, inundating further parts of Kahutara and Lake Ferry.

Parts of Cape Palliser, where soil erosion is already evident, will also be badly impacted with sections of road flooded, making the Cape Palliser Rd inaccessible.

Sections of road along White Rock, Kaiwhata, Homewood and Flatpoint could also be impacted if sea levels rise by just 1m over the next 100 years.

The beachside towns of Riversdale and Castlepoint will also be vastly different.

A rise of just 2m could have parts of the Riversdale Beach Golf Course covered, as well properties closest to the coast.

Also of concern is a swollen estuary which will flood most of the beach at the northern end.

The famed Castlepoint lighthouse and reef will soon become an island as the lagoon would be flooded if sea levels rise by less than 1m.

Parts of Mataikona and its geological rock formation features will also likely be underwater if sea levels rise by less than 1m and the estuary is also expected to flood at the boundary of the Masterton and Tararua districts.

Globally, the average sea level has risen by about 16-21 centimetres since 1900, with almost half this rise happening since 1993 as oceans have warmed and land-based ice has melted.

Sea levels across the region are rising at a rate of about three millimetres per year, though this is expected to increase due to climate change.

The data tool also allows users to model storm surge data available from NIWA to illustrate the extent of inundation under various scenarios, with values set from 0m to 1.5m.

More information can be found online at: mapping1.gw.govt.nz/GW/SLR/