Hi-tech surveying equipment has been brought in to help assess the threat of land slips at Waihi Village at Lake Taupo.
Fifty residents have now spent two nights away from their homes because of increased seismic and geothermal activity in the area.
Local Civil Defence controller Shamus Howard told Morning Report that scientists would put GPS surveying equipment into the area on Wednesday morning.
He said a helicopter would be used because the area in the upper catchment is not suitable for walking around on.
Mr Howard said State Highway 41 at the southern end of Lake Taupo will stay closed while the assessment is made.