A handful of Gisborne properties are at risk with forecasted large swells – coupled with high tide – set to batter the East Coast on Saturday.

Residents of three beachfront households have already left their Pare St homes at Wainui Beach after king tides washed away gabion baskets and dunes in front of their properties.

Five-metre swells had been forecasted by MetService, with the potential for damage highest during high tide – set to peak just before 12.30pm.

MetService meteorologist Peter Little said the swell would "gradually ease" to 4m later in the day.

Gisbourne City Council engineers and contractors, who visited the site on Friday night to assess emergency protection measures, were back again on Saturday morning shifting sand, a nearby resident said.

A Pare St resident of about 40 years, who asked not to be named, said while the area had had "exceptionally high" tides for the past two months, she wasn't concerned about today's forecast with swells "much higher" two days ago.

"We've had warnings like this since 1993 ... but like an earthquake, anything could happen so ... c'est la vie."

She could see large trucks on the beach working to protect three of the street's most vulnerable properties

The council's director of community lifelines David Wilson said there was a particular concern for the potential of an exposed septic system at one of the addresses to fall into the sea and the possibility of damage to properties.

"Residents of the three properties are staying elsewhere. We are in contact with them and will keep them informed of the next steps," Wilson said.

"We'll make a decision on what can be done tomorrow depending on the tides."

A king tide – also known as a spring tide – is one just after a new or full moon, when there is the greatest difference between high and low water.