West Coasters are hearing warnings that rising sea levels could eat away big chunks of their coastline.
Erosion is the topic at a big conference in the seaside town of Hokitika, which itself is building a wall to stop the sea encroaching into the heart of the town.
Boulder by boulder, a lone digger works to slowly build up a sea wall along Hokitika's beach front.
Waves have been eating away at the sea side park, and if it gets much worse the ocean could eventually reach businesses and houses, putting the whole township under threat.
One American expert warns that by the end of this century, sea levels here are projected to have risen by a metre.
"Satellites show sea levels are rising faster here, storm wave heights are increasing around the coast of New Zealand - that'll cause the waves to run up higher on the beaches," says Oregon State University's Paul Komar.
So, to try and hold off the waves, a $1.8 million sea wall is being built. It's a controversial issue as the council's considering a rate rise to pay for it.
Some say saving the land's more important. Others worry about the changing the look of the beach.
"Sea walls tend to remove beaches, they are more where you can't afford to lose any if your land area rather than your beach environment so there are major consequences of the quality if the coastal environment after you put in a sea wall," says the New Zealand Coastal Society's Deidre Hart.
But Hokitika's sea wall is going ahead - it's expected to be completed by Christmas.