Residents from three beachfront properties at Wainui, Gisborne, have had to leave their homes after Spring tides caused mass erosion yesterday.
Gisborne District Council director of community lifelines David Wilson said the waves had washed away preventative rock walls in front of the properties.
He said council engineers and contractors had been on site to determine emergency protection measures.
"We're concerned about the septic system for one of the properties being exposed and falling into the sea and the potential for significant damage to properties.
"We'll make a decision on what can be done tomorrow depending on the tides.
"Residents of the three properties are staying elsewhere. We are in contact with them and will keep them informed of the next steps."
Further swells of 3-4 metres are forecast for this evening and over the weekend.