Residents from about 30 homes above the Rocks Road slip in Nelson are to be evacuated as a precautionary measure.
Civil Defence says a slip inspection which has just been completed has identified further cracks in the slope near the homes in the Grenville Terrace area between Rocks Road and Bisley Avenue.
Controller Alec Louverdis says water, sewerage and wastewater may have been disrupted by the ground movements and further land movements could be possible.
He says even though a property may not show signs of damage, it's part of a larger block being affected by slope movements and every precaution must be taken.
Civil Defence urges affected residents to register with Civil Defence for care and support.