The coastline is retreating and beachfront homes have been damaged in recent years, but half of the people who live, play or work on the NSW coast do not believe rising sea levels will affect their lives.

Three years after a king tide left Collaroy mansions on the brink of collapse, a new report shows that while 85 per cent of coastal users believe the sea level is rising, a staggering 50 per cent do not think it will impact them.

Collaroy resident Garry Silk standing on the site where a row of beachside properties recieved severe erosion during the June 2016 storm surges. Credit:James Brickwood

The researchers from the University of NSW said the finding was worrying because the communities' understanding of rising sea levels - which are driving coastal erosion and inundation - can shape their coastal adaptation efforts, and determine their success.

One person among the 50 per cent who do believe rising sea levels will have an impact is Garry Silk, whose beachfront property on Collaroy Beach "got walloped" in the 2016 storms.